remove using global map for default codecs (#223)

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

.github/workflows/job_coverage.yml

@@ -0,0 +1,53 @@
+name: coverage
+
+on:
+  push:
+    branches: [ main, v3, v4 ]
+    paths-ignore:
+      - '.github/**'
+      - '.gitea/**'
+  pull_request:
+    branches: [ main, v3, v4 ]
+
+jobs:
+
+  build:
+    if: github.server_url != 'https://github.com'
+    runs-on: ubuntu-latest
+    steps:
+    - name: checkout code
+      uses: actions/checkout@v4
+      with:
+        filter: 'blob:none'
+
+    - name: setup go
+      uses: actions/setup-go@v5
+      with:
+        cache-dependency-path: "**/*.sum"
+        go-version: 'stable'
+
+    - name: test coverage
+      run: |
+        go test -v -cover ./... -covermode=count -coverprofile coverage.out -coverpkg ./...
+        go tool cover -func coverage.out -o coverage.out
+
+    - name: coverage badge
+      uses: tj-actions/coverage-badge-go@v2
+      with:
+        green: 80
+        filename: coverage.out
+
+    - uses: stefanzweifel/git-auto-commit-action@v4
+      name: autocommit
+      with:
+        commit_message: Apply Code Coverage Badge
+        skip_fetch: false
+        skip_checkout: false
+        file_pattern: ./README.md
+
+    - name: push
+      if: steps.auto-commit-action.outputs.changes_detected == 'true'
+      uses: ad-m/github-push-action@master
+      with:
+        github_token: ${{ github.token }}
+        branch: ${{ github.ref }}

.github/workflows/job_lint.yml

@@ -3,10 +3,10 @@ name: lint
 on:
   pull_request:
     types: [opened, reopened, synchronize]
-    branches:
+    branches: [ master, v3, v4 ]
-    - master
+    paths-ignore:
-    - v3
+      - '.github/**'
-    - v4
+      - '.gitea/**'
 
 jobs:
   lint:
@@ -20,10 +20,10 @@ jobs:
       uses: actions/setup-go@v5
       with:
         cache-dependency-path: "**/*.sum"
-        go-version: 'stable' 
+        go-version: 'stable'
     - name: setup deps
       run: go get -v ./...
     - name: run lint
-      uses: https://github.com/golangci/golangci-lint-action@v6
+      uses: golangci/golangci-lint-action@v6
       with:
         version: 'latest'

.github/workflows/job_sync.yml

@@ -0,0 +1,94 @@
+name: sync
+
+on:
+  schedule:
+    - cron: '*/5 * * * *'
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  sync:
+    if: github.server_url != 'https://github.com'
+    runs-on: ubuntu-latest
+    steps:
+    - name: init
+      run: |
+        git config --global user.email "vtolstov <vtolstov@users.noreply.github.com>"
+        git config --global user.name "github-actions[bot]"
+        echo "machine git.unistack.org login vtolstov password ${{ secrets.TOKEN_GITEA }}" >> /root/.netrc
+        echo "machine github.com login vtolstov password ${{ secrets.TOKEN_GITHUB }}" >> /root/.netrc
+
+    - name: check master
+      id: check_master
+      run: |
+        src_hash=$(git ls-remote https://github.com/${GITHUB_REPOSITORY} refs/heads/master | cut -f1)
+        dst_hash=$(git ls-remote ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} refs/heads/master | cut -f1)
+        echo "src_hash=$src_hash"
+        echo "dst_hash=$dst_hash"
+        if [ "$src_hash" != "$dst_hash" ]; then
+          echo "sync_needed=true" >> $GITHUB_OUTPUT
+        else
+          echo "sync_needed=false" >> $GITHUB_OUTPUT
+        fi
+
+    - name: sync master
+      if: steps.check_master.outputs.sync_needed == 'true'
+      run: |
+        git clone --filter=blob:none --filter=tree:0 --branch master --single-branch ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} repo
+        cd repo
+        git remote add --no-tags --fetch --track master upstream https://github.com/${GITHUB_REPOSITORY}
+        git pull --rebase upstream master
+        git push upstream master --progress
+        git push origin master --progress
+        cd ../
+        rm -rf repo
+
+    - name: check v3
+      id: check_v3
+      run: |
+        src_hash=$(git ls-remote https://github.com/${GITHUB_REPOSITORY} refs/heads/v3 | cut -f1)
+        dst_hash=$(git ls-remote ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} refs/heads/v3 | cut -f1)
+        echo "src_hash=$src_hash"
+        echo "dst_hash=$dst_hash"
+        if [ "$src_hash" != "$dst_hash" ]; then
+          echo "sync_needed=true" >> $GITHUB_OUTPUT
+        else
+          echo "sync_needed=false" >> $GITHUB_OUTPUT
+        fi
+
+    - name: sync v3
+      if: steps.check_v3.outputs.sync_needed == 'true'
+      run: |
+        git clone --filter=blob:none --filter=tree:0 --branch v3 --single-branch ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} repo
+        cd repo
+        git remote add --no-tags --fetch --track v3 upstream https://github.com/${GITHUB_REPOSITORY}
+        git pull --rebase upstream v3
+        git push upstream v3 --progress
+        git push origin v3 --progress
+        cd ../
+        rm -rf repo
+
+    - name: check v4
+      id: check_v4
+      run: |
+        src_hash=$(git ls-remote https://github.com/${GITHUB_REPOSITORY} refs/heads/v4 | cut -f1)
+        dst_hash=$(git ls-remote ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} refs/heads/v4 | cut -f1)
+        echo "src_hash=$src_hash"
+        echo "dst_hash=$dst_hash"
+        if [ "$src_hash" != "$dst_hash" ]; then
+          echo "sync_needed=true" >> $GITHUB_OUTPUT
+        else
+          echo "sync_needed=false" >> $GITHUB_OUTPUT
+        fi
+
+    - name: sync v4
+      if: steps.check_v4.outputs.sync_needed == 'true'
+      run: |
+        git clone --filter=blob:none --filter=tree:0 --branch v4 --single-branch ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} repo
+        cd repo
+        git remote add --no-tags --fetch --track v4 upstream https://github.com/${GITHUB_REPOSITORY}
+        git pull --rebase upstream v4
+        git push upstream v4 --progress
+        git push origin v4 --progress
+        cd ../
+        rm -rf repo

.github/workflows/job_test.yml

@@ -3,15 +3,12 @@ name: test
 on:
   pull_request:
     types: [opened, reopened, synchronize]
-    branches:
+    branches: [ master, v3, v4 ]
-    - master
-    - v3
-    - v4
   push:
-    branches:
+    branches: [ master, v3, v4 ]
-    - master
+    paths-ignore:
-    - v3
+      - '.github/**'
-    - v4
+      - '.gitea/**'
 
 jobs:
   test:

.github/workflows/job_tests.yml

@@ -3,15 +3,12 @@ name: test
 on:
   pull_request:
     types: [opened, reopened, synchronize]
-    branches:
+    branches: [ master, v3, v4 ]
-    - master
-    - v3
-    - v4
   push:
-    branches:
+    branches: [ master, v3, v4 ]
-    - master
+    paths-ignore:
-    - v3
+      - '.github/**'
-    - v4
+      - '.gitea/**'
 
 jobs:
   test:
@@ -35,19 +32,19 @@ jobs:
         go-version: 'stable'
     - name: setup go work
       env:
-        GOWORK: /workspace/${{ github.repository_owner }}/go.work
+        GOWORK: ${{ github.workspace }}/go.work
       run: |
         go work init
         go work use .
         go work use micro-tests
     - name: setup deps
       env:
-        GOWORK: /workspace/${{ github.repository_owner }}/go.work
+        GOWORK: ${{ github.workspace }}/go.work
       run: go get -v ./...
     - name: run tests
       env:
         INTEGRATION_TESTS: yes
-        GOWORK: /workspace/${{ github.repository_owner }}/go.work
+        GOWORK: ${{ github.workspace }}/go.work
       run: |
         cd micro-tests
         go test -mod readonly -v ./... || true

.golangci.yml

@@ -1,5 +1,5 @@
 run:
   concurrency: 8
-  deadline: 5m
+  timeout: 5m
   issues-exit-code: 1
   tests: true

README.md

@@ -1,4 +1,9 @@
-# Micro [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0) [![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/github.com/unistack-org/micro/v3?tab=overview) [![Status](https://git.unistack.org/unistack-org/micro/actions/workflows/job_tests.yml/badge.svg?branch=v3)](https://git.unistack.org/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Av3+event%3Apush) [![Lint](https://goreportcard.com/badge/go.unistack.org/micro/v3)](https://goreportcard.com/report/go.unistack.org/micro/v3)
+# Micro
+![Coverage](https://img.shields.io/badge/Coverage-33.6%25-yellow)
+[![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0)
+[![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/go.unistack.org/micro/v4?tab=overview)
+[![Status](https://git.unistack.org/unistack-org/micro/actions/workflows/job_tests.yml/badge.svg?branch=v4)](https://git.unistack.org/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Av4+event%3Apush)
+[![Lint](https://goreportcard.com/badge/go.unistack.org/micro/v4)](https://goreportcard.com/report/go.unistack.org/micro/v4)
 
 Micro is a standard library for microservices.
 
@@ -10,30 +15,20 @@ Micro provides the core requirements for distributed systems development includi
 
 Micro abstracts away the details of distributed systems. Here are the main features.
 
-- **Authentication** - Auth is built in as a first class citizen. Authentication and authorization enable secure 
-zero trust networking by providing every service an identity and certificates. This additionally includes rule 
-based access control.
-
 - **Dynamic Config** - Load and hot reload dynamic config from anywhere. The config interface provides a way to load application 
-level config from any source such as env vars, file, etcd. You can merge the sources and even define fallbacks.
+level config from any source such as env vars, cmdline, file, consul, vault... You can merge the sources and even define fallbacks.
 
 - **Data Storage** - A simple data store interface to read, write and delete records. It includes support for memory, file and 
-CockroachDB by default. State and persistence becomes a core requirement beyond prototyping and Micro looks to build that into the framework.
+s3. State and persistence becomes a core requirement beyond prototyping and Micro looks to build that into the framework.
 
 - **Service Discovery** - Automatic service registration and name resolution. Service discovery is at the core of micro service 
 development. When service A needs to speak to service B it needs the location of that service.
 
-- **Load Balancing** - Client side load balancing built on service discovery. Once we have the addresses of any number of instances 
-of a service we now need a way to decide which node to route to. We use random hashed load balancing to provide even distribution 
-across the services and retry a different node if there's a problem. 
-
 - **Message Encoding** - Dynamic message encoding based on content-type. The client and server will use codecs along with content-type 
 to seamlessly encode and decode Go types for you. Any variety of messages could be encoded and sent from different clients. The client 
 and server handle this by default.
 
-- **Transport** - gRPC or http based request/response with support for bidirectional streaming. We provide an abstraction for synchronous communication. A request made to a service will be automatically resolved, load balanced, dialled and streamed.
+- **Async Messaging** - Pub/Sub is built in as a first class citizen for asynchronous communication and event driven architectures.
-
-- **Async Messaging** - PubSub is built in as a first class citizen for asynchronous communication and event driven architectures.
 Event notifications are a core pattern in micro service development.
 
 - **Synchronization** - Distributed systems are often built in an eventually consistent manner. Support for distributed locking and 
@@ -42,10 +37,6 @@ leadership are built in as a Sync interface. When using an eventually consistent
 - **Pluggable Interfaces** - Micro makes use of Go interfaces for each system abstraction. Because of this these interfaces 
 are pluggable and allows Micro to be runtime agnostic.
 
-## Getting Started
-
-To be created.
-
 ## License
 
 Micro is Apache 2.0 licensed.

SECURITY.md

@@ -1,15 +0,0 @@
-# Security Policy
-
-## Supported Versions
-
-Use this section to tell people about which versions of your project are
-currently being supported with security updates.
-
-| Version | Supported          |
-| ------- | ------------------ |
-| 3.7.x   | :white_check_mark: |
-| < 3.7.0 | :x:                |
-
-## Reporting a Vulnerability
-
-If you find any issue, please create github issue in this repo

broker/broker.go

@@ -6,8 +6,8 @@ import (
 	"errors"
 	"time"
 
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/metadata"
 )
 
 // DefaultBroker default memory broker
@@ -18,6 +18,10 @@ var (
 	ErrNotConnected = errors.New("broker not connected")
 	// ErrDisconnected returns when broker disconnected
 	ErrDisconnected = errors.New("broker disconnected")
+	// ErrInvalidMessage returns when invalid Message passed
+	ErrInvalidMessage = errors.New("invalid message")
+	// ErrInvalidHandler returns when subscriber passed to Subscribe
+	ErrInvalidHandler = errors.New("invalid handler, ony func(Message) error and func([]Message) error supported")
 	// DefaultGracefulTimeout
 	DefaultGracefulTimeout = 5 * time.Second
 )
@@ -36,14 +40,12 @@ type Broker interface {
 	Connect(ctx context.Context) error
 	// Disconnect disconnect from broker
 	Disconnect(ctx context.Context) error
+	// NewMessage create new broker message to publish.
+	NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...MessageOption) (Message, error)
 	// Publish message to broker topic
-	Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error
+	Publish(ctx context.Context, topic string, messages ...Message) error
 	// Subscribe subscribes to topic message via handler
-	Subscribe(ctx context.Context, topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
+	Subscribe(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error)
-	// BatchPublish messages to broker with multiple topics
-	BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error
-	// BatchSubscribe subscribes to topic messages via handler
-	BatchSubscribe(ctx context.Context, topic string, h BatchHandler, opts ...SubscribeOption) (Subscriber, error)
 	// String type of broker
 	String() string
 	// Live returns broker liveness
@@ -55,72 +57,27 @@ type Broker interface {
 }
 
 type (
-	FuncPublish        func(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error
+	FuncPublish   func(ctx context.Context, topic string, messages ...Message) error
-	HookPublish        func(next FuncPublish) FuncPublish
+	HookPublish   func(next FuncPublish) FuncPublish
-	FuncBatchPublish   func(ctx context.Context, msgs []*Message, opts ...PublishOption) error
+	FuncSubscribe func(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error)
-	HookBatchPublish   func(next FuncBatchPublish) FuncBatchPublish
+	HookSubscribe func(next FuncSubscribe) FuncSubscribe
-	FuncSubscribe      func(ctx context.Context, topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
-	HookSubscribe      func(next FuncSubscribe) FuncSubscribe
-	FuncBatchSubscribe func(ctx context.Context, topic string, h BatchHandler, opts ...SubscribeOption) (Subscriber, error)
-	HookBatchSubscribe func(next FuncBatchSubscribe) FuncBatchSubscribe
 )
 
-// Handler is used to process messages via a subscription of a topic.
+// Message is given to a subscription handler for processing
-type Handler func(Event) error
+type Message interface {
-
+	// Context for the message.
-// Events contains multiple events
-type Events []Event
-
-// Ack try to ack all events and return
-func (evs Events) Ack() error {
-	var err error
-	for _, ev := range evs {
-		if err = ev.Ack(); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// SetError sets error on event
-func (evs Events) SetError(err error) {
-	for _, ev := range evs {
-		ev.SetError(err)
-	}
-}
-
-// BatchHandler is used to process messages in batches via a subscription of a topic.
-type BatchHandler func(Events) error
-
-// Event is given to a subscription handler for processing
-type Event interface {
-	// Context return context.Context for event
 	Context() context.Context
-	// Topic returns event topic
+	// Topic returns message destination topic.
 	Topic() string
-	// Message returns broker message
+	// Header returns message headers.
-	Message() *Message
+	Header() metadata.Metadata
-	// Ack acknowledge message
+	// Body returns broker message []byte slice
+	Body() []byte
+	// Unmarshal try to decode message body to dst.
+	// This is helper method that uses codec.Unmarshal.
+	Unmarshal(dst interface{}, opts ...codec.Option) error
+	// Ack acknowledge message if supported.
 	Ack() error
-	// Error returns message error (like decoding errors or some other)
-	Error() error
-	// SetError set event processing error
-	SetError(err error)
-}
-
-// Message is used to transfer data
-type Message struct {
-	// Header contains message metadata
-	Header metadata.Metadata
-	// Body contains message body
-	Body codec.RawMessage
-}
-
-// NewMessage create broker message with topic filled
-func NewMessage(topic string) *Message {
-	m := &Message{Header: metadata.New(2)}
-	m.Header.Set(metadata.HeaderTopic, topic)
-	return m
 }
 
 // Subscriber is a convenience return type for the Subscribe method

broker/context.go

@@ -42,6 +42,16 @@ func SetSubscribeOption(k, v interface{}) SubscribeOption {
 	}
 }
 
+// SetMessageOption returns a function to setup a context with given value
+func SetMessageOption(k, v interface{}) MessageOption {
+	return func(o *MessageOptions) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}
+
 // SetOption returns a function to setup a context with given value
 func SetOption(k, v interface{}) Option {
 	return func(o *Options) {
@@ -51,13 +61,3 @@ func SetOption(k, v interface{}) Option {
 		o.Context = context.WithValue(o.Context, k, v)
 	}
 }
-
-// SetPublishOption returns a function to setup a context with given value
-func SetPublishOption(k, v interface{}) PublishOption {
-	return func(o *PublishOptions) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, k, v)
-	}
-}

broker/context_test.go

@@ -49,17 +49,6 @@ func TestSetSubscribeOption(t *testing.T) {
 	}
 }
 
-func TestSetPublishOption(t *testing.T) {
-	type key struct{}
-	o := SetPublishOption(key{}, "test")
-	opts := &PublishOptions{}
-	o(opts)
-
-	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
-		t.Fatal("SetPublishOption not works")
-	}
-}
-
 func TestSetOption(t *testing.T) {
 	type key struct{}
 	o := SetOption(key{}, "test")

broker/memory/memory.go

@@ -2,66 +2,104 @@ package broker
 
 import (
 	"context"
+	"strings"
 	"sync"
 
-	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v4/metadata"
-	maddr "go.unistack.org/micro/v3/util/addr"
+	"go.unistack.org/micro/v4/options"
-	"go.unistack.org/micro/v3/util/id"
+	maddr "go.unistack.org/micro/v4/util/addr"
-	mnet "go.unistack.org/micro/v3/util/net"
+	"go.unistack.org/micro/v4/util/id"
-	"go.unistack.org/micro/v3/util/rand"
+	mnet "go.unistack.org/micro/v4/util/net"
+	"go.unistack.org/micro/v4/util/rand"
 )
 
-type memoryBroker struct {
+type Broker struct {
-	funcPublish        broker.FuncPublish
+	funcPublish   broker.FuncPublish
-	funcBatchPublish   broker.FuncBatchPublish
+	funcSubscribe broker.FuncSubscribe
-	funcSubscribe      broker.FuncSubscribe
+	subscribers   map[string][]*Subscriber
-	funcBatchSubscribe broker.FuncBatchSubscribe
+	addr          string
-	subscribers        map[string][]*memorySubscriber
+	opts          broker.Options
-	addr               string
+	mu            sync.RWMutex
-	opts               broker.Options
+	connected     bool
-	sync.RWMutex
-	connected bool
 }
 
-type memoryEvent struct {
+type memoryMessage struct {
-	err     error
+	c     codec.Codec
-	message interface{}
+	topic string
+	ctx   context.Context
+	body  []byte
+	hdr   metadata.Metadata
+	opts  broker.MessageOptions
+}
+
+func (m *memoryMessage) Ack() error {
+	return nil
+}
+
+func (m *memoryMessage) Body() []byte {
+	return m.body
+}
+
+func (m *memoryMessage) Header() metadata.Metadata {
+	return m.hdr
+}
+
+func (m *memoryMessage) Context() context.Context {
+	return m.ctx
+}
+
+func (m *memoryMessage) Topic() string {
+	return ""
+}
+
+func (m *memoryMessage) Unmarshal(dst interface{}, opts ...codec.Option) error {
+	return m.c.Unmarshal(m.body, dst)
+}
+
+type Subscriber struct {
+	ctx     context.Context
+	exit    chan bool
+	handler interface{}
+	id      string
 	topic   string
-	opts    broker.Options
+	opts    broker.SubscribeOptions
 }
 
-type memorySubscriber struct {
+func (b *Broker) newCodec(ct string) (codec.Codec, error) {
-	ctx          context.Context
+	if idx := strings.IndexRune(ct, ';'); idx >= 0 {
-	exit         chan bool
+		ct = ct[:idx]
-	handler      broker.Handler
+	}
-	batchhandler broker.BatchHandler
+	b.mu.RLock()
-	id           string
+	c, ok := b.opts.Codecs[ct]
-	topic        string
+	b.mu.RUnlock()
-	opts         broker.SubscribeOptions
+	if ok {
+		return c, nil
+	}
+	return nil, codec.ErrUnknownContentType
 }
 
-func (m *memoryBroker) Options() broker.Options {
+func (b *Broker) Options() broker.Options {
-	return m.opts
+	return b.opts
 }
 
-func (m *memoryBroker) Address() string {
+func (b *Broker) Address() string {
-	return m.addr
+	return b.addr
 }
 
-func (m *memoryBroker) Connect(ctx context.Context) error {
+func (b *Broker) Connect(ctx context.Context) error {
 	select {
 	case <-ctx.Done():
 		return ctx.Err()
 	default:
 	}
 
-	m.Lock()
+	b.mu.Lock()
-	defer m.Unlock()
+	defer b.mu.Unlock()
 
-	if m.connected {
+	if b.connected {
 		return nil
 	}
 
@@ -75,154 +113,129 @@ func (m *memoryBroker) Connect(ctx context.Context) error {
 	// set addr with port
 	addr = mnet.HostPort(addr, 10000+i)
 
-	m.addr = addr
+	b.addr = addr
-	m.connected = true
+	b.connected = true
 
 	return nil
 }
 
-func (m *memoryBroker) Disconnect(ctx context.Context) error {
+func (b *Broker) Disconnect(ctx context.Context) error {
 	select {
 	case <-ctx.Done():
 		return ctx.Err()
 	default:
 	}
 
-	m.Lock()
+	b.mu.Lock()
-	defer m.Unlock()
+	defer b.mu.Unlock()
 
-	if !m.connected {
+	if !b.connected {
 		return nil
 	}
 
-	m.connected = false
+	b.connected = false
 	return nil
 }
 
-func (m *memoryBroker) Init(opts ...broker.Option) error {
+func (b *Broker) Init(opts ...broker.Option) error {
 	for _, o := range opts {
-		o(&m.opts)
+		o(&b.opts)
 	}
 
-	m.funcPublish = m.fnPublish
+	b.funcPublish = b.fnPublish
-	m.funcBatchPublish = m.fnBatchPublish
+	b.funcSubscribe = b.fnSubscribe
-	m.funcSubscribe = m.fnSubscribe
-	m.funcBatchSubscribe = m.fnBatchSubscribe
 
-	m.opts.Hooks.EachPrev(func(hook options.Hook) {
+	b.opts.Hooks.EachPrev(func(hook options.Hook) {
 		switch h := hook.(type) {
 		case broker.HookPublish:
-			m.funcPublish = h(m.funcPublish)
+			b.funcPublish = h(b.funcPublish)
-		case broker.HookBatchPublish:
-			m.funcBatchPublish = h(m.funcBatchPublish)
 		case broker.HookSubscribe:
-			m.funcSubscribe = h(m.funcSubscribe)
+			b.funcSubscribe = h(b.funcSubscribe)
-		case broker.HookBatchSubscribe:
-			m.funcBatchSubscribe = h(m.funcBatchSubscribe)
 		}
 	})
 
 	return nil
 }
 
-func (m *memoryBroker) Publish(ctx context.Context, topic string, msg *broker.Message, opts ...broker.PublishOption) error {
+func (b *Broker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...broker.MessageOption) (broker.Message, error) {
-	return m.funcPublish(ctx, topic, msg, opts...)
+	options := broker.NewMessageOptions(opts...)
+	if options.ContentType == "" {
+		options.ContentType = b.opts.ContentType
+	}
+	m := &memoryMessage{ctx: ctx, hdr: hdr, opts: options}
+	c, err := b.newCodec(m.opts.ContentType)
+	if err == nil {
+		m.body, err = c.Marshal(body)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return m, nil
 }
 
-func (m *memoryBroker) fnPublish(ctx context.Context, topic string, msg *broker.Message, opts ...broker.PublishOption) error {
+func (b *Broker) Publish(ctx context.Context, topic string, messages ...broker.Message) error {
-	msg.Header.Set(metadata.HeaderTopic, topic)
+	return b.funcPublish(ctx, topic, messages...)
-	return m.publish(ctx, []*broker.Message{msg}, opts...)
 }
 
-func (m *memoryBroker) BatchPublish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
+func (b *Broker) fnPublish(ctx context.Context, topic string, messages ...broker.Message) error {
-	return m.funcBatchPublish(ctx, msgs, opts...)
+	return b.publish(ctx, topic, messages...)
 }
 
-func (m *memoryBroker) fnBatchPublish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
+func (b *Broker) publish(ctx context.Context, topic string, messages ...broker.Message) error {
-	return m.publish(ctx, msgs, opts...)
+	b.mu.RLock()
-}
+	if !b.connected {
-
+		b.mu.RUnlock()
-func (m *memoryBroker) publish(ctx context.Context, msgs []*broker.Message, opts ...broker.PublishOption) error {
-	m.RLock()
-	if !m.connected {
-		m.RUnlock()
 		return broker.ErrNotConnected
 	}
-	m.RUnlock()
+	b.mu.RUnlock()
-
-	var err error
 
 	select {
 	case <-ctx.Done():
 		return ctx.Err()
 	default:
-		options := broker.NewPublishOptions(opts...)
+	}
 
-		msgTopicMap := make(map[string]broker.Events)
+	b.mu.RLock()
-		for _, v := range msgs {
+	subs, ok := b.subscribers[topic]
-			p := &memoryEvent{opts: m.opts}
+	b.mu.RUnlock()
+	if !ok {
+		return nil
+	}
 
-			if m.opts.Codec == nil || options.BodyOnly {
+	var err error
-				p.topic, _ = v.Header.Get(metadata.HeaderTopic)
+
-				p.message = v.Body
+	for _, sub := range subs {
-			} else {
+		switch s := sub.handler.(type) {
-				p.topic, _ = v.Header.Get(metadata.HeaderTopic)
+		default:
-				p.message, err = m.opts.Codec.Marshal(v)
+			if b.opts.Logger.V(logger.ErrorLevel) {
-				if err != nil {
+				b.opts.Logger.Error(ctx, "broker  handler error", broker.ErrInvalidHandler)
-					return err
-				}
 			}
-			msgTopicMap[p.topic] = append(msgTopicMap[p.topic], p)
+		case func(broker.Message) error:
-		}
+			for _, message := range messages {
-
+				msg, ok := message.(*memoryMessage)
-		beh := m.opts.BatchErrorHandler
+				if !ok {
-		eh := m.opts.ErrorHandler
+					if b.opts.Logger.V(logger.ErrorLevel) {
-
+						b.opts.Logger.Error(ctx, "broker handler error", broker.ErrInvalidMessage)
-		for t, ms := range msgTopicMap {
-			m.RLock()
-			subs, ok := m.subscribers[t]
-			m.RUnlock()
-			if !ok {
-				continue
-			}
-
-			for _, sub := range subs {
-				if sub.opts.BatchErrorHandler != nil {
-					beh = sub.opts.BatchErrorHandler
-				}
-				if sub.opts.ErrorHandler != nil {
-					eh = sub.opts.ErrorHandler
-				}
-
-				switch {
-				// batch processing
-				case sub.batchhandler != nil:
-					if err = sub.batchhandler(ms); err != nil {
-						ms.SetError(err)
-						if beh != nil {
-							_ = beh(ms)
-						} else if m.opts.Logger.V(logger.ErrorLevel) {
-							m.opts.Logger.Error(m.opts.Context, err.Error())
-						}
-					} else if sub.opts.AutoAck {
-						if err = ms.Ack(); err != nil {
-							m.opts.Logger.Error(m.opts.Context, "broker ack error", err)
-						}
 					}
-					// single processing
+				}
-				case sub.handler != nil:
+				msg.topic = topic
-					for _, p := range ms {
+				if err = s(msg); err == nil && sub.opts.AutoAck {
-						if err = sub.handler(p); err != nil {
+					err = msg.Ack()
-							p.SetError(err)
+				}
-							if eh != nil {
+				if err != nil {
-								_ = eh(p)
+					if b.opts.Logger.V(logger.ErrorLevel) {
-							} else if m.opts.Logger.V(logger.ErrorLevel) {
+						b.opts.Logger.Error(ctx, "broker handler error", err)
-								m.opts.Logger.Error(m.opts.Context, "broker handler error", err)
+					}
-							}
+				}
-						} else if sub.opts.AutoAck {
+			}
-							if err = p.Ack(); err != nil {
+		case func([]broker.Message) error:
-								m.opts.Logger.Error(m.opts.Context, "broker ack error", err)
+			if err = s(messages); err == nil && sub.opts.AutoAck {
-							}
+				for _, message := range messages {
+					err = message.Ack()
+					if err != nil {
+						if b.opts.Logger.V(logger.ErrorLevel) {
+							b.opts.Logger.Error(ctx, "broker handler error", err)
 						}
 					}
 				}
@@ -233,17 +246,21 @@ func (m *memoryBroker) publish(ctx context.Context, msgs []*broker.Message, opts
 	return nil
 }
 
-func (m *memoryBroker) BatchSubscribe(ctx context.Context, topic string, handler broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+func (b *Broker) Subscribe(ctx context.Context, topic string, handler interface{}, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	return m.funcBatchSubscribe(ctx, topic, handler, opts...)
+	return b.funcSubscribe(ctx, topic, handler, opts...)
 }
 
-func (m *memoryBroker) fnBatchSubscribe(ctx context.Context, topic string, handler broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
+func (b *Broker) fnSubscribe(ctx context.Context, topic string, handler interface{}, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	m.RLock()
+	if err := broker.IsValidHandler(handler); err != nil {
-	if !m.connected {
+		return nil, err
-		m.RUnlock()
+	}
+
+	b.mu.RLock()
+	if !b.connected {
+		b.mu.RUnlock()
 		return nil, broker.ErrNotConnected
 	}
-	m.RUnlock()
+	b.mu.RUnlock()
 
 	sid, err := id.New()
 	if err != nil {
@@ -252,56 +269,7 @@ func (m *memoryBroker) fnBatchSubscribe(ctx context.Context, topic string, handl
 
 	options := broker.NewSubscribeOptions(opts...)
 
-	sub := &memorySubscriber{
+	sub := &Subscriber{
-		exit:         make(chan bool, 1),
-		id:           sid,
-		topic:        topic,
-		batchhandler: handler,
-		opts:         options,
-		ctx:          ctx,
-	}
-
-	m.Lock()
-	m.subscribers[topic] = append(m.subscribers[topic], sub)
-	m.Unlock()
-
-	go func() {
-		<-sub.exit
-		m.Lock()
-		newSubscribers := make([]*memorySubscriber, 0, len(m.subscribers)-1)
-		for _, sb := range m.subscribers[topic] {
-			if sb.id == sub.id {
-				continue
-			}
-			newSubscribers = append(newSubscribers, sb)
-		}
-		m.subscribers[topic] = newSubscribers
-		m.Unlock()
-	}()
-
-	return sub, nil
-}
-
-func (m *memoryBroker) Subscribe(ctx context.Context, topic string, handler broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	return m.funcSubscribe(ctx, topic, handler, opts...)
-}
-
-func (m *memoryBroker) fnSubscribe(ctx context.Context, topic string, handler broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
-	m.RLock()
-	if !m.connected {
-		m.RUnlock()
-		return nil, broker.ErrNotConnected
-	}
-	m.RUnlock()
-
-	sid, err := id.New()
-	if err != nil {
-		return nil, err
-	}
-
-	options := broker.NewSubscribeOptions(opts...)
-
-	sub := &memorySubscriber{
 		exit:    make(chan bool, 1),
 		id:      sid,
 		topic:   topic,
@@ -310,102 +278,64 @@ func (m *memoryBroker) fnSubscribe(ctx context.Context, topic string, handler br
 		ctx:     ctx,
 	}
 
-	m.Lock()
+	b.mu.Lock()
-	m.subscribers[topic] = append(m.subscribers[topic], sub)
+	b.subscribers[topic] = append(b.subscribers[topic], sub)
-	m.Unlock()
+	b.mu.Unlock()
 
 	go func() {
 		<-sub.exit
-		m.Lock()
+		b.mu.Lock()
-		newSubscribers := make([]*memorySubscriber, 0, len(m.subscribers)-1)
+		newSubscribers := make([]*Subscriber, 0, len(b.subscribers)-1)
-		for _, sb := range m.subscribers[topic] {
+		for _, sb := range b.subscribers[topic] {
 			if sb.id == sub.id {
 				continue
 			}
 			newSubscribers = append(newSubscribers, sb)
 		}
-		m.subscribers[topic] = newSubscribers
+		b.subscribers[topic] = newSubscribers
-		m.Unlock()
+		b.mu.Unlock()
 	}()
 
 	return sub, nil
 }
 
-func (m *memoryBroker) String() string {
+func (b *Broker) String() string {
 	return "memory"
 }
 
-func (m *memoryBroker) Name() string {
+func (b *Broker) Name() string {
-	return m.opts.Name
+	return b.opts.Name
 }
 
-func (m *memoryBroker) Live() bool {
+func (b *Broker) Live() bool {
 	return true
 }
 
-func (m *memoryBroker) Ready() bool {
+func (b *Broker) Ready() bool {
 	return true
 }
 
-func (m *memoryBroker) Health() bool {
+func (b *Broker) Health() bool {
 	return true
 }
 
-func (m *memoryEvent) Topic() string {
+func (m *Subscriber) Options() broker.SubscribeOptions {
-	return m.topic
-}
-
-func (m *memoryEvent) Message() *broker.Message {
-	switch v := m.message.(type) {
-	case *broker.Message:
-		return v
-	case []byte:
-		msg := &broker.Message{}
-		if err := m.opts.Codec.Unmarshal(v, msg); err != nil {
-			if m.opts.Logger.V(logger.ErrorLevel) {
-				m.opts.Logger.Error(m.opts.Context, "[memory]: failed to unmarshal: %v", err)
-			}
-			return nil
-		}
-		return msg
-	}
-
-	return nil
-}
-
-func (m *memoryEvent) Ack() error {
-	return nil
-}
-
-func (m *memoryEvent) Error() error {
-	return m.err
-}
-
-func (m *memoryEvent) SetError(err error) {
-	m.err = err
-}
-
-func (m *memoryEvent) Context() context.Context {
-	return m.opts.Context
-}
-
-func (m *memorySubscriber) Options() broker.SubscribeOptions {
 	return m.opts
 }
 
-func (m *memorySubscriber) Topic() string {
+func (m *Subscriber) Topic() string {
 	return m.topic
 }
 
-func (m *memorySubscriber) Unsubscribe(ctx context.Context) error {
+func (m *Subscriber) Unsubscribe(ctx context.Context) error {
 	m.exit <- true
 	return nil
 }
 
 // NewBroker return new memory broker
 func NewBroker(opts ...broker.Option) broker.Broker {
-	return &memoryBroker{
+	return &Broker{
 		opts:        broker.NewOptions(opts...),
-		subscribers: make(map[string][]*memorySubscriber),
+		subscribers: make(map[string][]*Subscriber),
 	}
 }

broker/memory/memory_test.go

@@ -5,62 +5,23 @@ import (
 	"fmt"
 	"testing"
 
-	"go.unistack.org/micro/v3/broker"
+	"go.uber.org/atomic"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/broker"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/metadata"
 )
 
-func TestMemoryBatchBroker(t *testing.T) {
+type hldr struct {
-	b := NewBroker()
+	c atomic.Int64
-	ctx := context.Background()
+}
 
-	if err := b.Init(); err != nil {
+func (h *hldr) Handler(m broker.Message) error {
-		t.Fatalf("Unexpected init error %v", err)
+	h.c.Add(1)
-	}
+	return nil
-
-	if err := b.Connect(ctx); err != nil {
-		t.Fatalf("Unexpected connect error %v", err)
-	}
-
-	topic := "test"
-	count := 10
-
-	fn := func(evts broker.Events) error {
-		return evts.Ack()
-	}
-
-	sub, err := b.BatchSubscribe(ctx, topic, fn)
-	if err != nil {
-		t.Fatalf("Unexpected error subscribing %v", err)
-	}
-
-	msgs := make([]*broker.Message, 0, count)
-	for i := 0; i < count; i++ {
-		message := &broker.Message{
-			Header: map[string]string{
-				metadata.HeaderTopic: topic,
-				"foo":                "bar",
-				"id":                 fmt.Sprintf("%d", i),
-			},
-			Body: []byte(`"hello world"`),
-		}
-		msgs = append(msgs, message)
-	}
-
-	if err := b.BatchPublish(ctx, msgs); err != nil {
-		t.Fatalf("Unexpected error publishing %v", err)
-	}
-
-	if err := sub.Unsubscribe(ctx); err != nil {
-		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
-	}
-
-	if err := b.Disconnect(ctx); err != nil {
-		t.Fatalf("Unexpected connect error %v", err)
-	}
 }
 
 func TestMemoryBroker(t *testing.T) {
-	b := NewBroker()
+	b := NewBroker(broker.Codec("application/octet-stream", codec.NewCodec()))
 	ctx := context.Background()
 
 	if err := b.Init(); err != nil {
@@ -72,38 +33,33 @@ func TestMemoryBroker(t *testing.T) {
 	}
 
 	topic := "test"
-	count := 10
+	count := int64(10)
 
-	fn := func(_ broker.Event) error {
+	h := &hldr{}
-		return nil
-	}
 
-	sub, err := b.Subscribe(ctx, topic, fn)
+	sub, err := b.Subscribe(ctx, topic, h.Handler)
 	if err != nil {
 		t.Fatalf("Unexpected error subscribing %v", err)
 	}
 
-	msgs := make([]*broker.Message, 0, count)
+	for i := int64(0); i < count; i++ {
-	for i := 0; i < count; i++ {
+		message, err := b.NewMessage(ctx,
-		message := &broker.Message{
+			metadata.Pairs(
-			Header: map[string]string{
+				"foo", "bar",
-				metadata.HeaderTopic: topic,
+				"id", fmt.Sprintf("%d", i),
-				"foo":                "bar",
+			),
-				"id":                 fmt.Sprintf("%d", i),
+			[]byte(`"hello world"`),
-			},
+			broker.MessageContentType("application/octet-stream"),
-			Body: []byte(`"hello world"`),
+		)
+		if err != nil {
+			t.Fatal(err)
 		}
-		msgs = append(msgs, message)
 
 		if err := b.Publish(ctx, topic, message); err != nil {
 			t.Fatalf("Unexpected error publishing %d err: %v", i, err)
 		}
 	}
 
-	if err := b.BatchPublish(ctx, msgs); err != nil {
-		t.Fatalf("Unexpected error publishing %v", err)
-	}
-
 	if err := sub.Unsubscribe(ctx); err != nil {
 		t.Fatalf("Unexpected error unsubscribing from %s: %v", topic, err)
 	}
@@ -111,4 +67,8 @@ func TestMemoryBroker(t *testing.T) {
 	if err := b.Disconnect(ctx); err != nil {
 		t.Fatalf("Unexpected connect error %v", err)
 	}
+
+	if h.c.Load() != count {
+		t.Fatal("invalid messages count received")
+	}
 }

broker/noop.go

@@ -3,24 +3,37 @@ package broker
 import (
 	"context"
 	"strings"
+	"sync"
 
-	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v4/options"
 )
 
 type NoopBroker struct {
-	funcPublish        FuncPublish
+	funcPublish   FuncPublish
-	funcBatchPublish   FuncBatchPublish
+	funcSubscribe FuncSubscribe
-	funcSubscribe      FuncSubscribe
+	opts          Options
-	funcBatchSubscribe FuncBatchSubscribe
+	mu            sync.RWMutex
-	opts               Options
+}
+
+func (b *NoopBroker) newCodec(ct string) (codec.Codec, error) {
+	if idx := strings.IndexRune(ct, ';'); idx >= 0 {
+		ct = ct[:idx]
+	}
+	b.mu.RLock()
+	c, ok := b.opts.Codecs[ct]
+	b.mu.RUnlock()
+	if ok {
+		return c, nil
+	}
+	return nil, codec.ErrUnknownContentType
 }
 
 func NewBroker(opts ...Option) *NoopBroker {
 	b := &NoopBroker{opts: NewOptions(opts...)}
 	b.funcPublish = b.fnPublish
-	b.funcBatchPublish = b.fnBatchPublish
 	b.funcSubscribe = b.fnSubscribe
-	b.funcBatchSubscribe = b.fnBatchSubscribe
 
 	return b
 }
@@ -55,20 +68,14 @@ func (b *NoopBroker) Init(opts ...Option) error {
 	}
 
 	b.funcPublish = b.fnPublish
-	b.funcBatchPublish = b.fnBatchPublish
 	b.funcSubscribe = b.fnSubscribe
-	b.funcBatchSubscribe = b.fnBatchSubscribe
 
 	b.opts.Hooks.EachPrev(func(hook options.Hook) {
 		switch h := hook.(type) {
 		case HookPublish:
 			b.funcPublish = h(b.funcPublish)
-		case HookBatchPublish:
-			b.funcBatchPublish = h(b.funcBatchPublish)
 		case HookSubscribe:
 			b.funcSubscribe = h(b.funcSubscribe)
-		case HookBatchSubscribe:
-			b.funcBatchSubscribe = h(b.funcBatchSubscribe)
 		}
 	})
 
@@ -87,43 +94,75 @@ func (b *NoopBroker) Address() string {
 	return strings.Join(b.opts.Addrs, ",")
 }
 
-func (b *NoopBroker) fnBatchPublish(_ context.Context, _ []*Message, _ ...PublishOption) error {
+type noopMessage struct {
+	c    codec.Codec
+	ctx  context.Context
+	body []byte
+	hdr  metadata.Metadata
+	opts MessageOptions
+}
+
+func (m *noopMessage) Ack() error {
 	return nil
 }
 
-func (b *NoopBroker) BatchPublish(ctx context.Context, msgs []*Message, opts ...PublishOption) error {
+func (m *noopMessage) Body() []byte {
-	return b.funcBatchPublish(ctx, msgs, opts...)
+	return m.body
 }
 
-func (b *NoopBroker) fnPublish(_ context.Context, _ string, _ *Message, _ ...PublishOption) error {
+func (m *noopMessage) Header() metadata.Metadata {
+	return m.hdr
+}
+
+func (m *noopMessage) Context() context.Context {
+	return m.ctx
+}
+
+func (m *noopMessage) Topic() string {
+	return ""
+}
+
+func (m *noopMessage) Unmarshal(dst interface{}, opts ...codec.Option) error {
+	return m.c.Unmarshal(m.body, dst)
+}
+
+func (b *NoopBroker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...MessageOption) (Message, error) {
+	options := NewMessageOptions(opts...)
+	if options.ContentType == "" {
+		options.ContentType = b.opts.ContentType
+	}
+	m := &noopMessage{ctx: ctx, hdr: hdr, opts: options}
+	c, err := b.newCodec(m.opts.ContentType)
+	if err == nil {
+		m.body, err = c.Marshal(body)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	return m, nil
+}
+
+func (b *NoopBroker) fnPublish(_ context.Context, _ string, _ ...Message) error {
 	return nil
 }
 
-func (b *NoopBroker) Publish(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error {
+func (b *NoopBroker) Publish(ctx context.Context, topic string, msg ...Message) error {
-	return b.funcPublish(ctx, topic, msg, opts...)
+	return b.funcPublish(ctx, topic, msg...)
 }
 
 type NoopSubscriber struct {
-	ctx          context.Context
+	ctx     context.Context
-	topic        string
+	topic   string
-	handler      Handler
+	handler interface{}
-	batchHandler BatchHandler
+	opts    SubscribeOptions
-	opts         SubscribeOptions
 }
 
-func (b *NoopBroker) fnBatchSubscribe(ctx context.Context, topic string, handler BatchHandler, opts ...SubscribeOption) (Subscriber, error) {
+func (b *NoopBroker) fnSubscribe(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error) {
-	return &NoopSubscriber{ctx: ctx, topic: topic, opts: NewSubscribeOptions(opts...), batchHandler: handler}, nil
-}
-
-func (b *NoopBroker) BatchSubscribe(ctx context.Context, topic string, handler BatchHandler, opts ...SubscribeOption) (Subscriber, error) {
-	return b.funcBatchSubscribe(ctx, topic, handler, opts...)
-}
-
-func (b *NoopBroker) fnSubscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
 	return &NoopSubscriber{ctx: ctx, topic: topic, opts: NewSubscribeOptions(opts...), handler: handler}, nil
 }
 
-func (b *NoopBroker) Subscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
+func (b *NoopBroker) Subscribe(ctx context.Context, topic string, handler interface{}, opts ...SubscribeOption) (Subscriber, error) {
 	return b.funcSubscribe(ctx, topic, handler, opts...)
 }
 

broker/noop_test.go

@@ -10,9 +10,9 @@ type testHook struct {
 }
 
 func (t *testHook) Publish1(fn FuncPublish) FuncPublish {
-	return func(ctx context.Context, topic string, msg *Message, opts ...PublishOption) error {
+	return func(ctx context.Context, topic string, messages ...Message) error {
 		t.f = true
-		return fn(ctx, topic, msg, opts...)
+		return fn(ctx, topic, messages...)
 	}
 }
 

broker/options.go

@@ -5,13 +5,13 @@ import (
 	"crypto/tls"
 	"time"
 
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v4/options"
-	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v3/sync"
+	"go.unistack.org/micro/v4/sync"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/tracer"
 )
 
 // Options struct
@@ -23,8 +23,8 @@ type Options struct {
 	Tracer tracer.Tracer
 	// Register can be used for clustering
 	Register register.Register
-	// Codec holds the codec for marshal/unmarshal
+	// Codecs holds the codecs for marshal/unmarshal based on content-type
-	Codec codec.Codec
+	Codecs map[string]codec.Codec
 	// Logger used for logging
 	Logger logger.Logger
 	// Meter used for metrics
@@ -37,11 +37,6 @@ type Options struct {
 	// TLSConfig holds tls.TLSConfig options
 	TLSConfig *tls.Config
 
-	// ErrorHandler used when broker can't unmarshal incoming message
-	ErrorHandler Handler
-	// BatchErrorHandler used when broker can't unmashal incoming messages
-	BatchErrorHandler BatchHandler
-
 	// Addrs holds the broker address
 	Addrs []string
 	// Hooks can be run before broker Publish/BatchPublish and
@@ -50,6 +45,9 @@ type Options struct {
 
 	// GracefulTimeout contains time to wait to finish in flight requests
 	GracefulTimeout time.Duration
+
+	// ContentType will be used if no content-type set when creating message
+	ContentType string
 }
 
 // NewOptions create new Options
@@ -59,16 +57,22 @@ func NewOptions(opts ...Option) Options {
 		Logger:          logger.DefaultLogger,
 		Context:         context.Background(),
 		Meter:           meter.DefaultMeter,
-		Codec:           codec.DefaultCodec,
+		Codecs:          make(map[string]codec.Codec),
 		Tracer:          tracer.DefaultTracer,
 		GracefulTimeout: DefaultGracefulTimeout,
+		ContentType:     DefaultContentType,
 	}
+
 	for _, o := range opts {
 		o(&options)
 	}
+
 	return options
 }
 
+// DefaultContentType is the default content-type if not specified
+var DefaultContentType = ""
+
 // Context sets the context option
 func Context(ctx context.Context) Option {
 	return func(o *Options) {
@@ -76,17 +80,27 @@ func Context(ctx context.Context) Option {
 	}
 }
 
-// PublishOptions struct
+// ContentType used by default if not specified
-type PublishOptions struct {
+func ContentType(ct string) Option {
-	// Context holds external options
+	return func(o *Options) {
-	Context context.Context
+		o.ContentType = ct
-	// BodyOnly flag says the message contains raw body bytes
+	}
-	BodyOnly bool
 }
 
-// NewPublishOptions creates PublishOptions struct
+// MessageOptions struct
-func NewPublishOptions(opts ...PublishOption) PublishOptions {
+type MessageOptions struct {
-	options := PublishOptions{
+	// ContentType for message body
+	ContentType string
+	// BodyOnly flag says the message contains raw body bytes and don't need
+	// codec Marshal method
+	BodyOnly bool
+	// Context holds custom options
+	Context context.Context
+}
+
+// NewMessageOptions creates MessageOptions struct
+func NewMessageOptions(opts ...MessageOption) MessageOptions {
+	options := MessageOptions{
 		Context: context.Background(),
 	}
 	for _, o := range opts {
@@ -99,10 +113,6 @@ func NewPublishOptions(opts ...PublishOption) PublishOptions {
 type SubscribeOptions struct {
 	// Context holds external options
 	Context context.Context
-	// ErrorHandler used when broker can't unmarshal incoming message
-	ErrorHandler Handler
-	// BatchErrorHandler used when broker can't unmashal incoming messages
-	BatchErrorHandler BatchHandler
 	// Group holds consumer group
 	Group string
 	// AutoAck flag specifies auto ack of incoming message when no error happens
@@ -118,20 +128,20 @@ type SubscribeOptions struct {
 // Option func
 type Option func(*Options)
 
-// PublishOption func
+// MessageOption func
-type PublishOption func(*PublishOptions)
+type MessageOption func(*MessageOptions)
 
-// PublishBodyOnly publish only body of the message
+// MessageContentType sets message content-type that used to Marshal
-func PublishBodyOnly(b bool) PublishOption {
+func MessageContentType(ct string) MessageOption {
-	return func(o *PublishOptions) {
+	return func(o *MessageOptions) {
-		o.BodyOnly = b
+		o.ContentType = ct
 	}
 }
 
-// PublishContext sets the context
+// MessageBodyOnly publish only body of the message
-func PublishContext(ctx context.Context) PublishOption {
+func MessageBodyOnly(b bool) MessageOption {
-	return func(o *PublishOptions) {
+	return func(o *MessageOptions) {
-		o.Context = ctx
+		o.BodyOnly = b
 	}
 }
 
@@ -142,51 +152,10 @@ func Addrs(addrs ...string) Option {
 	}
 }
 
-// Codec sets the codec used for encoding/decoding used where
+// Codec sets the codec used for encoding/decoding messages
-// a broker does not support headers
+func Codec(ct string, c codec.Codec) Option {
-func Codec(c codec.Codec) Option {
 	return func(o *Options) {
-		o.Codec = c
+		o.Codecs[ct] = c
-	}
-}
-
-// ErrorHandler will catch all broker errors that cant be handled
-// in normal way, for example Codec errors
-func ErrorHandler(h Handler) Option {
-	return func(o *Options) {
-		o.ErrorHandler = h
-	}
-}
-
-// BatchErrorHandler will catch all broker errors that cant be handled
-// in normal way, for example Codec errors
-func BatchErrorHandler(h BatchHandler) Option {
-	return func(o *Options) {
-		o.BatchErrorHandler = h
-	}
-}
-
-// SubscribeErrorHandler will catch all broker errors that cant be handled
-// in normal way, for example Codec errors
-func SubscribeErrorHandler(h Handler) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.ErrorHandler = h
-	}
-}
-
-// SubscribeBatchErrorHandler will catch all broker errors that cant be handled
-// in normal way, for example Codec errors
-func SubscribeBatchErrorHandler(h BatchHandler) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.BatchErrorHandler = h
-	}
-}
-
-// Queue sets the subscribers queue
-// Deprecated
-func Queue(name string) SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.Group = name
 	}
 }
 
@@ -253,14 +222,6 @@ func SubscribeContext(ctx context.Context) SubscribeOption {
 	}
 }
 
-// DisableAutoAck disables auto ack
-// Deprecated
-func DisableAutoAck() SubscribeOption {
-	return func(o *SubscribeOptions) {
-		o.AutoAck = false
-	}
-}
-
 // SubscribeAutoAck contol auto acking of messages
 // after they have been handled.
 func SubscribeAutoAck(b bool) SubscribeOption {

broker/subscriber.go

@@ -0,0 +1,14 @@
+package broker
+
+// IsValidHandler func signature
+func IsValidHandler(sub interface{}) error {
+	switch sub.(type) {
+	default:
+		return ErrInvalidHandler
+	case func(Message) error:
+		break
+	case func([]Message) error:
+		break
+	}
+	return nil
+}

client/backoff.go

@@ -5,7 +5,7 @@ import (
 	"math"
 	"time"
 
-	"go.unistack.org/micro/v3/util/backoff"
+	"go.unistack.org/micro/v4/util/backoff"
 )
 
 // BackoffFunc is the backoff call func

client/client.go

@@ -5,8 +5,8 @@ import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/metadata"
 )
 
 var (
@@ -29,40 +29,24 @@ var (
 )
 
 // Client is the interface used to make requests to services.
-// It supports Request/Response via Transport and Publishing via the Broker.
 // It also supports bidirectional streaming of requests.
 type Client interface {
 	Name() string
 	Init(opts ...Option) error
 	Options() Options
-	NewMessage(topic string, msg interface{}, opts ...MessageOption) Message
 	NewRequest(service string, endpoint string, req interface{}, opts ...RequestOption) Request
 	Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
 	Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
-	Publish(ctx context.Context, msg Message, opts ...PublishOption) error
-	BatchPublish(ctx context.Context, msg []Message, opts ...PublishOption) error
 	String() string
 }
 
 type (
-	FuncCall         func(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
+	FuncCall   func(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
-	HookCall         func(next FuncCall) FuncCall
+	HookCall   func(next FuncCall) FuncCall
-	FuncStream       func(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
+	FuncStream func(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
-	HookStream       func(next FuncStream) FuncStream
+	HookStream func(next FuncStream) FuncStream
-	FuncPublish      func(ctx context.Context, msg Message, opts ...PublishOption) error
-	HookPublish      func(next FuncPublish) FuncPublish
-	FuncBatchPublish func(ctx context.Context, msg []Message, opts ...PublishOption) error
-	HookBatchPublish func(next FuncBatchPublish) FuncBatchPublish
 )
 
-// Message is the interface for publishing asynchronously
-type Message interface {
-	Topic() string
-	Payload() interface{}
-	ContentType() string
-	Metadata() metadata.Metadata
-}
-
 // Request is the interface for a synchronous request used by Call or Stream
 type Request interface {
 	// The service to call
@@ -121,11 +105,5 @@ type Option func(*Options)
 // CallOption used by Call or Stream
 type CallOption func(*CallOptions)
 
-// PublishOption used by Publish
-type PublishOption func(*PublishOptions)
-
-// MessageOption used by NewMessage
-type MessageOption func(*MessageOptions)
-
 // RequestOption used by NewRequest
 type RequestOption func(*RequestOptions)

client/context.go

@@ -32,16 +32,6 @@ func NewContext(ctx context.Context, c Client) context.Context {
 	return context.WithValue(ctx, clientKey{}, c)
 }
 
-// SetPublishOption returns a function to setup a context with given value
-func SetPublishOption(k, v interface{}) PublishOption {
-	return func(o *PublishOptions) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, k, v)
-	}
-}
-
 // SetCallOption returns a function to setup a context with given value
 func SetCallOption(k, v interface{}) CallOption {
 	return func(o *CallOptions) {

client/context_test.go

@@ -39,17 +39,6 @@ func TestNewNilContext(t *testing.T) {
 	}
 }
 
-func TestSetPublishOption(t *testing.T) {
-	type key struct{}
-	o := SetPublishOption(key{}, "test")
-	opts := &PublishOptions{}
-	o(opts)
-
-	if v, ok := opts.Context.Value(key{}).(string); !ok || v == "" {
-		t.Fatal("SetPublishOption not works")
-	}
-}
-
 func TestSetCallOption(t *testing.T) {
 	type key struct{}
 	o := SetCallOption(key{}, "test")

client/lookup.go

@@ -4,8 +4,8 @@ import (
 	"context"
 	"sort"
 
-	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v4/errors"
-	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v4/router"
 )
 
 // LookupFunc is used to lookup routes for a service

client/noop.go

@@ -3,37 +3,22 @@ package client
 import (
 	"context"
 	"fmt"
-	"os"
 	"strconv"
 	"time"
 
-	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/errors"
-	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/options"
-	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v4/selector"
-	"go.unistack.org/micro/v3/selector"
+	"go.unistack.org/micro/v4/semconv"
-	"go.unistack.org/micro/v3/semconv"
+	"go.unistack.org/micro/v4/tracer"
-	"go.unistack.org/micro/v3/tracer"
 )
 
-// DefaultCodecs will be used to encode/decode data
-var DefaultCodecs = map[string]codec.Codec{
-	"application/octet-stream": codec.NewCodec(),
-}
-
 type noopClient struct {
-	funcPublish      FuncPublish
+	funcCall   FuncCall
-	funcBatchPublish FuncBatchPublish
+	funcStream FuncStream
-	funcCall         FuncCall
+	opts       Options
-	funcStream       FuncStream
-	opts             Options
-}
-
-type noopMessage struct {
-	topic   string
-	payload interface{}
-	opts    MessageOptions
 }
 
 type noopRequest struct {
@@ -52,8 +37,6 @@ func NewClient(opts ...Option) Client {
 
 	n.funcCall = n.fnCall
 	n.funcStream = n.fnStream
-	n.funcPublish = n.fnPublish
-	n.funcBatchPublish = n.fnBatchPublish
 
 	return n
 }
@@ -158,32 +141,6 @@ func (n *noopStream) CloseSend() error {
 	return n.err
 }
 
-func (n *noopMessage) Topic() string {
-	return n.topic
-}
-
-func (n *noopMessage) Payload() interface{} {
-	return n.payload
-}
-
-func (n *noopMessage) ContentType() string {
-	return n.opts.ContentType
-}
-
-func (n *noopMessage) Metadata() metadata.Metadata {
-	return n.opts.Metadata
-}
-
-func (n *noopClient) newCodec(contentType string) (codec.Codec, error) {
-	if cf, ok := n.opts.Codecs[contentType]; ok {
-		return cf, nil
-	}
-	if cf, ok := DefaultCodecs[contentType]; ok {
-		return cf, nil
-	}
-	return nil, codec.ErrUnknownContentType
-}
-
 func (n *noopClient) Init(opts ...Option) error {
 	for _, o := range opts {
 		o(&n.opts)
@@ -191,8 +148,6 @@ func (n *noopClient) Init(opts ...Option) error {
 
 	n.funcCall = n.fnCall
 	n.funcStream = n.fnStream
-	n.funcPublish = n.fnPublish
-	n.funcBatchPublish = n.fnBatchPublish
 
 	n.opts.Hooks.EachPrev(func(hook options.Hook) {
 		switch h := hook.(type) {
@@ -200,10 +155,6 @@ func (n *noopClient) Init(opts ...Option) error {
 			n.funcCall = h(n.funcCall)
 		case HookStream:
 			n.funcStream = h(n.funcStream)
-		case HookPublish:
-			n.funcPublish = h(n.funcPublish)
-		case HookBatchPublish:
-			n.funcBatchPublish = h(n.funcBatchPublish)
 		}
 	})
 
@@ -376,11 +327,6 @@ func (n *noopClient) NewRequest(service, endpoint string, _ interface{}, _ ...Re
 	return &noopRequest{service: service, endpoint: endpoint}
 }
 
-func (n *noopClient) NewMessage(topic string, msg interface{}, opts ...MessageOption) Message {
-	options := NewMessageOptions(append([]MessageOption{MessageContentType(n.opts.ContentType)}, opts...)...)
-	return &noopMessage{topic: topic, payload: msg, opts: options}
-}
-
 func (n *noopClient) Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error) {
 	ts := time.Now()
 	n.opts.Meter.Counter(semconv.ClientRequestInflight, "endpoint", req.Endpoint()).Inc()
@@ -549,89 +495,3 @@ func (n *noopClient) fnStream(ctx context.Context, req Request, opts ...CallOpti
 func (n *noopClient) stream(ctx context.Context, _ string, _ Request, _ CallOptions) (Stream, error) {
 	return &noopStream{ctx: ctx}, nil
 }
-
-func (n *noopClient) BatchPublish(ctx context.Context, ps []Message, opts ...PublishOption) error {
-	return n.funcBatchPublish(ctx, ps, opts...)
-}
-
-func (n *noopClient) fnBatchPublish(ctx context.Context, ps []Message, opts ...PublishOption) error {
-	return n.publish(ctx, ps, opts...)
-}
-
-func (n *noopClient) Publish(ctx context.Context, p Message, opts ...PublishOption) error {
-	return n.funcPublish(ctx, p, opts...)
-}
-
-func (n *noopClient) fnPublish(ctx context.Context, p Message, opts ...PublishOption) error {
-	return n.publish(ctx, []Message{p}, opts...)
-}
-
-func (n *noopClient) publish(ctx context.Context, ps []Message, opts ...PublishOption) error {
-	options := NewPublishOptions(opts...)
-
-	msgs := make([]*broker.Message, 0, len(ps))
-
-	// get proxy
-	exchange := ""
-	if v, ok := os.LookupEnv("MICRO_PROXY"); ok {
-		exchange = v
-	}
-	// get the exchange
-	if len(options.Exchange) > 0 {
-		exchange = options.Exchange
-	}
-
-	omd, ok := metadata.FromOutgoingContext(ctx)
-	if !ok {
-		omd = metadata.New(0)
-	}
-
-	for _, p := range ps {
-		md := metadata.Copy(omd)
-		md[metadata.HeaderContentType] = p.ContentType()
-		topic := p.Topic()
-		if len(exchange) > 0 {
-			topic = exchange
-		}
-		md[metadata.HeaderTopic] = topic
-		iter := p.Metadata().Iterator()
-		var k, v string
-		for iter.Next(&k, &v) {
-			md.Set(k, v)
-		}
-
-		var body []byte
-
-		// passed in raw data
-		if d, ok := p.Payload().(*codec.Frame); ok {
-			body = d.Data
-		} else {
-			// use codec for payload
-			cf, err := n.newCodec(p.ContentType())
-			if err != nil {
-				return errors.InternalServerError("go.micro.client", "%s", err)
-			}
-
-			// set the body
-			b, err := cf.Marshal(p.Payload())
-			if err != nil {
-				return errors.InternalServerError("go.micro.client", "%s", err)
-			}
-			body = b
-		}
-
-		msgs = append(msgs, &broker.Message{Header: md, Body: body})
-	}
-
-	if len(msgs) == 1 {
-		return n.opts.Broker.Publish(ctx, msgs[0].Header[metadata.HeaderTopic], msgs[0],
-			broker.PublishContext(options.Context),
-			broker.PublishBodyOnly(options.BodyOnly),
-		)
-	}
-
-	return n.opts.Broker.BatchPublish(ctx, msgs,
-		broker.PublishContext(options.Context),
-		broker.PublishBodyOnly(options.BodyOnly),
-	)
-}

client/noop_test.go

@@ -1,35 +0,0 @@
-package client
-
-import (
-	"context"
-	"testing"
-)
-
-type testHook struct {
-	f bool
-}
-
-func (t *testHook) Publish(fn FuncPublish) FuncPublish {
-	return func(ctx context.Context, msg Message, opts ...PublishOption) error {
-		t.f = true
-		return fn(ctx, msg, opts...)
-	}
-}
-
-func TestNoopHook(t *testing.T) {
-	h := &testHook{}
-
-	c := NewClient(Hooks(HookPublish(h.Publish)))
-
-	if err := c.Init(); err != nil {
-		t.Fatal(err)
-	}
-
-	if err := c.Publish(context.TODO(), c.NewMessage("", nil, MessageContentType("application/octet-stream"))); err != nil {
-		t.Fatal(err)
-	}
-
-	if !h.f {
-		t.Fatal("hook not works")
-	}
-}

client/options.go

@@ -6,17 +6,17 @@ import (
 	"net"
 	"time"
 
-	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v4/options"
-	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v3/selector"
+	"go.unistack.org/micro/v4/selector"
-	"go.unistack.org/micro/v3/selector/random"
+	"go.unistack.org/micro/v4/selector/random"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/tracer"
 )
 
 // Options holds client options
@@ -137,43 +137,6 @@ func Context(ctx context.Context) Option {
 	}
 }
 
-// NewPublishOptions create new PublishOptions struct from option
-func NewPublishOptions(opts ...PublishOption) PublishOptions {
-	options := PublishOptions{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
-// PublishOptions holds publish options
-type PublishOptions struct {
-	// Context used for external options
-	Context context.Context
-	// Exchange topic exchange name
-	Exchange string
-	// BodyOnly will publish only message body
-	BodyOnly bool
-}
-
-// NewMessageOptions creates message options struct
-func NewMessageOptions(opts ...MessageOption) MessageOptions {
-	options := MessageOptions{Metadata: metadata.New(1)}
-	for _, o := range opts {
-		o(&options)
-	}
-	return options
-}
-
-// MessageOptions holds client message options
-type MessageOptions struct {
-	// Metadata additional metadata
-	Metadata metadata.Metadata
-	// ContentType specify content-type of message
-	// deprecated
-	ContentType string
-}
-
 // NewRequestOptions creates new RequestOptions struct
 func NewRequestOptions(opts ...RequestOption) RequestOptions {
 	options := RequestOptions{}
@@ -198,7 +161,7 @@ func NewOptions(opts ...Option) Options {
 	options := Options{
 		Context:     context.Background(),
 		ContentType: DefaultContentType,
-		Codecs:      DefaultCodecs,
+		Codecs:      make(map[string]codec.Codec),
 		CallOptions: CallOptions{
 			Context:        context.Background(),
 			Backoff:        DefaultBackoff,
@@ -374,43 +337,6 @@ func DialTimeout(d time.Duration) Option {
 	}
 }
 
-// WithExchange sets the exchange to route a message through
-// Deprecated
-func WithExchange(e string) PublishOption {
-	return func(o *PublishOptions) {
-		o.Exchange = e
-	}
-}
-
-// PublishExchange sets the exchange to route a message through
-func PublishExchange(e string) PublishOption {
-	return func(o *PublishOptions) {
-		o.Exchange = e
-	}
-}
-
-// WithBodyOnly publish only message body
-// DERECATED
-func WithBodyOnly(b bool) PublishOption {
-	return func(o *PublishOptions) {
-		o.BodyOnly = b
-	}
-}
-
-// PublishBodyOnly publish only message body
-func PublishBodyOnly(b bool) PublishOption {
-	return func(o *PublishOptions) {
-		o.BodyOnly = b
-	}
-}
-
-// PublishContext sets the context in publish options
-func PublishContext(ctx context.Context) PublishOption {
-	return func(o *PublishOptions) {
-		o.Context = ctx
-	}
-}
-
 // WithContextDialer pass ContextDialer to client call
 func WithContextDialer(fn func(context.Context, string) (net.Conn, error)) CallOption {
 	return func(o *CallOptions) {
@@ -522,30 +448,6 @@ func WithSelectOptions(sops ...selector.SelectOption) CallOption {
 	}
 }
 
-// WithMessageContentType sets the message content type
-// Deprecated
-func WithMessageContentType(ct string) MessageOption {
-	return func(o *MessageOptions) {
-		o.Metadata.Set(metadata.HeaderContentType, ct)
-		o.ContentType = ct
-	}
-}
-
-// MessageContentType sets the message content type
-func MessageContentType(ct string) MessageOption {
-	return func(o *MessageOptions) {
-		o.Metadata.Set(metadata.HeaderContentType, ct)
-		o.ContentType = ct
-	}
-}
-
-// MessageMetadata sets the message metadata
-func MessageMetadata(k, v string) MessageOption {
-	return func(o *MessageOptions) {
-		o.Metadata.Set(k, v)
-	}
-}
-
 // StreamingRequest specifies that request is streaming
 func StreamingRequest(b bool) RequestOption {
 	return func(o *RequestOptions) {

client/retry.go

@@ -3,7 +3,7 @@ package client
 import (
 	"context"
 
-	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v4/errors"
 )
 
 // RetryFunc that returning either false or a non-nil error will result in the call not being retried

client/retry_test.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"testing"
 
-	"go.unistack.org/micro/v3/errors"
+	"go.unistack.org/micro/v4/errors"
 )
 
 func TestRetryAlways(t *testing.T) {

client/test_request.go

@@ -1,7 +1,7 @@
 package client
 
 import (
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
 )
 
 type testRequest struct {

cluster/cluster.go

@@ -3,7 +3,7 @@ package cluster
 import (
 	"context"
 
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/metadata"
 )
 
 // Message sent to member in cluster

cluster/hasql/cluster.go

@@ -0,0 +1,235 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+	"reflect"
+	"unsafe"
+
+	"golang.yandex/hasql/v2"
+)
+
+func newSQLRowError() *sql.Row {
+	row := &sql.Row{}
+	t := reflect.TypeOf(row).Elem()
+	field, _ := t.FieldByName("err")
+	rowPtr := unsafe.Pointer(row)
+	errFieldPtr := unsafe.Pointer(uintptr(rowPtr) + field.Offset)
+	errPtr := (*error)(errFieldPtr)
+	*errPtr = ErrorNoAliveNodes
+	return row
+}
+
+type ClusterQuerier interface {
+	Querier
+	WaitForNodes(ctx context.Context, criterion ...hasql.NodeStateCriterion) error
+}
+
+type Cluster struct {
+	hasql   *hasql.Cluster[Querier]
+	options ClusterOptions
+}
+
+// NewCluster returns [Querier] that provides cluster of nodes
+func NewCluster[T Querier](opts ...ClusterOption) (ClusterQuerier, error) {
+	options := ClusterOptions{Context: context.Background()}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	if options.NodeChecker == nil {
+		return nil, ErrClusterChecker
+	}
+	if options.NodeDiscoverer == nil {
+		return nil, ErrClusterDiscoverer
+	}
+	if options.NodePicker == nil {
+		return nil, ErrClusterPicker
+	}
+
+	if options.Retries < 1 {
+		options.Retries = 1
+	}
+
+	if options.NodeStateCriterion == 0 {
+		options.NodeStateCriterion = hasql.Primary
+	}
+
+	options.Options = append(options.Options, hasql.WithNodePicker(options.NodePicker))
+	if p, ok := options.NodePicker.(*CustomPicker[Querier]); ok {
+		p.opts.Priority = options.NodePriority
+	}
+
+	c, err := hasql.NewCluster(
+		options.NodeDiscoverer,
+		options.NodeChecker,
+		options.Options...,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Cluster{hasql: c, options: options}, nil
+}
+
+func (c *Cluster) BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error) {
+	var tx *sql.Tx
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if tx, err = n.DB().BeginTx(ctx, opts); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if tx == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return tx, err
+}
+
+func (c *Cluster) Close() error {
+	return c.hasql.Close()
+}
+
+func (c *Cluster) Conn(ctx context.Context) (*sql.Conn, error) {
+	var conn *sql.Conn
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if conn, err = n.DB().Conn(ctx); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if conn == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return conn, err
+}
+
+func (c *Cluster) ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error) {
+	var res sql.Result
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if res, err = n.DB().ExecContext(ctx, query, args...); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) PrepareContext(ctx context.Context, query string) (*sql.Stmt, error) {
+	var res *sql.Stmt
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if res, err = n.DB().PrepareContext(ctx, query); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error) {
+	var res *sql.Rows
+	var err error
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			if res, err = n.DB().QueryContext(ctx, query); err != nil && err != sql.ErrNoRows && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = ErrorNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row {
+	var res *sql.Row
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		for ; retries < c.options.Retries; retries++ {
+			res = n.DB().QueryRowContext(ctx, query, args...)
+			if res.Err() == nil {
+				return false
+			} else if res.Err() != nil && retries >= c.options.Retries {
+				return false
+			}
+		}
+		return true
+	})
+
+	if res == nil {
+		res = newSQLRowError()
+	}
+
+	return res
+}
+
+func (c *Cluster) PingContext(ctx context.Context) error {
+	var err error
+	var ok bool
+
+	retries := 0
+	c.hasql.NodesIter(c.getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		ok = true
+		for ; retries < c.options.Retries; retries++ {
+			if err = n.DB().PingContext(ctx); err != nil && retries >= c.options.Retries {
+				return true
+			}
+		}
+		return false
+	})
+
+	if !ok {
+		err = ErrorNoAliveNodes
+	}
+
+	return err
+}
+
+func (c *Cluster) WaitForNodes(ctx context.Context, criterions ...hasql.NodeStateCriterion) error {
+	for _, criterion := range criterions {
+		if _, err := c.hasql.WaitForNode(ctx, criterion); err != nil {
+			return err
+		}
+	}
+	return nil
+}

cluster/hasql/cluster_test.go

@@ -0,0 +1,171 @@
+package sql
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"golang.yandex/hasql/v2"
+)
+
+func TestNewCluster(t *testing.T) {
+	dbMaster, dbMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbMaster.Close()
+	dbMasterMock.MatchExpectationsInOrder(false)
+
+	dbMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(1, 0)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("master-dc1"))
+
+	dbDRMaster, dbDRMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbDRMaster.Close()
+	dbDRMasterMock.MatchExpectationsInOrder(false)
+
+	dbDRMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 40)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster1-dc2"))
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster"))
+
+	dbSlaveDC1, dbSlaveDC1Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC1.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC1Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC1Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	dbSlaveDC2, dbSlaveDC2Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC2.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC2Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC2Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	tctx, cancel := context.WithTimeout(t.Context(), 10*time.Second)
+	defer cancel()
+
+	c, err := NewCluster[Querier](
+		WithClusterContext(tctx),
+		WithClusterNodeChecker(hasql.PostgreSQLChecker),
+		WithClusterNodePicker(NewCustomPicker[Querier](
+			CustomPickerMaxLag(100),
+		)),
+		WithClusterNodes(
+			ClusterNode{"slave-dc1", dbSlaveDC1, 1},
+			ClusterNode{"master-dc1", dbMaster, 1},
+			ClusterNode{"slave-dc2", dbSlaveDC2, 2},
+			ClusterNode{"drmaster1-dc2", dbDRMaster, 0},
+		),
+		WithClusterOptions(
+			hasql.WithUpdateInterval[Querier](2*time.Second),
+			hasql.WithUpdateTimeout[Querier](1*time.Second),
+		),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	if err = c.WaitForNodes(tctx, hasql.Primary, hasql.Standby); err != nil {
+		t.Fatal(err)
+	}
+
+	time.Sleep(500 * time.Millisecond)
+
+	node1Name := ""
+	fmt.Printf("check for Standby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.Standby), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node1Name); err != nil {
+		t.Fatal(err)
+	} else if "slave-dc1" != node1Name {
+		t.Fatalf("invalid node name %s != %s", "slave-dc1", node1Name)
+	}
+
+	dbSlaveDC1Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	node2Name := ""
+	fmt.Printf("check for PreferStandby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferStandby), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node2Name); err != nil {
+		t.Fatal(err)
+	} else if "slave-dc1" != node2Name {
+		t.Fatalf("invalid node name %s != %s", "slave-dc1", node2Name)
+	}
+
+	node3Name := ""
+	fmt.Printf("check for PreferPrimary\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferPrimary), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node3Name); err != nil {
+		t.Fatal(err)
+	} else if "master-dc1" != node3Name {
+		t.Fatalf("invalid node name %s != %s", "master-dc1", node3Name)
+	}
+
+	dbSlaveDC1Mock.ExpectQuery(`.*`).WillReturnRows(sqlmock.NewRows([]string{"role"}).RowError(1, fmt.Errorf("row error")))
+
+	time.Sleep(2 * time.Second)
+
+	fmt.Printf("check for PreferStandby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferStandby), "SELECT node_name as name"); row.Err() == nil {
+		t.Fatal("must return error")
+	}
+
+	if dbMasterErr := dbMasterMock.ExpectationsWereMet(); dbMasterErr != nil {
+		t.Error(dbMasterErr)
+	}
+}

cluster/hasql/db.go

@@ -0,0 +1,25 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+)
+
+type Querier interface {
+	// Basic connection methods
+	PingContext(ctx context.Context) error
+	Close() error
+
+	// Query methods with context
+	ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
+	QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
+	QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row
+
+	// Prepared statements with context
+	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
+
+	// Transaction management with context
+	BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
+
+	Conn(ctx context.Context) (*sql.Conn, error)
+}

cluster/hasql/driver.go

@@ -0,0 +1,295 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"io"
+	"sync"
+	"time"
+)
+
+// OpenDBWithCluster creates a [*sql.DB] that uses the [ClusterQuerier]
+func OpenDBWithCluster(db ClusterQuerier) (*sql.DB, error) {
+	driver := NewClusterDriver(db)
+	connector, err := driver.OpenConnector("")
+	if err != nil {
+		return nil, err
+	}
+	return sql.OpenDB(connector), nil
+}
+
+// ClusterDriver implements [driver.Driver] and driver.Connector for an existing [Querier]
+type ClusterDriver struct {
+	db ClusterQuerier
+}
+
+// NewClusterDriver creates a new [driver.Driver] that uses an existing [ClusterQuerier]
+func NewClusterDriver(db ClusterQuerier) *ClusterDriver {
+	return &ClusterDriver{db: db}
+}
+
+// Open implements [driver.Driver.Open]
+func (d *ClusterDriver) Open(name string) (driver.Conn, error) {
+	return d.Connect(context.Background())
+}
+
+// OpenConnector implements [driver.DriverContext.OpenConnector]
+func (d *ClusterDriver) OpenConnector(name string) (driver.Connector, error) {
+	return d, nil
+}
+
+// Connect implements [driver.Connector.Connect]
+func (d *ClusterDriver) Connect(ctx context.Context) (driver.Conn, error) {
+	conn, err := d.db.Conn(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return &dbConn{conn: conn}, nil
+}
+
+// Driver implements [driver.Connector.Driver]
+func (d *ClusterDriver) Driver() driver.Driver {
+	return d
+}
+
+// dbConn implements driver.Conn with both context and legacy methods
+type dbConn struct {
+	conn *sql.Conn
+	mu   sync.Mutex
+}
+
+// Prepare implements [driver.Conn.Prepare] (legacy method)
+func (c *dbConn) Prepare(query string) (driver.Stmt, error) {
+	return c.PrepareContext(context.Background(), query)
+}
+
+// PrepareContext implements [driver.ConnPrepareContext.PrepareContext]
+func (c *dbConn) PrepareContext(ctx context.Context, query string) (driver.Stmt, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	stmt, err := c.conn.PrepareContext(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbStmt{stmt: stmt}, nil
+}
+
+// Exec implements [driver.Execer.Exec] (legacy method)
+func (c *dbConn) Exec(query string, args []driver.Value) (driver.Result, error) {
+	namedArgs := make([]driver.NamedValue, len(args))
+	for i, value := range args {
+		namedArgs[i] = driver.NamedValue{Value: value}
+	}
+	return c.ExecContext(context.Background(), query, namedArgs)
+}
+
+// ExecContext implements [driver.ExecerContext.ExecContext]
+func (c *dbConn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Convert driver.NamedValue to any
+	interfaceArgs := make([]any, len(args))
+	for i, arg := range args {
+		interfaceArgs[i] = arg.Value
+	}
+
+	return c.conn.ExecContext(ctx, query, interfaceArgs...)
+}
+
+// Query implements [driver.Queryer.Query] (legacy method)
+func (c *dbConn) Query(query string, args []driver.Value) (driver.Rows, error) {
+	namedArgs := make([]driver.NamedValue, len(args))
+	for i, value := range args {
+		namedArgs[i] = driver.NamedValue{Value: value}
+	}
+	return c.QueryContext(context.Background(), query, namedArgs)
+}
+
+// QueryContext implements [driver.QueryerContext.QueryContext]
+func (c *dbConn) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Convert driver.NamedValue to any
+	interfaceArgs := make([]any, len(args))
+	for i, arg := range args {
+		interfaceArgs[i] = arg.Value
+	}
+
+	rows, err := c.conn.QueryContext(ctx, query, interfaceArgs...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbRows{rows: rows}, nil
+}
+
+// Begin implements [driver.Conn.Begin] (legacy method)
+func (c *dbConn) Begin() (driver.Tx, error) {
+	return c.BeginTx(context.Background(), driver.TxOptions{})
+}
+
+// BeginTx implements [driver.ConnBeginTx.BeginTx]
+func (c *dbConn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	sqlOpts := &sql.TxOptions{
+		Isolation: sql.IsolationLevel(opts.Isolation),
+		ReadOnly:  opts.ReadOnly,
+	}
+
+	tx, err := c.conn.BeginTx(ctx, sqlOpts)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbTx{tx: tx}, nil
+}
+
+// Ping implements [driver.Pinger.Ping]
+func (c *dbConn) Ping(ctx context.Context) error {
+	return c.conn.PingContext(ctx)
+}
+
+// Close implements [driver.Conn.Close]
+func (c *dbConn) Close() error {
+	return c.conn.Close()
+}
+
+// IsValid implements [driver.Validator.IsValid]
+func (c *dbConn) IsValid() bool {
+	// Ping with a short timeout to check if the connection is still valid
+	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+	defer cancel()
+
+	return c.conn.PingContext(ctx) == nil
+}
+
+// dbStmt implements [driver.Stmt] with both context and legacy methods
+type dbStmt struct {
+	stmt *sql.Stmt
+	mu   sync.Mutex
+}
+
+// Close implements [driver.Stmt.Close]
+func (s *dbStmt) Close() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.stmt.Close()
+}
+
+// Close implements [driver.Stmt.NumInput]
+func (s *dbStmt) NumInput() int {
+	return -1 // Number of parameters is unknown
+}
+
+// Exec implements [driver.Stmt.Exec] (legacy method)
+func (s *dbStmt) Exec(args []driver.Value) (driver.Result, error) {
+	namedArgs := make([]driver.NamedValue, len(args))
+	for i, value := range args {
+		namedArgs[i] = driver.NamedValue{Value: value}
+	}
+	return s.ExecContext(context.Background(), namedArgs)
+}
+
+// ExecContext implements [driver.StmtExecContext.ExecContext]
+func (s *dbStmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver.Result, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	interfaceArgs := make([]any, len(args))
+	for i, arg := range args {
+		interfaceArgs[i] = arg.Value
+	}
+	return s.stmt.ExecContext(ctx, interfaceArgs...)
+}
+
+// Query implements [driver.Stmt.Query] (legacy method)
+func (s *dbStmt) Query(args []driver.Value) (driver.Rows, error) {
+	namedArgs := make([]driver.NamedValue, len(args))
+	for i, value := range args {
+		namedArgs[i] = driver.NamedValue{Value: value}
+	}
+	return s.QueryContext(context.Background(), namedArgs)
+}
+
+// QueryContext implements [driver.StmtQueryContext.QueryContext]
+func (s *dbStmt) QueryContext(ctx context.Context, args []driver.NamedValue) (driver.Rows, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	interfaceArgs := make([]any, len(args))
+	for i, arg := range args {
+		interfaceArgs[i] = arg.Value
+	}
+
+	rows, err := s.stmt.QueryContext(ctx, interfaceArgs...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &dbRows{rows: rows}, nil
+}
+
+// dbRows implements [driver.Rows]
+type dbRows struct {
+	rows *sql.Rows
+}
+
+// Columns implements [driver.Rows.Columns]
+func (r *dbRows) Columns() []string {
+	cols, err := r.rows.Columns()
+	if err != nil {
+		// This shouldn't happen if the query was successful
+		return []string{}
+	}
+	return cols
+}
+
+// Close implements [driver.Rows.Close]
+func (r *dbRows) Close() error {
+	return r.rows.Close()
+}
+
+// Next implements [driver.Rows.Next]
+func (r *dbRows) Next(dest []driver.Value) error {
+	if !r.rows.Next() {
+		if err := r.rows.Err(); err != nil {
+			return err
+		}
+		return io.EOF
+	}
+
+	// Create a slice of interfaces to scan into
+	scanArgs := make([]any, len(dest))
+	for i := range scanArgs {
+		scanArgs[i] = &dest[i]
+	}
+
+	return r.rows.Scan(scanArgs...)
+}
+
+// dbTx implements [driver.Tx]
+type dbTx struct {
+	tx *sql.Tx
+	mu sync.Mutex
+}
+
+// Commit implements [driver.Tx.Commit]
+func (t *dbTx) Commit() error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.tx.Commit()
+}
+
+// Rollback implements [driver.Tx.Rollback]
+func (t *dbTx) Rollback() error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.tx.Rollback()
+}

cluster/hasql/driver_test.go

@@ -0,0 +1,141 @@
+package sql
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"golang.yandex/hasql/v2"
+)
+
+func TestDriver(t *testing.T) {
+	dbMaster, dbMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbMaster.Close()
+	dbMasterMock.MatchExpectationsInOrder(false)
+
+	dbMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(1, 0)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("master-dc1"))
+
+	dbDRMaster, dbDRMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbDRMaster.Close()
+	dbDRMasterMock.MatchExpectationsInOrder(false)
+
+	dbDRMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 40)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster1-dc2"))
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster"))
+
+	dbSlaveDC1, dbSlaveDC1Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC1.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC1Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC1Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	dbSlaveDC2, dbSlaveDC2Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC2.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC2Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC2Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	tctx, cancel := context.WithTimeout(t.Context(), 10*time.Second)
+	defer cancel()
+
+	c, err := NewCluster[Querier](
+		WithClusterContext(tctx),
+		WithClusterNodeChecker(hasql.PostgreSQLChecker),
+		WithClusterNodePicker(NewCustomPicker[Querier](
+			CustomPickerMaxLag(100),
+		)),
+		WithClusterNodes(
+			ClusterNode{"slave-dc1", dbSlaveDC1, 1},
+			ClusterNode{"master-dc1", dbMaster, 1},
+			ClusterNode{"slave-dc2", dbSlaveDC2, 2},
+			ClusterNode{"drmaster1-dc2", dbDRMaster, 0},
+		),
+		WithClusterOptions(
+			hasql.WithUpdateInterval[Querier](2*time.Second),
+			hasql.WithUpdateTimeout[Querier](1*time.Second),
+		),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	if err = c.WaitForNodes(tctx, hasql.Primary, hasql.Standby); err != nil {
+		t.Fatal(err)
+	}
+
+	db, err := OpenDBWithCluster(c)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Use context methods
+	row := db.QueryRowContext(NodeStateCriterion(t.Context(), hasql.Primary), "SELECT node_name as name")
+	if err = row.Err(); err != nil {
+		t.Fatal(err)
+	}
+
+	nodeName := ""
+	if err = row.Scan(&nodeName); err != nil {
+		t.Fatal(err)
+	}
+
+	if nodeName != "master-dc1" {
+		t.Fatalf("invalid node_name %s != %s", "master-dc1", nodeName)
+	}
+}

cluster/hasql/error.go

@@ -0,0 +1,10 @@
+package sql
+
+import "errors"
+
+var (
+	ErrClusterChecker    = errors.New("cluster node checker required")
+	ErrClusterDiscoverer = errors.New("cluster node discoverer required")
+	ErrClusterPicker     = errors.New("cluster node picker required")
+	ErrorNoAliveNodes    = errors.New("cluster no alive nodes")
+)

cluster/hasql/options.go

@@ -0,0 +1,110 @@
+package sql
+
+import (
+	"context"
+	"math"
+
+	"golang.yandex/hasql/v2"
+)
+
+// ClusterOptions contains cluster specific options
+type ClusterOptions struct {
+	NodeChecker        hasql.NodeChecker
+	NodePicker         hasql.NodePicker[Querier]
+	NodeDiscoverer     hasql.NodeDiscoverer[Querier]
+	Options            []hasql.ClusterOpt[Querier]
+	Context            context.Context
+	Retries            int
+	NodePriority       map[string]int32
+	NodeStateCriterion hasql.NodeStateCriterion
+}
+
+// ClusterOption apply cluster options to ClusterOptions
+type ClusterOption func(*ClusterOptions)
+
+// WithClusterNodeChecker pass hasql.NodeChecker to cluster options
+func WithClusterNodeChecker(c hasql.NodeChecker) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodeChecker = c
+	}
+}
+
+// WithClusterNodePicker pass hasql.NodePicker to cluster options
+func WithClusterNodePicker(p hasql.NodePicker[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodePicker = p
+	}
+}
+
+// WithClusterNodeDiscoverer pass hasql.NodeDiscoverer to cluster options
+func WithClusterNodeDiscoverer(d hasql.NodeDiscoverer[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodeDiscoverer = d
+	}
+}
+
+// WithRetries retry count on other nodes in case of error
+func WithRetries(n int) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.Retries = n
+	}
+}
+
+// WithClusterContext pass context.Context to cluster options and used for checks
+func WithClusterContext(ctx context.Context) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.Context = ctx
+	}
+}
+
+// WithClusterOptions pass hasql.ClusterOpt
+func WithClusterOptions(opts ...hasql.ClusterOpt[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.Options = append(o.Options, opts...)
+	}
+}
+
+// WithClusterNodeStateCriterion pass default hasql.NodeStateCriterion
+func WithClusterNodeStateCriterion(c hasql.NodeStateCriterion) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodeStateCriterion = c
+	}
+}
+
+type ClusterNode struct {
+	Name     string
+	DB       Querier
+	Priority int32
+}
+
+// WithClusterNodes create cluster with static NodeDiscoverer
+func WithClusterNodes(cns ...ClusterNode) ClusterOption {
+	return func(o *ClusterOptions) {
+		nodes := make([]*hasql.Node[Querier], 0, len(cns))
+		if o.NodePriority == nil {
+			o.NodePriority = make(map[string]int32, len(cns))
+		}
+		for _, cn := range cns {
+			nodes = append(nodes, hasql.NewNode(cn.Name, cn.DB))
+			if cn.Priority == 0 {
+				cn.Priority = math.MaxInt32
+			}
+			o.NodePriority[cn.Name] = cn.Priority
+		}
+		o.NodeDiscoverer = hasql.NewStaticNodeDiscoverer(nodes...)
+	}
+}
+
+type nodeStateCriterionKey struct{}
+
+// NodeStateCriterion inject hasql.NodeStateCriterion to context
+func NodeStateCriterion(ctx context.Context, c hasql.NodeStateCriterion) context.Context {
+	return context.WithValue(ctx, nodeStateCriterionKey{}, c)
+}
+
+func (c *Cluster) getNodeStateCriterion(ctx context.Context) hasql.NodeStateCriterion {
+	if v, ok := ctx.Value(nodeStateCriterionKey{}).(hasql.NodeStateCriterion); ok {
+		return v
+	}
+	return c.options.NodeStateCriterion
+}

cluster/hasql/picker.go

@@ -0,0 +1,113 @@
+package sql
+
+import (
+	"fmt"
+	"math"
+	"time"
+
+	"golang.yandex/hasql/v2"
+)
+
+// compile time guard
+var _ hasql.NodePicker[Querier] = (*CustomPicker[Querier])(nil)
+
+// CustomPickerOptions holds options to pick nodes
+type CustomPickerOptions struct {
+	MaxLag   int
+	Priority map[string]int32
+	Retries  int
+}
+
+// CustomPickerOption func apply option to CustomPickerOptions
+type CustomPickerOption func(*CustomPickerOptions)
+
+// CustomPickerMaxLag specifies max lag for which node can be used
+func CustomPickerMaxLag(n int) CustomPickerOption {
+	return func(o *CustomPickerOptions) {
+		o.MaxLag = n
+	}
+}
+
+// NewCustomPicker creates new node picker
+func NewCustomPicker[T Querier](opts ...CustomPickerOption) *CustomPicker[Querier] {
+	options := CustomPickerOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return &CustomPicker[Querier]{opts: options}
+}
+
+// CustomPicker holds node picker options
+type CustomPicker[T Querier] struct {
+	opts CustomPickerOptions
+}
+
+// PickNode used to return specific node
+func (p *CustomPicker[T]) PickNode(cnodes []hasql.CheckedNode[T]) hasql.CheckedNode[T] {
+	for _, n := range cnodes {
+		fmt.Printf("node %s\n", n.Node.String())
+	}
+	return cnodes[0]
+}
+
+func (p *CustomPicker[T]) getPriority(nodeName string) int32 {
+	if prio, ok := p.opts.Priority[nodeName]; ok {
+		return prio
+	}
+	return math.MaxInt32 // Default to lowest priority
+}
+
+// CompareNodes used to sort nodes
+func (p *CustomPicker[T]) CompareNodes(a, b hasql.CheckedNode[T]) int {
+	// Get replication lag values
+	aLag := a.Info.(interface{ ReplicationLag() int }).ReplicationLag()
+	bLag := b.Info.(interface{ ReplicationLag() int }).ReplicationLag()
+
+	// First check that lag lower then MaxLag
+	if aLag > p.opts.MaxLag && bLag > p.opts.MaxLag {
+		return 0 // both are equal
+	}
+
+	// If one node exceeds MaxLag and the other doesn't, prefer the one that doesn't
+	if aLag > p.opts.MaxLag {
+		return 1 // b is better
+	}
+	if bLag > p.opts.MaxLag {
+		return -1 // a is better
+	}
+
+	// Get node priorities
+	aPrio := p.getPriority(a.Node.String())
+	bPrio := p.getPriority(b.Node.String())
+
+	// if both priority equals
+	if aPrio == bPrio {
+		// First compare by replication lag
+		if aLag < bLag {
+			return -1
+		}
+		if aLag > bLag {
+			return 1
+		}
+		// If replication lag is equal, compare by latency
+		aLatency := a.Info.(interface{ Latency() time.Duration }).Latency()
+		bLatency := b.Info.(interface{ Latency() time.Duration }).Latency()
+
+		if aLatency < bLatency {
+			return -1
+		}
+		if aLatency > bLatency {
+			return 1
+		}
+
+		// If lag and latency is equal
+		return 0
+	}
+
+	// If priorities are different, prefer the node with lower priority value
+	if aPrio < bPrio {
+		return -1
+	}
+
+	return 1
+}

codec/codec.go

@@ -54,3 +54,22 @@ func (m *RawMessage) UnmarshalJSON(data []byte) error {
 	*m = append((*m)[0:0], data...)
 	return nil
 }
+
+// MarshalYAML returns m as the JSON encoding of m.
+func (m *RawMessage) MarshalYAML() ([]byte, error) {
+	if m == nil {
+		return []byte("null"), nil
+	} else if len(*m) == 0 {
+		return []byte("null"), nil
+	}
+	return *m, nil
+}
+
+// UnmarshalYAML sets *m to a copy of data.
+func (m *RawMessage) UnmarshalYAML(data []byte) error {
+	if m == nil {
+		return errors.New("RawMessage UnmarshalYAML on nil pointer")
+	}
+	*m = append((*m)[0:0], data...)
+	return nil
+}

codec/frame.go

@@ -20,6 +20,17 @@ func (m *Frame) UnmarshalJSON(data []byte) error {
 	return m.Unmarshal(data)
 }
 
+// MarshalYAML returns frame data
+func (m *Frame) MarshalYAML() ([]byte, error) {
+	return m.Marshal()
+}
+
+// UnmarshalYAML set frame data
+func (m *Frame) UnmarshalYAML(data []byte) error {
+	m.Data = append((m.Data)[0:0], data...)
+	return nil
+}
+
 // ProtoMessage noop func
 func (m *Frame) ProtoMessage() {}
 

codec/frame.proto

@@ -17,7 +17,7 @@ syntax = "proto3";
 package micro.codec;
 
 option cc_enable_arenas = true;
-option go_package = "go.unistack.org/micro/v3/codec;codec";
+option go_package = "go.unistack.org/micro/v4/codec;codec";
 option java_multiple_files = true;
 option java_outer_classname = "MicroCodec";
 option java_package = "micro.codec";

codec/noop.go

@@ -3,7 +3,7 @@ package codec
 import (
 	"encoding/json"
 
-	codecpb "go.unistack.org/micro-proto/v3/codec"
+	codecpb "go.unistack.org/micro-proto/v4/codec"
 )
 
 type noopCodec struct {

codec/options.go

@@ -3,9 +3,9 @@ package codec
 import (
 	"context"
 
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/tracer"
 )
 
 // Option func

config/default.go

@@ -9,10 +9,10 @@ import (
 
 	"dario.cat/mergo"
 	"github.com/google/uuid"
-	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v4/options"
-	mid "go.unistack.org/micro/v3/util/id"
+	mid "go.unistack.org/micro/v4/util/id"
-	rutil "go.unistack.org/micro/v3/util/reflect"
+	rutil "go.unistack.org/micro/v4/util/reflect"
-	mtime "go.unistack.org/micro/v3/util/time"
+	mtime "go.unistack.org/micro/v4/util/time"
 )
 
 type defaultConfig struct {
@@ -210,7 +210,7 @@ func fillValue(value reflect.Value, val string) error {
 				return err
 			}
 			value.Set(reflect.ValueOf(v))
-		case value.Type().String() == "time.Duration" && value.Type().PkgPath() == "go.unistack.org/micro/v3/util/time":
+		case value.Type().String() == "time.Duration" && value.Type().PkgPath() == "go.unistack.org/micro/v4/util/time":
 			v, err := mtime.ParseDuration(val)
 			if err != nil {
 				return err

config/default_test.go

@@ -7,8 +7,8 @@ import (
 	"testing"
 	"time"
 
-	"go.unistack.org/micro/v3/config"
+	"go.unistack.org/micro/v4/config"
-	mtime "go.unistack.org/micro/v3/util/time"
+	mtime "go.unistack.org/micro/v4/util/time"
 )
 
 type cfg struct {

config/options.go

@@ -4,11 +4,11 @@ import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v4/options"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/tracer"
 )
 
 // Options hold the config options

errors/errors.proto

@@ -17,7 +17,7 @@ syntax = "proto3";
 package micro.errors;
 
 option cc_enable_arenas = true;
-option go_package = "go.unistack.org/micro/v3/errors;errors";
+option go_package = "go.unistack.org/micro/v4/errors;errors";
 option java_multiple_files = true;
 option java_outer_classname = "MicroErrors";
 option java_package = "micro.errors";

event.go

@@ -1,27 +0,0 @@
-package micro
-
-import (
-	"context"
-
-	"go.unistack.org/micro/v3/client"
-)
-
-// Event is used to publish messages to a topic
-type Event interface {
-	// Publish publishes a message to the event topic
-	Publish(ctx context.Context, msg interface{}, opts ...client.PublishOption) error
-}
-
-type event struct {
-	c     client.Client
-	topic string
-}
-
-// NewEvent creates a new event publisher
-func NewEvent(topic string, c client.Client) Event {
-	return &event{c, topic}
-}
-
-func (e *event) Publish(ctx context.Context, msg interface{}, opts ...client.PublishOption) error {
-	return e.c.Publish(ctx, e.c.NewMessage(e.topic, msg), opts...)
-}

flow/context.go

@@ -15,15 +15,6 @@ func FromContext(ctx context.Context) (Flow, bool) {
 	return c, ok
 }
 
-// MustContext returns Flow from context
-func MustContext(ctx context.Context) Flow {
-	f, ok := FromContext(ctx)
-	if !ok {
-		panic("missing flow")
-	}
-	return f
-}
-
 // NewContext stores Flow to context
 func NewContext(ctx context.Context, f Flow) context.Context {
 	if ctx == nil {

flow/context_test.go

@@ -1,3 +1,5 @@
+//go:build ignore
+
 package flow
 
 import (

flow/default.go

@@ -1,17 +1,19 @@
+//go:build ignore
+
 package flow
 
 import (
 	"context"
 	"fmt"
+	"path/filepath"
 	"sync"
 
-	"github.com/silas/dag"
+	"github.com/heimdalr/dag"
-	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/metadata"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/store"
-	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v4/util/id"
-	"go.unistack.org/micro/v3/util/id"
 )
 
 type microFlow struct {
@@ -20,7 +22,7 @@ type microFlow struct {
 
 type microWorkflow struct {
 	opts   Options
-	g      *dag.AcyclicGraph
+	g      *dag.DAG
 	steps  map[string]Step
 	id     string
 	status Status
@@ -32,20 +34,20 @@ func (w *microWorkflow) ID() string {
 	return w.id
 }
 
-func (w *microWorkflow) Steps() ([][]Step, error) {
-	return w.getSteps("", false)
-}
-
 func (w *microWorkflow) Status() Status {
 	return w.status
 }
 
 func (w *microWorkflow) AppendSteps(steps ...Step) error {
+	var err error
 	w.Lock()
+	defer w.Unlock()
 
 	for _, s := range steps {
 		w.steps[s.String()] = s
-		w.g.Add(s)
+		if _, err = w.g.AddVertex(s); err != nil {
+			return err
+		}
 	}
 
 	for _, dst := range steps {
@@ -54,18 +56,13 @@ func (w *microWorkflow) AppendSteps(steps ...Step) error {
 			if !ok {
 				return ErrStepNotExists
 			}
-			w.g.Connect(dag.BasicEdge(src, dst))
+			if err = w.g.AddEdge(src.String(), dst.String()); err != nil {
+				return err
+			}
 		}
 	}
 
-	if err := w.g.Validate(); err != nil {
+	w.g.ReduceTransitively()
-		w.Unlock()
-		return err
-	}
-
-	w.g.TransitiveReduction()
-
-	w.Unlock()
 
 	return nil
 }
@@ -74,10 +71,11 @@ func (w *microWorkflow) RemoveSteps(steps ...Step) error {
 	// TODO: handle case when some step requires or required by removed step
 
 	w.Lock()
+	defer w.Unlock()
 
 	for _, s := range steps {
 		delete(w.steps, s.String())
-		w.g.Remove(s)
+		w.g.DeleteVertex(s.String())
 	}
 
 	for _, dst := range steps {
@@ -86,91 +84,34 @@ func (w *microWorkflow) RemoveSteps(steps ...Step) error {
 			if !ok {
 				return ErrStepNotExists
 			}
-			w.g.Connect(dag.BasicEdge(src, dst))
+			w.g.AddEdge(src.String(), dst.String())
 		}
 	}
 
-	if err := w.g.Validate(); err != nil {
+	w.g.ReduceTransitively()
-		w.Unlock()
-		return err
-	}
-
-	w.g.TransitiveReduction()
-
-	w.Unlock()
 
 	return nil
 }
 
-func (w *microWorkflow) getSteps(start string, reverse bool) ([][]Step, error) {
-	var steps [][]Step
-	var root dag.Vertex
-	var err error
-
-	fn := func(n dag.Vertex, idx int) error {
-		if idx == 0 {
-			steps = make([][]Step, 1)
-			steps[0] = make([]Step, 0, 1)
-		} else if idx >= len(steps) {
-			tsteps := make([][]Step, idx+1)
-			copy(tsteps, steps)
-			steps = tsteps
-			steps[idx] = make([]Step, 0, 1)
-		}
-		steps[idx] = append(steps[idx], n.(Step))
-		return nil
-	}
-
-	if start != "" {
-		var ok bool
-		w.RLock()
-		root, ok = w.steps[start]
-		w.RUnlock()
-		if !ok {
-			return nil, ErrStepNotExists
-		}
-	} else {
-		root, err = w.g.Root()
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	if reverse {
-		err = w.g.SortedReverseDepthFirstWalk([]dag.Vertex{root}, fn)
-	} else {
-		err = w.g.SortedDepthFirstWalk([]dag.Vertex{root}, fn)
-	}
-	if err != nil {
-		return nil, err
-	}
-
-	return steps, nil
-}
-
 func (w *microWorkflow) Abort(ctx context.Context, id string) error {
-	workflowStore := store.NewNamespaceStore(w.opts.Store, "workflows"+w.opts.Store.Options().Separator+id)
+	workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", id))
 	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusAborted.String())})
 }
 
 func (w *microWorkflow) Suspend(ctx context.Context, id string) error {
-	workflowStore := store.NewNamespaceStore(w.opts.Store, "workflows"+w.opts.Store.Options().Separator+id)
+	workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", id))
 	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusSuspend.String())})
 }
 
 func (w *microWorkflow) Resume(ctx context.Context, id string) error {
-	workflowStore := store.NewNamespaceStore(w.opts.Store, "workflows"+w.opts.Store.Options().Separator+id)
+	workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", id))
 	return workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusRunning.String())})
 }
 
 func (w *microWorkflow) Execute(ctx context.Context, req *Message, opts ...ExecuteOption) (string, error) {
 	w.Lock()
 	if !w.init {
-		if err := w.g.Validate(); err != nil {
+		w.g.ReduceTransitively()
-			w.Unlock()
-			return "", err
-		}
-		w.g.TransitiveReduction()
 		w.init = true
 	}
 	w.Unlock()
@@ -180,26 +121,11 @@ func (w *microWorkflow) Execute(ctx context.Context, req *Message, opts ...Execu
 		return "", err
 	}
 
-	stepStore := store.NewNamespaceStore(w.opts.Store, "steps"+w.opts.Store.Options().Separator+eid)
+	//	stepStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("steps", eid))
-	workflowStore := store.NewNamespaceStore(w.opts.Store, "workflows"+w.opts.Store.Options().Separator+eid)
+	workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", eid))
 
 	options := NewExecuteOptions(opts...)
 
-	steps, err := w.getSteps(options.Start, options.Reverse)
-	if err != nil {
-		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusPending.String())}); werr != nil {
-			w.opts.Logger.Error(w.opts.Context, "store write error", werr)
-		}
-		return "", err
-	}
-
-	var wg sync.WaitGroup
-	cherr := make(chan error, 1)
-	chstatus := make(chan Status, 1)
-
-	nctx, cancel := context.WithCancel(ctx)
-	defer cancel()
-
 	nopts := make([]ExecuteOption, 0, len(opts)+5)
 
 	nopts = append(nopts,
@@ -209,143 +135,274 @@ func (w *microWorkflow) Execute(ctx context.Context, req *Message, opts ...Execu
 		ExecuteMeter(w.opts.Meter),
 	)
 	nopts = append(nopts, opts...)
-	done := make(chan struct{})
 
-	if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+	if werr := workflowStore.Write(ctx, "status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
-		w.opts.Logger.Error(w.opts.Context, "store write error", werr)
+		w.opts.Logger.Error(ctx, "store error: %v", werr)
 		return eid, werr
 	}
-	for idx := range steps {
+
-		for nidx := range steps[idx] {
+	var startID string
-			cstep := steps[idx][nidx]
+	if options.Start == "" {
-			if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusPending.String())}); werr != nil {
+		mp := w.g.GetRoots()
-				return eid, werr
+		if len(mp) != 1 {
+			return eid, ErrStepNotExists
+		}
+		for k := range mp {
+			startID = k
+		}
+	} else {
+		for k, v := range w.g.GetVertices() {
+			if v == options.Start {
+				startID = k
 			}
 		}
 	}
 
-	go func() {
+	if startID == "" {
-		for idx := range steps {
+		return eid, ErrStepNotExists
-			for nidx := range steps[idx] {
+	}
-				wStatus := &codec.Frame{}
+
-				if werr := workflowStore.Read(w.opts.Context, "status", wStatus); werr != nil {
+	if options.Async {
-					cherr <- werr
+		go w.handleWorkflow(startID, nopts...)
-					return
+		return eid, nil
+	}
+
+	return eid, w.handleWorkflow(startID, nopts...)
+}
+
+func (w *microWorkflow) handleWorkflow(startID string, opts ...ExecuteOption) error {
+	w.RLock()
+	defer w.RUnlock()
+
+	//	stepStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("steps", eid))
+	// workflowStore := store.NewNamespaceStore(w.opts.Store, filepath.Join("workflows", eid))
+
+	// Get IDs of all descendant vertices.
+	flowIDs, errDes := w.g.GetDescendants(startID)
+	if errDes != nil {
+		return errDes
+	}
+
+	// inputChannels provides for input channels for each of the descendant vertices (+ the start-vertex).
+	inputChannels := make(map[string]chan FlowResult, len(flowIDs)+1)
+
+	// Iterate vertex IDs and create an input channel for each of them and a single
+	// output channel for leaves. Note, this "pre-flight" is needed to ensure we
+	// really have an input channel regardless of how we traverse the tree and spawn
+	// workers.
+	leafCount := 0
+
+	for id := range flowIDs {
+
+		// Get all parents of this vertex.
+		parents, errPar := w.g.GetParents(id)
+		if errPar != nil {
+			return errPar
+		}
+
+		// Create a buffered input channel that has capacity for all parent results.
+		inputChannels[id] = make(chan FlowResult, len(parents))
+
+		if ok, err := w.g.IsLeaf(id); ok && err == nil {
+			leafCount += 1
+		}
+	}
+
+	// outputChannel caries the results of leaf vertices.
+	outputChannel := make(chan FlowResult, leafCount)
+
+	// To also process the start vertex and to have its results being passed to its
+	// children, add it to the vertex IDs. Also add an input channel for the start
+	// vertex and feed the inputs to this channel.
+	flowIDs[startID] = struct{}{}
+	inputChannels[startID] = make(chan FlowResult, len(inputs))
+	for _, i := range inputs {
+		inputChannels[startID] <- i
+	}
+
+	wg := sync.WaitGroup{}
+
+	// Iterate all vertex IDs (now incl. start vertex) and handle each worker (incl.
+	// inputs and outputs) in a separate goroutine.
+	for id := range flowIDs {
+
+		// Get all children of this vertex that later need to be notified. Note, we
+		// collect all children before the goroutine to be able to release the read
+		// lock as early as possible.
+		children, errChildren := w.g.GetChildren(id)
+		if errChildren != nil {
+			return errChildren
+		}
+
+		// Remember to wait for this goroutine.
+		wg.Add(1)
+
+		go func(id string) {
+			// Get this vertex's input channel.
+			// Note, only concurrent read here, which is fine.
+			c := inputChannels[id]
+
+			// Await all parent inputs and stuff them into a slice.
+			parentCount := cap(c)
+			parentResults := make([]FlowResult, parentCount)
+			for i := 0; i < parentCount; i++ {
+				parentResults[i] = <-c
+			}
+
+			// Execute the worker.
+			errWorker := callback(w.g, id, parentResults)
+			if errWorker != nil {
+				return errWorker
+			}
+
+			// Send this worker's FlowResult onto all children's input channels or, if it is
+			// a leaf (i.e. no children), send the result onto the output channel.
+			if len(children) > 0 {
+				for child := range children {
+					inputChannels[child] <- flowResult
 				}
-				if status := StringStatus[string(wStatus.Data)]; status != StatusRunning {
+			} else {
-					chstatus <- status
+				outputChannel <- flowResult
-					return
+			}
-				}
+
-				if w.opts.Logger.V(logger.TraceLevel) {
+			// "Sign off".
-					w.opts.Logger.Trace(nctx, fmt.Sprintf("will be executed %v", steps[idx][nidx]))
+			wg.Done()
-				}
+		}(id)
-				cstep := steps[idx][nidx]
+	}
-				// nolint: nestif
+
-				if len(cstep.Requires()) == 0 {
+	// Wait for all go routines to finish.
-					wg.Add(1)
+	wg.Wait()
-					go func(step Step) {
+
-						defer wg.Done()
+	// Await all leaf vertex results and stuff them into a slice.
-						if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"req", req); werr != nil {
+	resultCount := cap(outputChannel)
-							cherr <- werr
+	results := make([]FlowResult, resultCount)
-							return
+	for i := 0; i < resultCount; i++ {
-						}
+		results[i] = <-outputChannel
-						if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+	}
-							cherr <- werr
+
-							return
+	/*
-						}
+		go func() {
-						rsp, serr := step.Execute(nctx, req, nopts...)
+			for idx := range steps {
-						if serr != nil {
+				for nidx := range steps[idx] {
-							step.SetStatus(StatusFailure)
+					wStatus := &codec.Frame{}
-							if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"rsp", serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+					if werr := workflowStore.Read(w.opts.Context, "status", wStatus); werr != nil {
-								w.opts.Logger.Error(ctx, "store write error", werr)
+						cherr <- werr
+						return
+					}
+					if status := StringStatus[string(wStatus.Data)]; status != StatusRunning {
+						chstatus <- status
+						return
+					}
+					if w.opts.Logger.V(logger.TraceLevel) {
+						w.opts.Logger.Tracef(nctx, "will be executed %v", steps[idx][nidx])
+					}
+					cstep := steps[idx][nidx]
+					// nolint: nestif
+					if len(cstep.Requires()) == 0 {
+						wg.Add(1)
+						go func(step Step) {
+							defer wg.Done()
+							if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "req"), req); werr != nil {
+								cherr <- werr
+								return
 							}
-							if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+							if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
-								w.opts.Logger.Error(ctx, "store write error", werr)
+								cherr <- werr
+								return
+							}
+							rsp, serr := step.Execute(nctx, req, nopts...)
+							if serr != nil {
+								step.SetStatus(StatusFailure)
+								if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "rsp"), serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+									w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+								}
+								if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+									w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+								}
+								cherr <- serr
+								return
+							}
+							if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "rsp"), rsp); werr != nil {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+								cherr <- werr
+								return
+							}
+							if werr := stepStore.Write(ctx, filepath.Join(step.ID(), "status"), &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+								cherr <- werr
+								return
+							}
+						}(cstep)
+						wg.Wait()
+					} else {
+						if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "req"), req); werr != nil {
+							cherr <- werr
+							return
+						}
+						if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
+							cherr <- werr
+							return
+						}
+						rsp, serr := cstep.Execute(nctx, req, nopts...)
+						if serr != nil {
+							cstep.SetStatus(StatusFailure)
+							if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "rsp"), serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
+							}
+							if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
+								w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
 							}
 							cherr <- serr
 							return
 						}
-						if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"rsp", rsp); werr != nil {
+						if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "rsp"), rsp); werr != nil {
-							w.opts.Logger.Error(ctx, "store write error", werr)
+							w.opts.Logger.Errorf(ctx, "store write error: %v", werr)
 							cherr <- werr
 							return
 						}
-						if werr := stepStore.Write(ctx, step.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+						if werr := stepStore.Write(ctx, filepath.Join(cstep.ID(), "status"), &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
-							w.opts.Logger.Error(ctx, "store write error", werr)
 							cherr <- werr
 							return
 						}
-					}(cstep)
-					wg.Wait()
-				} else {
-					if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"req", req); werr != nil {
-						cherr <- werr
-						return
-					}
-					if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusRunning.String())}); werr != nil {
-						cherr <- werr
-						return
-					}
-					rsp, serr := cstep.Execute(nctx, req, nopts...)
-					if serr != nil {
-						cstep.SetStatus(StatusFailure)
-						if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"rsp", serr); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
-							w.opts.Logger.Error(ctx, "store write error", werr)
-						}
-						if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil && w.opts.Logger.V(logger.ErrorLevel) {
-							w.opts.Logger.Error(ctx, "store write error", werr)
-						}
-						cherr <- serr
-						return
-					}
-					if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"rsp", rsp); werr != nil {
-						w.opts.Logger.Error(ctx, "store write error", werr)
-						cherr <- werr
-						return
-					}
-					if werr := stepStore.Write(ctx, cstep.ID()+w.opts.Store.Options().Separator+"status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
-						cherr <- werr
-						return
 					}
 				}
 			}
-		}
+			close(done)
-		close(done)
+		}()
-	}()
 
-	if options.Async {
+		if options.Async {
-		return eid, nil
+			return eid, nil
-	}
-
-	logger.DefaultLogger.Trace(ctx, "wait for finish or error")
-	select {
-	case <-nctx.Done():
-		err = nctx.Err()
-	case cerr := <-cherr:
-		err = cerr
-	case <-done:
-		close(cherr)
-	case <-chstatus:
-		close(chstatus)
-		return eid, nil
-	}
-
-	switch {
-	case nctx.Err() != nil:
-		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusAborted.String())}); werr != nil {
-			w.opts.Logger.Error(w.opts.Context, "store write error", werr)
 		}
-	case err == nil:
-		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
-			w.opts.Logger.Error(w.opts.Context, "store write error", werr)
-		}
-	case err != nil:
-		if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil {
-			w.opts.Logger.Error(w.opts.Context, "store write error", werr)
-		}
-	}
 
-	return eid, err
+		logger.Tracef(ctx, "wait for finish or error")
+		select {
+		case <-nctx.Done():
+			err = nctx.Err()
+		case cerr := <-cherr:
+			err = cerr
+		case <-done:
+			close(cherr)
+		case <-chstatus:
+			close(chstatus)
+			return eid, nil
+		}
+
+		switch {
+		case nctx.Err() != nil:
+			if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusAborted.String())}); werr != nil {
+				w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+			}
+		case err == nil:
+			if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusSuccess.String())}); werr != nil {
+				w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+			}
+		case err != nil:
+			if werr := workflowStore.Write(w.opts.Context, "status", &codec.Frame{Data: []byte(StatusFailure.String())}); werr != nil {
+				w.opts.Logger.Errorf(w.opts.Context, "store error: %v", werr)
+			}
+		}
+	*/
+	return err
 }
 
 // NewFlow create new flow
@@ -385,11 +442,11 @@ func (f *microFlow) WorkflowList(ctx context.Context) ([]Workflow, error) {
 }
 
 func (f *microFlow) WorkflowCreate(ctx context.Context, id string, steps ...Step) (Workflow, error) {
-	w := &microWorkflow{opts: f.opts, id: id, g: &dag.AcyclicGraph{}, steps: make(map[string]Step, len(steps))}
+	w := &microWorkflow{opts: f.opts, id: id, g: &dag.DAG{}, steps: make(map[string]Step, len(steps))}
 
 	for _, s := range steps {
 		w.steps[s.String()] = s
-		w.g.Add(s)
+		w.g.AddVertex(s)
 	}
 
 	for _, dst := range steps {
@@ -398,14 +455,11 @@ func (f *microFlow) WorkflowCreate(ctx context.Context, id string, steps ...Step
 			if !ok {
 				return nil, ErrStepNotExists
 			}
-			w.g.Connect(dag.BasicEdge(src, dst))
+			w.g.AddEdge(src.String(), dst.String())
 		}
 	}
 
-	if err := w.g.Validate(); err != nil {
+	w.g.ReduceTransitively()
-		return nil, err
-	}
-	w.g.TransitiveReduction()
 
 	w.init = true
 

flow/flow.go

@@ -1,5 +1,5 @@
 // Package flow is an interface used for saga pattern microservice workflow
-package flow
+package flow // import "go.unistack.org/micro/v4/flow"
 
 import (
 	"context"
@@ -7,7 +7,7 @@ import (
 	"sync"
 	"sync/atomic"
 
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/metadata"
 )
 
 var (
@@ -125,8 +125,6 @@ type Workflow interface {
 	AppendSteps(steps ...Step) error
 	// Status returns workflow status
 	Status() Status
-	// Steps returns steps slice where parallel steps returned on the same level
-	Steps() ([][]Step, error)
 	// Suspend suspends execution
 	Suspend(ctx context.Context, id string) error
 	// Resume resumes execution

flow/options.go

@@ -4,11 +4,11 @@ import (
 	"context"
 	"time"
 
-	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v4/store"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/tracer"
 )
 
 // Option func
@@ -123,8 +123,6 @@ type ExecuteOptions struct {
 	Start string
 	// Timeout for execution
 	Timeout time.Duration
-	// Reverse execution
-	Reverse bool
 	// Async enables async execution
 	Async bool
 }
@@ -167,13 +165,6 @@ func ExecuteContext(ctx context.Context) ExecuteOption {
 	}
 }
 
-// ExecuteReverse says that dag must be run in reverse order
-func ExecuteReverse(b bool) ExecuteOption {
-	return func(o *ExecuteOptions) {
-		o.Reverse = b
-	}
-}
-
 // ExecuteTimeout pass timeout time.Duration for execution
 func ExecuteTimeout(td time.Duration) ExecuteOption {
 	return func(o *ExecuteOptions) {

fsm/fsm_test.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"testing"
 
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
 )
 
 func TestFSMStart(t *testing.T) {

go.mod

@@ -1,43 +1,35 @@
-module go.unistack.org/micro/v3
+module go.unistack.org/micro/v4
 
-go 1.23.4
+go 1.24
 
 require (
 	dario.cat/mergo v1.0.1
-	github.com/DATA-DOG/go-sqlmock v1.5.0
+	github.com/DATA-DOG/go-sqlmock v1.5.2
-	github.com/KimMachineGun/automemlimit v0.6.1
+	github.com/KimMachineGun/automemlimit v0.7.0
-	github.com/ash3in/uuidv8 v1.0.1
+	github.com/goccy/go-yaml v1.17.1
 	github.com/google/uuid v1.6.0
 	github.com/matoous/go-nanoid v1.5.1
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5
+	github.com/spf13/cast v1.7.1
+	github.com/stretchr/testify v1.10.0
+	go.uber.org/atomic v1.11.0
 	go.uber.org/automaxprocs v1.6.0
-	go.unistack.org/micro-proto/v3 v3.4.1
+	go.unistack.org/micro-proto/v4 v4.1.0
 	golang.org/x/sync v0.10.0
-	google.golang.org/grpc v1.68.1
+	golang.yandex/hasql/v2 v2.1.0
-	google.golang.org/protobuf v1.35.2
+	google.golang.org/grpc v1.69.4
-	gopkg.in/yaml.v3 v3.0.1
+	google.golang.org/protobuf v1.36.3
 )
 
 require (
-	github.com/cilium/ebpf v0.16.0 // indirect
-	github.com/containerd/cgroups/v3 v3.0.4 // indirect
-	github.com/containerd/log v0.1.0 // indirect
-	github.com/coreos/go-systemd/v22 v22.5.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
-	github.com/docker/go-units v0.5.0 // indirect
-	github.com/godbus/dbus/v5 v5.1.0 // indirect
-	github.com/moby/sys/userns v0.1.0 // indirect
-	github.com/opencontainers/runtime-spec v1.2.0 // indirect
 	github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/rogpeppe/go-internal v1.13.1 // indirect
-	github.com/sirupsen/logrus v1.9.3 // indirect
+	golang.org/x/net v0.34.0 // indirect
-	github.com/stretchr/testify v1.10.0 // indirect
+	golang.org/x/sys v0.29.0 // indirect
-	go.uber.org/goleak v1.3.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484 // indirect
-	golang.org/x/exp v0.0.0-20241210194714-1829a127f884 // indirect
-	golang.org/x/net v0.32.0 // indirect
-	golang.org/x/sys v0.28.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,40 +1,22 @@
 dario.cat/mergo v1.0.1 h1:Ra4+bf83h2ztPIQYNP99R6m+Y7KfnARDfID+a+vLl4s=
 dario.cat/mergo v1.0.1/go.mod h1:uNxQE+84aUszobStD9th8a29P2fMDhsBdgRYvZOxGmk=
-github.com/DATA-DOG/go-sqlmock v1.5.0 h1:Shsta01QNfFxHCfpW6YH2STWB0MudeXXEWMr20OEh60=
+github.com/DATA-DOG/go-sqlmock v1.5.2 h1:OcvFkGmslmlZibjAjaHm3L//6LiuBgolP7OputlJIzU=
-github.com/DATA-DOG/go-sqlmock v1.5.0/go.mod h1:f/Ixk793poVmq4qj/V1dPUg2JEAKC73Q5eFN3EC/SaM=
+github.com/DATA-DOG/go-sqlmock v1.5.2/go.mod h1:88MAG/4G7SMwSE3CeA0ZKzrT5CiOU3OJ+JlNzwDqpNU=
-github.com/KimMachineGun/automemlimit v0.6.1 h1:ILa9j1onAAMadBsyyUJv5cack8Y1WT26yLj/V+ulKp8=
+github.com/KimMachineGun/automemlimit v0.7.0 h1:7G06p/dMSf7G8E6oq+f2uOPuVncFyIlDI/pBWK49u88=
-github.com/KimMachineGun/automemlimit v0.6.1/go.mod h1:T7xYht7B8r6AG/AqFcUdc7fzd2bIdBKmepfP2S1svPY=
+github.com/KimMachineGun/automemlimit v0.7.0/go.mod h1:QZxpHaGOQoYvFhv/r4u3U0JTC2ZcOwbSr11UZF46UBM=
-github.com/ash3in/uuidv8 v1.0.1 h1:dIq1XRkWT8lGA7N5s7WRTB4V3k49WTBLvILz7aCLp80=
-github.com/ash3in/uuidv8 v1.0.1/go.mod h1:EoyUgCtxNBnrnpc9efw5rVN1cQ+LFGCoJiFuD6maOMw=
-github.com/cilium/ebpf v0.16.0 h1:+BiEnHL6Z7lXnlGUsXQPPAE7+kenAd4ES8MQ5min0Ok=
-github.com/cilium/ebpf v0.16.0/go.mod h1:L7u2Blt2jMM/vLAVgjxluxtBKlz3/GWjB0dMOEngfwE=
-github.com/containerd/cgroups/v3 v3.0.4 h1:2fs7l3P0Qxb1nKWuJNFiwhp2CqiKzho71DQkDrHJIo4=
-github.com/containerd/cgroups/v3 v3.0.4/go.mod h1:SA5DLYnXO8pTGYiAHXz94qvLQTKfVM5GEVisn4jpins=
-github.com/containerd/log v0.1.0 h1:TCJt7ioM2cr/tfR8GPbGf9/VRAX8D2B4PjzCpfX540I=
-github.com/containerd/log v0.1.0/go.mod h1:VRRf09a7mHDIRezVKTRCrOq78v577GXq3bSa3EhrzVo=
-github.com/coreos/go-systemd/v22 v22.5.0 h1:RrqgGjYQKalulkV8NGVIfkXQf6YYmOyiJKk8iXXhfZs=
-github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4=
+github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
-github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
+github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
-github.com/go-quicktest/qt v1.101.0 h1:O1K29Txy5P2OK0dGo59b7b0LR6wKfIhttaAhHUyn7eI=
+github.com/goccy/go-yaml v1.17.1 h1:LI34wktB2xEE3ONG/2Ar54+/HJVBriAGJ55PHls4YuY=
-github.com/go-quicktest/qt v1.101.0/go.mod h1:14Bz/f7NwaXPtdYEgzsx46kqSxVwTbzVZsDC26tQJow=
+github.com/goccy/go-yaml v1.17.1/go.mod h1:XBurs7gK8ATbW4ZPGKgcbrY1Br56PdM69F7LkFRi1kA=
-github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
-github.com/godbus/dbus/v5 v5.1.0 h1:4KLkAxT3aOY8Li4FRJe/KvhoNFFxo0m6fNuFUO8QJUk=
-github.com/godbus/dbus/v5 v5.1.0/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/josharian/native v1.1.0 h1:uuaP0hAbW7Y4l0ZRQ6C9zfb7Mg1mbFKry/xzDAfmtLA=
+github.com/kisielk/sqlstruct v0.0.0-20201105191214-5f3e10d3ab46/go.mod h1:yyMNCyc/Ib3bDTKd379tNMpB/7/H5TjM2Y9QJ5THLbE=
-github.com/josharian/native v1.1.0/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
-github.com/jsimonetti/rtnetlink/v2 v2.0.1 h1:xda7qaHDSVOsADNouv7ukSuicKZO7GgVUCXxpaIEIlM=
-github.com/jsimonetti/rtnetlink/v2 v2.0.1/go.mod h1:7MoNYNbb3UaDHtF8udiJo/RH6VsTKP1pqKLUTVCvToE=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
@@ -44,19 +26,10 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/matoous/go-nanoid v1.5.1 h1:aCjdvTyO9LLnTIi0fgdXhOPPvOHjpXN6Ik9DaNjIct4=
 github.com/matoous/go-nanoid v1.5.1/go.mod h1:zyD2a71IubI24efhpvkJz+ZwfwagzgSO6UNiFsZKN7U=
-github.com/mdlayher/netlink v1.7.2 h1:/UtM3ofJap7Vl4QWCPDGXY8d3GIY2UGSDbK+QWmY8/g=
-github.com/mdlayher/netlink v1.7.2/go.mod h1:xraEF7uJbxLhc5fpHL4cPe221LI2bdttWlU+ZGLfQSw=
-github.com/mdlayher/socket v0.4.1 h1:eM9y2/jlbs1M615oshPQOHZzj6R6wMT7bX5NPiQvn2U=
-github.com/mdlayher/socket v0.4.1/go.mod h1:cAqeGjoufqdxWkD7DkpyS+wcefOtmu5OQ8KuoJGIReA=
-github.com/moby/sys/userns v0.1.0 h1:tVLXkFOxVu9A64/yh59slHVv9ahO9UIev4JZusOLG/g=
-github.com/moby/sys/userns v0.1.0/go.mod h1:IHUYgu/kao6N8YZlp9Cf444ySSvCmDlmzUcYfDHOl28=
-github.com/opencontainers/runtime-spec v1.2.0 h1:z97+pHb3uELt/yiAWD691HNHQIF07bE7dzrbT927iTk=
-github.com/opencontainers/runtime-spec v1.2.0/go.mod h1:jwyrGlmzljRJv/Fgzds9SsS/C5hL+LL3ko9hs6T5lQ0=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58 h1:onHthvaw9LFnH4t2DcNVpwGmV9E1BkGknEliJkfwQj0=
 github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58/go.mod h1:DXv8WO4yhMYhSNPKjeNKa5WY9YCIEBRbNzFFPJbWO6Y=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prashantv/gostub v1.1.0 h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=
@@ -65,38 +38,34 @@ github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR
 github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
 github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5 h1:G/FZtUu7a6NTWl3KUHMV9jkLAh/Rvtf03NWMHaEDl+E=
 github.com/silas/dag v0.0.0-20220518035006-a7e85ada93c5/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
-github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/spf13/cast v1.7.1 h1:cuNEagBQEHWN1FnbGEjCXL2szYEXqfJPbP2HNUaca9Y=
-github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/spf13/cast v1.7.1/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=
+go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 go.uber.org/automaxprocs v1.6.0 h1:O3y2/QNTOdbF+e/dpXNNW7Rx2hZ4sTIPyybbxyNqTUs=
 go.uber.org/automaxprocs v1.6.0/go.mod h1:ifeIMSnPZuznNm6jmdzmU3/bfk01Fe2fotchwEFJ8r8=
-go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.unistack.org/micro-proto/v4 v4.1.0 h1:qPwL2n/oqh9RE3RTTDgt28XK3QzV597VugQPaw9lKUk=
-go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
+go.unistack.org/micro-proto/v4 v4.1.0/go.mod h1:ArmK7o+uFvxSY3dbJhKBBX4Pm1rhWdLEFf3LxBrMtec=
-go.unistack.org/micro-proto/v3 v3.4.1 h1:UTjLSRz2YZuaHk9iSlVqqsA50JQNAEK2ZFboGqtEa9Q=
+golang.org/x/net v0.34.0 h1:Mb7Mrk043xzHgnRM88suvJFwzVrRfHEHJEl5/71CKw0=
-go.unistack.org/micro-proto/v3 v3.4.1/go.mod h1:okx/cnOhzuCX0ggl/vToatbCupi0O44diiiLLsZ93Zo=
+golang.org/x/net v0.34.0/go.mod h1:di0qlW3YNM5oh6GqDGQr92MyTozJPmybPK4Ev/Gm31k=
-golang.org/x/exp v0.0.0-20241210194714-1829a127f884 h1:Y/Mj/94zIQQGHVSv1tTtQBDaQaJe62U9bkDZKKyhPCU=
-golang.org/x/exp v0.0.0-20241210194714-1829a127f884/go.mod h1:qj5a5QZpwLU2NLQudwIN5koi3beDhSAlJwa67PuM98c=
-golang.org/x/net v0.32.0 h1:ZqPmj8Kzc+Y6e0+skZsuACbx+wzMgo5MQsJh9Qd6aYI=
-golang.org/x/net v0.32.0/go.mod h1:CwU0IoeOlnQQWJ6ioyFrfRuomB8GKF6KbYXZVyeXNfs=
 golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
 golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
-golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
 golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576 h1:8ZmaLZE4XWrtU3MyClkYqqtl6Oegr3235h7jxsDyqCY=
+golang.yandex/hasql/v2 v2.1.0 h1:7CaFFWeHoK5TvA+QvZzlKHlIN5sqNpqM8NSrXskZD/k=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576/go.mod h1:5uTbfoYQed2U9p3KIj2/Zzm02PYhndfdmML0qC3q3FU=
+golang.yandex/hasql/v2 v2.1.0/go.mod h1:3Au1AxuJDCTXmS117BpbI6e+70kGWeyLR1qJAH6HdtA=
-google.golang.org/grpc v1.68.1 h1:oI5oTa11+ng8r8XMMN7jAOmWfPZWbYpCFaMUTACxkM0=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484 h1:Z7FRVJPSMaHQxD0uXU8WdgFh8PseLM8Q8NzhnpMrBhQ=
-google.golang.org/grpc v1.68.1/go.mod h1:+q1XYFJjShcqn0QZHvCyeR4CXPA+llXIeUIfIe00waw=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484/go.mod h1:lcTa1sDdWEIHMWlITnIczmw5w60CF9ffkb8Z+DVmmjA=
-google.golang.org/protobuf v1.35.2 h1:8Ar7bF+apOIoThw1EdZl0p1oWvMqTHmpA2fRTyZO8io=
+google.golang.org/grpc v1.69.4 h1:MF5TftSMkd8GLw/m0KM6V8CMOCY6NZ1NQDPGFgbTt4A=
-google.golang.org/protobuf v1.35.2/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
+google.golang.org/grpc v1.69.4/go.mod h1:vyjdE6jLBI76dgpDojsFGNaHlxdjXN9ghpnd2o7JGZ4=
+google.golang.org/protobuf v1.36.3 h1:82DV7MYdb8anAVi3qge1wSnMDrnKK7ebr+I0hHRN1BU=
+google.golang.org/protobuf v1.36.3/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

hooks/metadata/metadata.go

@@ -0,0 +1,117 @@
+package metadata
+
+import (
+	"context"
+
+	"go.unistack.org/micro/v4/client"
+	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v4/server"
+)
+
+type wrapper struct {
+	keys []string
+
+	client.Client
+}
+
+func NewClientWrapper(keys ...string) client.Wrapper {
+	return func(c client.Client) client.Client {
+		handler := &wrapper{
+			Client: c,
+			keys:   keys,
+		}
+		return handler
+	}
+}
+
+func NewClientCallWrapper(keys ...string) client.CallWrapper {
+	return func(fn client.CallFunc) client.CallFunc {
+		return func(ctx context.Context, addr string, req client.Request, rsp interface{}, opts client.CallOptions) error {
+			if keys == nil {
+				return fn(ctx, addr, req, rsp, opts)
+			}
+			if imd, iok := metadata.FromIncomingContext(ctx); iok && imd != nil {
+				omd, ook := metadata.FromOutgoingContext(ctx)
+				if !ook || omd == nil {
+					omd = metadata.New(len(imd))
+				}
+				for _, k := range keys {
+					if v := imd.Get(k); v != nil {
+						omd.Set(k, v...)
+					}
+				}
+				if !ook {
+					ctx = metadata.NewOutgoingContext(ctx, omd)
+				}
+			}
+			return fn(ctx, addr, req, rsp, opts)
+		}
+	}
+}
+
+func (w *wrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
+	if w.keys == nil {
+		return w.Client.Call(ctx, req, rsp, opts...)
+	}
+	if imd, iok := metadata.FromIncomingContext(ctx); iok && imd != nil {
+		omd, ook := metadata.FromOutgoingContext(ctx)
+		if !ook || omd == nil {
+			omd = metadata.New(len(imd))
+		}
+		for _, k := range w.keys {
+			if v := imd.Get(k); v != nil {
+				omd.Set(k, v...)
+			}
+		}
+		if !ook {
+			ctx = metadata.NewOutgoingContext(ctx, omd)
+		}
+	}
+	return w.Client.Call(ctx, req, rsp, opts...)
+}
+
+func (w *wrapper) Stream(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) {
+	if w.keys == nil {
+		return w.Client.Stream(ctx, req, opts...)
+	}
+	if imd, iok := metadata.FromIncomingContext(ctx); iok && imd != nil {
+		omd, ook := metadata.FromOutgoingContext(ctx)
+		if !ook || omd == nil {
+			omd = metadata.New(len(imd))
+		}
+		for _, k := range w.keys {
+			if v := imd.Get(k); v != nil {
+				omd.Set(k, v...)
+			}
+		}
+		if !ook {
+			ctx = metadata.NewOutgoingContext(ctx, omd)
+		}
+	}
+	return w.Client.Stream(ctx, req, opts...)
+}
+
+func NewServerHandlerWrapper(keys ...string) server.HandlerWrapper {
+	return func(fn server.HandlerFunc) server.HandlerFunc {
+		return func(ctx context.Context, req server.Request, rsp interface{}) error {
+			if keys == nil {
+				return fn(ctx, req, rsp)
+			}
+			if imd, iok := metadata.FromIncomingContext(ctx); iok && imd != nil {
+				omd, ook := metadata.FromOutgoingContext(ctx)
+				if !ook || omd == nil {
+					omd = metadata.New(len(imd))
+				}
+				for _, k := range keys {
+					if v := imd.Get(k); v != nil {
+						omd.Set(k, v...)
+					}
+				}
+				if !ook {
+					ctx = metadata.NewOutgoingContext(ctx, omd)
+				}
+			}
+			return fn(ctx, req, rsp)
+		}
+	}
+}

hooks/recovery/recovery.go

@@ -0,0 +1,63 @@
+package recovery
+
+import (
+	"context"
+	"fmt"
+
+	"go.unistack.org/micro/v4/errors"
+	"go.unistack.org/micro/v4/server"
+)
+
+func NewOptions(opts ...Option) Options {
+	options := Options{
+		ServerHandlerFn: DefaultServerHandlerFn,
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+type Options struct {
+	ServerHandlerFn func(context.Context, server.Request, interface{}, error) error
+}
+
+type Option func(*Options)
+
+func ServerHandlerFunc(fn func(context.Context, server.Request, interface{}, error) error) Option {
+	return func(o *Options) {
+		o.ServerHandlerFn = fn
+	}
+}
+
+var DefaultServerHandlerFn = func(ctx context.Context, req server.Request, rsp interface{}, err error) error {
+	return errors.BadRequest("", "%v", err)
+}
+
+var Hook = NewHook()
+
+type hook struct {
+	opts Options
+}
+
+func NewHook(opts ...Option) *hook {
+	return &hook{opts: NewOptions(opts...)}
+}
+
+func (w *hook) ServerHandler(next server.FuncHandler) server.FuncHandler {
+	return func(ctx context.Context, req server.Request, rsp interface{}) (err error) {
+		defer func() {
+			r := recover()
+			switch verr := r.(type) {
+			case nil:
+				return
+			case error:
+				err = w.opts.ServerHandlerFn(ctx, req, rsp, verr)
+			default:
+				err = w.opts.ServerHandlerFn(ctx, req, rsp, fmt.Errorf("%v", r))
+			}
+		}()
+		err = next(ctx, req, rsp)
+		return err
+	}
+}

hooks/requestid/requestid.go

@@ -0,0 +1,103 @@
+package requestid
+
+import (
+	"context"
+	"net/textproto"
+
+	"go.unistack.org/micro/v4/client"
+	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v4/server"
+	"go.unistack.org/micro/v4/util/id"
+)
+
+type XRequestIDKey struct{}
+
+// DefaultMetadataKey contains metadata key
+var DefaultMetadataKey = textproto.CanonicalMIMEHeaderKey("x-request-id")
+
+// DefaultMetadataFunc wil be used if user not provide own func to fill metadata
+var DefaultMetadataFunc = func(ctx context.Context) (context.Context, error) {
+	var xid string
+
+	cid, cok := ctx.Value(XRequestIDKey{}).(string)
+	if cok && cid != "" {
+		xid = cid
+	}
+
+	imd, iok := metadata.FromIncomingContext(ctx)
+	if !iok || imd == nil {
+		imd = metadata.New(1)
+		ctx = metadata.NewIncomingContext(ctx, imd)
+	}
+
+	omd, ook := metadata.FromOutgoingContext(ctx)
+	if !ook || omd == nil {
+		omd = metadata.New(1)
+		ctx = metadata.NewOutgoingContext(ctx, omd)
+	}
+
+	if xid == "" {
+		xid = imd.GetJoined(DefaultMetadataKey)
+		if xid == "" {
+			xid = omd.GetJoined(DefaultMetadataKey)
+		}
+	}
+
+	if xid == "" {
+		var err error
+		xid, err = id.New()
+		if err != nil {
+			return ctx, err
+		}
+	}
+
+	if !cok {
+		ctx = context.WithValue(ctx, XRequestIDKey{}, xid)
+	}
+
+	if !iok {
+		imd.Set(DefaultMetadataKey, xid)
+	}
+
+	if !ook {
+		omd.Set(DefaultMetadataKey, xid)
+	}
+
+	return ctx, nil
+}
+
+type hook struct{}
+
+func NewHook() *hook {
+	return &hook{}
+}
+
+func (w *hook) ServerHandler(next server.FuncHandler) server.FuncHandler {
+	return func(ctx context.Context, req server.Request, rsp interface{}) error {
+		var err error
+		if ctx, err = DefaultMetadataFunc(ctx); err != nil {
+			return err
+		}
+		return next(ctx, req, rsp)
+	}
+}
+
+func (w *hook) ClientCall(next client.FuncCall) client.FuncCall {
+	return func(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
+		var err error
+		if ctx, err = DefaultMetadataFunc(ctx); err != nil {
+			return err
+		}
+		return next(ctx, req, rsp, opts...)
+	}
+}
+
+func (w *hook) ClientStream(next client.FuncStream) client.FuncStream {
+	return func(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) {
+		var err error
+		if ctx, err = DefaultMetadataFunc(ctx); err != nil {
+			return nil, err
+		}
+		return next(ctx, req, opts...)
+	}
+}

hooks/requestid/requestid_test.go

@@ -0,0 +1,34 @@
+package requestid
+
+import (
+	"context"
+	"slices"
+	"testing"
+
+	"go.unistack.org/micro/v4/metadata"
+)
+
+func TestDefaultMetadataFunc(t *testing.T) {
+	ctx := context.TODO()
+
+	nctx, err := DefaultMetadataFunc(ctx)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	imd, ok := metadata.FromIncomingContext(nctx)
+	if !ok {
+		t.Fatalf("md missing in incoming context")
+	}
+	omd, ok := metadata.FromOutgoingContext(nctx)
+	if !ok {
+		t.Fatalf("md missing in outgoing context")
+	}
+
+	iv := imd.Get(DefaultMetadataKey)
+	ov := omd.Get(DefaultMetadataKey)
+
+	if !slices.Equal(iv, ov) {
+		t.Fatalf("missing metadata key value %v != %v", iv, ov)
+	}
+}

hooks/sql/common.go

@@ -0,0 +1,51 @@
+package sql
+
+import (
+	"database/sql/driver"
+	"errors"
+	"fmt"
+	"runtime"
+)
+
+//go:generate sh -c "go run gen.go > wrap_gen.go"
+
+// namedValueToValue converts driver arguments of NamedValue format to Value format. Implemented in the same way as in
+// database/sql ctxutil.go.
+func namedValueToValue(named []driver.NamedValue) ([]driver.Value, error) {
+	dargs := make([]driver.Value, len(named))
+	for n, param := range named {
+		if len(param.Name) > 0 {
+			return nil, errors.New("sql: driver does not support the use of Named Parameters")
+		}
+		dargs[n] = param.Value
+	}
+	return dargs, nil
+}
+
+// namedValueToLabels convert driver arguments to interface{} slice
+func namedValueToLabels(named []driver.NamedValue) []interface{} {
+	largs := make([]interface{}, 0, len(named)*2)
+	var name string
+	for _, param := range named {
+		if param.Name != "" {
+			name = param.Name
+		} else {
+			name = fmt.Sprintf("$%d", param.Ordinal)
+		}
+		largs = append(largs, fmt.Sprintf("%s=%v", name, param.Value))
+	}
+	return largs
+}
+
+// getCallerName get the name of the function A where A() -> B() -> GetFunctionCallerName()
+func getCallerName() string {
+	pc, _, _, ok := runtime.Caller(3)
+	details := runtime.FuncForPC(pc)
+	var callerName string
+	if ok && details != nil {
+		callerName = details.Name()
+	} else {
+		callerName = labelUnknown
+	}
+	return callerName
+}

hooks/sql/conn.go

@@ -0,0 +1,467 @@
+package sql
+
+import (
+	"context"
+	"database/sql/driver"
+	"fmt"
+	"time"
+
+	"go.unistack.org/micro/v4/hooks/requestid"
+	"go.unistack.org/micro/v4/tracer"
+)
+
+var (
+	_ driver.Conn               = (*wrapperConn)(nil)
+	_ driver.ConnBeginTx        = (*wrapperConn)(nil)
+	_ driver.ConnPrepareContext = (*wrapperConn)(nil)
+	_ driver.Pinger             = (*wrapperConn)(nil)
+	_ driver.Validator          = (*wrapperConn)(nil)
+	_ driver.Queryer            = (*wrapperConn)(nil) // nolint:staticcheck
+	_ driver.QueryerContext     = (*wrapperConn)(nil)
+	_ driver.Execer             = (*wrapperConn)(nil) // nolint:staticcheck
+	_ driver.ExecerContext      = (*wrapperConn)(nil)
+	//	_ driver.Connector
+	//	_ driver.Driver
+	//	_ driver.DriverContext
+)
+
+// wrapperConn defines a wrapper for driver.Conn
+type wrapperConn struct {
+	d     *wrapperDriver
+	dname string
+	conn  driver.Conn
+	opts  Options
+	ctx   context.Context
+	//span  tracer.Span
+}
+
+// Close implements driver.Conn Close
+func (w *wrapperConn) Close() error {
+	var ctx context.Context
+	if w.ctx != nil {
+		ctx = w.ctx
+	} else {
+		ctx = context.Background()
+	}
+	_ = ctx
+	labels := []string{labelMethod, "Close"}
+	ts := time.Now()
+	err := w.conn.Close()
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Close", getCallerName(), td, err)...)
+		}
+	*/
+	return err
+}
+
+// Begin implements driver.Conn Begin
+func (w *wrapperConn) Begin() (driver.Tx, error) {
+	var ctx context.Context
+	if w.ctx != nil {
+		ctx = w.ctx
+	} else {
+		ctx = context.Background()
+	}
+
+	labels := []string{labelMethod, "Begin"}
+	ts := time.Now()
+	tx, err := w.conn.Begin() // nolint:staticcheck
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+		w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Begin", getCallerName(), td, err)...)
+			}
+		*/
+		return nil, err
+	}
+	w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Begin", getCallerName(), td, err)...)
+		}
+	*/
+	return &wrapperTx{tx: tx, opts: w.opts, ctx: ctx}, nil
+}
+
+// BeginTx implements driver.ConnBeginTx BeginTx
+func (w *wrapperConn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
+	name := getQueryName(ctx)
+	nctx, span := w.opts.Tracer.Start(ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	span.AddLabels("db.method", "BeginTx")
+	span.AddLabels("db.statement", name)
+	if id, ok := ctx.Value(requestid.XRequestIDKey{}).(string); ok {
+		span.AddLabels("x-request-id", id)
+	}
+	labels := []string{labelMethod, "BeginTx", labelQuery, name}
+
+	connBeginTx, ok := w.conn.(driver.ConnBeginTx)
+	if !ok {
+		return w.Begin()
+	}
+
+	ts := time.Now()
+	tx, err := connBeginTx.BeginTx(nctx, opts)
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+		w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "BeginTx", getCallerName(), td, err)...)
+			}
+		*/
+		return nil, err
+	}
+	w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "BeginTx", getCallerName(), td, err)...)
+		}
+	*/
+	return &wrapperTx{tx: tx, opts: w.opts, ctx: ctx, span: span}, nil
+}
+
+// Prepare implements driver.Conn Prepare
+func (w *wrapperConn) Prepare(query string) (driver.Stmt, error) {
+	var ctx context.Context
+	if w.ctx != nil {
+		ctx = w.ctx
+	} else {
+		ctx = context.Background()
+	}
+	_ = ctx
+	labels := []string{labelMethod, "Prepare", labelQuery, getCallerName()}
+	ts := time.Now()
+	stmt, err := w.conn.Prepare(query)
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+		w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Prepare", getCallerName(), td, err)...)
+			}
+		*/
+		return nil, err
+	}
+	w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Prepare", getCallerName(), td, err)...)
+		}
+	*/
+	return wrapStmt(stmt, query, w.opts), nil
+}
+
+// PrepareContext implements driver.ConnPrepareContext PrepareContext
+func (w *wrapperConn) PrepareContext(ctx context.Context, query string) (driver.Stmt, error) {
+	var nctx context.Context
+	var span tracer.Span
+
+	name := getQueryName(ctx)
+	if w.ctx != nil {
+		nctx, span = w.opts.Tracer.Start(w.ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	} else {
+		nctx, span = w.opts.Tracer.Start(ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	}
+	span.AddLabels("db.method", "PrepareContext")
+	span.AddLabels("db.statement", name)
+	if id, ok := ctx.Value(requestid.XRequestIDKey{}).(string); ok {
+		span.AddLabels("x-request-id", id)
+	}
+	labels := []string{labelMethod, "PrepareContext", labelQuery, name}
+	conn, ok := w.conn.(driver.ConnPrepareContext)
+	if !ok {
+		return w.Prepare(query)
+	}
+
+	ts := time.Now()
+	stmt, err := conn.PrepareContext(nctx, query)
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+		w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "PrepareContext", getCallerName(), td, err)...)
+			}
+		*/
+		return nil, err
+	}
+	w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "PrepareContext", getCallerName(), td, err)...)
+		}
+	*/
+	return wrapStmt(stmt, query, w.opts), nil
+}
+
+// Exec implements driver.Execer Exec
+func (w *wrapperConn) Exec(query string, args []driver.Value) (driver.Result, error) {
+	var ctx context.Context
+	if w.ctx != nil {
+		ctx = w.ctx
+	} else {
+		ctx = context.Background()
+	}
+	_ = ctx
+	labels := []string{labelMethod, "Exec", labelQuery, getCallerName()}
+
+	// nolint:staticcheck
+	conn, ok := w.conn.(driver.Execer)
+	if !ok {
+		return nil, driver.ErrSkip
+	}
+
+	ts := time.Now()
+	res, err := conn.Exec(query, args)
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Exec", getCallerName(), td, err)...)
+		}
+	*/
+	return res, err
+}
+
+// Exec implements driver.StmtExecContext ExecContext
+func (w *wrapperConn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
+	var nctx context.Context
+	var span tracer.Span
+
+	name := getQueryName(ctx)
+	if w.ctx != nil {
+		nctx, span = w.opts.Tracer.Start(w.ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	} else {
+		nctx, span = w.opts.Tracer.Start(ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	}
+	span.AddLabels("db.method", "ExecContext")
+	span.AddLabels("db.statement", name)
+	if id, ok := ctx.Value(requestid.XRequestIDKey{}).(string); ok {
+		span.AddLabels("x-request-id", id)
+	}
+	defer span.Finish()
+	if len(args) > 0 {
+		span.AddLabels("db.args", fmt.Sprintf("%v", namedValueToLabels(args)))
+	}
+	labels := []string{labelMethod, "ExecContext", labelQuery, name}
+
+	conn, ok := w.conn.(driver.ExecerContext)
+	if !ok {
+		// nolint:staticcheck
+		return nil, driver.ErrSkip
+	}
+
+	ts := time.Now()
+	res, err := conn.ExecContext(nctx, query, args)
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "ExecContext", getCallerName(), td, err)...)
+		}
+	*/
+	return res, err
+}
+
+// Ping implements driver.Pinger Ping
+func (w *wrapperConn) Ping(ctx context.Context) error {
+	conn, ok := w.conn.(driver.Pinger)
+
+	if !ok {
+		// fallback path to check db alive
+		pc, err := w.d.Open(w.dname)
+		if err != nil {
+			return err
+		}
+		return pc.Close()
+	}
+
+	var nctx context.Context //nolint:gosimple
+	nctx = ctx
+	/*
+		var span tracer.Span
+		if w.ctx != nil {
+			nctx, span = w.opts.Tracer.Start(w.ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+		} else {
+			nctx, span = w.opts.Tracer.Start(ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+		}
+		span.AddLabels("db.method", "Ping")
+		defer span.Finish()
+	*/
+	labels := []string{labelMethod, "Ping"}
+	ts := time.Now()
+	err := conn.Ping(nctx)
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		// span.SetStatus(tracer.SpanStatusError, err.Error())
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Ping", getCallerName(), td, err)...)
+			}
+		*/
+		return err
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+
+	return nil
+}
+
+// Query implements driver.Queryer Query
+func (w *wrapperConn) Query(query string, args []driver.Value) (driver.Rows, error) {
+	var ctx context.Context
+	if w.ctx != nil {
+		ctx = w.ctx
+	} else {
+		ctx = context.Background()
+	}
+	_ = ctx
+	// nolint:staticcheck
+	conn, ok := w.conn.(driver.Queryer)
+	if !ok {
+		return nil, driver.ErrSkip
+	}
+
+	labels := []string{labelMethod, "Query", labelQuery, getCallerName()}
+	ts := time.Now()
+	rows, err := conn.Query(query, args)
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Query", getCallerName(), td, err)...)
+		}
+	*/
+	return rows, err
+}
+
+// QueryContext implements Driver.QueryerContext QueryContext
+func (w *wrapperConn) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
+	var nctx context.Context
+	var span tracer.Span
+
+	name := getQueryName(ctx)
+	if w.ctx != nil {
+		nctx, span = w.opts.Tracer.Start(w.ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	} else {
+		nctx, span = w.opts.Tracer.Start(ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	}
+	span.AddLabels("db.method", "QueryContext")
+	span.AddLabels("db.statement", name)
+	if id, ok := ctx.Value(requestid.XRequestIDKey{}).(string); ok {
+		span.AddLabels("x-request-id", id)
+	}
+	defer span.Finish()
+	if len(args) > 0 {
+		span.AddLabels("db.args", fmt.Sprintf("%v", namedValueToLabels(args)))
+	}
+	labels := []string{labelMethod, "QueryContext", labelQuery, name}
+	conn, ok := w.conn.(driver.QueryerContext)
+	if !ok {
+		return nil, driver.ErrSkip
+	}
+
+	ts := time.Now()
+	rows, err := conn.QueryContext(nctx, query, args)
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "QueryContext", getCallerName(), td, err)...)
+		}
+	*/
+	return rows, err
+}
+
+// CheckNamedValue implements driver.NamedValueChecker
+func (w *wrapperConn) CheckNamedValue(v *driver.NamedValue) error {
+	s, ok := w.conn.(driver.NamedValueChecker)
+	if !ok {
+		return driver.ErrSkip
+	}
+	return s.CheckNamedValue(v)
+}
+
+// IsValid implements driver.Validator
+func (w *wrapperConn) IsValid() bool {
+	v, ok := w.conn.(driver.Validator)
+	if !ok {
+		return w.conn != nil
+	}
+	return v.IsValid()
+}
+
+func (w *wrapperConn) ResetSession(ctx context.Context) error {
+	s, ok := w.conn.(driver.SessionResetter)
+	if !ok {
+		return driver.ErrSkip
+	}
+	return s.ResetSession(ctx)
+}

hooks/sql/driver.go

@@ -0,0 +1,94 @@
+package sql
+
+import (
+	"context"
+	"database/sql/driver"
+	"time"
+)
+
+var (
+// _ driver.DriverContext = (*wrapperDriver)(nil)
+// _ driver.Connector     = (*wrapperDriver)(nil)
+)
+
+/*
+type conn interface {
+	driver.Pinger
+	driver.Execer
+	driver.ExecerContext
+	driver.Queryer
+	driver.QueryerContext
+	driver.Conn
+	driver.ConnPrepareContext
+	driver.ConnBeginTx
+}
+*/
+
+// wrapperDriver defines a wrapper for driver.Driver
+type wrapperDriver struct {
+	driver driver.Driver
+	opts   Options
+	ctx    context.Context
+}
+
+// NewWrapper creates and returns a new SQL driver with passed capabilities
+func NewWrapper(d driver.Driver, opts ...Option) driver.Driver {
+	return &wrapperDriver{driver: d, opts: NewOptions(opts...), ctx: context.Background()}
+}
+
+type wrappedConnector struct {
+	connector driver.Connector
+//	name      string
+	opts      Options
+	ctx       context.Context
+}
+
+func NewWrapperConnector(c driver.Connector, opts ...Option) driver.Connector {
+	return &wrappedConnector{connector: c, opts: NewOptions(opts...), ctx: context.Background()}
+}
+
+// Connect implements driver.Driver Connect
+func (w *wrappedConnector) Connect(ctx context.Context) (driver.Conn, error) {
+	return w.connector.Connect(ctx)
+}
+
+// Driver implements driver.Driver Driver
+func (w *wrappedConnector) Driver() driver.Driver {
+	return w.connector.Driver()
+}
+
+/*
+// Connect implements driver.Driver OpenConnector
+func (w *wrapperDriver) OpenConnector(name string) (driver.Conn, error) {
+	return &wrapperConnector{driver: w.driver, name: name, opts: w.opts}, nil
+}
+*/
+
+// Open implements driver.Driver Open
+func (w *wrapperDriver) Open(name string) (driver.Conn, error) {
+	// ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second) // Ensure eventual timeout
+	// defer cancel()
+
+	/*
+		connector, err := w.OpenConnector(name)
+		if err != nil {
+			return nil, err
+		}
+		return connector.Connect(ctx)
+	*/
+
+	ts := time.Now()
+	c, err := w.driver.Open(name)
+	td := time.Since(ts)
+	/*
+		if w.opts.LoggerEnabled {
+			w.opts.Logger.Log(w.ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(w.ctx, "Open", getCallerName(), td, err)...)
+		}
+	*/
+	_ = td
+	if err != nil {
+		return nil, err
+	}
+
+	return wrapConn(c, w.opts), nil
+}

hooks/sql/gen.go

@@ -0,0 +1,167 @@
+//go:build ignore
+
+package main
+
+import (
+	"bytes"
+	"crypto/md5"
+	"fmt"
+	"io"
+	"sort"
+	"strings"
+)
+
+var connIfaces = []string{
+	"driver.ConnBeginTx",
+	"driver.ConnPrepareContext",
+	"driver.Execer",
+	"driver.ExecerContext",
+	"driver.NamedValueChecker",
+	"driver.Pinger",
+	"driver.Queryer",
+	"driver.QueryerContext",
+	"driver.SessionResetter",
+	"driver.Validator",
+}
+
+var stmtIfaces = []string{
+	"driver.StmtExecContext",
+	"driver.StmtQueryContext",
+	"driver.ColumnConverter",
+	"driver.NamedValueChecker",
+}
+
+func getHash(s []string) string {
+	h := md5.New()
+	io.WriteString(h, strings.Join(s, "|"))
+	return fmt.Sprintf("%x", h.Sum(nil))
+}
+
+func main() {
+	comboConn := all(connIfaces)
+
+	sort.Slice(comboConn, func(i, j int) bool {
+		return len(comboConn[i]) < len(comboConn[j])
+	})
+
+	comboStmt := all(stmtIfaces)
+
+	sort.Slice(comboStmt, func(i, j int) bool {
+		return len(comboStmt[i]) < len(comboStmt[j])
+	})
+
+	b := bytes.NewBuffer(nil)
+	b.WriteString("// Code generated. DO NOT EDIT.\n\n")
+	b.WriteString("package sql\n\n")
+	b.WriteString(`import "database/sql/driver"`)
+	b.WriteString("\n\n")
+
+	b.WriteString("func wrapConn(dc driver.Conn, opts Options) driver.Conn {\n")
+	b.WriteString("\tc := &wrapperConn{conn: dc, opts: opts}\n")
+
+	for idx := len(comboConn) - 1; idx >= 0; idx-- {
+		ifaces := comboConn[idx]
+		n := len(ifaces)
+		if n == 0 {
+			continue
+		}
+		h := getHash(ifaces)
+		b.WriteString(fmt.Sprintf("\tif _, ok := dc.(wrapConn%04d_%s); ok {\n", n, h))
+		b.WriteString("\treturn struct {\n")
+		b.WriteString("\t\tdriver.Conn\n")
+		b.WriteString(fmt.Sprintf("\t\t\t%s", strings.Join(ifaces, "\n\t\t\t")))
+		b.WriteString("\t\t\n}{")
+		for idx := range ifaces {
+			if idx > 0 {
+				b.WriteString(", ")
+				b.WriteString("c")
+			} else if idx == 0 {
+				b.WriteString("c")
+			} else {
+				b.WriteString("c")
+			}
+		}
+		b.WriteString(", c}\n")
+		b.WriteString("}\n\n")
+	}
+	b.WriteString("return c\n")
+	b.WriteString("}\n")
+
+	for idx := len(comboConn) - 1; idx >= 0; idx-- {
+		ifaces := comboConn[idx]
+		n := len(ifaces)
+		if n == 0 {
+			continue
+		}
+		h := getHash(ifaces)
+		b.WriteString(fmt.Sprintf("// %s\n", strings.Join(ifaces, "|")))
+		b.WriteString(fmt.Sprintf("type wrapConn%04d_%s interface {\n", n, h))
+		for _, iface := range ifaces {
+			b.WriteString(fmt.Sprintf("\t%s\n", iface))
+		}
+		b.WriteString("}\n\n")
+	}
+
+	b.WriteString("func wrapStmt(stmt driver.Stmt, query string, opts Options) driver.Stmt {\n")
+	b.WriteString("\tc := &wrapperStmt{stmt: stmt, query: query, opts: opts}\n")
+
+	for idx := len(comboStmt) - 1; idx >= 0; idx-- {
+		ifaces := comboStmt[idx]
+		n := len(ifaces)
+		if n == 0 {
+			continue
+		}
+		h := getHash(ifaces)
+		b.WriteString(fmt.Sprintf("\tif _, ok := stmt.(wrapStmt%04d_%s); ok {\n", n, h))
+		b.WriteString("\treturn struct {\n")
+		b.WriteString("\t\tdriver.Stmt\n")
+		b.WriteString(fmt.Sprintf("\t\t\t%s", strings.Join(ifaces, "\n\t\t\t")))
+		b.WriteString("\t\t\n}{")
+		for idx := range ifaces {
+			if idx > 0 {
+				b.WriteString(", ")
+				b.WriteString("c")
+			} else if idx == 0 {
+				b.WriteString("c")
+			} else {
+				b.WriteString("c")
+			}
+		}
+		b.WriteString(", c}\n")
+		b.WriteString("}\n\n")
+	}
+	b.WriteString("return c\n")
+	b.WriteString("}\n")
+
+	for idx := len(comboStmt) - 1; idx >= 0; idx-- {
+		ifaces := comboStmt[idx]
+		n := len(ifaces)
+		if n == 0 {
+			continue
+		}
+		h := getHash(ifaces)
+		b.WriteString(fmt.Sprintf("// %s\n", strings.Join(ifaces, "|")))
+		b.WriteString(fmt.Sprintf("type wrapStmt%04d_%s interface {\n", n, h))
+		for _, iface := range ifaces {
+			b.WriteString(fmt.Sprintf("\t%s\n", iface))
+		}
+		b.WriteString("}\n\n")
+	}
+
+	fmt.Printf("%s\n", b.String())
+}
+
+// all returns all combinations for a given string array.
+func all[T any](set []T) (subsets [][]T) {
+	length := uint(len(set))
+	for subsetBits := 1; subsetBits < (1 << length); subsetBits++ {
+		var subset []T
+		for object := uint(0); object < length; object++ {
+			if (subsetBits>>object)&1 == 1 {
+				subset = append(subset, set[object])
+			}
+		}
+		subsets = append(subsets, subset)
+	}
+	return subsets
+}

hooks/sql/options.go

@@ -0,0 +1,172 @@
+package sql
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"go.unistack.org/micro/v4/logger"
+	"go.unistack.org/micro/v4/meter"
+	"go.unistack.org/micro/v4/tracer"
+)
+
+var (
+	// DefaultMeterStatsInterval holds default stats interval
+	DefaultMeterStatsInterval = 5 * time.Second
+	// DefaultLoggerObserver used to prepare labels for logger
+	DefaultLoggerObserver = func(ctx context.Context, method string, query string, td time.Duration, err error) []interface{} {
+		labels := []interface{}{"db.method", method, "took", fmt.Sprintf("%v", td)}
+		if err != nil {
+			labels = append(labels, "error", err.Error())
+		}
+		if query != labelUnknown {
+			labels = append(labels, "query", query)
+		}
+		return labels
+	}
+)
+
+var (
+	MaxOpenConnections = "micro_sql_max_open_conn"
+	OpenConnections    = "micro_sql_open_conn"
+	InuseConnections   = "micro_sql_inuse_conn"
+	IdleConnections    = "micro_sql_idle_conn"
+	WaitConnections    = "micro_sql_waited_conn"
+	BlockedSeconds     = "micro_sql_blocked_seconds"
+	MaxIdleClosed      = "micro_sql_max_idle_closed"
+	MaxIdletimeClosed  = "micro_sql_closed_max_idle"
+	MaxLifetimeClosed  = "micro_sql_closed_max_lifetime"
+
+	meterRequestTotal               = "micro_sql_request_total"
+	meterRequestLatencyMicroseconds = "micro_sql_latency_microseconds"
+	meterRequestDurationSeconds     = "micro_sql_request_duration_seconds"
+
+	labelUnknown  = "unknown"
+	labelQuery    = "db_statement"
+	labelMethod   = "db_method"
+	labelStatus   = "status"
+	labelSuccess  = "success"
+	labelFailure  = "failure"
+	labelHost     = "db_host"
+	labelDatabase = "db_name"
+)
+
+// Options struct holds wrapper options
+type Options struct {
+	Logger             logger.Logger
+	Meter              meter.Meter
+	Tracer             tracer.Tracer
+	DatabaseHost       string
+	DatabaseName       string
+	MeterStatsInterval time.Duration
+	LoggerLevel        logger.Level
+	LoggerEnabled      bool
+	LoggerObserver     func(ctx context.Context, method string, name string, td time.Duration, err error) []interface{}
+}
+
+// Option func signature
+type Option func(*Options)
+
+// NewOptions create new Options struct from provided option slice
+func NewOptions(opts ...Option) Options {
+	options := Options{
+		Logger:             logger.DefaultLogger,
+		Meter:              meter.DefaultMeter,
+		Tracer:             tracer.DefaultTracer,
+		MeterStatsInterval: DefaultMeterStatsInterval,
+		LoggerLevel:        logger.ErrorLevel,
+		LoggerObserver:     DefaultLoggerObserver,
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+
+	options.Meter = options.Meter.Clone(
+		meter.Labels(
+			labelHost, options.DatabaseHost,
+			labelDatabase, options.DatabaseName,
+		),
+	)
+
+	options.Logger = options.Logger.Clone(logger.WithAddCallerSkipCount(1))
+
+	return options
+}
+
+// MetricInterval specifies stats interval for *sql.DB
+func MetricInterval(td time.Duration) Option {
+	return func(o *Options) {
+		o.MeterStatsInterval = td
+	}
+}
+
+func DatabaseHost(host string) Option {
+	return func(o *Options) {
+		o.DatabaseHost = host
+	}
+}
+
+func DatabaseName(name string) Option {
+	return func(o *Options) {
+		o.DatabaseName = name
+	}
+}
+
+// Meter passes meter.Meter to wrapper
+func Meter(m meter.Meter) Option {
+	return func(o *Options) {
+		o.Meter = m
+	}
+}
+
+// Logger passes logger.Logger to wrapper
+func Logger(l logger.Logger) Option {
+	return func(o *Options) {
+		o.Logger = l
+	}
+}
+
+// LoggerEnabled enable sql logging
+func LoggerEnabled(b bool) Option {
+	return func(o *Options) {
+		o.LoggerEnabled = b
+	}
+}
+
+// LoggerLevel passes logger.Level option
+func LoggerLevel(lvl logger.Level) Option {
+	return func(o *Options) {
+		o.LoggerLevel = lvl
+	}
+}
+
+// LoggerObserver passes observer to fill logger fields
+func LoggerObserver(obs func(context.Context, string, string, time.Duration, error) []interface{}) Option {
+	return func(o *Options) {
+		o.LoggerObserver = obs
+	}
+}
+
+// Tracer passes tracer.Tracer to wrapper
+func Tracer(t tracer.Tracer) Option {
+	return func(o *Options) {
+		o.Tracer = t
+	}
+}
+
+type queryNameKey struct{}
+
+// QueryName passes query name to wrapper func
+func QueryName(ctx context.Context, name string) context.Context {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	return context.WithValue(ctx, queryNameKey{}, name)
+}
+
+func getQueryName(ctx context.Context) string {
+	if v, ok := ctx.Value(queryNameKey{}).(string); ok && v != labelUnknown {
+		return v
+	}
+	return getCallerName()
+}

hooks/sql/stats.go

@@ -0,0 +1,95 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+	"sync"
+	"time"
+)
+
+type Statser interface {
+	Stats() sql.DBStats
+}
+
+func NewStatsMeter(ctx context.Context, db Statser, opts ...Option) {
+	if db == nil {
+		return
+	}
+
+	options := NewOptions(opts...)
+
+	var (
+		statsMu                                                     sync.Mutex
+		lastUpdated                                                 time.Time
+		maxOpenConnections, openConnections, inUse, idle, waitCount float64
+		maxIdleClosed, maxIdleTimeClosed, maxLifetimeClosed         float64
+		waitDuration                                                float64
+	)
+
+	updateFn := func() {
+		statsMu.Lock()
+		defer statsMu.Unlock()
+
+		if time.Since(lastUpdated) < options.MeterStatsInterval {
+			return
+		}
+
+		stats := db.Stats()
+		maxOpenConnections = float64(stats.MaxOpenConnections)
+		openConnections = float64(stats.OpenConnections)
+		inUse = float64(stats.InUse)
+		idle = float64(stats.Idle)
+		waitCount = float64(stats.WaitCount)
+		maxIdleClosed = float64(stats.MaxIdleClosed)
+		maxIdleTimeClosed = float64(stats.MaxIdleTimeClosed)
+		maxLifetimeClosed = float64(stats.MaxLifetimeClosed)
+		waitDuration = float64(stats.WaitDuration.Seconds())
+
+		lastUpdated = time.Now()
+	}
+
+	options.Meter.Gauge(MaxOpenConnections, func() float64 {
+		updateFn()
+		return maxOpenConnections
+	})
+
+	options.Meter.Gauge(OpenConnections, func() float64 {
+		updateFn()
+		return openConnections
+	})
+
+	options.Meter.Gauge(InuseConnections, func() float64 {
+		updateFn()
+		return inUse
+	})
+
+	options.Meter.Gauge(IdleConnections, func() float64 {
+		updateFn()
+		return idle
+	})
+
+	options.Meter.Gauge(WaitConnections, func() float64 {
+		updateFn()
+		return waitCount
+	})
+
+	options.Meter.Gauge(BlockedSeconds, func() float64 {
+		updateFn()
+		return waitDuration
+	})
+
+	options.Meter.Gauge(MaxIdleClosed, func() float64 {
+		updateFn()
+		return maxIdleClosed
+	})
+
+	options.Meter.Gauge(MaxIdletimeClosed, func() float64 {
+		updateFn()
+		return maxIdleTimeClosed
+	})
+
+	options.Meter.Gauge(MaxLifetimeClosed, func() float64 {
+		updateFn()
+		return maxLifetimeClosed
+	})
+}

hooks/sql/stmt.go

@@ -0,0 +1,287 @@
+package sql
+
+import (
+	"context"
+	"database/sql/driver"
+	"fmt"
+	"time"
+
+	requestid "go.unistack.org/micro/v4/hooks/requestid"
+	"go.unistack.org/micro/v4/tracer"
+)
+
+var (
+	_ driver.Stmt              = (*wrapperStmt)(nil)
+	_ driver.StmtQueryContext  = (*wrapperStmt)(nil)
+	_ driver.StmtExecContext   = (*wrapperStmt)(nil)
+	_ driver.NamedValueChecker = (*wrapperStmt)(nil)
+)
+
+// wrapperStmt defines a wrapper for driver.Stmt
+type wrapperStmt struct {
+	stmt  driver.Stmt
+	opts  Options
+	query string
+	ctx   context.Context
+}
+
+// Close implements driver.Stmt Close
+func (w *wrapperStmt) Close() error {
+	var ctx context.Context
+	if w.ctx != nil {
+		ctx = w.ctx
+	} else {
+		ctx = context.Background()
+	}
+	_ = ctx
+	labels := []string{labelMethod, "Close"}
+	ts := time.Now()
+	err := w.stmt.Close()
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Close", getCallerName(), td, err)...)
+		}
+	*/
+	return err
+}
+
+// NumInput implements driver.Stmt NumInput
+func (w *wrapperStmt) NumInput() int {
+	return w.stmt.NumInput()
+}
+
+// CheckNamedValue implements driver.NamedValueChecker
+func (w *wrapperStmt) CheckNamedValue(v *driver.NamedValue) error {
+	s, ok := w.stmt.(driver.NamedValueChecker)
+	if !ok {
+		return driver.ErrSkip
+	}
+	return s.CheckNamedValue(v)
+}
+
+// Exec implements driver.Stmt Exec
+func (w *wrapperStmt) Exec(args []driver.Value) (driver.Result, error) {
+	var ctx context.Context
+	if w.ctx != nil {
+		ctx = w.ctx
+	} else {
+		ctx = context.Background()
+	}
+	_ = ctx
+	labels := []string{labelMethod, "Exec"}
+	ts := time.Now()
+	res, err := w.stmt.Exec(args) // nolint:staticcheck
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Exec", getCallerName(), td, err)...)
+		}
+	*/
+	return res, err
+}
+
+// Query implements driver.Stmt Query
+func (w *wrapperStmt) Query(args []driver.Value) (driver.Rows, error) {
+	var ctx context.Context
+	if w.ctx != nil {
+		ctx = w.ctx
+	} else {
+		ctx = context.Background()
+	}
+	_ = ctx
+	labels := []string{labelMethod, "Query"}
+	ts := time.Now()
+	rows, err := w.stmt.Query(args) // nolint:staticcheck
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "Query", getCallerName(), td, err)...)
+		}
+	*/
+	return rows, err
+}
+
+// ColumnConverter implements driver.ColumnConverter
+func (w *wrapperStmt) ColumnConverter(idx int) driver.ValueConverter {
+	s, ok := w.stmt.(driver.ColumnConverter) // nolint:staticcheck
+	if !ok {
+		return nil
+	}
+	return s.ColumnConverter(idx)
+}
+
+// ExecContext implements driver.StmtExecContext ExecContext
+func (w *wrapperStmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver.Result, error) {
+	var nctx context.Context
+	var span tracer.Span
+
+	name := getQueryName(ctx)
+	if w.ctx != nil {
+		nctx, span = w.opts.Tracer.Start(w.ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	} else {
+		nctx, span = w.opts.Tracer.Start(ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	}
+	span.AddLabels("db.method", "ExecContext")
+	span.AddLabels("db.statement", name)
+	defer span.Finish()
+	if len(args) > 0 {
+		span.AddLabels("db.args", fmt.Sprintf("%v", namedValueToLabels(args)))
+	}
+	if id, ok := ctx.Value(requestid.XRequestIDKey{}).(string); ok {
+		span.AddLabels("x-request-id", id)
+	}
+	labels := []string{labelMethod, "ExecContext", labelQuery, name}
+
+	if conn, ok := w.stmt.(driver.StmtExecContext); ok {
+		ts := time.Now()
+		res, err := conn.ExecContext(nctx, args)
+		td := time.Since(ts)
+		te := td.Seconds()
+		if err != nil {
+			w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+			span.SetStatus(tracer.SpanStatusError, err.Error())
+		} else {
+			w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+		}
+		w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+		w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "ExecContext", name, td, err)...)
+			}
+		*/
+		return res, err
+	}
+
+	values, err := namedValueToValue(args)
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "ExecContext", name, 0, err)...)
+			}
+		*/
+		return nil, err
+	}
+	ts := time.Now()
+	res, err := w.Exec(values) // nolint:staticcheck
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "ExecContext", name, td, err)...)
+		}
+	*/
+	return res, err
+}
+
+// QueryContext implements driver.StmtQueryContext StmtQueryContext
+func (w *wrapperStmt) QueryContext(ctx context.Context, args []driver.NamedValue) (driver.Rows, error) {
+	var nctx context.Context
+	var span tracer.Span
+
+	name := getQueryName(ctx)
+	if w.ctx != nil {
+		nctx, span = w.opts.Tracer.Start(w.ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	} else {
+		nctx, span = w.opts.Tracer.Start(ctx, "sdk.database", tracer.WithSpanKind(tracer.SpanKindClient))
+	}
+	span.AddLabels("db.method", "QueryContext")
+	span.AddLabels("db.statement", name)
+	defer span.Finish()
+	if len(args) > 0 {
+		span.AddLabels("db.args", fmt.Sprintf("%v", namedValueToLabels(args)))
+	}
+	if id, ok := ctx.Value(requestid.XRequestIDKey{}).(string); ok {
+		span.AddLabels("x-request-id", id)
+	}
+	labels := []string{labelMethod, "QueryContext", labelQuery, name}
+	if conn, ok := w.stmt.(driver.StmtQueryContext); ok {
+		ts := time.Now()
+		rows, err := conn.QueryContext(nctx, args)
+		td := time.Since(ts)
+		te := td.Seconds()
+		if err != nil {
+			w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+			span.SetStatus(tracer.SpanStatusError, err.Error())
+		} else {
+			w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+		}
+
+		w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+		w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "QueryContext", name, td, err)...)
+			}
+		*/
+		return rows, err
+	}
+
+	values, err := namedValueToValue(args)
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+		/*
+			if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+				w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "QueryContext", name, 0, err)...)
+			}
+		*/
+		return nil, err
+	}
+	ts := time.Now()
+	rows, err := w.Query(values) // nolint:staticcheck
+	td := time.Since(ts)
+	te := td.Seconds()
+	if err != nil {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelFailure)...).Inc()
+		span.SetStatus(tracer.SpanStatusError, err.Error())
+	} else {
+		w.opts.Meter.Counter(meterRequestTotal, append(labels, labelStatus, labelSuccess)...).Inc()
+	}
+
+	w.opts.Meter.Summary(meterRequestLatencyMicroseconds, labels...).Update(te)
+	w.opts.Meter.Histogram(meterRequestDurationSeconds, labels...).Update(te)
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(ctx, "QueryContext", name, td, err)...)
+		}
+	*/
+	return rows, err
+}

hooks/sql/tx.go

@@ -0,0 +1,63 @@
+package sql
+
+import (
+	"context"
+	"database/sql/driver"
+	"time"
+
+	"go.unistack.org/micro/v4/tracer"
+)
+
+var _ driver.Tx = (*wrapperTx)(nil)
+
+// wrapperTx defines a wrapper for driver.Tx
+type wrapperTx struct {
+	tx   driver.Tx
+	span tracer.Span
+	opts Options
+	ctx  context.Context
+}
+
+// Commit implements driver.Tx Commit
+func (w *wrapperTx) Commit() error {
+	ts := time.Now()
+	err := w.tx.Commit()
+	td := time.Since(ts)
+	_ = td
+	if w.span != nil {
+		if err != nil {
+			w.span.SetStatus(tracer.SpanStatusError, err.Error())
+		}
+		w.span.Finish()
+	}
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(w.ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(w.ctx, "Commit", getCallerName(), td, err)...)
+		}
+	*/
+	w.ctx = nil
+
+	return err
+}
+
+// Rollback implements driver.Tx Rollback
+func (w *wrapperTx) Rollback() error {
+	ts := time.Now()
+	err := w.tx.Rollback()
+	td := time.Since(ts)
+	_ = td
+	if w.span != nil {
+		if err != nil {
+			w.span.SetStatus(tracer.SpanStatusError, err.Error())
+		}
+		w.span.Finish()
+	}
+	/*
+		if w.opts.LoggerEnabled && w.opts.Logger.V(w.opts.LoggerLevel) {
+			w.opts.Logger.Log(w.ctx, w.opts.LoggerLevel, w.opts.LoggerObserver(w.ctx, "Rollback", getCallerName(), td, err)...)
+		}
+	*/
+	w.ctx = nil
+
+	return err
+}

hooks/sql/wrap.go

@@ -0,0 +1,19 @@
+package sql
+
+import (
+	"database/sql/driver"
+)
+
+/*
+func wrapDriver(d driver.Driver, opts Options) driver.Driver {
+	if _, ok := d.(driver.DriverContext); ok {
+		return &wrapperDriver{driver: d, opts: opts}
+	}
+	return struct{ driver.Driver }{&wrapperDriver{driver: d, opts: opts}}
+}
+*/
+
+// WrapConn allows an existing driver.Conn to be wrapped.
+func WrapConn(c driver.Conn, opts ...Option) driver.Conn {
+	return wrapConn(c, NewOptions(opts...))
+}

hooks/validator/validator.go

@@ -0,0 +1,133 @@
+package validator
+
+import (
+	"context"
+
+	"go.unistack.org/micro/v4/client"
+	"go.unistack.org/micro/v4/errors"
+	"go.unistack.org/micro/v4/server"
+)
+
+var (
+	DefaultClientErrorFunc = func(req client.Request, rsp interface{}, err error) error {
+		if rsp != nil {
+			return errors.BadGateway(req.Service(), "%v", err)
+		}
+		return errors.BadRequest(req.Service(), "%v", err)
+	}
+
+	DefaultServerErrorFunc = func(req server.Request, rsp interface{}, err error) error {
+		if rsp != nil {
+			return errors.BadGateway(req.Service(), "%v", err)
+		}
+		return errors.BadRequest(req.Service(), "%v", err)
+	}
+)
+
+type (
+	ClientErrorFunc func(client.Request, interface{}, error) error
+	ServerErrorFunc func(server.Request, interface{}, error) error
+)
+
+// Options struct holds wrapper options
+type Options struct {
+	ClientErrorFn          ClientErrorFunc
+	ServerErrorFn          ServerErrorFunc
+	ClientValidateResponse bool
+	ServerValidateResponse bool
+}
+
+// Option func signature
+type Option func(*Options)
+
+func ClientValidateResponse(b bool) Option {
+	return func(o *Options) {
+		o.ClientValidateResponse = b
+	}
+}
+
+func ServerValidateResponse(b bool) Option {
+	return func(o *Options) {
+		o.ClientValidateResponse = b
+	}
+}
+
+func ClientReqErrorFn(fn ClientErrorFunc) Option {
+	return func(o *Options) {
+		o.ClientErrorFn = fn
+	}
+}
+
+func ServerErrorFn(fn ServerErrorFunc) Option {
+	return func(o *Options) {
+		o.ServerErrorFn = fn
+	}
+}
+
+func NewOptions(opts ...Option) Options {
+	options := Options{
+		ClientErrorFn: DefaultClientErrorFunc,
+		ServerErrorFn: DefaultServerErrorFunc,
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+func NewHook(opts ...Option) *hook {
+	return &hook{opts: NewOptions(opts...)}
+}
+
+type validator interface {
+	Validate() error
+}
+
+type hook struct {
+	opts Options
+}
+
+func (w *hook) ClientCall(next client.FuncCall) client.FuncCall {
+	return func(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
+		if v, ok := req.Body().(validator); ok {
+			if err := v.Validate(); err != nil {
+				return w.opts.ClientErrorFn(req, nil, err)
+			}
+		}
+		err := next(ctx, req, rsp, opts...)
+		if v, ok := rsp.(validator); ok && w.opts.ClientValidateResponse {
+			if verr := v.Validate(); verr != nil {
+				return w.opts.ClientErrorFn(req, rsp, verr)
+			}
+		}
+		return err
+	}
+}
+
+func (w *hook) ClientStream(next client.FuncStream) client.FuncStream {
+	return func(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) {
+		if v, ok := req.Body().(validator); ok {
+			if err := v.Validate(); err != nil {
+				return nil, w.opts.ClientErrorFn(req, nil, err)
+			}
+		}
+		return next(ctx, req, opts...)
+	}
+}
+
+func (w *hook) ServerHandler(next server.FuncHandler) server.FuncHandler {
+	return func(ctx context.Context, req server.Request, rsp interface{}) error {
+		if v, ok := req.Body().(validator); ok {
+			if err := v.Validate(); err != nil {
+				return w.opts.ServerErrorFn(req, nil, err)
+			}
+		}
+		err := next(ctx, req, rsp)
+		if v, ok := rsp.(validator); ok && w.opts.ServerValidateResponse {
+			if verr := v.Validate(); verr != nil {
+				return w.opts.ServerErrorFn(req, rsp, verr)
+			}
+		}
+		return err
+	}
+}

logger/level.go

@@ -4,18 +4,20 @@ package logger
 type Level int8
 
 const (
-	// TraceLevel level usually used to find bugs, very verbose
+	// TraceLevel usually used to find bugs, very verbose
 	TraceLevel Level = iota - 2
-	// DebugLevel level used only when enabled debugging
+	// DebugLevel used only when enabled debugging
 	DebugLevel
-	// InfoLevel level used for general info about what's going on inside the application
+	// InfoLevel used for general info about what's going on inside the application
 	InfoLevel
-	// WarnLevel level used for non-critical entries
+	// WarnLevel used for non-critical entries
 	WarnLevel
-	// ErrorLevel level used for errors that should definitely be noted
+	// ErrorLevel used for errors that should definitely be noted
 	ErrorLevel
-	// FatalLevel level used for critical errors and then calls `os.Exit(1)`
+	// FatalLevel used for critical errors and then calls `os.Exit(1)`
 	FatalLevel
+	// NoneLevel used to disable logging
+	NoneLevel
 )
 
 // String returns logger level string representation
@@ -33,6 +35,8 @@ func (l Level) String() string {
 		return "error"
 	case FatalLevel:
 		return "fatal"
+	case NoneLevel:
+		return "none"
 	}
 	return "info"
 }
@@ -58,6 +62,8 @@ func ParseLevel(lvl string) Level {
 		return ErrorLevel
 	case FatalLevel.String():
 		return FatalLevel
+	case NoneLevel.String():
+		return NoneLevel
 	}
 	return InfoLevel
 }

logger/options.go

@@ -8,7 +8,7 @@ import (
 	"slices"
 	"time"
 
-	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v4/meter"
 )
 
 // Option func signature
@@ -52,6 +52,12 @@ type Options struct {
 	AddStacktrace bool
 	// DedupKeys deduplicate keys in log output
 	DedupKeys bool
+	// FatalFinalizers runs in order in [logger.Fatal] method
+	FatalFinalizers []func(context.Context)
+}
+
+var DefaultFatalFinalizer = func(ctx context.Context) {
+	os.Exit(1)
 }
 
 // NewOptions creates new options struct
@@ -65,6 +71,7 @@ func NewOptions(opts ...Option) Options {
 		AddSource:        true,
 		TimeFunc:         time.Now,
 		Meter:            meter.DefaultMeter,
+		FatalFinalizers:  []func(context.Context){DefaultFatalFinalizer},
 	}
 
 	WithMicroKeys()(&options)
@@ -76,6 +83,13 @@ func NewOptions(opts ...Option) Options {
 	return options
 }
 
+// WithFatalFinalizers set logger.Fatal finalizers
+func WithFatalFinalizers(fncs ...func(context.Context)) Option {
+	return func(o *Options) {
+		o.FatalFinalizers = fncs
+	}
+}
+
 // WithContextAttrFuncs appends default funcs for the context attrs filler
 func WithContextAttrFuncs(fncs ...ContextAttrFunc) Option {
 	return func(o *Options) {
@@ -99,6 +113,7 @@ func WithAddFields(fields ...interface{}) Option {
 					iv, iok := o.Fields[i].(string)
 					jv, jok := fields[j].(string)
 					if iok && jok && iv == jv {
+						o.Fields[i+1] = fields[j+1]
 						fields = slices.Delete(fields, j, j+2)
 					}
 				}

logger/slog/slog.go

@@ -4,24 +4,23 @@ import (
 	"context"
 	"io"
 	"log/slog"
-	"os"
 	"reflect"
 	"regexp"
 	"runtime"
 	"strconv"
 	"sync"
 	"sync/atomic"
-	"time"
 
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/semconv"
+	"go.unistack.org/micro/v4/semconv"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/tracer"
 )
 
 const (
 	badKey = "!BADKEY"
 	// defaultCallerSkipCount used by logger
 	defaultCallerSkipCount = 3
+	timeFormat             = "2006-01-02T15:04:05.000000000Z07:00"
 )
 
 var reTrace = regexp.MustCompile(`.*/slog/logger\.go.*\n`)
@@ -33,6 +32,7 @@ var (
 	warnValue  = slog.StringValue("warn")
 	errorValue = slog.StringValue("error")
 	fatalValue = slog.StringValue("fatal")
+	noneValue  = slog.StringValue("none")
 )
 
 type wrapper struct {
@@ -64,6 +64,7 @@ func (s *slogLogger) renameAttr(_ []string, a slog.Attr) slog.Attr {
 		a.Key = s.opts.SourceKey
 	case slog.TimeKey:
 		a.Key = s.opts.TimeKey
+		a.Value = slog.StringValue(a.Value.Time().Format(timeFormat))
 	case slog.MessageKey:
 		a.Key = s.opts.MessageKey
 	case slog.LevelKey:
@@ -83,6 +84,8 @@ func (s *slogLogger) renameAttr(_ []string, a slog.Attr) slog.Attr {
 			a.Value = errorValue
 		case lvl >= logger.FatalLevel:
 			a.Value = fatalValue
+		case lvl >= logger.NoneLevel:
+			a.Value = noneValue
 		default:
 			a.Value = infoValue
 		}
@@ -226,11 +229,12 @@ func (s *slogLogger) Error(ctx context.Context, msg string, attrs ...interface{}
 
 func (s *slogLogger) Fatal(ctx context.Context, msg string, attrs ...interface{}) {
 	s.printLog(ctx, logger.FatalLevel, msg, attrs...)
+	for _, fn := range s.opts.FatalFinalizers {
+		fn(ctx)
+	}
 	if closer, ok := s.opts.Out.(io.Closer); ok {
 		closer.Close()
 	}
-	time.Sleep(1 * time.Second)
-	os.Exit(1)
 }
 
 func (s *slogLogger) Warn(ctx context.Context, msg string, attrs ...interface{}) {
@@ -276,7 +280,7 @@ func (s *slogLogger) printLog(ctx context.Context, lvl logger.Level, msg string,
 		}
 	}
 
-	if (s.opts.AddStacktrace || lvl == logger.FatalLevel) || (s.opts.AddStacktrace && lvl == logger.ErrorLevel) {
+	if s.opts.AddStacktrace && (lvl == logger.FatalLevel || lvl == logger.ErrorLevel) {
 		stackInfo := make([]byte, 1024*1024)
 		if stackSize := runtime.Stack(stackInfo, false); stackSize > 0 {
 			traceLines := reTrace.Split(string(stackInfo[:stackSize]), -1)
@@ -314,6 +318,8 @@ func loggerToSlogLevel(level logger.Level) slog.Level {
 		return slog.LevelDebug - 1
 	case logger.FatalLevel:
 		return slog.LevelError + 1
+	case logger.NoneLevel:
+		return slog.LevelError + 2
 	default:
 		return slog.LevelInfo
 	}
@@ -331,6 +337,8 @@ func slogToLoggerLevel(level slog.Level) logger.Level {
 		return logger.TraceLevel
 	case slog.LevelError + 1:
 		return logger.FatalLevel
+	case slog.LevelError + 2:
+		return logger.NoneLevel
 	default:
 		return logger.InfoLevel
 	}

logger/slog/slog_test.go

@@ -9,16 +9,19 @@ import (
 	"log/slog"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/google/uuid"
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v4/util/buffer"
 )
 
+// always first to have proper check
 func TestStacktrace(t *testing.T) {
 	ctx := context.TODO()
 	buf := bytes.NewBuffer(nil)
-	l := NewLogger(logger.WithLevel(logger.ErrorLevel), logger.WithOutput(buf),
+	l := NewLogger(logger.WithLevel(logger.DebugLevel), logger.WithOutput(buf),
 		WithHandlerFunc(slog.NewTextHandler),
 		logger.WithAddStacktrace(true),
 	)
@@ -28,7 +31,65 @@ func TestStacktrace(t *testing.T) {
 
 	l.Error(ctx, "msg1", errors.New("err"))
 
-	if !bytes.Contains(buf.Bytes(), []byte(`slog_test.go:29`)) {
+	if !bytes.Contains(buf.Bytes(), []byte(`slog_test.go:32`)) {
+		t.Fatalf("logger error not works, buf contains: %s", buf.Bytes())
+	}
+}
+
+func TestNoneLevel(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.NoneLevel), logger.WithOutput(buf),
+		WithHandlerFunc(slog.NewTextHandler),
+		logger.WithAddStacktrace(true),
+	)
+	if err := l.Init(logger.WithFields("key1", "val1")); err != nil {
+		t.Fatal(err)
+	}
+
+	l.Error(ctx, "msg1", errors.New("err"))
+
+	if buf.Len() != 0 {
+		t.Fatalf("logger none level not works, buf contains: %s", buf.Bytes())
+	}
+}
+
+func TestDelayedBuffer(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	dbuf := buffer.NewDelayedBuffer(100, 100*time.Millisecond, buf)
+	l := NewLogger(logger.WithLevel(logger.ErrorLevel), logger.WithOutput(dbuf),
+		WithHandlerFunc(slog.NewTextHandler),
+		logger.WithAddStacktrace(true),
+	)
+	if err := l.Init(logger.WithFields("key1", "val1")); err != nil {
+		t.Fatal(err)
+	}
+
+	l.Error(ctx, "msg1", errors.New("err"))
+	time.Sleep(120 * time.Millisecond)
+	if !bytes.Contains(buf.Bytes(), []byte(`key1=val1`)) {
+		t.Fatalf("logger delayed buffer not works, buf contains: %s", buf.Bytes())
+	}
+}
+
+func TestTime(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.ErrorLevel), logger.WithOutput(buf),
+		WithHandlerFunc(slog.NewTextHandler),
+		logger.WithAddStacktrace(true),
+		logger.WithTimeFunc(func() time.Time {
+			return time.Unix(0, 0).UTC()
+		}),
+	)
+	if err := l.Init(logger.WithFields("key1", "val1")); err != nil {
+		t.Fatal(err)
+	}
+
+	l.Error(ctx, "msg1", errors.New("err"))
+
+	if !bytes.Contains(buf.Bytes(), []byte(`timestamp=1970-01-01T00:00:00.000000000Z`)) {
 		t.Fatalf("logger error not works, buf contains: %s", buf.Bytes())
 	}
 }
@@ -80,7 +141,7 @@ func TestWithDedupKeysWithAddFields(t *testing.T) {
 
 	l.Info(ctx, "msg3")
 
-	if !bytes.Contains(buf.Bytes(), []byte(`msg=msg3 key1=val1 key2=val2`)) {
+	if !bytes.Contains(buf.Bytes(), []byte(`msg=msg3 key1=val4 key2=val3`)) {
 		t.Fatalf("logger error not works, buf contains: %s", buf.Bytes())
 	}
 }
@@ -362,15 +423,16 @@ func TestLogger(t *testing.T) {
 func Test_WithContextAttrFunc(t *testing.T) {
 	loggerContextAttrFuncs := []logger.ContextAttrFunc{
 		func(ctx context.Context) []interface{} {
-			md, ok := metadata.FromIncomingContext(ctx)
+			md, ok := metadata.FromOutgoingContext(ctx)
 			if !ok {
 				return nil
 			}
 			attrs := make([]interface{}, 0, 10)
 			for k, v := range md {
-				switch k {
+				key := strings.ToLower(k)
-				case "X-Request-Id", "Phone", "External-Id", "Source-Service", "X-App-Install-Id", "Client-Id", "Client-Ip":
+				switch key {
-					attrs = append(attrs, strings.ToLower(k), v)
+				case "x-request-id", "phone", "external-Id", "source-service", "x-app-install-id", "client-id", "client-ip":
+					attrs = append(attrs, key, v[0])
 				}
 			}
 			return attrs
@@ -380,7 +442,7 @@ func Test_WithContextAttrFunc(t *testing.T) {
 	logger.DefaultContextAttrFuncs = append(logger.DefaultContextAttrFuncs, loggerContextAttrFuncs...)
 
 	ctx := context.TODO()
-	ctx = metadata.AppendIncomingContext(ctx, "X-Request-Id", uuid.New().String(),
+	ctx = metadata.AppendOutgoingContext(ctx, "X-Request-Id", uuid.New().String(),
 		"Source-Service", "Test-System")
 
 	buf := bytes.NewBuffer(nil)
@@ -400,10 +462,32 @@ func Test_WithContextAttrFunc(t *testing.T) {
 		t.Fatalf("logger info, buf %s", buf.Bytes())
 	}
 	buf.Reset()
-	imd, _ := metadata.FromIncomingContext(ctx)
+	omd, _ := metadata.FromOutgoingContext(ctx)
 	l.Info(ctx, "test message1")
-	imd.Set("Source-Service", "Test-System2")
+	omd.Set("Source-Service", "Test-System2")
 	l.Info(ctx, "test message2")
 
 	// t.Logf("xxx %s", buf.Bytes())
 }
+
+func TestFatalFinalizers(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(
+		logger.WithLevel(logger.TraceLevel),
+		logger.WithOutput(buf),
+	)
+	if err := l.Init(
+		logger.WithFatalFinalizers(func(ctx context.Context) {
+			l.Info(ctx, "fatal finalizer")
+		})); err != nil {
+		t.Fatal(err)
+	}
+	l.Fatal(ctx, "info_msg1")
+	if !bytes.Contains(buf.Bytes(), []byte("fatal finalizer")) {
+		t.Fatalf("logger dont have fatal message, buf %s", buf.Bytes())
+	}
+	if !bytes.Contains(buf.Bytes(), []byte("info_msg1")) {
+		t.Fatalf("logger dont have info_msg1 message, buf %s", buf.Bytes())
+	}
+}

logger/unwrap/unwrap.go

@@ -8,7 +8,7 @@ import (
 	"strconv"
 	"strings"
 
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
 )
 
 const sf = "0-+# "

logger/unwrap/unwrap_test.go

@@ -5,7 +5,7 @@ import (
 	"strings"
 	"testing"
 
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
 )
 
 func TestUnwrap(t *testing.T) {

metadata/context.go

@@ -1,79 +1,147 @@
-// Package metadata is a way of defining message headers
 package metadata
 
 import (
 	"context"
+	"fmt"
+	"strings"
 )
 
+// In the metadata package, context and metadata are treated as immutable.
+// Deep copies of metadata are made to keep things safe and correct.
+// If a user takes a map and changes it across threads, it's their responsibility.
+//
+// 1. Incoming Context
+//
+// This context is provided by an external system and populated by the server or broker of the micro framework.
+// It should not be modified. The idea is to extract all necessary data from it,
+// validate the data, and transfer it into the current context.
+// After that, only the current context should be used throughout the code.
+//
+// 2. Current Context
+//
+// This is the context used during the execution flow.
+// You can add any needed metadata to it and pass it through your code.
+//
+// 3. Outgoing Context
+//
+// This context is for sending data to external systems.
+// You can add what you need before sending it out.
+// But it’s usually better to build and prepare this context right before making the external call,
+// instead of changing it in many places.
+//
+// Execution Flow:
+//
+// [External System]
+//       ↓
+// [Incoming Context]
+//       ↓
+// [Extract & Validate Metadata from Incoming Context]
+//       ↓
+// [Prepare Current Context]
+//       ↓
+// [Enrich Current Context]
+//       ↓
+// [Business Logic]
+//       ↓
+// [Prepare Outgoing Context]
+//       ↓
+// [External System Call]
+
 type (
-	mdIncomingKey struct{}
+	metadataCurrentKey  struct{}
-	mdOutgoingKey struct{}
+	metadataIncomingKey struct{}
-	mdKey         struct{}
+	metadataOutgoingKey struct{}
+
+	rawMetadata struct {
+		md    Metadata
+		added [][]string
+	}
 )
 
-// FromIncomingContext returns metadata from incoming ctx
+// NewContext creates a new context with the provided Metadata attached.
-// returned metadata shoud not be modified or race condition happens
+// The Metadata must not be modified after calling this function.
-func FromIncomingContext(ctx context.Context) (Metadata, bool) {
+func NewContext(ctx context.Context, md Metadata) context.Context {
-	if ctx == nil {
+	return context.WithValue(ctx, metadataCurrentKey{}, rawMetadata{md: md})
-		return nil, false
-	}
-	md, ok := ctx.Value(mdIncomingKey{}).(*rawMetadata)
-	if !ok || md.md == nil {
-		return nil, false
-	}
-	return md.md, ok
 }
 
-// MustIncomingContext returns metadata from incoming ctx
+// NewIncomingContext creates a new context with the provided incoming Metadata attached.
-// returned metadata shoud not be modified or race condition happens.
+// The Metadata must not be modified after calling this function.
-// If metadata not exists panics.
+func NewIncomingContext(ctx context.Context, md Metadata) context.Context {
-func MustIncomingContext(ctx context.Context) Metadata {
+	return context.WithValue(ctx, metadataIncomingKey{}, rawMetadata{md: md})
-	md, ok := FromIncomingContext(ctx)
-	if !ok {
-		panic("missing metadata")
-	}
-	return md
 }
 
-// FromOutgoingContext returns metadata from outgoing ctx
+// NewOutgoingContext creates a new context with the provided outgoing Metadata attached.
-// returned metadata shoud not be modified or race condition happens
+// The Metadata must not be modified after calling this function.
-func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
+func NewOutgoingContext(ctx context.Context, md Metadata) context.Context {
-	if ctx == nil {
+	return context.WithValue(ctx, metadataOutgoingKey{}, rawMetadata{md: md})
-		return nil, false
-	}
-	md, ok := ctx.Value(mdOutgoingKey{}).(*rawMetadata)
-	if !ok || md.md == nil {
-		return nil, false
-	}
-	return md.md, ok
 }
 
-// MustOutgoingContext returns metadata from outgoing ctx
+// AppendContext returns a new context with the provided key-value pairs (kv)
-// returned metadata shoud not be modified or race condition happens.
+// merged with any existing metadata in the context. For a description of kv,
-// If metadata not exists panics.
+// please refer to the Pairs documentation.
-func MustOutgoingContext(ctx context.Context) Metadata {
+func AppendContext(ctx context.Context, kv ...string) context.Context {
-	md, ok := FromOutgoingContext(ctx)
+	if len(kv)%2 == 1 {
-	if !ok {
+		panic(fmt.Sprintf("metadata: AppendContext got an odd number of input pairs for metadata: %d", len(kv)))
-		panic("missing metadata")
 	}
-	return md
+	md, _ := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	added := make([][]string, len(md.added)+1)
+	copy(added, md.added)
+	kvCopy := make([]string, 0, len(kv))
+	for i := 0; i < len(kv); i += 2 {
+		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
+	}
+	added[len(added)-1] = kvCopy
+	return context.WithValue(ctx, metadataCurrentKey{}, rawMetadata{md: md.md, added: added})
 }
 
-// FromContext returns metadata from the given context
+// AppendOutgoingContext returns a new context with the provided key-value pairs (kv)
-// returned metadata shoud not be modified or race condition happens
+// merged with any existing metadata in the context. For a description of kv,
+// please refer to the Pairs documentation.
+func AppendOutgoingContext(ctx context.Context, kv ...string) context.Context {
+	if len(kv)%2 == 1 {
+		panic(fmt.Sprintf("metadata: AppendOutgoingContext got an odd number of input pairs for metadata: %d", len(kv)))
+	}
+	md, _ := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
+	added := make([][]string, len(md.added)+1)
+	copy(added, md.added)
+	kvCopy := make([]string, 0, len(kv))
+	for i := 0; i < len(kv); i += 2 {
+		kvCopy = append(kvCopy, strings.ToLower(kv[i]), kv[i+1])
+	}
+	added[len(added)-1] = kvCopy
+	return context.WithValue(ctx, metadataOutgoingKey{}, rawMetadata{md: md.md, added: added})
+}
+
+// FromContext retrieves a deep copy of the metadata from the context and returns it
+// with a boolean indicating if it was found.
 func FromContext(ctx context.Context) (Metadata, bool) {
-	if ctx == nil {
+	raw, ok := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	if !ok {
 		return nil, false
 	}
-	md, ok := ctx.Value(mdKey{}).(*rawMetadata)
+	metadataSize := len(raw.md)
-	if !ok || md.md == nil {
+	for i := range raw.added {
-		return nil, false
+		metadataSize += len(raw.added[i]) / 2
 	}
-	return md.md, ok
+
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
+	}
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, true
 }
 
-// MustContext returns metadata from the given context
+// MustContext retrieves a deep copy of the metadata from the context and panics
-// returned metadata shoud not be modified or race condition happens
+// if the metadata is not found.
 func MustContext(ctx context.Context) Metadata {
 	md, ok := FromContext(ctx)
 	if !ok {
@@ -82,98 +150,145 @@ func MustContext(ctx context.Context) Metadata {
 	return md
 }
 
-// NewContext creates a new context with the given metadata
+// FromIncomingContext retrieves a deep copy of the metadata from the context and returns it
-func NewContext(ctx context.Context, md Metadata) context.Context {
+// with a boolean indicating if it was found.
-	if ctx == nil {
+func FromIncomingContext(ctx context.Context) (Metadata, bool) {
-		ctx = context.Background()
+	raw, ok := ctx.Value(metadataIncomingKey{}).(rawMetadata)
-	}
-	return context.WithValue(ctx, mdKey{}, &rawMetadata{md})
-}
-
-// SetOutgoingContext modify outgoing context with given metadata
-func SetOutgoingContext(ctx context.Context, md Metadata) bool {
-	if ctx == nil {
-		return false
-	}
-	if omd, ok := ctx.Value(mdOutgoingKey{}).(*rawMetadata); ok {
-		omd.md = md
-		return true
-	}
-	return false
-}
-
-// SetIncomingContext modify incoming context with given metadata
-func SetIncomingContext(ctx context.Context, md Metadata) bool {
-	if ctx == nil {
-		return false
-	}
-	if omd, ok := ctx.Value(mdIncomingKey{}).(*rawMetadata); ok {
-		omd.md = md
-		return true
-	}
-	return false
-}
-
-// NewIncomingContext creates a new context with incoming metadata attached
-func NewIncomingContext(ctx context.Context, md Metadata) context.Context {
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	return context.WithValue(ctx, mdIncomingKey{}, &rawMetadata{md})
-}
-
-// NewOutgoingContext creates a new context with outcoming metadata attached
-func NewOutgoingContext(ctx context.Context, md Metadata) context.Context {
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	return context.WithValue(ctx, mdOutgoingKey{}, &rawMetadata{md})
-}
-
-// AppendOutgoingContext apends new md to context
-func AppendOutgoingContext(ctx context.Context, kv ...string) context.Context {
-	md, ok := Pairs(kv...)
 	if !ok {
-		return ctx
+		return nil, false
 	}
-	omd, ok := FromOutgoingContext(ctx)
+	metadataSize := len(raw.md)
-	if !ok {
+	for i := range raw.added {
-		return NewOutgoingContext(ctx, md)
+		metadataSize += len(raw.added[i]) / 2
 	}
-	for k, v := range md {
+
-		omd.Set(k, v)
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
 	}
-	return ctx
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromIncomingContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, true
 }
 
-// AppendIncomingContext apends new md to context
+// MustIncomingContext retrieves a deep copy of the metadata from the context and panics
-func AppendIncomingContext(ctx context.Context, kv ...string) context.Context {
+// if the metadata is not found.
-	md, ok := Pairs(kv...)
+func MustIncomingContext(ctx context.Context) Metadata {
+	md, ok := FromIncomingContext(ctx)
 	if !ok {
-		return ctx
+		panic("missing metadata")
 	}
-	omd, ok := FromIncomingContext(ctx)
+	return md
-	if !ok {
-		return NewIncomingContext(ctx, md)
-	}
-	for k, v := range md {
-		omd.Set(k, v)
-	}
-	return ctx
 }
 
-// AppendContext apends new md to context
+// FromOutgoingContext retrieves a deep copy of the metadata from the context and returns it
-func AppendContext(ctx context.Context, kv ...string) context.Context {
+// with a boolean indicating if it was found.
-	md, ok := Pairs(kv...)
+func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
+	raw, ok := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
 	if !ok {
-		return ctx
+		return nil, false
 	}
-	omd, ok := FromContext(ctx)
+
-	if !ok {
+	metadataSize := len(raw.md)
-		return NewContext(ctx, md)
+	for i := range raw.added {
+		metadataSize += len(raw.added[i]) / 2
 	}
-	for k, v := range md {
+
-		omd.Set(k, v)
+	out := make(Metadata, metadataSize)
+	for k, v := range raw.md {
+		out[k] = copyOf(v)
 	}
-	return ctx
+	for _, added := range raw.added {
+		if len(added)%2 == 1 {
+			panic(fmt.Sprintf("metadata: FromOutgoingContext got an odd number of input pairs for metadata: %d", len(added)))
+		}
+
+		for i := 0; i < len(added); i += 2 {
+			out[added[i]] = append(out[added[i]], added[i+1])
+		}
+	}
+	return out, ok
+}
+
+// MustOutgoingContext retrieves a deep copy of the metadata from the context and panics
+// if the metadata is not found.
+func MustOutgoingContext(ctx context.Context) Metadata {
+	md, ok := FromOutgoingContext(ctx)
+	if !ok {
+		panic("missing metadata")
+	}
+	return md
+}
+
+// ValueFromCurrentContext retrieves a deep copy of the metadata for the given key
+// from the context, performing a case-insensitive search if needed. Returns nil if not found.
+func ValueFromCurrentContext(ctx context.Context, key string) []string {
+	md, ok := ctx.Value(metadataCurrentKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := md.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range md.md {
+		// Case-insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
+}
+
+// ValueFromIncomingContext retrieves a deep copy of the metadata for the given key
+// from the context, performing a case-insensitive search if needed. Returns nil if not found.
+func ValueFromIncomingContext(ctx context.Context, key string) []string {
+	raw, ok := ctx.Value(metadataIncomingKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := raw.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range raw.md {
+		// Case-insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
+}
+
+// ValueFromOutgoingContext retrieves a deep copy of the metadata for the given key
+// from the context, performing a case-insensitive search if needed. Returns nil if not found.
+func ValueFromOutgoingContext(ctx context.Context, key string) []string {
+	md, ok := ctx.Value(metadataOutgoingKey{}).(rawMetadata)
+	if !ok {
+		return nil
+	}
+
+	if v, ok := md.md[key]; ok {
+		return copyOf(v)
+	}
+	for k, v := range md.md {
+		// Case-insensitive comparison: Metadata is a map, and there's no guarantee
+		// that the Metadata attached to the context is created using our helper
+		// functions.
+		if strings.EqualFold(k, key) {
+			return copyOf(v)
+		}
+	}
+	return nil
 }

metadata/context_test.go

@@ -1,140 +0,0 @@
-package metadata
-
-import (
-	"context"
-	"testing"
-)
-
-func TestFromNilContext(t *testing.T) {
-	// nolint: staticcheck
-	c, ok := FromContext(nil)
-	if ok || c != nil {
-		t.Fatal("FromContext not works")
-	}
-}
-
-func TestNewNilContext(t *testing.T) {
-	// nolint: staticcheck
-	ctx := NewContext(nil, New(0))
-
-	c, ok := FromContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("NewContext not works")
-	}
-}
-
-func TestFromContext(t *testing.T) {
-	ctx := context.WithValue(context.TODO(), mdKey{}, &rawMetadata{New(0)})
-
-	c, ok := FromContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("FromContext not works")
-	}
-}
-
-func TestNewContext(t *testing.T) {
-	ctx := NewContext(context.TODO(), New(0))
-
-	c, ok := FromContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("NewContext not works")
-	}
-}
-
-func TestFromIncomingContext(t *testing.T) {
-	ctx := context.WithValue(context.TODO(), mdIncomingKey{}, &rawMetadata{New(0)})
-
-	c, ok := FromIncomingContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("FromIncomingContext not works")
-	}
-}
-
-func TestFromOutgoingContext(t *testing.T) {
-	ctx := context.WithValue(context.TODO(), mdOutgoingKey{}, &rawMetadata{New(0)})
-
-	c, ok := FromOutgoingContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("FromOutgoingContext not works")
-	}
-}
-
-func TestSetIncomingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key", "val")
-	ctx := context.WithValue(context.TODO(), mdIncomingKey{}, &rawMetadata{})
-	if !SetIncomingContext(ctx, md) {
-		t.Fatal("SetIncomingContext not works")
-	}
-	md, ok := FromIncomingContext(ctx)
-	if md == nil || !ok {
-		t.Fatal("SetIncomingContext not works")
-	} else if v, ok := md.Get("key"); !ok || v != "val" {
-		t.Fatal("SetIncomingContext not works")
-	}
-}
-
-func TestSetOutgoingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key", "val")
-	ctx := context.WithValue(context.TODO(), mdOutgoingKey{}, &rawMetadata{})
-	if !SetOutgoingContext(ctx, md) {
-		t.Fatal("SetOutgoingContext not works")
-	}
-	md, ok := FromOutgoingContext(ctx)
-	if md == nil || !ok {
-		t.Fatal("SetOutgoingContext not works")
-	} else if v, ok := md.Get("key"); !ok || v != "val" {
-		t.Fatal("SetOutgoingContext not works")
-	}
-}
-
-func TestNewIncomingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key", "val")
-	ctx := NewIncomingContext(context.TODO(), md)
-
-	c, ok := FromIncomingContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("NewIncomingContext not works")
-	}
-}
-
-func TestNewOutgoingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key", "val")
-	ctx := NewOutgoingContext(context.TODO(), md)
-
-	c, ok := FromOutgoingContext(ctx)
-	if c == nil || !ok {
-		t.Fatal("NewOutgoingContext not works")
-	}
-}
-
-func TestAppendIncomingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key1", "val1")
-	ctx := AppendIncomingContext(context.TODO(), "key2", "val2")
-
-	nmd, ok := FromIncomingContext(ctx)
-	if nmd == nil || !ok {
-		t.Fatal("AppendIncomingContext not works")
-	}
-	if v, ok := nmd.Get("key2"); !ok || v != "val2" {
-		t.Fatal("AppendIncomingContext not works")
-	}
-}
-
-func TestAppendOutgoingContext(t *testing.T) {
-	md := New(1)
-	md.Set("key1", "val1")
-	ctx := AppendOutgoingContext(context.TODO(), "key2", "val2")
-
-	nmd, ok := FromOutgoingContext(ctx)
-	if nmd == nil || !ok {
-		t.Fatal("AppendOutgoingContext not works")
-	}
-	if v, ok := nmd.Get("key2"); !ok || v != "val2" {
-		t.Fatal("AppendOutgoingContext not works")
-	}
-}

metadata/headers.go

@@ -0,0 +1,19 @@
+// Package metadata is a way of defining message headers
+package metadata
+
+var (
+	// HeaderTopic is the header name that contains topic name.
+	HeaderTopic = "Micro-Topic"
+	// HeaderContentType specifies content type of message.
+	HeaderContentType = "Content-Type"
+	// HeaderEndpoint specifies endpoint in service.
+	HeaderEndpoint = "Micro-Endpoint"
+	// HeaderService specifies service.
+	HeaderService = "Micro-Service"
+	// HeaderTimeout specifies timeout of operation.
+	HeaderTimeout = "Micro-Timeout"
+	// HeaderAuthorization specifies Authorization header.
+	HeaderAuthorization = "Authorization"
+	// HeaderXRequestID specifies request id.
+	HeaderXRequestID = "X-Request-Id"
+)

metadata/helpers.go

@@ -0,0 +1,7 @@
+package metadata
+
+func copyOf(v []string) []string {
+	vals := make([]string, len(v))
+	copy(vals, v)
+	return vals
+}

metadata/iterator.go

@@ -0,0 +1,37 @@
+package metadata
+
+import "sort"
+
+type Iterator struct {
+	md   Metadata
+	keys []string
+	cur  int
+	cnt  int
+}
+
+// Next advances the iterator to the next element.
+func (iter *Iterator) Next(k *string, v *[]string) bool {
+	if iter.cur+1 > iter.cnt {
+		return false
+	}
+
+	if k != nil && v != nil {
+		*k = iter.keys[iter.cur]
+		vv := iter.md[*k]
+		*v = make([]string, len(vv))
+		copy(*v, vv)
+		iter.cur++
+	}
+	return true
+}
+
+// Iterator returns an iterator for iterating over metadata in sorted order.
+func (md Metadata) Iterator() *Iterator {
+	iter := &Iterator{md: md, cnt: len(md)}
+	iter.keys = make([]string, 0, iter.cnt)
+	for k := range md {
+		iter.keys = append(iter.keys, k)
+	}
+	sort.Strings(iter.keys)
+	return iter
+}

metadata/metadata.go

@@ -1,167 +1,160 @@
-// Package metadata is a way of defining message headers
 package metadata
 
 import (
+	"fmt"
 	"net/textproto"
-	"sort"
 	"strings"
 )
 
-var (
+// defaultMetadataSize is used when initializing new Metadata.
-	// HeaderTopic is the header name that contains topic name
-	HeaderTopic = "Micro-Topic"
-	// HeaderContentType specifies content type of message
-	HeaderContentType = "Content-Type"
-	// HeaderEndpoint specifies endpoint in service
-	HeaderEndpoint = "Micro-Endpoint"
-	// HeaderService specifies service
-	HeaderService = "Micro-Service"
-	// HeaderTimeout specifies timeout of operation
-	HeaderTimeout = "Micro-Timeout"
-	// HeaderAuthorization specifies Authorization header
-	HeaderAuthorization = "Authorization"
-	// HeaderXRequestID specifies request id
-	HeaderXRequestID = "X-Request-Id"
-)
-
-// Metadata is our way of representing request headers internally.
-// They're used at the RPC level and translate back and forth
-// from Transport headers.
-type Metadata map[string]string
-
-type rawMetadata struct {
-	md Metadata
-}
-
-// defaultMetadataSize used when need to init new Metadata
 var defaultMetadataSize = 2
 
-// Iterator used to iterate over metadata with order
+// Metadata maps keys to values. Use the New, NewWithMetadata and Pairs functions to create it.
-type Iterator struct {
+type Metadata map[string][]string
-	md   Metadata
-	keys []string
-	cur  int
-	cnt  int
-}
 
-// Next advance iterator to next element
+// New creates a zero-value Metadata with the specified size.
-func (iter *Iterator) Next(k, v *string) bool {
+func New(l int) Metadata {
-	if iter.cur+1 > iter.cnt {
+	if l == 0 {
-		return false
+		l = defaultMetadataSize
 	}
-
+	md := make(Metadata, l)
-	*k = iter.keys[iter.cur]
+	return md
-	*v = iter.md[*k]
-	iter.cur++
-	return true
 }
 
-// Iterator returns the itarator for metadata in sorted order
+// NewWithMetadata creates a Metadata from the provided key-value map.
-func (md Metadata) Iterator() *Iterator {
+func NewWithMetadata(m map[string]string) Metadata {
-	iter := &Iterator{md: md, cnt: len(md)}
+	md := make(Metadata, len(m))
-	iter.keys = make([]string, 0, iter.cnt)
+	for key, val := range m {
-	for k := range md {
+		md[key] = append(md[key], val)
-		iter.keys = append(iter.keys, k)
 	}
-	sort.Strings(iter.keys)
+	return md
-	return iter
 }
 
-func (md Metadata) MustGet(key string) string {
+// Pairs returns a Metadata formed from the key-value mapping. It panics if the length of kv is odd.
-	val, ok := md.Get(key)
+func Pairs(kv ...string) Metadata {
-	if !ok {
+	if len(kv)%2 == 1 {
-		panic("missing metadata key")
+		panic(fmt.Sprintf("metadata: Pairs got the odd number of input pairs for metadata: %d", len(kv)))
 	}
-	return val
+	md := make(Metadata, len(kv)/2)
+	for i := 0; i < len(kv); i += 2 {
+		md[kv[i]] = append(md[kv[i]], kv[i+1])
+	}
+	return md
 }
 
-// Get returns value from metadata by key
+// Join combines multiple Metadatas into a single Metadata.
-func (md Metadata) Get(key string) (string, bool) {
+// The order of values for each key is determined by the order in which the Metadatas are provided to Join.
-	// fast path
+func Join(mds ...Metadata) Metadata {
-	val, ok := md[key]
+	out := Metadata{}
-	if !ok {
+	for _, md := range mds {
-		// slow path
+		for k, v := range md {
-		val, ok = md[textproto.CanonicalMIMEHeaderKey(key)]
+			out[k] = append(out[k], v...)
-		if !ok {
-			val, ok = md[strings.ToLower(key)]
 		}
 	}
-	return val, ok
+	return out
 }
 
-// Set is used to store value in metadata
+// Copy returns a deep copy of Metadata.
-func (md Metadata) Set(kv ...string) {
+func Copy(src Metadata) Metadata {
-	if len(kv)%2 == 1 {
+	out := make(Metadata, len(src))
-		kv = kv[:len(kv)-1]
+	for k, v := range src {
-	}
+		out[k] = copyOf(v)
-	for idx := 0; idx < len(kv); idx += 2 {
-		md[textproto.CanonicalMIMEHeaderKey(kv[idx])] = kv[idx+1]
 	}
+	return out
 }
 
-// Del is used to remove value from metadata
+// Copy returns a deep copy of Metadata.
-func (md Metadata) Del(keys ...string) {
+func (md Metadata) Copy() Metadata {
-	for _, key := range keys {
+	out := make(Metadata, len(md))
-		// fast path
-		delete(md, key)
-		// slow path
-		delete(md, textproto.CanonicalMIMEHeaderKey(key))
-		// very slow path
-		delete(md, strings.ToLower(key))
-	}
-}
-
-// Copy makes a copy of the metadata
-func (md Metadata) CopyTo(dst Metadata) {
 	for k, v := range md {
-		dst[k] = v
+		out[k] = copyOf(v)
 	}
+	return out
 }
 
-// Copy makes a copy of the metadata
+// CopyTo performs a deep copy of Metadata to the out.
-func Copy(md Metadata, exclude ...string) Metadata {
+func (md Metadata) CopyTo(out Metadata) {
-	nmd := New(len(md))
 	for k, v := range md {
-		nmd[k] = v
+		out[k] = copyOf(v)
 	}
-	nmd.Del(exclude...)
-	return nmd
 }
 
-// New return new sized metadata
+// Len returns the number of items in Metadata.
-func New(size int) Metadata {
+func (md Metadata) Len() int {
-	if size == 0 {
+	return len(md)
-		size = defaultMetadataSize
-	}
-	return make(Metadata, size)
 }
 
-// Merge merges metadata to existing metadata, overwriting if specified
+// AsMap returns a deep copy of Metadata as a map[string]string
-func Merge(omd Metadata, mmd Metadata, overwrite bool) Metadata {
+func (md Metadata) AsMap() map[string]string {
-	var ok bool
+	out := make(map[string]string, len(md))
-	nmd := Copy(omd)
+	for k, v := range md {
-	for key, val := range mmd {
+		out[k] = strings.Join(v, ",")
-		_, ok = nmd[key]
-		switch {
-		case ok && !overwrite:
-			continue
-		case val != "":
-			nmd[key] = val
-		case ok && val == "":
-			nmd.Del(key)
-		}
 	}
-	return nmd
+	return out
 }
 
-// Pairs from which metadata created
+// AsHTTP1 returns a deep copy of Metadata with keys converted to canonical MIME header key format.
-func Pairs(kv ...string) (Metadata, bool) {
+func (md Metadata) AsHTTP1() map[string][]string {
-	if len(kv)%2 == 1 {
+	out := make(map[string][]string, len(md))
-		return nil, false
+	for k, v := range md {
+		out[textproto.CanonicalMIMEHeaderKey(k)] = copyOf(v)
+	}
+	return out
+}
+
+// AsHTTP2 returns a deep copy of Metadata with keys converted to lowercase.
+func (md Metadata) AsHTTP2() map[string][]string {
+	out := make(map[string][]string, len(md))
+	for k, v := range md {
+		out[strings.ToLower(k)] = copyOf(v)
+	}
+	return out
+}
+
+// Get retrieves the values for a given key, checking the key in three formats:
+// - exact case,
+// - lower case,
+// - canonical MIME header key format.
+func (md Metadata) Get(k string) []string {
+	v, ok := md[k]
+	if !ok {
+		v, ok = md[strings.ToLower(k)]
+	}
+	if !ok {
+		v = md[textproto.CanonicalMIMEHeaderKey(k)]
+	}
+	return v
+}
+
+// GetJoined retrieves the values for a given key and joins them into a single string, separated by commas.
+func (md Metadata) GetJoined(k string) string {
+	return strings.Join(md.Get(k), ",")
+}
+
+// Set assigns the values to the given key.
+func (md Metadata) Set(key string, vals ...string) {
+	if len(vals) == 0 {
+		return
+	}
+	md[key] = vals
+}
+
+// Append adds values to the existing values for the given key.
+func (md Metadata) Append(key string, vals ...string) {
+	if len(vals) == 0 {
+		return
+	}
+	md[key] = append(md[key], vals...)
+}
+
+// Del removes the values for the given keys k. It checks and removes the keys in the following formats:
+// - exact case,
+// - lower case,
+// - canonical MIME header key format.
+func (md Metadata) Del(k ...string) {
+	for i := range k {
+		delete(md, k[i])
+		delete(md, strings.ToLower(k[i]))
+		delete(md, textproto.CanonicalMIMEHeaderKey(k[i]))
 	}
-	md := New(len(kv) / 2)
-	for idx := 0; idx < len(kv); idx += 2 {
-		md[kv[idx]] = kv[idx+1]
-	}
-	return md, true
 }

metadata/metadata_test.go

@@ -5,11 +5,31 @@ import (
 	"testing"
 )
 
+func TesSet(t *testing.T) {
+	md := Pairs("key1", "val1", "key2", "val2")
+	md.Set("key1", "val2", "val3")
+	v := md.GetJoined("X-Request-Id")
+	if v != "val2, val3" {
+		t.Fatal("set not works")
+	}
+}
+
+/*
+func TestAppendOutgoingContextModify(t *testing.T) {
+	md := Pairs("key1", "val1")
+	ctx := NewOutgoingContext(context.TODO(), md)
+	nctx := AppendOutgoingContext(ctx, "key1", "val3", "key2", "val2")
+	_ = nctx
+	omd := MustOutgoingContext(nctx)
+	fmt.Printf("%#+v\n", omd)
+}
+*/
+
 func TestLowercase(t *testing.T) {
 	md := New(1)
-	md["x-request-id"] = "12345"
+	md["x-request-id"] = []string{"12345"}
-	v, ok := md.Get("X-Request-Id")
+	v := md.GetJoined("X-Request-Id")
-	if !ok || v == "" {
+	if v == "" {
 		t.Fatalf("metadata invalid %#+v", md)
 	}
 }
@@ -36,50 +56,13 @@ func TestMultipleUsage(t *testing.T) {
 	_ = omd
 }
 
-func TestMetadataSetMultiple(t *testing.T) {
-	md := New(4)
-	md.Set("key1", "val1", "key2", "val2", "key3")
-
-	if v, ok := md.Get("key1"); !ok || v != "val1" {
-		t.Fatalf("invalid kv %#+v", md)
-	}
-	if v, ok := md.Get("key2"); !ok || v != "val2" {
-		t.Fatalf("invalid kv %#+v", md)
-	}
-	if _, ok := md.Get("key3"); ok {
-		t.Fatalf("invalid kv %#+v", md)
-	}
-}
-
-func TestAppend(t *testing.T) {
-	ctx := context.Background()
-	ctx = AppendIncomingContext(ctx, "key1", "val1", "key2", "val2")
-	md, ok := FromIncomingContext(ctx)
-	if !ok {
-		t.Fatal("metadata empty")
-	}
-	if _, ok := md.Get("key1"); !ok {
-		t.Fatal("key1 not found")
-	}
-}
-
 func TestPairs(t *testing.T) {
-	md, ok := Pairs("key1", "val1", "key2", "val2")
+	md := Pairs("key1", "val1", "key2", "val2")
-	if !ok {
+	if v := md.Get("key1"); v == nil {
-		t.Fatal("odd number of kv")
-	}
-	if _, ok = md.Get("key1"); !ok {
 		t.Fatal("key1 not found")
 	}
 }
 
-func testCtx(ctx context.Context) {
-	md := New(2)
-	md.Set("Key1", "Val1_new")
-	md.Set("Key3", "Val3")
-	SetOutgoingContext(ctx, md)
-}
-
 func TestPassing(t *testing.T) {
 	ctx := context.TODO()
 	md1 := New(2)
@@ -87,70 +70,63 @@ func TestPassing(t *testing.T) {
 	md1.Set("Key2", "Val2")
 
 	ctx = NewIncomingContext(ctx, md1)
-	testCtx(ctx)
+
 	_, ok := FromOutgoingContext(ctx)
 	if ok {
 		t.Fatalf("create outgoing context")
 	}
 
-	ctx = NewOutgoingContext(ctx, New(1))
+	ctx = NewOutgoingContext(ctx, md1)
-	testCtx(ctx)
+
 	md, ok := FromOutgoingContext(ctx)
 	if !ok {
 		t.Fatalf("missing metadata from outgoing context")
 	}
-	if v, ok := md.Get("Key1"); !ok || v != "Val1_new" {
+	if v := md.Get("Key1"); v == nil || v[0] != "Val1" {
 		t.Fatalf("invalid metadata value %#+v", md)
 	}
 }
 
-func TestMerge(t *testing.T) {
+func TestIterator(t *testing.T) {
-	omd := Metadata{
+	md := Pairs(
-		"key1": "val1",
+		"1Last", "last",
-	}
+		"2First", "first",
-	mmd := Metadata{
+		"3Second", "second",
-		"key2": "val2",
+	)
-	}
-
-	nmd := Merge(omd, mmd, true)
-	if len(nmd) != 2 {
-		t.Fatalf("merge failed: %v", nmd)
-	}
-}
-
-func TestIterator(_ *testing.T) {
-	md := Metadata{
-		"1Last":   "last",
-		"2First":  "first",
-		"3Second": "second",
-	}
 
 	iter := md.Iterator()
-	var k, v string
+	var k string
-
+	var v []string
+	chk := New(3)
 	for iter.Next(&k, &v) {
-		// fmt.Printf("k: %s, v: %s\n", k, v)
+		chk[k] = v
+	}
+
+	for k, v := range chk {
+		if cv, ok := md[k]; !ok || len(cv) != len(v) || cv[0] != v[0] {
+			t.Fatalf("XXXX %#+v %#+v", chk, md)
+		}
 	}
 }
 
 func TestMedataCanonicalKey(t *testing.T) {
 	md := New(1)
 	md.Set("x-request-id", "12345")
-	v, ok := md.Get("x-request-id")
+	v := md.GetJoined("x-request-id")
-	if !ok {
+	if v == "" {
 		t.Fatalf("failed to get x-request-id")
 	} else if v != "12345" {
 		t.Fatalf("invalid metadata value: %s != %s", "12345", v)
 	}
 
-	v, ok = md.Get("X-Request-Id")
+	v = md.GetJoined("X-Request-Id")
-	if !ok {
+	if v == "" {
 		t.Fatalf("failed to get x-request-id")
 	} else if v != "12345" {
 		t.Fatalf("invalid metadata value: %s != %s", "12345", v)
 	}
-	v, ok = md.Get("X-Request-ID")
+	v = md.GetJoined("X-Request-ID")
-	if !ok {
+	if v == "" {
 		t.Fatalf("failed to get x-request-id")
 	} else if v != "12345" {
 		t.Fatalf("invalid metadata value: %s != %s", "12345", v)
@@ -162,8 +138,8 @@ func TestMetadataSet(t *testing.T) {
 
 	md.Set("Key", "val")
 
-	val, ok := md.Get("Key")
+	val := md.GetJoined("Key")
-	if !ok {
+	if val == "" {
 		t.Fatal("key Key not found")
 	}
 	if val != "val" {
@@ -173,36 +149,27 @@ func TestMetadataSet(t *testing.T) {
 
 func TestMetadataDelete(t *testing.T) {
 	md := Metadata{
-		"Foo": "bar",
+		"Foo": []string{"bar"},
-		"Baz": "empty",
+		"Baz": []string{"empty"},
 	}
 
 	md.Del("Baz")
-	_, ok := md.Get("Baz")
+	v := md.Get("Baz")
-	if ok {
+	if v != nil {
 		t.Fatal("key Baz not deleted")
 	}
 }
 
-func TestNilContext(t *testing.T) {
-	var ctx context.Context
-
-	_, ok := FromContext(ctx)
-	if ok {
-		t.Fatal("nil context")
-	}
-}
-
 func TestMetadataCopy(t *testing.T) {
 	md := Metadata{
-		"Foo": "bar",
+		"Foo": []string{"bar"},
-		"Bar": "baz",
+		"Bar": []string{"baz"},
 	}
 
 	cp := Copy(md)
 
 	for k, v := range md {
-		if cv := cp[k]; cv != v {
+		if cv := cp[k]; cv[0] != v[0] {
 			t.Fatalf("Got %s:%s for %s:%s", k, cv, k, v)
 		}
 	}
@@ -210,7 +177,7 @@ func TestMetadataCopy(t *testing.T) {
 
 func TestMetadataContext(t *testing.T) {
 	md := Metadata{
-		"Foo": "bar",
+		"Foo": []string{"bar"},
 	}
 
 	ctx := NewContext(context.TODO(), md)
@@ -220,7 +187,7 @@ func TestMetadataContext(t *testing.T) {
 		t.Errorf("Unexpected error retrieving metadata, got %t", ok)
 	}
 
-	if emd["Foo"] != md["Foo"] {
+	if emd["Foo"][0] != md["Foo"][0] {
 		t.Errorf("Expected key: %s val: %s, got key: %s val: %s", "Foo", md["Foo"], "Foo", emd["Foo"])
 	}
 
@@ -229,13 +196,74 @@ func TestMetadataContext(t *testing.T) {
 	}
 }
 
-func TestCopy(t *testing.T) {
+func TestFromContext(t *testing.T) {
-	md := New(2)
+	ctx := context.WithValue(context.TODO(), metadataCurrentKey{}, rawMetadata{md: New(0)})
-	md.Set("key1", "val1", "key2", "val2")
+
-	nmd := Copy(md, "key2")
+	c, ok := FromContext(ctx)
-	if len(nmd) != 1 {
+	if c == nil || !ok {
-		t.Fatal("Copy exclude not works")
+		t.Fatal("FromContext not works")
-	} else if nmd["Key1"] != "val1" {
+	}
-		t.Fatal("Copy exclude not works")
+}
+
+func TestNewContext(t *testing.T) {
+	ctx := NewContext(context.TODO(), New(0))
+
+	c, ok := FromContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewContext not works")
+	}
+}
+
+func TestFromIncomingContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), metadataIncomingKey{}, rawMetadata{md: New(0)})
+
+	c, ok := FromIncomingContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromIncomingContext not works")
+	}
+}
+
+func TestFromOutgoingContext(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), metadataOutgoingKey{}, rawMetadata{md: New(0)})
+
+	c, ok := FromOutgoingContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("FromOutgoingContext not works")
+	}
+}
+
+func TestNewIncomingContext(t *testing.T) {
+	md := New(1)
+	md.Set("key", "val")
+	ctx := NewIncomingContext(context.TODO(), md)
+
+	c, ok := FromIncomingContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewIncomingContext not works")
+	}
+}
+
+func TestNewOutgoingContext(t *testing.T) {
+	md := New(1)
+	md.Set("key", "val")
+	ctx := NewOutgoingContext(context.TODO(), md)
+
+	c, ok := FromOutgoingContext(ctx)
+	if c == nil || !ok {
+		t.Fatal("NewOutgoingContext not works")
+	}
+}
+
+func TestAppendOutgoingContext(t *testing.T) {
+	md := New(1)
+	md.Set("key1", "val1")
+	ctx := AppendOutgoingContext(context.TODO(), "key2", "val2")
+
+	nmd, ok := FromOutgoingContext(ctx)
+	if nmd == nil || !ok {
+		t.Fatal("AppendOutgoingContext not works")
+	}
+	if v := nmd.GetJoined("key2"); v != "val2" {
+		t.Fatal("AppendOutgoingContext not works")
 	}
 }

meter/meter.go

@@ -4,8 +4,8 @@ package meter
 import (
 	"io"
 	"sort"
-	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
@@ -49,9 +49,11 @@ type Meter interface {
 	Set(opts ...Option) Meter
 	// Histogram get or create histogram
 	Histogram(name string, labels ...string) Histogram
+	// HistogramExt get or create histogram with specified quantiles
+	HistogramExt(name string, quantiles []float64, labels ...string) Histogram
 	// Summary get or create summary
 	Summary(name string, labels ...string) Summary
-	// SummaryExt get or create summary with spcified quantiles and window time
+	// SummaryExt get or create summary with specified quantiles and window time
 	SummaryExt(name string, window time.Duration, quantiles []float64, labels ...string) Summary
 	// Write writes metrics to io.Writer
 	Write(w io.Writer, opts ...Option) error
@@ -59,6 +61,8 @@ type Meter interface {
 	Options() Options
 	// String return meter type
 	String() string
+	// Unregister metric name and drop all data
+	Unregister(name string, labels ...string) bool
 }
 
 // Counter is a counter
@@ -80,7 +84,11 @@ type FloatCounter interface {
 
 // Gauge is a float64 gauge
 type Gauge interface {
+	Add(float64)
 	Get() float64
+	Set(float64)
+	Dec()
+	Inc()
 }
 
 // Histogram is a histogram for non-negative values with automatically created buckets
@@ -117,6 +125,39 @@ func BuildLabels(labels ...string) []string {
 	return labels
 }
 
+var spool = newStringsPool(500)
+
+type stringsPool struct {
+	p *sync.Pool
+	c int
+}
+
+func newStringsPool(size int) *stringsPool {
+	p := &stringsPool{c: size}
+	p.p = &sync.Pool{
+		New: func() interface{} {
+			return &strings.Builder{}
+		},
+	}
+	return p
+}
+
+func (p *stringsPool) Cap() int {
+	return p.c
+}
+
+func (p *stringsPool) Get() *strings.Builder {
+	return p.p.Get().(*strings.Builder)
+}
+
+func (p *stringsPool) Put(b *strings.Builder) {
+	if b.Cap() > p.c {
+		return
+	}
+	b.Reset()
+	p.p.Put(b)
+}
+
 // BuildName used to combine metric with labels.
 // If labels count is odd, drop last element
 func BuildName(name string, labels ...string) string {
@@ -125,8 +166,6 @@ func BuildName(name string, labels ...string) string {
 	}
 
 	if len(labels) > 2 {
-		sort.Sort(byKey(labels))
-
 		idx := 0
 		for {
 			if labels[idx] == labels[idx+2] {
@@ -141,7 +180,9 @@ func BuildName(name string, labels ...string) string {
 		}
 	}
 
-	var b strings.Builder
+	b := spool.Get()
+	defer spool.Put(b)
+
 	_, _ = b.WriteString(name)
 	_, _ = b.WriteRune('{')
 	for idx := 0; idx < len(labels); idx += 2 {
@@ -149,8 +190,9 @@ func BuildName(name string, labels ...string) string {
 			_, _ = b.WriteRune(',')
 		}
 		_, _ = b.WriteString(labels[idx])
-		_, _ = b.WriteString(`=`)
+		_, _ = b.WriteString(`="`)
-		_, _ = b.WriteString(strconv.Quote(labels[idx+1]))
+		_, _ = b.WriteString(labels[idx+1])
+		_, _ = b.WriteRune('"')
 	}
 	_, _ = b.WriteRune('}')
 

meter/meter_test.go

@@ -50,11 +50,12 @@ func TestBuildName(t *testing.T) {
 	data := map[string][]string{
 		`my_metric{firstlabel="value2",zerolabel="value3"}`: {
 			"my_metric",
-			"zerolabel", "value3", "firstlabel", "value2",
+			"firstlabel", "value2",
+			"zerolabel", "value3",
 		},
 		`my_metric{broker="broker2",register="mdns",server="tcp"}`: {
 			"my_metric",
-			"broker", "broker1", "broker", "broker2", "server", "http", "server", "tcp", "register", "mdns",
+			"broker", "broker1", "broker", "broker2", "register", "mdns", "server", "http", "server", "tcp",
 		},
 		`my_metric{aaa="aaa"}`: {
 			"my_metric",

meter/noop.go

@@ -28,6 +28,10 @@ func (r *noopMeter) Name() string {
 	return r.opts.Name
 }
 
+func (r *noopMeter) Unregister(name string, labels ...string) bool {
+	return true
+}
+
 // Init initialize options
 func (r *noopMeter) Init(opts ...Option) error {
 	for _, o := range opts {
@@ -66,6 +70,11 @@ func (r *noopMeter) Histogram(_ string, labels ...string) Histogram {
 	return &noopHistogram{labels: labels}
 }
 
+// HistogramExt implements the Meter interface
+func (r *noopMeter) HistogramExt(_ string, quantiles []float64, labels ...string) Histogram {
+	return &noopHistogram{labels: labels}
+}
+
 // Set implements the Meter interface
 func (r *noopMeter) Set(opts ...Option) Meter {
 	m := &noopMeter{opts: r.opts}
@@ -132,6 +141,18 @@ type noopGauge struct {
 	labels []string
 }
 
+func (r *noopGauge) Add(float64) {
+}
+
+func (r *noopGauge) Set(float64) {
+}
+
+func (r *noopGauge) Inc() {
+}
+
+func (r *noopGauge) Dec() {
+}
+
 func (r *noopGauge) Get() float64 {
 	return 0
 }

meter/options.go

@@ -4,6 +4,8 @@ import (
 	"context"
 )
 
+var DefaultQuantiles = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10}
+
 // Option powers the configuration for metrics implementations:
 type Option func(*Options)
 
@@ -23,6 +25,8 @@ type Options struct {
 	WriteProcessMetrics bool
 	// WriteFDMetrics flag to write fd metrics
 	WriteFDMetrics bool
+	// Quantiles specifies buckets for histogram
+	Quantiles []float64
 }
 
 // NewOptions prepares a set of options:
@@ -61,14 +65,12 @@ func Address(value string) Option {
 	}
 }
 
-/*
+// Quantiles defines the desired spread of statistics for histogram metrics:
-// TimingObjectives defines the desired spread of statistics for histogram / timing metrics:
+func Quantiles(quantiles []float64) Option {
-func TimingObjectives(value map[float64]float64) Option {
 	return func(o *Options) {
-		o.TimingObjectives = value
+		o.Quantiles = quantiles
 	}
 }
-*/
 
 // Labels add the meter labels
 func Labels(ls ...string) Option {

micro.go

@@ -3,21 +3,21 @@ package micro
 import (
 	"reflect"
 
-	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v3/client"
+	"go.unistack.org/micro/v4/client"
-	"go.unistack.org/micro/v3/codec"
+	"go.unistack.org/micro/v4/codec"
-	"go.unistack.org/micro/v3/flow"
+	"go.unistack.org/micro/v4/flow"
-	"go.unistack.org/micro/v3/fsm"
+	"go.unistack.org/micro/v4/fsm"
-	"go.unistack.org/micro/v3/logger"
+	"go.unistack.org/micro/v4/logger"
-	"go.unistack.org/micro/v3/meter"
+	"go.unistack.org/micro/v4/meter"
-	"go.unistack.org/micro/v3/register"
+	"go.unistack.org/micro/v4/register"
-	"go.unistack.org/micro/v3/resolver"
+	"go.unistack.org/micro/v4/resolver"
-	"go.unistack.org/micro/v3/router"
+	"go.unistack.org/micro/v4/router"
-	"go.unistack.org/micro/v3/selector"
+	"go.unistack.org/micro/v4/selector"
-	"go.unistack.org/micro/v3/server"
+	"go.unistack.org/micro/v4/server"
-	"go.unistack.org/micro/v3/store"
+	"go.unistack.org/micro/v4/store"
-	"go.unistack.org/micro/v3/sync"
+	"go.unistack.org/micro/v4/sync"
-	"go.unistack.org/micro/v3/tracer"
+	"go.unistack.org/micro/v4/tracer"
 )
 
 func As(b any, target any) bool {

micro_test.go

@@ -6,8 +6,9 @@ import (
 	"reflect"
 	"testing"
 
-	"go.unistack.org/micro/v3/broker"
+	"go.unistack.org/micro/v4/broker"
-	"go.unistack.org/micro/v3/fsm"
+	"go.unistack.org/micro/v4/fsm"
+	"go.unistack.org/micro/v4/metadata"
 )
 
 func TestAs(t *testing.T) {
@@ -61,6 +62,8 @@ func TestAs(t *testing.T) {
 	}
 }
 
+var _ broker.Broker = (*bro)(nil)
+
 type bro struct {
 	name string
 }
@@ -87,23 +90,18 @@ func (p *bro) Connect(_ context.Context) error { return nil }
 // Disconnect disconnect from broker
 func (p *bro) Disconnect(_ context.Context) error { return nil }
 
-// Publish message, msg can be single broker.Message or []broker.Message
+// NewMessage creates new message
-func (p *bro) Publish(_ context.Context, _ string, _ *broker.Message, _ ...broker.PublishOption) error {
+func (p *bro) NewMessage(_ context.Context, _ metadata.Metadata, _ interface{}, _ ...broker.MessageOption) (broker.Message, error) {
-	return nil
-}
-
-// BatchPublish messages to broker with multiple topics
-func (p *bro) BatchPublish(_ context.Context, _ []*broker.Message, _ ...broker.PublishOption) error {
-	return nil
-}
-
-// BatchSubscribe subscribes to topic messages via handler
-func (p *bro) BatchSubscribe(_ context.Context, _ string, _ broker.BatchHandler, _ ...broker.SubscribeOption) (broker.Subscriber, error) {
 	return nil, nil
 }
 
+// Publish message, msg can be single broker.Message or []broker.Message
+func (p *bro) Publish(_ context.Context, _ string, _ ...broker.Message) error {
+	return nil
+}
+
 // Subscribe subscribes to topic message via handler
-func (p *bro) Subscribe(_ context.Context, _ string, _ broker.Handler, _ ...broker.SubscribeOption) (broker.Subscriber, error) {
+func (p *bro) Subscribe(_ context.Context, _ string, _ interface{}, _ ...broker.SubscribeOption) (broker.Subscriber, error) {
 	return nil, nil
 }
 

network/network.go

@@ -1,55 +0,0 @@
-// Package network is for creating internetworks
-package network
-
-import (
-	"go.unistack.org/micro/v3/client"
-	"go.unistack.org/micro/v3/server"
-)
-
-// Error is network node errors
-type Error interface {
-	// Count is current count of errors
-	Count() int
-	// Msg is last error message
-	Msg() string
-}
-
-// Status is node status
-type Status interface {
-	// Error reports error status
-	Error() Error
-}
-
-// Node is network node
-type Node interface {
-	// Id is node id
-	Id() string
-	// Address is node bind address
-	Address() string
-	// Peers returns node peers
-	Peers() []Node
-	// Network is the network node is in
-	Network() Network
-	// Status returns node status
-	Status() Status
-}
-
-// Network is micro network
-type Network interface {
-	// Node is network node
-	Node
-	// Initialise options
-	Init(...Option) error
-	// Options returns the network options
-	Options() Options
-	// Name of the network
-	Name() string
-	// Connect starts the resolver and tunnel server
-	Connect() error
-	// Close stops the tunnel and resolving
-	Close() error
-	// Client is micro client
-	Client() client.Client
-	// Server is micro server
-	Server() server.Server
-}

network/options.go

@@ -1,135 +0,0 @@
-package network
-
-import (
-	"go.unistack.org/micro/v3/logger"
-	"go.unistack.org/micro/v3/meter"
-	"go.unistack.org/micro/v3/network/tunnel"
-	"go.unistack.org/micro/v3/proxy"
-	"go.unistack.org/micro/v3/router"
-	"go.unistack.org/micro/v3/tracer"
-	"go.unistack.org/micro/v3/util/id"
-)
-
-// Option func
-type Option func(*Options)
-
-// Options configure network
-type Options struct {
-	// Router used for routing
-	Router router.Router
-	// Proxy holds the proxy
-	Proxy proxy.Proxy
-	// Logger used for logging
-	Logger logger.Logger
-	// Meter used for metrics
-	Meter meter.Meter
-	// Tracer used for tracing
-	Tracer tracer.Tracer
-	// Tunnel used for transfer data
-	Tunnel tunnel.Tunnel
-	// ID of the node
-	ID string
-	// Name of the network
-	Name string
-	// Address to bind to
-	Address string
-	// Advertise sets the address to advertise
-	Advertise string
-	// Nodes is a list of nodes to connect to
-	Nodes []string
-}
-
-// ID sets the id of the network node
-func ID(id string) Option {
-	return func(o *Options) {
-		o.ID = id
-	}
-}
-
-// Name sets the network name
-func Name(n string) Option {
-	return func(o *Options) {
-		o.Name = n
-	}
-}
-
-// Address sets the network address
-func Address(a string) Option {
-	return func(o *Options) {
-		o.Address = a
-	}
-}
-
-// Advertise sets the address to advertise
-func Advertise(a string) Option {
-	return func(o *Options) {
-		o.Advertise = a
-	}
-}
-
-// Nodes is a list of nodes to connect to
-func Nodes(n ...string) Option {
-	return func(o *Options) {
-		o.Nodes = n
-	}
-}
-
-// Tunnel sets the network tunnel
-func Tunnel(t tunnel.Tunnel) Option {
-	return func(o *Options) {
-		o.Tunnel = t
-	}
-}
-
-// Router sets the network router
-func Router(r router.Router) Option {
-	return func(o *Options) {
-		o.Router = r
-	}
-}
-
-// Proxy sets the network proxy
-func Proxy(p proxy.Proxy) Option {
-	return func(o *Options) {
-		o.Proxy = p
-	}
-}
-
-// Logger sets the network logger
-func Logger(l logger.Logger) Option {
-	return func(o *Options) {
-		o.Logger = l
-	}
-}
-
-// Meter sets the meter
-func Meter(m meter.Meter) Option {
-	return func(o *Options) {
-		o.Meter = m
-	}
-}
-
-// Tracer to be used for tracing
-func Tracer(t tracer.Tracer) Option {
-	return func(o *Options) {
-		o.Tracer = t
-	}
-}
-
-// NewOptions returns network default options
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		ID:      id.MustNew(),
-		Name:    "go.micro",
-		Address: ":0",
-		Logger:  logger.DefaultLogger,
-		Meter:   meter.DefaultMeter,
-		Tracer:  tracer.DefaultTracer,
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}

network/transport/context.go

@@ -1,34 +0,0 @@
-package transport
-
-import (
-	"context"
-)
-
-type transportKey struct{}
-
-// FromContext get transport from context
-func FromContext(ctx context.Context) (Transport, bool) {
-	if ctx == nil {
-		return nil, false
-	}
-	c, ok := ctx.Value(transportKey{}).(Transport)
-	return c, ok
-}
-
-// NewContext put transport in context
-func NewContext(ctx context.Context, c Transport) context.Context {
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	return context.WithValue(ctx, transportKey{}, c)
-}
-
-// SetOption returns a function to setup a context with given value
-func SetOption(k, v interface{}) Option {
-	return func(o *Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, k, v)
-	}
-}

network/transport/memory.go

@@ -1,258 +0,0 @@
-package transport
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"net"
-	"sync"
-	"time"
-
-	maddr "go.unistack.org/micro/v3/util/addr"
-	mnet "go.unistack.org/micro/v3/util/net"
-	"go.unistack.org/micro/v3/util/rand"
-)
-
-type memorySocket struct {
-	ctx     context.Context
-	recv    chan *Message
-	exit    chan bool
-	lexit   chan bool
-	send    chan *Message
-	local   string
-	remote  string
-	timeout time.Duration
-	sync.RWMutex
-}
-
-type memoryClient struct {
-	*memorySocket
-	opts DialOptions
-}
-
-type memoryListener struct {
-	lopts ListenOptions
-	ctx   context.Context
-	exit  chan bool
-	conn  chan *memorySocket
-	addr  string
-	topts Options
-	sync.RWMutex
-}
-
-type memoryTransport struct {
-	listeners map[string]*memoryListener
-	opts      Options
-	sync.RWMutex
-}
-
-func (ms *memorySocket) Recv(m *Message) error {
-	ms.RLock()
-	defer ms.RUnlock()
-
-	ctx := ms.ctx
-	if ms.timeout > 0 {
-		var cancel context.CancelFunc
-		ctx, cancel = context.WithTimeout(ms.ctx, ms.timeout)
-		defer cancel()
-	}
-
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	case <-ms.exit:
-		return errors.New("connection closed")
-	case <-ms.lexit:
-		return errors.New("server connection closed")
-	case cm := <-ms.recv:
-		*m = *cm
-	}
-	return nil
-}
-
-func (ms *memorySocket) Local() string {
-	return ms.local
-}
-
-func (ms *memorySocket) Remote() string {
-	return ms.remote
-}
-
-func (ms *memorySocket) Send(m *Message) error {
-	ms.RLock()
-	defer ms.RUnlock()
-
-	ctx := ms.ctx
-	if ms.timeout > 0 {
-		var cancel context.CancelFunc
-		ctx, cancel = context.WithTimeout(ms.ctx, ms.timeout)
-		defer cancel()
-	}
-
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	case <-ms.exit:
-		return errors.New("connection closed")
-	case <-ms.lexit:
-		return errors.New("server connection closed")
-	case ms.send <- m:
-	}
-	return nil
-}
-
-func (ms *memorySocket) Close() error {
-	ms.Lock()
-	defer ms.Unlock()
-	select {
-	case <-ms.exit:
-		return nil
-	default:
-		close(ms.exit)
-	}
-	return nil
-}
-
-func (m *memoryListener) Addr() string {
-	return m.addr
-}
-
-func (m *memoryListener) Close() error {
-	m.Lock()
-	defer m.Unlock()
-	select {
-	case <-m.exit:
-		return nil
-	default:
-		close(m.exit)
-	}
-	return nil
-}
-
-func (m *memoryListener) Accept(fn func(Socket)) error {
-	for {
-		select {
-		case <-m.exit:
-			return nil
-		case c := <-m.conn:
-			go fn(&memorySocket{
-				lexit:   c.lexit,
-				exit:    c.exit,
-				send:    c.recv,
-				recv:    c.send,
-				local:   c.Remote(),
-				remote:  c.Local(),
-				timeout: m.topts.Timeout,
-				ctx:     m.topts.Context,
-			})
-		}
-	}
-}
-
-func (m *memoryTransport) Dial(ctx context.Context, addr string, opts ...DialOption) (Client, error) {
-	m.RLock()
-	defer m.RUnlock()
-
-	listener, ok := m.listeners[addr]
-	if !ok {
-		return nil, errors.New("could not dial " + addr)
-	}
-
-	options := NewDialOptions(opts...)
-
-	client := &memoryClient{
-		&memorySocket{
-			send:    make(chan *Message),
-			recv:    make(chan *Message),
-			exit:    make(chan bool),
-			lexit:   listener.exit,
-			local:   addr,
-			remote:  addr,
-			timeout: m.opts.Timeout,
-			ctx:     m.opts.Context,
-		},
-		options,
-	}
-
-	// pseudo connect
-	select {
-	case <-listener.exit:
-		return nil, errors.New("connection error")
-	case listener.conn <- client.memorySocket:
-	}
-
-	return client, nil
-}
-
-func (m *memoryTransport) Listen(ctx context.Context, addr string, opts ...ListenOption) (Listener, error) {
-	m.Lock()
-	defer m.Unlock()
-
-	options := NewListenOptions(opts...)
-
-	host, port, err := net.SplitHostPort(addr)
-	if err != nil {
-		return nil, err
-	}
-
-	addr, err = maddr.Extract(host)
-	if err != nil {
-		return nil, err
-	}
-
-	// if zero port then randomly assign one
-	if len(port) > 0 && port == "0" {
-		var rng rand.Rand
-		i := rng.Intn(20000)
-		port = fmt.Sprintf("%d", 10000+i)
-	}
-
-	// set addr with port
-	addr = mnet.HostPort(addr, port)
-
-	if _, ok := m.listeners[addr]; ok {
-		return nil, errors.New("already listening on " + addr)
-	}
-
-	listener := &memoryListener{
-		lopts: options,
-		topts: m.opts,
-		addr:  addr,
-		conn:  make(chan *memorySocket),
-		exit:  make(chan bool),
-		ctx:   m.opts.Context,
-	}
-
-	m.listeners[addr] = listener
-
-	return listener, nil
-}
-
-func (m *memoryTransport) Init(opts ...Option) error {
-	for _, o := range opts {
-		o(&m.opts)
-	}
-	return nil
-}
-
-func (m *memoryTransport) Options() Options {
-	return m.opts
-}
-
-func (m *memoryTransport) String() string {
-	return "memory"
-}
-
-func (m *memoryTransport) Name() string {
-	return m.opts.Name
-}
-
-// NewTransport returns new memory transport with options
-func NewTransport(opts ...Option) Transport {
-	options := NewOptions(opts...)
-
-	return &memoryTransport{
-		opts:      options,
-		listeners: make(map[string]*memoryListener),
-	}
-}

network/transport/memory_test.go

@@ -1,100 +0,0 @@
-package transport
-
-import (
-	"context"
-	"os"
-	"testing"
-)
-
-func TestMemoryTransport(t *testing.T) {
-	tr := NewTransport()
-	ctx := context.Background()
-	// bind / listen
-	l, err := tr.Listen(ctx, "127.0.0.1:8080")
-	if err != nil {
-		t.Fatalf("Unexpected error listening %v", err)
-	}
-	defer l.Close()
-
-	cherr := make(chan error, 1)
-	// accept
-	go func() {
-		if nerr := l.Accept(func(sock Socket) {
-			for {
-				var m Message
-				if rerr := sock.Recv(&m); rerr != nil {
-					cherr <- rerr
-					return
-				}
-				if len(os.Getenv("INTEGRATION_TESTS")) == 0 {
-					t.Logf("Server Received %s", string(m.Body))
-				}
-				if cerr := sock.Send(&Message{
-					Body: []byte(`pong`),
-				}); cerr != nil {
-					cherr <- cerr
-					return
-				}
-			}
-		}); nerr != nil {
-			cherr <- err
-		}
-	}()
-
-	// dial
-	c, err := tr.Dial(ctx, "127.0.0.1:8080")
-	if err != nil {
-		t.Fatalf("Unexpected error dialing %v", err)
-	}
-	defer c.Close()
-
-	select {
-	case err := <-cherr:
-		t.Fatal(err)
-	default:
-		// send <=> receive
-		for i := 0; i < 3; i++ {
-			if err := c.Send(&Message{
-				Body: []byte(`ping`),
-			}); err != nil {
-				return
-			}
-			var m Message
-			if err := c.Recv(&m); err != nil {
-				return
-			}
-			if len(os.Getenv("INTEGRATION_TESTS")) == 0 {
-				t.Logf("Client Received %s", string(m.Body))
-			}
-		}
-	}
-}
-
-func TestListener(t *testing.T) {
-	tr := NewTransport()
-	ctx := context.Background()
-	// bind / listen on random port
-	l, err := tr.Listen(ctx, ":0")
-	if err != nil {
-		t.Fatalf("Unexpected error listening %v", err)
-	}
-	defer l.Close()
-
-	// try again
-	l2, err := tr.Listen(ctx, ":0")
-	if err != nil {
-		t.Fatalf("Unexpected error listening %v", err)
-	}
-	defer l2.Close()
-
-	// now make sure it still fails
-	l3, err := tr.Listen(ctx, ":8080")
-	if err != nil {
-		t.Fatalf("Unexpected error listening %v", err)
-	}
-	defer l3.Close()
-
-	if _, err := tr.Listen(ctx, ":8080"); err == nil {
-		t.Fatal("Expected error binding to :8080 got nil")
-	}
-}

network/transport/options.go

@@ -1,175 +0,0 @@
-package transport
-
-import (
-	"context"
-	"crypto/tls"
-	"time"
-
-	"go.unistack.org/micro/v3/codec"
-	"go.unistack.org/micro/v3/logger"
-	"go.unistack.org/micro/v3/meter"
-	"go.unistack.org/micro/v3/tracer"
-)
-
-// Options struct holds the transport options
-type Options struct {
-	// Meter used for metrics
-	Meter meter.Meter
-	// Tracer used for tracing
-	Tracer tracer.Tracer
-	// Codec used for marshal/unmarshal messages
-	Codec codec.Codec
-	// Logger used for logging
-	Logger logger.Logger
-	// Context holds external options
-	Context context.Context
-	// TLSConfig holds tls.TLSConfig options
-	TLSConfig *tls.Config
-	// Name holds the transport name
-	Name string
-	// Addrs holds the transport addrs
-	Addrs []string
-	// Timeout holds the timeout
-	Timeout time.Duration
-}
-
-// NewOptions returns new options
-func NewOptions(opts ...Option) Options {
-	options := Options{
-		Logger:  logger.DefaultLogger,
-		Meter:   meter.DefaultMeter,
-		Tracer:  tracer.DefaultTracer,
-		Context: context.Background(),
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
-
-// DialOptions struct
-type DialOptions struct {
-	// Context holds the external options
-	Context context.Context
-	// Timeout holds the timeout
-	Timeout time.Duration
-	// Stream flag
-	Stream bool
-}
-
-// NewDialOptions returns new DialOptions
-func NewDialOptions(opts ...DialOption) DialOptions {
-	options := DialOptions{
-		Timeout: DefaultDialTimeout,
-		Context: context.Background(),
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
-
-// ListenOptions struct
-type ListenOptions struct {
-	// TODO: add tls options when listening
-	// Currently set in global options
-	// Context holds the external options
-	Context context.Context
-	// TLSConfig holds the *tls.Config options
-	TLSConfig *tls.Config
-}
-
-// NewListenOptions returns new ListenOptions
-func NewListenOptions(opts ...ListenOption) ListenOptions {
-	options := ListenOptions{
-		Context: context.Background(),
-	}
-
-	for _, o := range opts {
-		o(&options)
-	}
-
-	return options
-}
-
-// Addrs to use for transport
-func Addrs(addrs ...string) Option {
-	return func(o *Options) {
-		o.Addrs = addrs
-	}
-}
-
-// Logger sets the logger
-func Logger(l logger.Logger) Option {
-	return func(o *Options) {
-		o.Logger = l
-	}
-}
-
-// Meter sets the meter
-func Meter(m meter.Meter) Option {
-	return func(o *Options) {
-		o.Meter = m
-	}
-}
-
-// Context sets the context
-func Context(ctx context.Context) Option {
-	return func(o *Options) {
-		o.Context = ctx
-	}
-}
-
-// Codec sets the codec used for encoding where the transport
-// does not support message headers
-func Codec(c codec.Codec) Option {
-	return func(o *Options) {
-		o.Codec = c
-	}
-}
-
-// Timeout sets the timeout for Send/Recv execution
-func Timeout(t time.Duration) Option {
-	return func(o *Options) {
-		o.Timeout = t
-	}
-}
-
-// TLSConfig to be used for the transport.
-func TLSConfig(t *tls.Config) Option {
-	return func(o *Options) {
-		o.TLSConfig = t
-	}
-}
-
-// WithStream indicates whether this is a streaming connection
-func WithStream() DialOption {
-	return func(o *DialOptions) {
-		o.Stream = true
-	}
-}
-
-// WithTimeout used when dialling the remote side
-func WithTimeout(d time.Duration) DialOption {
-	return func(o *DialOptions) {
-		o.Timeout = d
-	}
-}
-
-// Tracer to be used for tracing
-func Tracer(t tracer.Tracer) Option {
-	return func(o *Options) {
-		o.Tracer = t
-	}
-}
-
-// Name sets the name
-func Name(n string) Option {
-	return func(o *Options) {
-		o.Name = n
-	}
-}