replace default go resolver with caching resolver

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

broker/broker.go

@@ -46,6 +46,12 @@ type Broker interface {
 	BatchSubscribe(ctx context.Context, topic string, h BatchHandler, opts ...SubscribeOption) (Subscriber, error)
 	// String type of broker
 	String() string
+	// Live returns broker liveness
+	Live() bool
+	// Ready returns broker readiness
+	Ready() bool
+	// Health returns broker health
+	Health() bool
 }
 
 type (

broker/memory/memory.go

@@ -339,6 +339,18 @@ func (m *memoryBroker) Name() string {
 	return m.opts.Name
 }
 
+func (m *memoryBroker) Live() bool {
+	return true
+}
+
+func (m *memoryBroker) Ready() bool {
+	return true
+}
+
+func (m *memoryBroker) Health() bool {
+	return true
+}
+
 func (m *memoryEvent) Topic() string {
 	return m.topic
 }

broker/noop.go

@@ -25,6 +25,18 @@ func NewBroker(opts ...Option) *NoopBroker {
 	return b
 }
 
+func (b *NoopBroker) Health() bool {
+	return true
+}
+
+func (b *NoopBroker) Live() bool {
+	return true
+}
+
+func (b *NoopBroker) Ready() bool {
+	return true
+}
+
 func (b *NoopBroker) Name() string {
 	return b.opts.Name
 }

client/options.go

@@ -11,7 +11,6 @@ import (
 	"go.unistack.org/micro/v3/logger"
 	"go.unistack.org/micro/v3/metadata"
 	"go.unistack.org/micro/v3/meter"
-	"go.unistack.org/micro/v3/network/transport"
 	"go.unistack.org/micro/v3/options"
 	"go.unistack.org/micro/v3/register"
 	"go.unistack.org/micro/v3/router"
@@ -22,8 +21,6 @@ import (
 
 // Options holds client options
 type Options struct {
-	// Transport used for transfer messages
-	Transport transport.Transport
 	// Selector used to select needed address
 	Selector selector.Selector
 	// Logger used to log messages
@@ -194,18 +191,16 @@ func NewOptions(opts ...Option) Options {
 			Retry:          DefaultRetry,
 			Retries:        DefaultRetries,
 			RequestTimeout: DefaultRequestTimeout,
-			DialTimeout:    transport.DefaultDialTimeout,
 		},
-		Lookup:    LookupRoute,
-		PoolSize:  DefaultPoolSize,
-		PoolTTL:   DefaultPoolTTL,
-		Selector:  random.NewSelector(),
-		Logger:    logger.DefaultLogger,
-		Broker:    broker.DefaultBroker,
-		Meter:     meter.DefaultMeter,
-		Tracer:    tracer.DefaultTracer,
-		Router:    router.DefaultRouter,
-		Transport: transport.DefaultTransport,
+		Lookup:   LookupRoute,
+		PoolSize: DefaultPoolSize,
+		PoolTTL:  DefaultPoolTTL,
+		Selector: random.NewSelector(),
+		Logger:   logger.DefaultLogger,
+		Broker:   broker.DefaultBroker,
+		Meter:    meter.DefaultMeter,
+		Tracer:   tracer.DefaultTracer,
+		Router:   router.DefaultRouter,
 	}
 
 	for _, o := range opts {
@@ -278,13 +273,6 @@ func PoolTTL(d time.Duration) Option {
 	}
 }
 
-// Transport to use for communication e.g http, rabbitmq, etc
-func Transport(t transport.Transport) Option {
-	return func(o *Options) {
-		o.Transport = t
-	}
-}
-
 // Register sets the routers register
 func Register(r register.Register) Option {
 	return func(o *Options) {
@@ -334,14 +322,6 @@ func TLSConfig(t *tls.Config) Option {
 	return func(o *Options) {
 		// set the internal tls
 		o.TLSConfig = t
-
-		// set the default transport if one is not
-		// already set. Required for Init call below.
-
-		// set the transport tls
-		_ = o.Transport.Init(
-			transport.TLSConfig(t),
-		)
 	}
 }
 
@@ -507,13 +487,6 @@ func WithAuthToken(t string) CallOption {
 	}
 }
 
-// WithNetwork is a CallOption which sets the network attribute
-func WithNetwork(n string) CallOption {
-	return func(o *CallOptions) {
-		o.Network = n
-	}
-}
-
 // WithRouter sets the router to use for this call
 func WithRouter(r router.Router) CallOption {
 	return func(o *CallOptions) {

cluster/cluster.go

@@ -38,4 +38,10 @@ type Cluster interface {
 	Broadcast(ctx context.Context, msg Message, filter ...string) error
 	// Unicast send message to single member in cluster
 	Unicast(ctx context.Context, node Node, msg Message) error
+	// Live returns cluster liveness
+	Live() bool
+	// Ready returns cluster readiness
+	Ready() bool
+	// Health returns cluster health
+	Health() bool
 }

config/config.go

@@ -4,7 +4,6 @@ package config
 import (
 	"context"
 	"errors"
-	"fmt"
 	"reflect"
 	"time"
 )
@@ -139,7 +138,7 @@ var (
 				return nil
 			}
 			if err := fn(ctx, c); err != nil {
-				c.Options().Logger.Error(ctx, fmt.Sprintf("%s BeforeLoad error", c.String()), err)
+				c.Options().Logger.Error(ctx, c.String()+" BeforeLoad error", err)
 				if !c.Options().AllowFail {
 					return err
 				}
@@ -154,7 +153,7 @@ var (
 				return nil
 			}
 			if err := fn(ctx, c); err != nil {
-				c.Options().Logger.Error(ctx, fmt.Sprintf("%s AfterLoad error", c.String()), err)
+				c.Options().Logger.Error(ctx, c.String()+" AfterLoad error", err)
 				if !c.Options().AllowFail {
 					return err
 				}
@@ -169,7 +168,7 @@ var (
 				return nil
 			}
 			if err := fn(ctx, c); err != nil {
-				c.Options().Logger.Error(ctx, fmt.Sprintf("%s BeforeSave error", c.String()), err)
+				c.Options().Logger.Error(ctx, c.String()+" BeforeSave error", err)
 				if !c.Options().AllowFail {
 					return err
 				}
@@ -184,7 +183,7 @@ var (
 				return nil
 			}
 			if err := fn(ctx, c); err != nil {
-				c.Options().Logger.Error(ctx, fmt.Sprintf("%s AfterSave error", c.String()), err)
+				c.Options().Logger.Error(ctx, c.String()+" AfterSave error", err)
 				if !c.Options().AllowFail {
 					return err
 				}
@@ -199,7 +198,7 @@ var (
 				return nil
 			}
 			if err := fn(ctx, c); err != nil {
-				c.Options().Logger.Error(ctx, fmt.Sprintf("%s BeforeInit error", c.String()), err)
+				c.Options().Logger.Error(ctx, c.String()+" BeforeInit error", err)
 				if !c.Options().AllowFail {
 					return err
 				}
@@ -214,7 +213,7 @@ var (
 				return nil
 			}
 			if err := fn(ctx, c); err != nil {
-				c.Options().Logger.Error(ctx, fmt.Sprintf("%s AfterInit error", c.String(), err), err)
+				c.Options().Logger.Error(ctx, c.String()+" AfterInit error", err)
 				if !c.Options().AllowFail {
 					return err
 				}

logger/options.go

@@ -80,6 +80,13 @@ func WithContextAttrFuncs(fncs ...ContextAttrFunc) Option {
 	}
 }
 
+// WithAddFields add fields for the logger
+func WithAddFields(fields ...interface{}) Option {
+	return func(o *Options) {
+		o.Fields = append(o.Fields, fields...)
+	}
+}
+
 // WithFields set default fields for the logger
 func WithFields(fields ...interface{}) Option {
 	return func(o *Options) {

logger/slog/slog.go

@@ -8,6 +8,7 @@ import (
 	"runtime"
 	"strconv"
 	"sync"
+	"sync/atomic"
 
 	"go.unistack.org/micro/v3/logger"
 	"go.unistack.org/micro/v3/semconv"
@@ -33,12 +34,11 @@ var (
 
 type wrapper struct {
 	h     slog.Handler
-	level logger.Level
+	level atomic.Int64
 }
 
 func (h *wrapper) Enabled(ctx context.Context, level slog.Level) bool {
-	lvl := slogToLoggerLevel(level)
-	return h.level.Enabled(lvl)
+	return level >= slog.Level(int(h.level.Load()))
 }
 
 func (h *wrapper) Handle(ctx context.Context, rec slog.Record) error {
@@ -110,20 +110,25 @@ func (s *slogLogger) Clone(opts ...logger.Option) logger.Logger {
 
 	attrs, _ := s.argsAttrs(options.Fields)
 	l := &slogLogger{
-		handler: &wrapper{level: options.Level, h: s.handler.h.WithAttrs(attrs)},
+		handler: &wrapper{h: s.handler.h.WithAttrs(attrs)},
 		opts:    options,
 	}
+	l.handler.level.Store(int64(loggerToSlogLevel(options.Level)))
 
 	return l
 }
 
 func (s *slogLogger) V(level logger.Level) bool {
-	return s.opts.Level.Enabled(level)
+	s.mu.Lock()
+	v := s.opts.Level.Enabled(level)
+	s.mu.Unlock()
+	return v
 }
 
 func (s *slogLogger) Level(level logger.Level) {
 	s.mu.Lock()
 	s.opts.Level = level
+	s.handler.level.Store(int64(loggerToSlogLevel(level)))
 	s.mu.Unlock()
 }
 
@@ -143,7 +148,8 @@ func (s *slogLogger) Fields(fields ...interface{}) logger.Logger {
 	}
 
 	attrs, _ := s.argsAttrs(fields)
-	l.handler = &wrapper{level: s.opts.Level, h: s.handler.h.WithAttrs(attrs)}
+	l.handler = &wrapper{h: s.handler.h.WithAttrs(attrs)}
+	l.handler.level.Store(int64(loggerToSlogLevel(l.opts.Level)))
 
 	return l
 }
@@ -166,7 +172,8 @@ func (s *slogLogger) Init(opts ...logger.Option) error {
 	}
 
 	attrs, _ := s.argsAttrs(s.opts.Fields)
-	s.handler = &wrapper{level: s.opts.Level, h: slog.NewJSONHandler(s.opts.Out, handleOpt).WithAttrs(attrs)}
+	s.handler = &wrapper{h: slog.NewJSONHandler(s.opts.Out, handleOpt).WithAttrs(attrs)}
+	s.handler.level.Store(int64(loggerToSlogLevel(s.opts.Level)))
 	s.mu.Unlock()
 
 	return nil

logger/slog/slog_test.go

@@ -15,6 +15,34 @@ import (
 	"go.unistack.org/micro/v3/logger"
 )
 
+func TestWithAddFields(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(logger.WithLevel(logger.InfoLevel), logger.WithOutput(buf))
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+
+	l.Info(ctx, "msg1")
+
+	if err := l.Init(logger.WithAddFields("key1", "val1")); err != nil {
+		t.Fatal(err)
+	}
+	l.Info(ctx, "msg2")
+
+	if err := l.Init(logger.WithAddFields("key2", "val2")); err != nil {
+		t.Fatal(err)
+	}
+	l.Info(ctx, "msg3")
+
+	if !bytes.Contains(buf.Bytes(), []byte(`"key1"`)) {
+		t.Fatalf("logger error not works, buf contains: %s", buf.Bytes())
+	}
+	if !bytes.Contains(buf.Bytes(), []byte(`"key2"`)) {
+		t.Fatalf("logger error not works, buf contains: %s", buf.Bytes())
+	}
+}
+
 func TestMultipleFieldsWithLevel(t *testing.T) {
 	ctx := context.TODO()
 	buf := bytes.NewBuffer(nil)

metadata/metadata_test.go

@@ -5,6 +5,28 @@ import (
 	"testing"
 )
 
+func TestMultipleUsage(t *testing.T) {
+	ctx := context.TODO()
+	md := New(0)
+	md.Set("key1_1", "val1_1", "key1_2", "val1_2", "key1_3", "val1_3")
+	ctx = NewIncomingContext(ctx, Copy(md))
+	ctx = NewOutgoingContext(ctx, Copy(md))
+	imd, _ := FromIncomingContext(ctx)
+	omd, _ := FromOutgoingContext(ctx)
+	_ = func(x context.Context) context.Context {
+		m, _ := FromIncomingContext(x)
+		m.Del("key1_2")
+		return ctx
+	}(ctx)
+	_ = func(x context.Context) context.Context {
+		m, _ := FromIncomingContext(x)
+		m.Del("key1_3")
+		return ctx
+	}(ctx)
+	t.Logf("imd %#+v", imd)
+	t.Logf("omd %#+v", omd)
+}
+
 func TestMetadataSetMultiple(t *testing.T) {
 	md := New(4)
 	md.Set("key1", "val1", "key2", "val2", "key3")

micro_test.go

@@ -66,6 +66,12 @@ type bro struct {
 
 func (p *bro) Name() string { return p.name }
 
+func (p *bro) Live() bool { return true }
+
+func (p *bro) Ready() bool { return true }
+
+func (p *bro) Health() bool { return true }
+
 func (p *bro) Init(opts ...broker.Option) error { return nil }
 
 // Options returns broker options

network/tunnel/broker/broker.go

@@ -45,6 +45,18 @@ type (
 	tunnelAddr struct{}
 )
 
+func (t *tunBroker) Live() bool {
+	return true
+}
+
+func (t *tunBroker) Ready() bool {
+	return true
+}
+
+func (t *tunBroker) Health() bool {
+	return true
+}
+
 func (t *tunBroker) Init(opts ...broker.Option) error {
 	for _, o := range opts {
 		o(&t.opts)

register/register.go

@@ -29,17 +29,32 @@ var (
 // and an abstraction over varying implementations
 // {consul, etcd, zookeeper, ...}
 type Register interface {
+	// Name returns register name
 	Name() string
+	// Init initialize register
 	Init(...Option) error
+	// Options returns options for register
 	Options() Options
+	// Connect initialize connect to register
 	Connect(context.Context) error
+	// Disconnect initialize discconection from register
 	Disconnect(context.Context) error
+	// Register service in registry
 	Register(context.Context, *Service, ...RegisterOption) error
+	// Deregister service from registry
 	Deregister(context.Context, *Service, ...DeregisterOption) error
+	// LookupService in registry
 	LookupService(context.Context, string, ...LookupOption) ([]*Service, error)
+	// ListServices in registry
 	ListServices(context.Context, ...ListOption) ([]*Service, error)
+	// Watch registry events
 	Watch(context.Context, ...WatchOption) (Watcher, error)
+	// String returns registry string representation
 	String() string
+	// Live returns register liveness
+	// Live() bool
+	// Ready returns register readiness
+	// Ready() bool
 }
 
 // Service holds service register info

resolver/dns/dns.go

@@ -12,9 +12,9 @@ import (
 
 // Resolver is a DNS network resolve
 type Resolver struct {
-	sync.RWMutex
 	goresolver *net.Resolver
 	Address    string
+	mu         sync.RWMutex
 }
 
 // Resolve tries to resolve endpoint address
@@ -39,12 +39,12 @@ func (r *Resolver) Resolve(name string) ([]*resolver.Record, error) {
 		return []*resolver.Record{rec}, nil
 	}
 
-	r.RLock()
+	r.mu.RLock()
 	goresolver := r.goresolver
-	r.RUnlock()
+	r.mu.RUnlock()
 
 	if goresolver == nil {
-		r.Lock()
+		r.mu.Lock()
 		r.goresolver = &net.Resolver{
 			Dial: func(ctx context.Context, _ string, _ string) (net.Conn, error) {
 				d := net.Dialer{
@@ -53,7 +53,7 @@ func (r *Resolver) Resolve(name string) ([]*resolver.Record, error) {
 				return d.DialContext(ctx, "udp", r.Address)
 			},
 		}
-		r.Unlock()
+		r.mu.Unlock()
 	}
 
 	addrs, err := goresolver.LookupIP(context.TODO(), "ip", host)

server/noop.go

@@ -121,6 +121,18 @@ func (n *noopServer) newCodec(contentType string) (codec.Codec, error) {
 	return nil, codec.ErrUnknownContentType
 }
 
+func (n *noopServer) Live() bool {
+	return true
+}
+
+func (n *noopServer) Ready() bool {
+	return true
+}
+
+func (n *noopServer) Health() bool {
+	return true
+}
+
 func (n *noopServer) Handle(handler Handler) error {
 	n.h = handler
 	return nil

server/options.go

@@ -12,7 +12,6 @@ import (
 	"go.unistack.org/micro/v3/logger"
 	"go.unistack.org/micro/v3/metadata"
 	"go.unistack.org/micro/v3/meter"
-	"go.unistack.org/micro/v3/network/transport"
 	"go.unistack.org/micro/v3/options"
 	"go.unistack.org/micro/v3/register"
 	msync "go.unistack.org/micro/v3/sync"
@@ -37,8 +36,6 @@ type Options struct {
 	Logger logger.Logger
 	// Meter holds the meter
 	Meter meter.Meter
-	// Transport holds the transport
-	Transport transport.Transport
 
 	/*
 		// Router for requests
@@ -100,7 +97,6 @@ func NewOptions(opts ...Option) Options {
 		Tracer:           tracer.DefaultTracer,
 		Broker:           broker.DefaultBroker,
 		Register:         register.DefaultRegister,
-		Transport:        transport.DefaultTransport,
 		Address:          DefaultAddress,
 		Name:             DefaultName,
 		Version:          DefaultVersion,
@@ -209,13 +205,6 @@ func Tracer(t tracer.Tracer) Option {
 	}
 }
 
-// Transport mechanism for communication e.g http, rabbitmq, etc
-func Transport(t transport.Transport) Option {
-	return func(o *Options) {
-		o.Transport = t
-	}
-}
-
 // Metadata associated with the server
 func Metadata(md metadata.Metadata) Option {
 	return func(o *Options) {
@@ -249,14 +238,6 @@ func TLSConfig(t *tls.Config) Option {
 	return func(o *Options) {
 		// set the internal tls
 		o.TLSConfig = t
-
-		// set the default transport if one is not
-		// already set. Required for Init call below.
-
-		// set the transport tls
-		_ = o.Transport.Init(
-			transport.TLSConfig(t),
-		)
 	}
 }
 

server/server.go

@@ -62,6 +62,12 @@ type Server interface {
 	Stop() error
 	// Server implementation
 	String() string
+	// Live returns server liveness
+	Live() bool
+	// Ready returns server readiness
+	Ready() bool
+	// Health returns server health
+	Health() bool
 }
 
 type (

service.go

@@ -1,9 +1,11 @@
 // Package micro is a pluggable framework for microservices
-package micro // import "go.unistack.org/micro/v3"
+package micro
 
 import (
 	"fmt"
+	"net"
 	"sync"
+	"time"
 
 	"github.com/KimMachineGun/automemlimit/memlimit"
 	"go.uber.org/automaxprocs/maxprocs"
@@ -17,6 +19,7 @@ import (
 	"go.unistack.org/micro/v3/server"
 	"go.unistack.org/micro/v3/store"
 	"go.unistack.org/micro/v3/tracer"
+	utildns "go.unistack.org/micro/v3/util/dns"
 )
 
 func init() {
@@ -30,6 +33,8 @@ func init() {
 			),
 		),
 	)
+
+	net.DefaultResolver = utildns.NewNetResolver(utildns.Timeout(1 * time.Second))
 }
 
 // Service is an interface that wraps the lower level components.
@@ -72,8 +77,14 @@ type Service interface {
 	Start() error
 	// Stop the service
 	Stop() error
-	// The service implementation
+	// String service representation
 	String() string
+	// Live returns service liveness
+	Live() bool
+	// Ready returns service readiness
+	Ready() bool
+	// Health returns service health
+	Health() bool
 }
 
 // RegisterHandler is syntactic sugar for registering a handler
@@ -101,9 +112,7 @@ func (s *service) Name() string {
 	return s.opts.Name
 }
 
-// Init initialises options. Additionally it calls cmd.Init
-// which parses command line flags. cmd.Init is only called
-// on first Init.
+// Init initialises options.
 //
 //nolint:gocyclo
 func (s *service) Init(opts ...Option) error {
@@ -252,6 +261,63 @@ func (s *service) String() string {
 	return s.opts.Name
 }
 
+func (s *service) Live() bool {
+	for _, v := range s.opts.Brokers {
+		if !v.Live() {
+			return false
+		}
+	}
+	for _, v := range s.opts.Servers {
+		if !v.Live() {
+			return false
+		}
+	}
+	for _, v := range s.opts.Stores {
+		if !v.Live() {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *service) Ready() bool {
+	for _, v := range s.opts.Brokers {
+		if !v.Ready() {
+			return false
+		}
+	}
+	for _, v := range s.opts.Servers {
+		if !v.Ready() {
+			return false
+		}
+	}
+	for _, v := range s.opts.Stores {
+		if !v.Ready() {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *service) Health() bool {
+	for _, v := range s.opts.Brokers {
+		if !v.Health() {
+			return false
+		}
+	}
+	for _, v := range s.opts.Servers {
+		if !v.Health() {
+			return false
+		}
+	}
+	for _, v := range s.opts.Stores {
+		if !v.Health() {
+			return false
+		}
+	}
+	return true
+}
+
 //nolint:gocyclo
 func (s *service) Start() error {
 	var err error
@@ -281,10 +347,6 @@ func (s *service) Start() error {
 		config.Loggers[0].Info(s.opts.Context, fmt.Sprintf("starting [service] %s version %s", s.Options().Name, s.Options().Version))
 	}
 
-	if len(s.opts.Servers) == 0 {
-		return fmt.Errorf("cant start nil server")
-	}
-
 	for _, reg := range s.opts.Registers {
 		if err = reg.Connect(s.opts.Context); err != nil {
 			return err

store/memory/memory.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"sort"
 	"strings"
+	"sync/atomic"
 	"time"
 
 	cache "github.com/patrickmn/go-cache"
@@ -20,7 +21,10 @@ func NewStore(opts ...store.Option) store.Store {
 }
 
 func (m *memoryStore) Connect(ctx context.Context) error {
-	return nil
+	if m.opts.LazyConnect {
+		return nil
+	}
+	return m.connect(ctx)
 }
 
 func (m *memoryStore) Disconnect(ctx context.Context) error {
@@ -29,13 +33,14 @@ func (m *memoryStore) Disconnect(ctx context.Context) error {
 }
 
 type memoryStore struct {
-	funcRead   store.FuncRead
-	funcWrite  store.FuncWrite
-	funcExists store.FuncExists
-	funcList   store.FuncList
-	funcDelete store.FuncDelete
-	store      *cache.Cache
-	opts       store.Options
+	funcRead    store.FuncRead
+	funcWrite   store.FuncWrite
+	funcExists  store.FuncExists
+	funcList    store.FuncList
+	funcDelete  store.FuncDelete
+	store       *cache.Cache
+	opts        store.Options
+	isConnected atomic.Int32
 }
 
 func (m *memoryStore) key(prefix, key string) string {
@@ -144,7 +149,24 @@ func (m *memoryStore) Name() string {
 	return m.opts.Name
 }
 
+func (m *memoryStore) Live() bool {
+	return true
+}
+
+func (m *memoryStore) Ready() bool {
+	return true
+}
+
+func (m *memoryStore) Health() bool {
+	return true
+}
+
 func (m *memoryStore) Exists(ctx context.Context, key string, opts ...store.ExistsOption) error {
+	if m.opts.LazyConnect {
+		if err := m.connect(ctx); err != nil {
+			return err
+		}
+	}
 	return m.funcExists(ctx, key, opts...)
 }
 
@@ -157,6 +179,11 @@ func (m *memoryStore) fnExists(ctx context.Context, key string, opts ...store.Ex
 }
 
 func (m *memoryStore) Read(ctx context.Context, key string, val interface{}, opts ...store.ReadOption) error {
+	if m.opts.LazyConnect {
+		if err := m.connect(ctx); err != nil {
+			return err
+		}
+	}
 	return m.funcRead(ctx, key, val, opts...)
 }
 
@@ -169,6 +196,11 @@ func (m *memoryStore) fnRead(ctx context.Context, key string, val interface{}, o
 }
 
 func (m *memoryStore) Write(ctx context.Context, key string, val interface{}, opts ...store.WriteOption) error {
+	if m.opts.LazyConnect {
+		if err := m.connect(ctx); err != nil {
+			return err
+		}
+	}
 	return m.funcWrite(ctx, key, val, opts...)
 }
 
@@ -193,6 +225,11 @@ func (m *memoryStore) fnWrite(ctx context.Context, key string, val interface{},
 }
 
 func (m *memoryStore) Delete(ctx context.Context, key string, opts ...store.DeleteOption) error {
+	if m.opts.LazyConnect {
+		if err := m.connect(ctx); err != nil {
+			return err
+		}
+	}
 	return m.funcDelete(ctx, key, opts...)
 }
 
@@ -211,6 +248,11 @@ func (m *memoryStore) Options() store.Options {
 }
 
 func (m *memoryStore) List(ctx context.Context, opts ...store.ListOption) ([]string, error) {
+	if m.opts.LazyConnect {
+		if err := m.connect(ctx); err != nil {
+			return nil, err
+		}
+	}
 	return m.funcList(ctx, opts...)
 }
 
@@ -244,3 +286,21 @@ func (m *memoryStore) fnList(ctx context.Context, opts ...store.ListOption) ([]s
 
 	return keys, nil
 }
+
+func (m *memoryStore) connect(ctx context.Context) error {
+	m.isConnected.CompareAndSwap(0, 1)
+	return nil
+}
+
+func (m *memoryStore) Watch(ctx context.Context, opts ...store.WatchOption) (store.Watcher, error) {
+	return &watcher{}, nil
+}
+
+type watcher struct{}
+
+func (w *watcher) Next() (store.Event, error) {
+	return nil, nil
+}
+
+func (w *watcher) Stop() {
+}

store/noop.go

@@ -2,19 +2,37 @@ package store
 
 import (
 	"context"
+	"sync"
+	"sync/atomic"
 
 	"go.unistack.org/micro/v3/options"
+	"go.unistack.org/micro/v3/util/id"
 )
 
 var _ Store = (*noopStore)(nil)
 
 type noopStore struct {
-	funcRead   FuncRead
-	funcWrite  FuncWrite
-	funcExists FuncExists
-	funcList   FuncList
-	funcDelete FuncDelete
-	opts       Options
+	mu          sync.Mutex
+	watchers    map[string]Watcher
+	funcRead    FuncRead
+	funcWrite   FuncWrite
+	funcExists  FuncExists
+	funcList    FuncList
+	funcDelete  FuncDelete
+	opts        Options
+	isConnected atomic.Int32
+}
+
+func (n *noopStore) Live() bool {
+	return true
+}
+
+func (n *noopStore) Ready() bool {
+	return true
+}
+
+func (n *noopStore) Health() bool {
+	return true
 }
 
 func NewStore(opts ...Option) *noopStore {
@@ -52,12 +70,10 @@ func (n *noopStore) Init(opts ...Option) error {
 }
 
 func (n *noopStore) Connect(ctx context.Context) error {
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	default:
+	if n.opts.LazyConnect {
+		return nil
 	}
-	return nil
+	return n.connect(ctx)
 }
 
 func (n *noopStore) Disconnect(ctx context.Context) error {
@@ -70,6 +86,11 @@ func (n *noopStore) Disconnect(ctx context.Context) error {
 }
 
 func (n *noopStore) Read(ctx context.Context, key string, val interface{}, opts ...ReadOption) error {
+	if n.opts.LazyConnect {
+		if err := n.connect(ctx); err != nil {
+			return err
+		}
+	}
 	return n.funcRead(ctx, key, val, opts...)
 }
 
@@ -83,6 +104,11 @@ func (n *noopStore) fnRead(ctx context.Context, key string, val interface{}, opt
 }
 
 func (n *noopStore) Delete(ctx context.Context, key string, opts ...DeleteOption) error {
+	if n.opts.LazyConnect {
+		if err := n.connect(ctx); err != nil {
+			return err
+		}
+	}
 	return n.funcDelete(ctx, key, opts...)
 }
 
@@ -96,6 +122,11 @@ func (n *noopStore) fnDelete(ctx context.Context, key string, opts ...DeleteOpti
 }
 
 func (n *noopStore) Exists(ctx context.Context, key string, opts ...ExistsOption) error {
+	if n.opts.LazyConnect {
+		if err := n.connect(ctx); err != nil {
+			return err
+		}
+	}
 	return n.funcExists(ctx, key, opts...)
 }
 
@@ -109,6 +140,11 @@ func (n *noopStore) fnExists(ctx context.Context, key string, opts ...ExistsOpti
 }
 
 func (n *noopStore) Write(ctx context.Context, key string, val interface{}, opts ...WriteOption) error {
+	if n.opts.LazyConnect {
+		if err := n.connect(ctx); err != nil {
+			return err
+		}
+	}
 	return n.funcWrite(ctx, key, val, opts...)
 }
 
@@ -122,6 +158,11 @@ func (n *noopStore) fnWrite(ctx context.Context, key string, val interface{}, op
 }
 
 func (n *noopStore) List(ctx context.Context, opts ...ListOption) ([]string, error) {
+	if n.opts.LazyConnect {
+		if err := n.connect(ctx); err != nil {
+			return nil, err
+		}
+	}
 	return n.funcList(ctx, opts...)
 }
 
@@ -145,3 +186,53 @@ func (n *noopStore) String() string {
 func (n *noopStore) Options() Options {
 	return n.opts
 }
+
+func (n *noopStore) connect(ctx context.Context) error {
+	if n.isConnected.CompareAndSwap(0, 1) {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
+		}
+	}
+
+	return nil
+}
+
+type watcher struct {
+	exit chan bool
+	id   string
+	ch   chan Event
+	opts WatchOptions
+}
+
+func (m *noopStore) Watch(ctx context.Context, opts ...WatchOption) (Watcher, error) {
+	id, err := id.New()
+	if err != nil {
+		return nil, err
+	}
+	wo, err := NewWatchOptions(opts...)
+	if err != nil {
+		return nil, err
+	}
+	// construct the watcher
+	w := &watcher{
+		exit: make(chan bool),
+		ch:   make(chan Event),
+		id:   id,
+		opts: wo,
+	}
+
+	m.mu.Lock()
+	m.watchers[w.id] = w
+	m.mu.Unlock()
+
+	return w, nil
+}
+
+func (w *watcher) Next() (Event, error) {
+	return nil, nil
+}
+
+func (w *watcher) Stop() {
+}

store/options.go

@@ -41,6 +41,8 @@ type Options struct {
 	Timeout time.Duration
 	// Hooks can be run before/after store Read/List/Write/Exists/Delete
 	Hooks options.Hooks
+	// LazyConnect creates a connection when using store
+	LazyConnect bool
 }
 
 // NewOptions creates options struct
@@ -132,6 +134,13 @@ func Timeout(td time.Duration) Option {
 	}
 }
 
+// LazyConnect initialize connection only when needed
+func LazyConnect(b bool) Option {
+	return func(o *Options) {
+		o.LazyConnect = b
+	}
+}
+
 // Addrs contains the addresses or other connection information of the backing storage.
 // For example, an etcd implementation would contain the nodes of the cluster.
 // A SQL implementation could contain one or more connection strings.

store/store.go

@@ -4,9 +4,11 @@ package store
 import (
 	"context"
 	"errors"
+	"time"
 )
 
 var (
+	ErrWatcherStopped = errors.New("watcher stopped")
 	// ErrNotConnected is returned when a store is not connected
 	ErrNotConnected = errors.New("not conected")
 	// ErrNotFound is returned when a key doesn't exist
@@ -43,6 +45,14 @@ type Store interface {
 	Disconnect(ctx context.Context) error
 	// String returns the name of the implementation.
 	String() string
+	// Watch returns events watcher
+	Watch(ctx context.Context, opts ...WatchOption) (Watcher, error)
+	// Live returns store liveness
+	Live() bool
+	// Ready returns store readiness
+	Ready() bool
+	// Health returns store health
+	Health() bool
 }
 
 type (
@@ -57,3 +67,41 @@ type (
 	FuncList   func(ctx context.Context, opts ...ListOption) ([]string, error)
 	HookList   func(next FuncList) FuncList
 )
+
+type EventType int
+
+const (
+	EventTypeUnknown = iota
+	EventTypeConnect
+	EventTypeDisconnect
+	EventTypeOpError
+)
+
+type Event interface {
+	Timestamp() time.Time
+	Error() error
+	Type() EventType
+}
+
+type Watcher interface {
+	// Next is a blocking call
+	Next() (Event, error)
+	// Stop stops the watcher
+	Stop()
+}
+
+type WatchOption func(*WatchOptions) error
+
+type WatchOptions struct{}
+
+func NewWatchOptions(opts ...WatchOption) (WatchOptions, error) {
+	options := WatchOptions{}
+	var err error
+	for _, o := range opts {
+		if err = o(&options); err != nil {
+			break
+		}
+	}
+
+	return options, err
+}

store/wrapper.go

@@ -67,16 +67,18 @@ func (w *NamespaceStore) String() string {
 	return w.s.String()
 }
 
-// type NamespaceWrapper struct{}
-
-// func NewNamespaceWrapper() Wrapper {
-//	return &NamespaceWrapper{}
-// }
-
-/*
-func (w *OmitWrapper) Logf(fn LogfFunc) LogfFunc {
-	return func(ctx context.Context, level Level, msg string, args ...interface{}) {
-		fn(ctx, level, msg, getArgs(args)...)
-	}
+func (w *NamespaceStore) Watch(ctx context.Context, opts ...WatchOption) (Watcher, error) {
+	return w.s.Watch(ctx, opts...)
+}
+
+func (w *NamespaceStore) Live() bool {
+	return w.s.Live()
+}
+
+func (w *NamespaceStore) Ready() bool {
+	return w.s.Ready()
+}
+
+func (w *NamespaceStore) Health() bool {
+	return w.s.Health()
 }
-*/

util/dns/cache.go

@@ -0,0 +1,377 @@
+package dns
+
+import (
+	"context"
+	"math"
+	"net"
+	"sync"
+	"time"
+)
+
+// DialFunc is a [net.Resolver.Dial] function.
+type DialFunc func(ctx context.Context, network, address string) (net.Conn, error)
+
+// NewNetResolver creates a caching [net.Resolver] that uses parent to resolve names.
+func NewNetResolver(opts ...Option) *net.Resolver {
+	options := Options{Resolver: &net.Resolver{}}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return &net.Resolver{
+		PreferGo:     true,
+		StrictErrors: options.Resolver.StrictErrors,
+		Dial:         NewNetDialer(options.Resolver.Dial, append(opts, Resolver(options.Resolver))...),
+	}
+}
+
+// NewNetDialer adds caching to a [net.Resolver.Dial] function.
+func NewNetDialer(parent DialFunc, opts ...Option) DialFunc {
+	cache := cache{dial: parent, opts: Options{}}
+	for _, o := range opts {
+		o(&cache.opts)
+	}
+	if cache.opts.MaxCacheEntries == 0 {
+		cache.opts.MaxCacheEntries = DefaultMaxCacheEntries
+	}
+	return func(ctx context.Context, network, address string) (net.Conn, error) {
+		conn := &dnsConn{}
+		conn.roundTrip = cachingRoundTrip(&cache, network, address)
+		return conn, nil
+	}
+}
+
+const DefaultMaxCacheEntries = 300
+
+// A Option customizes the resolver cache.
+type Option func(*Options)
+
+type Options struct {
+	Resolver        *net.Resolver
+	MaxCacheEntries int
+	MaxCacheTTL     time.Duration
+	MinCacheTTL     time.Duration
+	NegativeCache   bool
+	PreferIPV4      bool
+	PreferIPV6      bool
+	Timeout         time.Duration
+}
+
+// MaxCacheEntries sets the maximum number of entries to cache.
+// If zero, [DefaultMaxCacheEntries] is used; negative means no limit.
+func MaxCacheEntries(n int) Option {
+	return func(o *Options) {
+		o.MaxCacheEntries = n
+	}
+}
+
+// MaxCacheTTL sets the maximum time-to-live for entries in the cache.
+func MaxCacheTTL(td time.Duration) Option {
+	return func(o *Options) {
+		o.MaxCacheTTL = td
+	}
+}
+
+// MinCacheTTL sets the minimum time-to-live for entries in the cache.
+func MinCacheTTL(td time.Duration) Option {
+	return func(o *Options) {
+		o.MinCacheTTL = td
+	}
+}
+
+// NegativeCache sets whether to cache negative responses.
+func NegativeCache(b bool) Option {
+	return func(o *Options) {
+		o.NegativeCache = b
+	}
+}
+
+// Timeout sets upstream *net.Resolver timeout
+func Timeout(td time.Duration) Option {
+	return func(o *Options) {
+		o.Timeout = td
+	}
+}
+
+// Resolver sets upstream *net.Resolver.
+func Resolver(r *net.Resolver) Option {
+	return func(o *Options) {
+		o.Resolver = r
+	}
+}
+
+// PreferIPV4 resolve ipv4 records.
+func PreferIPV4(b bool) Option {
+	return func(o *Options) {
+		o.PreferIPV4 = b
+	}
+}
+
+// PreferIPV6 resolve ipv4 records.
+func PreferIPV6(b bool) Option {
+	return func(o *Options) {
+		o.PreferIPV6 = b
+	}
+}
+
+type cache struct {
+	sync.RWMutex
+
+	dial    DialFunc
+	entries map[string]cacheEntry
+
+	opts Options
+}
+
+type cacheEntry struct {
+	deadline time.Time
+	value    string
+}
+
+func (c *cache) put(req string, res string) {
+	// ignore uncacheable/unparseable answers
+	if invalid(req, res) {
+		return
+	}
+
+	// ignore errors (if requested)
+	if nameError(res) && !c.opts.NegativeCache {
+		return
+	}
+
+	// ignore uncacheable/unparseable answers
+	ttl := getTTL(res)
+	if ttl <= 0 {
+		return
+	}
+
+	// adjust TTL
+	if ttl < c.opts.MinCacheTTL {
+		ttl = c.opts.MinCacheTTL
+	}
+	// maxTTL overrides minTTL
+	if ttl > c.opts.MaxCacheTTL && c.opts.MaxCacheTTL != 0 {
+		ttl = c.opts.MaxCacheTTL
+	}
+
+	c.Lock()
+	defer c.Unlock()
+	if c.entries == nil {
+		c.entries = make(map[string]cacheEntry)
+	}
+
+	// do some cache evition
+	var tested, evicted int
+	for k, e := range c.entries {
+		if time.Until(e.deadline) <= 0 {
+			// delete expired entry
+			delete(c.entries, k)
+			evicted++
+		}
+		tested++
+
+		if tested < 8 {
+			continue
+		}
+		if evicted == 0 && c.opts.MaxCacheEntries > 0 && len(c.entries) >= c.opts.MaxCacheEntries {
+			// delete at least one entry
+			delete(c.entries, k)
+		}
+		break
+	}
+
+	// remove message IDs
+	c.entries[req[2:]] = cacheEntry{
+		deadline: time.Now().Add(ttl),
+		value:    res[2:],
+	}
+}
+
+func (c *cache) get(req string) (res string) {
+	// ignore invalid messages
+	if len(req) < 12 {
+		return ""
+	}
+	if req[2] >= 0x7f {
+		return ""
+	}
+
+	c.RLock()
+	defer c.RUnlock()
+
+	if c.entries == nil {
+		return ""
+	}
+
+	// remove message ID
+	entry, ok := c.entries[req[2:]]
+	if ok && time.Until(entry.deadline) > 0 {
+		// prepend correct ID
+		return req[:2] + entry.value
+	}
+	return ""
+}
+
+func invalid(req string, res string) bool {
+	if len(req) < 12 || len(res) < 12 { // header size
+		return true
+	}
+	if req[0] != res[0] || req[1] != res[1] { // IDs match
+		return true
+	}
+	if req[2] >= 0x7f || res[2] < 0x7f { // query, response
+		return true
+	}
+	if req[2]&0x7a != 0 || res[2]&0x7a != 0 { // standard query, not truncated
+		return true
+	}
+	if res[3]&0xf != 0 && res[3]&0xf != 3 { // no error, or name error
+		return true
+	}
+	return false
+}
+
+func nameError(res string) bool {
+	return res[3]&0xf == 3
+}
+
+func getTTL(msg string) time.Duration {
+	ttl := math.MaxInt32
+
+	qdcount := getUint16(msg[4:])
+	ancount := getUint16(msg[6:])
+	nscount := getUint16(msg[8:])
+	arcount := getUint16(msg[10:])
+	rdcount := ancount + nscount + arcount
+
+	msg = msg[12:] // skip header
+
+	// skip questions
+	for i := 0; i < qdcount; i++ {
+		name := getNameLen(msg)
+		if name < 0 || name+4 > len(msg) {
+			return -1
+		}
+		msg = msg[name+4:]
+	}
+
+	// parse records
+	for i := 0; i < rdcount; i++ {
+		name := getNameLen(msg)
+		if name < 0 || name+10 > len(msg) {
+			return -1
+		}
+		rtyp := getUint16(msg[name+0:])
+		rttl := getUint32(msg[name+4:])
+		rlen := getUint16(msg[name+8:])
+		if name+10+rlen > len(msg) {
+			return -1
+		}
+		// skip EDNS OPT since it doesn't have a TTL
+		if rtyp != 41 && rttl < ttl {
+			ttl = rttl
+		}
+		msg = msg[name+10+rlen:]
+	}
+
+	return time.Duration(ttl) * time.Second
+}
+
+func getNameLen(msg string) int {
+	i := 0
+	for i < len(msg) {
+		if msg[i] == 0 {
+			// end of name
+			i += 1
+			break
+		}
+		if msg[i] >= 0xc0 {
+			// compressed name
+			i += 2
+			break
+		}
+		if msg[i] >= 0x40 {
+			// reserved
+			return -1
+		}
+		i += int(msg[i] + 1)
+	}
+	return i
+}
+
+func getUint16(s string) int {
+	return int(s[1]) | int(s[0])<<8
+}
+
+func getUint32(s string) int {
+	return int(s[3]) | int(s[2])<<8 | int(s[1])<<16 | int(s[0])<<24
+}
+
+func cachingRoundTrip(cache *cache, network, address string) roundTripper {
+	return func(ctx context.Context, req string) (res string, err error) {
+		// check cache
+		if res := cache.get(req); res != "" {
+			return res, nil
+		}
+
+		switch {
+		case cache.opts.PreferIPV4 && cache.opts.PreferIPV6:
+			network = "udp"
+		case cache.opts.PreferIPV4:
+			network = "udp4"
+		case cache.opts.PreferIPV6:
+			network = "udp6"
+		default:
+			network = "udp"
+		}
+
+		if cache.opts.Timeout > 0 {
+			var cancel func()
+			ctx, cancel = context.WithTimeout(ctx, cache.opts.Timeout)
+			defer cancel()
+		}
+
+		// dial connection
+		var conn net.Conn
+		if cache.dial != nil {
+			conn, err = cache.dial(ctx, network, address)
+		} else {
+			var d net.Dialer
+			conn, err = d.DialContext(ctx, network, address)
+		}
+		if err != nil {
+			return "", err
+		}
+
+		ctx, cancel := context.WithCancel(ctx)
+		go func() {
+			<-ctx.Done()
+			conn.Close()
+		}()
+		defer cancel()
+
+		if t, ok := ctx.Deadline(); ok {
+			err = conn.SetDeadline(t)
+			if err != nil {
+				return "", err
+			}
+		}
+
+		// send request
+		err = writeMessage(conn, req)
+		if err != nil {
+			return "", err
+		}
+
+		// read response
+		res, err = readMessage(conn)
+		if err != nil {
+			return "", err
+		}
+
+		// cache response
+		cache.put(req, res)
+		return res, nil
+	}
+}

util/dns/cache_test.go

@@ -0,0 +1,16 @@
+package dns
+
+import (
+	"net"
+	"testing"
+)
+
+func TestCache(t *testing.T) {
+	net.DefaultResolver = NewNetResolver(PreferIPV4(true))
+
+	addrs, err := net.LookupHost("unistack.org")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("addrs %v", addrs)
+}

util/dns/conn.go

@@ -0,0 +1,178 @@
+package dns
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"net"
+	"strings"
+	"sync"
+	"time"
+)
+
+type dnsConn struct {
+	sync.Mutex
+
+	ibuf bytes.Buffer
+	obuf bytes.Buffer
+
+	ctx       context.Context
+	cancel    context.CancelFunc
+	deadline  time.Time
+	roundTrip roundTripper
+}
+
+type roundTripper func(ctx context.Context, req string) (res string, err error)
+
+func (c *dnsConn) Read(b []byte) (n int, err error) {
+	imsg, n, err := c.drainBuffers(b)
+	if n != 0 || err != nil {
+		return n, err
+	}
+
+	ctx, cancel := c.childContext()
+	omsg, err := c.roundTrip(ctx, imsg)
+	cancel()
+	if err != nil {
+		return 0, err
+	}
+
+	return c.fillBuffer(b, omsg)
+}
+
+func (c *dnsConn) Write(b []byte) (n int, err error) {
+	c.Lock()
+	defer c.Unlock()
+	return c.ibuf.Write(b)
+}
+
+func (c *dnsConn) Close() error {
+	c.Lock()
+	cancel := c.cancel
+	c.Unlock()
+
+	if cancel != nil {
+		cancel()
+	}
+	return nil
+}
+
+func (c *dnsConn) LocalAddr() net.Addr {
+	return nil
+}
+
+func (c *dnsConn) RemoteAddr() net.Addr {
+	return nil
+}
+
+func (c *dnsConn) SetDeadline(t time.Time) error {
+	c.SetReadDeadline(t)
+	c.SetWriteDeadline(t)
+	return nil
+}
+
+func (c *dnsConn) SetReadDeadline(t time.Time) error {
+	c.Lock()
+	defer c.Unlock()
+	c.deadline = t
+	return nil
+}
+
+func (c *dnsConn) SetWriteDeadline(t time.Time) error {
+	// writes do not timeout
+	return nil
+}
+
+func (c *dnsConn) drainBuffers(b []byte) (string, int, error) {
+	c.Lock()
+	defer c.Unlock()
+
+	// drain the output buffer
+	if c.obuf.Len() > 0 {
+		n, err := c.obuf.Read(b)
+		return "", n, err
+	}
+
+	// otherwise, get the next message from the input buffer
+	sz := c.ibuf.Next(2)
+	if len(sz) < 2 {
+		return "", 0, io.ErrUnexpectedEOF
+	}
+
+	size := int64(sz[0])<<8 | int64(sz[1])
+
+	var str strings.Builder
+	_, err := io.CopyN(&str, &c.ibuf, size)
+	if err == io.EOF {
+		return "", 0, io.ErrUnexpectedEOF
+	}
+	if err != nil {
+		return "", 0, err
+	}
+	return str.String(), 0, nil
+}
+
+func (c *dnsConn) fillBuffer(b []byte, str string) (int, error) {
+	c.Lock()
+	defer c.Unlock()
+	c.obuf.WriteByte(byte(len(str) >> 8))
+	c.obuf.WriteByte(byte(len(str)))
+	c.obuf.WriteString(str)
+	return c.obuf.Read(b)
+}
+
+func (c *dnsConn) childContext() (context.Context, context.CancelFunc) {
+	c.Lock()
+	defer c.Unlock()
+	if c.ctx == nil {
+		c.ctx, c.cancel = context.WithCancel(context.Background())
+	}
+	return context.WithDeadline(c.ctx, c.deadline)
+}
+
+func writeMessage(conn net.Conn, msg string) error {
+	var buf []byte
+	if _, ok := conn.(net.PacketConn); ok {
+		buf = []byte(msg)
+	} else {
+		buf = make([]byte, len(msg)+2)
+		buf[0] = byte(len(msg) >> 8)
+		buf[1] = byte(len(msg))
+		copy(buf[2:], msg)
+	}
+	// SHOULD do a single write on TCP (RFC 7766, section 8).
+	// MUST do a single write on UDP.
+	_, err := conn.Write(buf)
+	return err
+}
+
+func readMessage(c net.Conn) (string, error) {
+	if _, ok := c.(net.PacketConn); ok {
+		// RFC 1035 specifies 512 as the maximum message size for DNS over UDP.
+		// RFC 6891 OTOH suggests 4096 as the maximum payload size for EDNS.
+		b := make([]byte, 4096)
+		n, err := c.Read(b)
+		if err != nil {
+			return "", err
+		}
+		return string(b[:n]), nil
+	} else {
+		var sz [2]byte
+		_, err := io.ReadFull(c, sz[:])
+		if err != nil {
+			return "", err
+		}
+
+		size := int64(sz[0])<<8 | int64(sz[1])
+
+		var str strings.Builder
+		_, err = io.CopyN(&str, c, size)
+		if err == io.EOF {
+			return "", io.ErrUnexpectedEOF
+		}
+		if err != nil {
+			return "", err
+		}
+		return str.String(), nil
+	}
+}

util/io/io.go

@@ -1,40 +0,0 @@
-// Package io is for io management
-package io
-
-import (
-	"io"
-
-	"go.unistack.org/micro/v3/network/transport"
-)
-
-type rwc struct {
-	socket transport.Socket
-}
-
-func (r *rwc) Read(p []byte) (n int, err error) {
-	m := new(transport.Message)
-	if err := r.socket.Recv(m); err != nil {
-		return 0, err
-	}
-	copy(p, m.Body)
-	return len(m.Body), nil
-}
-
-func (r *rwc) Write(p []byte) (n int, err error) {
-	err = r.socket.Send(&transport.Message{
-		Body: p,
-	})
-	if err != nil {
-		return 0, err
-	}
-	return len(p), nil
-}
-
-func (r *rwc) Close() error {
-	return r.socket.Close()
-}
-
-// NewRWC returns a new ReadWriteCloser
-func NewRWC(sock transport.Socket) io.ReadWriteCloser {
-	return &rwc{sock}
-}

util/pool/default.go

@@ -1,118 +0,0 @@
-package pool
-
-import (
-	"context"
-	"sync"
-	"time"
-
-	"go.unistack.org/micro/v3/network/transport"
-	"go.unistack.org/micro/v3/util/id"
-)
-
-type pool struct {
-	tr    transport.Transport
-	conns map[string][]*poolConn
-	size  int
-	ttl   time.Duration
-	sync.Mutex
-}
-
-type poolConn struct {
-	created time.Time
-	transport.Client
-	id string
-}
-
-func newPool(options Options) *pool {
-	return &pool{
-		size:  options.Size,
-		tr:    options.Transport,
-		ttl:   options.TTL,
-		conns: make(map[string][]*poolConn),
-	}
-}
-
-func (p *pool) Close() error {
-	p.Lock()
-	for k, c := range p.conns {
-		for _, conn := range c {
-			conn.Client.Close()
-		}
-		delete(p.conns, k)
-	}
-	p.Unlock()
-	return nil
-}
-
-// NoOp the Close since we manage it
-func (p *poolConn) Close() error {
-	return nil
-}
-
-func (p *poolConn) ID() string {
-	return p.id
-}
-
-func (p *poolConn) Created() time.Time {
-	return p.created
-}
-
-func (p *pool) Get(ctx context.Context, addr string, opts ...transport.DialOption) (Conn, error) {
-	p.Lock()
-	conns := p.conns[addr]
-
-	// while we have conns check age and then return one
-	// otherwise we'll create a new conn
-	for len(conns) > 0 {
-		conn := conns[len(conns)-1]
-		conns = conns[:len(conns)-1]
-		p.conns[addr] = conns
-
-		// if conn is old kill it and move on
-		if d := time.Since(conn.Created()); d > p.ttl {
-			conn.Client.Close()
-			continue
-		}
-
-		// we got a good conn, lets unlock and return it
-		p.Unlock()
-
-		return conn, nil
-	}
-
-	p.Unlock()
-
-	// create new conn
-	c, err := p.tr.Dial(ctx, addr, opts...)
-	if err != nil {
-		return nil, err
-	}
-	id, err := id.New()
-	if err != nil {
-		return nil, err
-	}
-	return &poolConn{
-		Client:  c,
-		id:      id,
-		created: time.Now(),
-	}, nil
-}
-
-func (p *pool) Release(conn Conn, err error) error {
-	// don't store the conn if it has errored
-	if err != nil {
-		return conn.(*poolConn).Client.Close()
-	}
-
-	// otherwise put it back for reuse
-	p.Lock()
-	conns := p.conns[conn.Remote()]
-	if len(conns) >= p.size {
-		p.Unlock()
-		return conn.(*poolConn).Client.Close()
-	}
-	p.conns[conn.Remote()] = append(conns, conn.(*poolConn))
-	p.Unlock()
-
-	return nil
-}

util/pool/default_test.go

@@ -1,92 +0,0 @@
-//go:build ignore
-// +build ignore
-
-package pool
-
-import (
-	"testing"
-	"time"
-
-	"go.unistack.org/micro/v3/network/transport"
-	"go.unistack.org/micro/v3/network/transport/memory"
-)
-
-func testPool(t *testing.T, size int, ttl time.Duration) {
-	// mock transport
-	tr := memory.NewTransport()
-
-	options := Options{
-		TTL:       ttl,
-		Size:      size,
-		Transport: tr,
-	}
-	// zero pool
-	p := newPool(options)
-
-	// listen
-	l, err := tr.Listen(":0")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer l.Close()
-
-	// accept loop
-	go func() {
-		for {
-			if err := l.Accept(func(s transport.Socket) {
-				for {
-					var msg transport.Message
-					if err := s.Recv(&msg); err != nil {
-						return
-					}
-					if err := s.Send(&msg); err != nil {
-						return
-					}
-				}
-			}); err != nil {
-				return
-			}
-		}
-	}()
-
-	for i := 0; i < 10; i++ {
-		// get a conn
-		c, err := p.Get(l.Addr())
-		if err != nil {
-			t.Fatal(err)
-		}
-
-		msg := &transport.Message{
-			Body: []byte(`hello world`),
-		}
-
-		if err := c.Send(msg); err != nil {
-			t.Fatal(err)
-		}
-
-		var rcv transport.Message
-
-		if err := c.Recv(&rcv); err != nil {
-			t.Fatal(err)
-		}
-
-		if string(rcv.Body) != string(msg.Body) {
-			t.Fatalf("got %v, expected %v", rcv.Body, msg.Body)
-		}
-
-		// release the conn
-		p.Release(c, nil)
-
-		p.Lock()
-		if i := len(p.conns[l.Addr()]); i > size {
-			p.Unlock()
-			t.Fatalf("pool size %d is greater than expected %d", i, size)
-		}
-		p.Unlock()
-	}
-}
-
-func TestClientPool(t *testing.T) {
-	testPool(t, 0, time.Minute)
-	testPool(t, 2, time.Minute)
-}

util/pool/options.go

@@ -1,38 +0,0 @@
-package pool
-
-import (
-	"time"
-
-	"go.unistack.org/micro/v3/network/transport"
-)
-
-// Options struct
-type Options struct {
-	Transport transport.Transport
-	TTL       time.Duration
-	Size      int
-}
-
-// Option func signature
-type Option func(*Options)
-
-// Size sets the size
-func Size(i int) Option {
-	return func(o *Options) {
-		o.Size = i
-	}
-}
-
-// Transport sets the transport
-func Transport(t transport.Transport) Option {
-	return func(o *Options) {
-		o.Transport = t
-	}
-}
-
-// TTL specifies ttl
-func TTL(t time.Duration) Option {
-	return func(o *Options) {
-		o.TTL = t
-	}
-}

util/pool/pool.go

@@ -1,38 +0,0 @@
-// Package pool is a connection pool
-package pool
-
-import (
-	"context"
-	"time"
-
-	"go.unistack.org/micro/v3/network/transport"
-)
-
-// Pool is an interface for connection pooling
-type Pool interface {
-	// Close the pool
-	Close() error
-	// Get a connection
-	Get(ctx context.Context, addr string, opts ...transport.DialOption) (Conn, error)
-	// Release the connection
-	Release(c Conn, status error) error
-}
-
-// Conn conn pool interface
-type Conn interface {
-	// unique id of connection
-	ID() string
-	// time it was created
-	Created() time.Time
-	// embedded connection
-	transport.Client
-}
-
-// NewPool creates new connection pool
-func NewPool(opts ...Option) Pool {
-	options := Options{}
-	for _, o := range opts {
-		o(&options)
-	}
-	return newPool(options)
-}

util/time/duration_test.go

@@ -23,7 +23,7 @@ func TestMarshalYAML(t *testing.T) {
 
 func TestUnmarshalYAML(t *testing.T) {
 	type str struct {
-		TTL Duration `yaml:"ttl"`
+		TTL *Duration `yaml:"ttl"`
 	}
 	v := &str{}
 	var err error
@@ -31,14 +31,14 @@ func TestUnmarshalYAML(t *testing.T) {
 	err = yaml.Unmarshal([]byte(`{"ttl":"10ms"}`), v)
 	if err != nil {
 		t.Fatal(err)
-	} else if v.TTL != 10000000 {
+	} else if *(v.TTL) != 10000000 {
 		t.Fatalf("invalid duration %v != 10000000", v.TTL)
 	}
 
 	err = yaml.Unmarshal([]byte(`{"ttl":"1y"}`), v)
 	if err != nil {
 		t.Fatal(err)
-	} else if v.TTL != 31622400000000000 {
+	} else if *(v.TTL) != 31622400000000000 {
 		t.Fatalf("invalid duration %v != 31622400000000000", v.TTL)
 	}
 }