Merge pull request 'update for latest micro changes' (#96) from microv4 into master

Reviewed-on: #96

.github/dependabot.yml

@@ -0,0 +1,19 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"
+
+  # Maintain dependencies for Golang
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "daily"

.github/renovate.json

@@ -1,20 +0,0 @@
-{
-  "extends": [
-    "config:base"
-  ],
-  "postUpdateOptions": ["gomodTidy"],
-  "packageRules": [
-    {
-      "matchUpdateTypes": ["minor", "patch", "pin", "digest"],
-      "automerge": true
-    },
-    {
-      "groupName": "all deps",
-      "separateMajorMinor": true,
-      "groupSlug": "all",
-      "packagePatterns": [
-        "*"
-      ]
-    }
-  ]
-}

.github/workflows/autoapprove.yml

@@ -0,0 +1,20 @@
+name: "autoapprove"
+
+on:
+  pull_request_target:
+    types: [assigned, opened, synchronize, reopened]
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  autoapprove:
+    runs-on: ubuntu-latest
+    steps:
+      - name: approve
+        uses: hmarr/auto-approve-action@v3
+        if: github.actor == 'vtolstov' || github.actor == 'dependabot[bot]'
+        id: approve
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/automerge.yml

@@ -0,0 +1,21 @@
+name: "automerge"
+
+on:
+  pull_request_target:
+    types: [assigned, opened, synchronize, reopened]
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.actor == 'vtolstov'
+    steps:
+      - name: merge
+        id: merge
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GITHUB_TOKEN: ${{secrets.TOKEN}}

.github/workflows/build.yml

@@ -3,19 +3,20 @@ on:
  push:
     branches:
     - master
+    - v3
 jobs:
   test:
     name: test
     runs-on: ubuntu-latest
     steps:
     - name: setup
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version: 1.17
     - name: checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
     - name: cache
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
@@ -31,9 +32,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: lint
-        uses: golangci/golangci-lint-action@v2
+        uses: golangci/golangci-lint-action@v3.4.0
         continue-on-error: true
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,78 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "codeql"
+
+on:
+  workflow_run:
+    workflows: ["prbuild"]
+    types:
+      - completed
+  push:
+    branches: [ master, v3 ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master, v3 ]
+  schedule:
+    - cron: '34 1 * * 0'
+
+jobs:
+  analyze:
+    name: analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: checkout
+      uses: actions/checkout@v3
+    - name: setup
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.17
+    # Initializes the CodeQL tools for scanning.
+    - name: init
+      uses: github/codeql-action/init@v2
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: autobuild
+      uses: github/codeql-action/autobuild@v2
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: analyze
+      uses: github/codeql-action/analyze@v2

.github/workflows/dependabot-automerge.yml

@@ -0,0 +1,27 @@
+name: "dependabot-automerge"
+
+on:
+  pull_request_target:
+    types: [assigned, opened, synchronize, reopened]
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.actor == 'dependabot[bot]'
+    steps:
+      - name: metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@v1.3.6
+        with:
+          github-token: "${{ secrets.TOKEN }}"
+      - name: merge
+        id: merge
+        if: ${{contains(steps.metadata.outputs.dependency-names, 'go.unistack.org')}}
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GITHUB_TOKEN: ${{secrets.TOKEN}}

.github/workflows/pr.yml

@@ -3,19 +3,20 @@ on:
   pull_request:
     branches:
     - master
+    - v3
 jobs:
   test:
     name: test
     runs-on: ubuntu-latest
     steps:
     - name: setup
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v3
       with:
-        go-version: 1.16
+        go-version: 1.17
     - name: checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
     - name: cache
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
@@ -31,9 +32,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: lint
-        uses: golangci/golangci-lint-action@v2
+        uses: golangci/golangci-lint-action@v3.4.0
         continue-on-error: true
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.

file.go

@@ -1,23 +1,19 @@
-package file
+package file // import "go.unistack.org/micro-config-file/v4"
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 
 	"github.com/imdario/mergo"
-	"github.com/unistack-org/micro/v3/codec"
-	"github.com/unistack-org/micro/v3/config"
-	rutil "github.com/unistack-org/micro/v3/util/reflect"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/config"
+	"go.unistack.org/micro/v4/options"
+	rutil "go.unistack.org/micro/v4/util/reflect"
 )
 
-var (
-	DefaultStructTag = "file"
-	ErrPathNotExist  = errors.New("path is not exist")
-)
+var DefaultStructTag = "file"
 
 type fileConfig struct {
 	opts config.Options
@@ -28,94 +24,92 @@ func (c *fileConfig) Options() config.Options {
 	return c.opts
 }
 
-func (c *fileConfig) Init(opts ...config.Option) error {
+func (c *fileConfig) Init(opts ...options.Option) error {
+	if err := config.DefaultBeforeInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
 	for _, o := range opts {
 		o(&c.opts)
 	}
 
-	path := ""
-
 	if c.opts.Context != nil {
 		if v, ok := c.opts.Context.Value(pathKey{}).(string); ok {
+			c.path = v
+		}
+	}
+
+	if c.path == "" {
+		err := fmt.Errorf("file path not exists: %v", c.path)
+		if !c.opts.AllowFail {
+			return err
+		}
+	}
+
+	if err := config.DefaultAfterInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	return nil
+}
+
+func (c *fileConfig) Load(ctx context.Context, opts ...options.Option) error {
+	if err := config.DefaultBeforeLoad(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	path := c.path
+	options := config.NewLoadOptions(opts...)
+	if options.Context != nil {
+		if v, ok := options.Context.Value(pathKey{}).(string); ok && v != "" {
 			path = v
 		}
 	}
 
-	if path == "" {
-		return ErrPathNotExist
-	}
-
-	c.path = path
-
-	return nil
-}
-
-func (c *fileConfig) Load(ctx context.Context, opts ...config.LoadOption) error {
-	for _, fn := range c.opts.BeforeLoad {
-		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
+	fp, err := os.OpenFile(path, os.O_RDONLY, os.FileMode(0400))
+	if err != nil {
+		if !c.opts.AllowFail {
+			return fmt.Errorf("file load path %s error: %w", path, err)
+		}
+		if err = config.DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
 			return err
 		}
+
+		return nil
 	}
 
-	fp, err := os.OpenFile(c.path, os.O_RDONLY, os.FileMode(0400))
-	if err != nil && !c.opts.AllowFail {
-		return fmt.Errorf("failed to open: %s, error: %w", c.path, ErrPathNotExist)
-	} else if err == nil {
-		defer fp.Close()
-		var buf []byte
-		buf, err = ioutil.ReadAll(io.LimitReader(fp, int64(codec.DefaultMaxMsgSize)))
-		if err == nil {
-			src, err := rutil.Zero(c.opts.Struct)
-			if err == nil {
-				err = c.opts.Codec.Unmarshal(buf, src)
-				if err == nil {
-					options := config.NewLoadOptions(opts...)
-					mopts := []func(*mergo.Config){mergo.WithTypeCheck}
-					if options.Override {
-						mopts = append(mopts, mergo.WithOverride)
-					}
-					if options.Append {
-						mopts = append(mopts, mergo.WithAppendSlice)
-					}
-					err = mergo.Merge(c.opts.Struct, src, mopts...)
-				}
-			}
-		}
-		if err != nil && !c.opts.AllowFail {
+	defer fp.Close()
+
+	buf, err := io.ReadAll(io.LimitReader(fp, int64(codec.DefaultMaxMsgSize)))
+	if err != nil {
+		if !c.opts.AllowFail {
 			return err
 		}
-	}
-
-	for _, fn := range c.opts.AfterLoad {
-		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
+		if err = config.DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
 			return err
 		}
+
+		return nil
 	}
 
-	return nil
-}
-
-func (c *fileConfig) Save(ctx context.Context, opts ...config.SaveOption) error {
-	for _, fn := range c.opts.BeforeSave {
-		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
-			return err
-		}
+	dst := c.opts.Struct
+	if options.Struct != nil {
+		dst = options.Struct
 	}
 
-	buf, err := c.opts.Codec.Marshal(c.opts.Struct)
+	src, err := rutil.Zero(dst)
 	if err == nil {
-		var fp *os.File
-		fp, err = os.OpenFile(c.path, os.O_RDONLY, os.FileMode(0400))
-		if err != nil && c.opts.AllowFail {
-			return nil
-		} else if err != nil && !c.opts.AllowFail {
-			return fmt.Errorf("failed to open: %s, error: %w", c.path, ErrPathNotExist)
-		}
-
-		if _, werr := fp.Write(buf); werr == nil {
-			err = fp.Close()
-		} else {
-			err = werr
+		err = c.opts.Codec.Unmarshal(buf, src)
+		if err == nil {
+			options := config.NewLoadOptions(opts...)
+			mopts := []func(*mergo.Config){mergo.WithTypeCheck}
+			if options.Override {
+				mopts = append(mopts, mergo.WithOverride)
+			}
+			if options.Append {
+				mopts = append(mopts, mergo.WithAppendSlice)
+			}
+			err = mergo.Merge(dst, src, mopts...)
 		}
 	}
 
@@ -123,10 +117,66 @@ func (c *fileConfig) Save(ctx context.Context, opts ...config.SaveOption) error
 		return err
 	}
 
-	for _, fn := range c.opts.AfterSave {
-		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
+	if err := config.DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	return nil
+}
+
+func (c *fileConfig) Save(ctx context.Context, opts ...options.Option) error {
+	if err := config.DefaultBeforeSave(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	path := c.path
+	options := config.NewSaveOptions(opts...)
+	if options.Context != nil {
+		if v, ok := options.Context.Value(pathKey{}).(string); ok && v != "" {
+			path = v
+		}
+	}
+
+	dst := c.opts.Struct
+	if options.Struct != nil {
+		dst = options.Struct
+	}
+
+	buf, err := c.opts.Codec.Marshal(dst)
+	if err != nil {
+		if !c.opts.AllowFail {
 			return err
 		}
+		if err = config.DefaultAfterSave(ctx, c); err != nil && !c.opts.AllowFail {
+			return err
+		}
+
+		return nil
+	}
+
+	fp, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE, os.FileMode(0600))
+	if err != nil {
+		if !c.opts.AllowFail {
+			return err
+		}
+		if err = config.DefaultAfterSave(ctx, c); err != nil && !c.opts.AllowFail {
+			return err
+		}
+
+		return nil
+	}
+	defer fp.Close()
+
+	if _, err = fp.Write(buf); err == nil {
+		err = fp.Close()
+	}
+
+	if err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	if err := config.DefaultAfterSave(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
 	}
 
 	return nil
@@ -140,7 +190,30 @@ func (c *fileConfig) Name() string {
 	return c.opts.Name
 }
 
-func NewConfig(opts ...config.Option) config.Config {
+func (c *fileConfig) Watch(ctx context.Context, opts ...options.Option) (config.Watcher, error) {
+	path := c.path
+	options := config.NewWatchOptions(opts...)
+	if options.Context != nil {
+		if v, ok := options.Context.Value(pathKey{}).(string); ok && v != "" {
+			path = v
+		}
+	}
+
+	w := &fileWatcher{
+		path:  path,
+		opts:  c.opts,
+		wopts: config.NewWatchOptions(opts...),
+		done:  make(chan struct{}),
+		vchan: make(chan map[string]interface{}),
+		echan: make(chan error),
+	}
+
+	go w.run()
+
+	return w, nil
+}
+
+func NewConfig(opts ...options.Option) config.Config {
 	options := config.NewOptions(opts...)
 	if len(options.StructTag) == 0 {
 		options.StructTag = DefaultStructTag

go.mod

@@ -1,8 +1,10 @@
-module github.com/unistack-org/micro-config-file/v3
+module go.unistack.org/micro-config-file/v4
 
-go 1.16
+go 1.20
 
 require (
-	github.com/imdario/mergo v0.3.12
-	github.com/unistack-org/micro/v3 v3.4.0
+	github.com/imdario/mergo v0.3.16
+	go.unistack.org/micro/v4 v4.0.6
 )
+
+require github.com/google/uuid v1.3.0 // indirect

go.sum

@@ -1,18 +1,12 @@
-github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
-github.com/ef-ds/deque v1.0.4/go.mod h1:gXDnTC3yqvBcHbq2lcExjtAcVrOnJCbMcZXmuj8Z4tg=
-github.com/google/uuid v1.2.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/imdario/mergo v0.3.12 h1:b6R2BslTbIEToALKP7LxUvijTsNI9TAe80pLWN2g/HU=
-github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
-github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
-github.com/silas/dag v0.0.0-20210121180416-41cf55125c34/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
-github.com/unistack-org/micro/v3 v3.4.0 h1:z9F3lgAb2j4cZ1ib5qBj66JPYUAzR4sNIJqUDjVwyVQ=
-github.com/unistack-org/micro/v3 v3.4.0/go.mod h1:LXmPfbJnJNvL0kQs8HfnkV3Wya2Wb+C7keVq++RCZnk=
-golang.org/x/net v0.0.0-20210510120150-4163338589ed/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/imdario/mergo v0.3.15 h1:M8XP7IuFNsqUx6VPK2P9OSmsYsI/YFaGil0uD21V3dM=
+github.com/imdario/mergo v0.3.16 h1:wwQJbIsHYGMUyLSPrEq1CT16AhnhNJQ51+4fdHUnCl4=
+github.com/imdario/mergo v0.3.16/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
+go.unistack.org/micro/v4 v4.0.1 h1:xo1IxbVfgh8i0eY0VeYa3cbb13u5n/Mxnp3FOgWD4Jo=
+go.unistack.org/micro/v4 v4.0.1/go.mod h1:p/J5UcSJjfHsWGT31uKoghQ5rUQZzQJBAFy+Z4+ZVMs=
+go.unistack.org/micro/v4 v4.0.6 h1:YFWvTh3VwyOd6NHYTQcf47n2TF5+p/EhpnbuBQX3qhk=
+go.unistack.org/micro/v4 v4.0.6/go.mod h1:bVEYTlPi0EsdgZZt311bIroDg9ict7ky3C87dSCCAGk=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
-gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

options.go

@@ -1,11 +1,11 @@
 package file
 
 import (
-	"github.com/unistack-org/micro/v3/config"
+	"go.unistack.org/micro/v4/options"
 )
 
 type pathKey struct{}
 
-func Path(path string) config.Option {
-	return config.SetOption(pathKey{}, path)
+func Path(path string) options.Option {
+	return options.ContextOption(pathKey{}, path)
 }

watcher.go

@@ -0,0 +1,103 @@
+package file
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"reflect"
+
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/config"
+	"go.unistack.org/micro/v4/util/jitter"
+	rutil "go.unistack.org/micro/v4/util/reflect"
+)
+
+type fileWatcher struct {
+	path  string
+	opts  config.Options
+	wopts config.WatchOptions
+	done  chan struct{}
+	vchan chan map[string]interface{}
+	echan chan error
+}
+
+func (w *fileWatcher) run() {
+	ticker := jitter.NewTicker(w.wopts.MinInterval, w.wopts.MaxInterval)
+	defer ticker.Stop()
+
+	src := w.opts.Struct
+	if w.wopts.Struct != nil {
+		src = w.wopts.Struct
+	}
+
+	for {
+		select {
+		case <-w.done:
+			return
+		case <-ticker.C:
+			dst, err := rutil.Zero(src)
+			if err == nil {
+				var fp *os.File
+				if fp, err = os.OpenFile(w.path, os.O_RDONLY, os.FileMode(0400)); err != nil {
+					w.echan <- fmt.Errorf("failed to open: %s, error: %w", w.path, err)
+					return
+				}
+				var buf []byte
+				buf, err = ioutil.ReadAll(io.LimitReader(fp, int64(codec.DefaultMaxMsgSize)))
+				if err == nil {
+					err = w.opts.Codec.Unmarshal(buf, dst)
+				}
+				if err != nil {
+					_ = fp.Close()
+					w.echan <- err
+					return
+				}
+				err = fp.Close()
+			}
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			srcmp, err := rutil.StructFieldsMap(src)
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			dstmp, err := rutil.StructFieldsMap(dst)
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			for sk, sv := range srcmp {
+				if reflect.DeepEqual(dstmp[sk], sv) {
+					delete(dstmp, sk)
+				}
+			}
+			if len(dstmp) > 0 {
+				w.vchan <- dstmp
+				src = dst
+			}
+		}
+	}
+}
+
+func (w *fileWatcher) Next() (map[string]interface{}, error) {
+	select {
+	case <-w.done:
+		break
+	case err := <-w.echan:
+		return nil, err
+	case v, ok := <-w.vchan:
+		if !ok {
+			break
+		}
+		return v, nil
+	}
+	return nil, config.ErrWatcherStopped
+}
+
+func (w *fileWatcher) Stop() error {
+	close(w.done)
+	return nil
+}