fix file watcher event bug on Linux

the watcher can not normally get events of file changes on linux. it just can get the first two changes.
This commit is contained in:
Shu Xian 2019-08-19 15:28:24 +08:00
parent 9c820445a4
commit 2413cbcd80
3 changed files with 134 additions and 0 deletions

View File

@ -1,6 +1,7 @@
package config package config
import ( import (
"encoding/json"
"fmt" "fmt"
"os" "os"
"path/filepath" "path/filepath"
@ -8,10 +9,15 @@ import (
"testing" "testing"
"time" "time"
"github.com/google/uuid"
"github.com/micro/go-micro/config/source/env" "github.com/micro/go-micro/config/source/env"
"github.com/micro/go-micro/config/source/file" "github.com/micro/go-micro/config/source/file"
) )
var (
sep = string(os.PathSeparator)
)
func createFileForIssue18(t *testing.T, content string) *os.File { func createFileForIssue18(t *testing.T, content string) *os.File {
data := []byte(content) data := []byte(content)
path := filepath.Join(os.TempDir(), fmt.Sprintf("file.%d", time.Now().UnixNano())) path := filepath.Join(os.TempDir(), fmt.Sprintf("file.%d", time.Now().UnixNano()))
@ -116,3 +122,57 @@ func TestConfigMerge(t *testing.T) {
actualHost) actualHost)
} }
} }
func TestFileChange(t *testing.T) {
// create a temp file
fileName := uuid.New().String() + "testWatcher.json"
f, err := os.OpenFile("."+sep+fileName, os.O_WRONLY|os.O_CREATE, 0666)
if err != nil {
t.Error(err)
}
defer f.Close()
defer os.Remove("." + sep + fileName)
// load the file
if err := Load(file.NewSource(
file.WithPath("." + sep + fileName),
)); err != nil {
t.Error(err)
}
// watch changes
watcher, err := Watch()
if err != nil {
t.Error(err)
}
changeTimes := 0
go func() {
for {
v, err := watcher.Next()
if err != nil {
t.Error(err)
return
}
changeTimes++
t.Logf("file change%s", string(v.Bytes()))
}
}()
content := map[int]string{}
// change the file
for i := 0; i < 5; i++ {
content[i] = time.Now().String()
bytes, _ := json.Marshal(content)
f.Truncate(0)
f.Seek(0, 0)
if _, err := f.Write(bytes); err != nil {
t.Error(err)
}
time.Sleep(time.Second)
}
if changeTimes != 4 {
t.Error(fmt.Errorf("watcher error: change times %d is not enough", changeTimes))
}
}

View File

@ -1,3 +1,5 @@
//+build !linux
package file package file
import ( import (

View File

@ -0,0 +1,72 @@
//+build linux
package file
import (
"errors"
"os"
"github.com/fsnotify/fsnotify"
"github.com/micro/go-micro/config/source"
)
type watcher struct {
f *file
fw *fsnotify.Watcher
exit chan bool
}
func newWatcher(f *file) (source.Watcher, error) {
fw, err := fsnotify.NewWatcher()
if err != nil {
return nil, err
}
fw.Add(f.path)
return &watcher{
f: f,
fw: fw,
exit: make(chan bool),
}, nil
}
func (w *watcher) Next() (*source.ChangeSet, error) {
// is it closed?
select {
case <-w.exit:
return nil, errors.New("watcher stopped")
default:
}
// try get the event
select {
case event, _ := <-w.fw.Events:
if event.Op == fsnotify.Rename {
// check existence of file, and add watch again
_, err := os.Stat(event.Name)
if err == nil || os.IsExist(err) {
w.fw.Add(event.Name)
}
}
c, err := w.f.Read()
if err != nil {
return nil, err
}
// add path again for the event bug of fsnotify
w.fw.Add(w.f.path)
return c, nil
case err := <-w.fw.Errors:
return nil, err
case <-w.exit:
return nil, errors.New("watcher stopped")
}
}
func (w *watcher) Stop() error {
return w.fw.Close()
}