Merge pull request #53 from wagerlabs/v1

Single inotify instance with multiple watchers

tail.go

@@ -5,16 +5,17 @@ package tail
 import (
 	"bufio"
 	"fmt"
-	"github.com/ActiveState/tail/ratelimiter"
-	"github.com/ActiveState/tail/util"
-	"github.com/ActiveState/tail/watch"
-	"gopkg.in/tomb.v1"
 	"io"
 	"io/ioutil"
 	"log"
 	"os"
 	"strings"
 	"time"
+
+	"github.com/ActiveState/tail/ratelimiter"
+	"github.com/ActiveState/tail/util"
+	"github.com/ActiveState/tail/watch"
+	"gopkg.in/tomb.v1"
 )
 
 var (
@@ -63,6 +64,8 @@ type Tail struct {
 
 	file    *os.File
 	reader  *bufio.Reader
+	tracker *watch.InotifyTracker
+
 	watcher watch.FileWatcher
 	changes *watch.FileChanges
 
@@ -99,7 +102,12 @@ func TailFile(filename string, config Config) (*Tail, error) {
 	if t.Poll {
 		t.watcher = watch.NewPollingFileWatcher(filename)
 	} else {
-		t.watcher = watch.NewInotifyFileWatcher(filename)
+		t.tracker = watch.NewInotifyTracker()
+		w, err := t.tracker.NewWatcher()
+		if err != nil {
+			return nil, err
+		}
+		t.watcher = watch.NewInotifyFileWatcher(filename, w)
 	}
 
 	if t.MustExist {
@@ -381,6 +389,8 @@ func (tail *Tail) sendLine(line string) bool {
 // Cleanup removes inotify watches added by the tail package. This function is
 // meant to be invoked from a process's exit handler. Linux kernel may not
 // automatically remove inotify watches after the process exits.
-func Cleanup() {
+func (tail *Tail) Cleanup() {
-	watch.Cleanup()
+	if tail.tracker != nil {
+		tail.tracker.CloseAll()
+	}
 }

tail_test.go

@@ -6,14 +6,15 @@
 package tail
 
 import (
-	"./watch"
 	_ "fmt"
-	"github.com/ActiveState/tail/ratelimiter"
 	"io/ioutil"
 	"os"
 	"strings"
 	"testing"
 	"time"
+
+	"./watch"
+	"github.com/ActiveState/tail/ratelimiter"
 )
 
 func init() {
@@ -40,7 +41,7 @@ func TestMustExist(t *testing.T) {
 		t.Error("MustExist:true on an existing file is violated")
 	}
 	tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 func TestStop(t *testing.T) {
@@ -51,7 +52,7 @@ func TestStop(t *testing.T) {
 	if tail.Stop() != nil {
 		t.Error("Should be stoped successfully")
 	}
-	Cleanup()
+	tail.Cleanup()
 }
 
 func MaxLineSizeT(_t *testing.T, follow bool, fileContent string, expected []string) {
@@ -65,7 +66,7 @@ func MaxLineSizeT(_t *testing.T, follow bool, fileContent string, expected []str
 	<-time.After(100 * time.Millisecond)
 	t.RemoveFile("test.txt")
 	tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 func TestMaxLineSizeFollow(_t *testing.T) {
@@ -89,7 +90,7 @@ func TestOver4096ByteLine(_t *testing.T) {
 	<-time.After(100 * time.Millisecond)
 	t.RemoveFile("test.txt")
 	tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 func TestOver4096ByteLineWithSetMaxLineSize(_t *testing.T) {
 	t := NewTailTest("Over4096ByteLineMaxLineSize", _t)
@@ -103,7 +104,7 @@ func TestOver4096ByteLineWithSetMaxLineSize(_t *testing.T) {
 	<-time.After(100 * time.Millisecond)
 	t.RemoveFile("test.txt")
 	// tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 func TestLocationFull(_t *testing.T) {
@@ -117,7 +118,7 @@ func TestLocationFull(_t *testing.T) {
 	<-time.After(100 * time.Millisecond)
 	t.RemoveFile("test.txt")
 	tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 func TestLocationFullDontFollow(_t *testing.T) {
@@ -132,7 +133,7 @@ func TestLocationFullDontFollow(_t *testing.T) {
 	<-time.After(100 * time.Millisecond)
 
 	tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 func TestLocationEnd(_t *testing.T) {
@@ -149,7 +150,7 @@ func TestLocationEnd(_t *testing.T) {
 	<-time.After(100 * time.Millisecond)
 	t.RemoveFile("test.txt")
 	tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 func TestLocationMiddle(_t *testing.T) {
@@ -167,7 +168,7 @@ func TestLocationMiddle(_t *testing.T) {
 	<-time.After(100 * time.Millisecond)
 	t.RemoveFile("test.txt")
 	tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 func _TestReOpen(_t *testing.T, poll bool) {
@@ -210,7 +211,7 @@ func _TestReOpen(_t *testing.T, poll bool) {
 	// the reading of data written above. Timings can vary based on
 	// test environment.
 	// tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 // The use of polling file watcher could affect file rotation
@@ -253,7 +254,7 @@ func _TestReSeek(_t *testing.T, poll bool) {
 	// the reading of data written above. Timings can vary based on
 	// test environment.
 	// tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 // The use of polling file watcher could affect file rotation
@@ -293,7 +294,7 @@ func TestRateLimiting(_t *testing.T) {
 	t.RemoveFile("test.txt")
 
 	// tail.Stop()
-	Cleanup()
+	tail.Cleanup()
 }
 
 func TestTell(_t *testing.T) {
@@ -327,7 +328,7 @@ func TestTell(_t *testing.T) {
 	}
 	t.RemoveFile("test.txt")
 	tail.Done()
-	Cleanup()
+	tail.Cleanup()
 }
 
 // Test library

watch/inotify.go

@@ -4,40 +4,35 @@ package watch
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
+
 	"github.com/ActiveState/tail/util"
 	"gopkg.in/fsnotify.v0"
 	"gopkg.in/tomb.v1"
-	"os"
-	"path/filepath"
 )
 
-var inotifyTracker *InotifyTracker
-
 // InotifyFileWatcher uses inotify to monitor file changes.
 type InotifyFileWatcher struct {
 	Filename string
 	Size     int64
+	w        *fsnotify.Watcher
 }
 
-func NewInotifyFileWatcher(filename string) *InotifyFileWatcher {
+func NewInotifyFileWatcher(filename string, w *fsnotify.Watcher) *InotifyFileWatcher {
-	fw := &InotifyFileWatcher{filename, 0}
+	fw := &InotifyFileWatcher{filename, 0, w}
 	return fw
 }
 
 func (fw *InotifyFileWatcher) BlockUntilExists(t *tomb.Tomb) error {
-	w, err := inotifyTracker.NewWatcher()
-	if err != nil {
-		return err
-	}
-	defer inotifyTracker.CloseWatcher(w)
-
 	dirname := filepath.Dir(fw.Filename)
 
 	// Watch for new files to be created in the parent directory.
-	err = w.WatchFlags(dirname, fsnotify.FSN_CREATE)
+	err := fw.w.WatchFlags(dirname, fsnotify.FSN_CREATE)
 	if err != nil {
 		return err
 	}
+	defer fw.w.RemoveWatch(dirname)
 
 	// Do a real check now as the file might have been created before
 	// calling `WatchFlags` above.
@@ -48,7 +43,7 @@ func (fw *InotifyFileWatcher) BlockUntilExists(t *tomb.Tomb) error {
 
 	for {
 		select {
-		case evt, ok := <-w.Event:
+		case evt, ok := <-fw.w.Event:
 			if !ok {
 				return fmt.Errorf("inotify watcher has been closed")
 			} else if evt.Name == fw.Filename {
@@ -64,11 +59,7 @@ func (fw *InotifyFileWatcher) BlockUntilExists(t *tomb.Tomb) error {
 func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, fi os.FileInfo) *FileChanges {
 	changes := NewFileChanges()
 
-	w, err := inotifyTracker.NewWatcher()
+	err := fw.w.Watch(fw.Filename)
-	if err != nil {
-		util.Fatal("Error creating fsnotify watcher: %v", err)
-	}
-	err = w.Watch(fw.Filename)
 	if err != nil {
 		util.Fatal("Error watching %v: %v", fw.Filename, err)
 	}
@@ -76,7 +67,7 @@ func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, fi os.FileInfo) *FileCh
 	fw.Size = fi.Size()
 
 	go func() {
-		defer inotifyTracker.CloseWatcher(w)
+		defer fw.w.RemoveWatch(fw.Filename)
 		defer changes.Close()
 
 		for {
@@ -86,7 +77,7 @@ func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, fi os.FileInfo) *FileCh
 			var ok bool
 
 			select {
-			case evt, ok = <-w.Event:
+			case evt, ok = <-fw.w.Event:
 				if !ok {
 					return
 				}
@@ -126,11 +117,3 @@ func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, fi os.FileInfo) *FileCh
 
 	return changes
 }
-
-func Cleanup() {
-	inotifyTracker.CloseAll()
-}
-
-func init() {
-	inotifyTracker = NewInotifyTracker()
-}