libs: Call Flush() before rename #2428 (#2439)

* fix Group.RotateFile need call Flush() before rename. #2428
* fix some review issue. #2428
 refactor Group's config: replace  setting member with initial option
* fix a handwriting mistake
* fix a time window error between rename and write.
* fix a syntax mistake.
* change option name Get_ to With_
* fix review issue
* fix review issue

libs/autofile/cmd/logjack.go

@@ -39,13 +39,12 @@ func main() {
 	}
 
 	// Open Group
-	group, err := auto.OpenGroup(headPath)
+	group, err := auto.OpenGroup(headPath, auto.GroupHeadSizeLimit(chopSize), auto.GroupTotalSizeLimit(limitSize))
 	if err != nil {
 		fmt.Printf("logjack couldn't create output file %v\n", headPath)
 		os.Exit(1)
 	}
-	group.SetHeadSizeLimit(chopSize)
-	group.SetTotalSizeLimit(limitSize)
+
 	err = group.Start()
 	if err != nil {
 		fmt.Printf("logjack couldn't start with file %v\n", headPath)

libs/autofile/group.go

@@ -19,10 +19,10 @@ import (
 )
 
 const (
-	groupCheckDuration    = 5000 * time.Millisecond
-	defaultHeadSizeLimit  = 10 * 1024 * 1024       // 10MB
-	defaultTotalSizeLimit = 1 * 1024 * 1024 * 1024 // 1GB
-	maxFilesToRemove      = 4                      // needs to be greater than 1
+	defaultGroupCheckDuration = 5000 * time.Millisecond
+	defaultHeadSizeLimit      = 10 * 1024 * 1024       // 10MB
+	defaultTotalSizeLimit     = 1 * 1024 * 1024 * 1024 // 1GB
+	maxFilesToRemove          = 4                      // needs to be greater than 1
 )
 
 /*
@@ -56,16 +56,17 @@ assuming that marker lines are written occasionally.
 type Group struct {
 	cmn.BaseService
 
-	ID             string
-	Head           *AutoFile // The head AutoFile to write to
-	headBuf        *bufio.Writer
-	Dir            string // Directory that contains .Head
-	ticker         *time.Ticker
-	mtx            sync.Mutex
-	headSizeLimit  int64
-	totalSizeLimit int64
-	minIndex       int // Includes head
-	maxIndex       int // Includes head, where Head will move to
+	ID                 string
+	Head               *AutoFile // The head AutoFile to write to
+	headBuf            *bufio.Writer
+	Dir                string // Directory that contains .Head
+	ticker             *time.Ticker
+	mtx                sync.Mutex
+	headSizeLimit      int64
+	totalSizeLimit     int64
+	groupCheckDuration time.Duration
+	minIndex           int // Includes head
+	maxIndex           int // Includes head, where Head will move to
 
 	// TODO: When we start deleting files, we need to start tracking GroupReaders
 	// and their dependencies.
@@ -73,7 +74,7 @@ type Group struct {
 
 // OpenGroup creates a new Group with head at headPath. It returns an error if
 // it fails to open head file.
-func OpenGroup(headPath string) (g *Group, err error) {
+func OpenGroup(headPath string, groupOptions ...func(*Group)) (g *Group, err error) {
 	dir := path.Dir(headPath)
 	head, err := OpenAutoFile(headPath)
 	if err != nil {
@@ -81,15 +82,21 @@ func OpenGroup(headPath string) (g *Group, err error) {
 	}
 
 	g = &Group{
-		ID:             "group:" + head.ID,
-		Head:           head,
-		headBuf:        bufio.NewWriterSize(head, 4096*10),
-		Dir:            dir,
-		headSizeLimit:  defaultHeadSizeLimit,
-		totalSizeLimit: defaultTotalSizeLimit,
-		minIndex:       0,
-		maxIndex:       0,
+		ID:                 "group:" + head.ID,
+		Head:               head,
+		headBuf:            bufio.NewWriterSize(head, 4096*10),
+		Dir:                dir,
+		headSizeLimit:      defaultHeadSizeLimit,
+		totalSizeLimit:     defaultTotalSizeLimit,
+		groupCheckDuration: defaultGroupCheckDuration,
+		minIndex:           0,
+		maxIndex:           0,
 	}
+
+	for _, option := range groupOptions {
+		option(g)
+	}
+
 	g.BaseService = *cmn.NewBaseService(nil, "Group", g)
 
 	gInfo := g.readGroupInfo()
@@ -98,10 +105,31 @@ func OpenGroup(headPath string) (g *Group, err error) {
 	return
 }
 
+// GroupCheckDuration allows you to overwrite default groupCheckDuration.
+func GroupCheckDuration(duration time.Duration) func(*Group) {
+	return func(g *Group) {
+		g.groupCheckDuration = duration
+	}
+}
+
+// GroupHeadSizeLimit allows you to overwrite default head size limit - 10MB.
+func GroupHeadSizeLimit(limit int64) func(*Group) {
+	return func(g *Group) {
+		g.headSizeLimit = limit
+	}
+}
+
+// GroupTotalSizeLimit allows you to overwrite default total size limit of the group - 1GB.
+func GroupTotalSizeLimit(limit int64) func(*Group) {
+	return func(g *Group) {
+		g.totalSizeLimit = limit
+	}
+}
+
 // OnStart implements Service by starting the goroutine that checks file and
 // group limits.
 func (g *Group) OnStart() error {
-	g.ticker = time.NewTicker(groupCheckDuration)
+	g.ticker = time.NewTicker(g.groupCheckDuration)
 	go g.processTicks()
 	return nil
 }
@@ -122,13 +150,6 @@ func (g *Group) Close() {
 	g.mtx.Unlock()
 }
 
-// SetHeadSizeLimit allows you to overwrite default head size limit - 10MB.
-func (g *Group) SetHeadSizeLimit(limit int64) {
-	g.mtx.Lock()
-	g.headSizeLimit = limit
-	g.mtx.Unlock()
-}
-
 // HeadSizeLimit returns the current head size limit.
 func (g *Group) HeadSizeLimit() int64 {
 	g.mtx.Lock()
@@ -136,14 +157,6 @@ func (g *Group) HeadSizeLimit() int64 {
 	return g.headSizeLimit
 }
 
-// SetTotalSizeLimit allows you to overwrite default total size limit of the
-// group - 1GB.
-func (g *Group) SetTotalSizeLimit(limit int64) {
-	g.mtx.Lock()
-	g.totalSizeLimit = limit
-	g.mtx.Unlock()
-}
-
 // TotalSizeLimit returns total size limit of the group.
 func (g *Group) TotalSizeLimit() int64 {
 	g.mtx.Lock()
@@ -266,6 +279,14 @@ func (g *Group) RotateFile() {
 
 	headPath := g.Head.Path
 
+	if err := g.headBuf.Flush(); err != nil {
+		panic(err) //panic is used for consistent with below
+	}
+
+	if err := g.Head.Sync(); err != nil {
+		panic(err)
+	}
+
 	if err := g.Head.closeFile(); err != nil {
 		panic(err)
 	}
@@ -275,6 +296,12 @@ func (g *Group) RotateFile() {
 		panic(err)
 	}
 
+	//make sure head file exist, there is a window time between rename and next write
+	//when NewReader(maxIndex), lead to "open /tmp/wal058868562/wal: no such file or directory"
+	if err := g.Head.openFile(); err != nil {
+		panic(err)
+	}
+
 	g.maxIndex++
 }
 

libs/autofile/group_test.go

@@ -23,12 +23,10 @@ func createTestGroupWithHeadSizeLimit(t *testing.T, headSizeLimit int64) *Group
 	require.NoError(t, err, "Error creating dir")
 
 	headPath := testDir + "/myfile"
-	g, err := OpenGroup(headPath)
+	g, err := OpenGroup(headPath, GroupHeadSizeLimit(headSizeLimit))
 	require.NoError(t, err, "Error opening Group")
 	require.NotEqual(t, nil, g, "Failed to create Group")
 
-	g.SetHeadSizeLimit(headSizeLimit)
-
 	return g
 }