using close channel to wait new bin log

ledis/binlog.go

@@ -105,6 +105,8 @@ type BinLog struct {
 	lastLogIndex int64
 
 	batchId uint32
+
+	ch chan struct{}
 }
 
 func NewBinLog(cfg *config.Config) (*BinLog, error) {
@@ -121,6 +123,8 @@ func NewBinLog(cfg *config.Config) (*BinLog, error) {
 
 	l.logNames = make([]string, 0, 16)
 
+	l.ch = make(chan struct{})
+
 	if err := l.loadIndex(); err != nil {
 		return nil, err
 	}
@@ -375,5 +379,12 @@ func (l *BinLog) Log(args ...[]byte) error {
 
 	l.checkLogFileSize()
 
+	close(l.ch)
+	l.ch = make(chan struct{})
+
 	return nil
 }
+
+func (l *BinLog) Wait() <-chan struct{} {
+	return l.ch
+}

ledis/replication.go

@@ -8,6 +8,7 @@ import (
 	"github.com/siddontang/ledisdb/store/driver"
 	"io"
 	"os"
+	"time"
 )
 
 const (
@@ -186,6 +187,31 @@ func (l *Ledis) ReplicateFromBinLog(filePath string) error {
 	return err
 }
 
+// try to read events, if no events read, try to wait the new event singal until timeout seconds
+func (l *Ledis) ReadEventsToTimeout(info *BinLogAnchor, w io.Writer, timeout int) (n int, err error) {
+	lastIndex := info.LogFileIndex
+	lastPos := info.LogPos
+
+	n = 0
+	if l.binlog == nil {
+		//binlog not supported
+		info.LogFileIndex = 0
+		info.LogPos = 0
+		return
+	}
+
+	n, err = l.ReadEventsTo(info, w)
+	if err == nil && info.LogFileIndex == lastIndex && info.LogPos == lastPos {
+		//no events read
+		select {
+		case <-l.binlog.Wait():
+		case <-time.After(time.Duration(timeout) * time.Second):
+		}
+		return l.ReadEventsTo(info, w)
+	}
+	return
+}
+
 func (l *Ledis) ReadEventsTo(info *BinLogAnchor, w io.Writer) (n int, err error) {
 	n = 0
 	if l.binlog == nil {

server/cmd_replication.go

@@ -89,7 +89,7 @@ func syncCommand(c *client) error {
 
 	c.syncBuf.Reset()
 
-	//reserve space to write master info
+	//reserve space to write binlog anchor
 	if _, err := c.syncBuf.Write(reserveInfoSpace); err != nil {
 		return err
 	}