fix: client connection error

redis/client/client.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	"errors"
 	"github.com/hdt3213/godis/interface/redis"
 	"github.com/hdt3213/godis/lib/logger"
 	"github.com/hdt3213/godis/lib/sync/wait"
@@ -8,6 +9,7 @@ import (
 	"github.com/hdt3213/godis/redis/protocol"
 	"net"
 	"runtime/debug"
+	"strings"
 	"sync"
 	"time"
 )
@@ -57,12 +59,7 @@ func MakeClient(addr string) (*Client, error) {
 func (client *Client) Start() {
 	client.ticker = time.NewTicker(10 * time.Second)
 	go client.handleWrite()
-	go func() {
-		err := client.handleRead()
-		if err != nil {
-			logger.Error(err)
-		}
-	}()
+	go client.handleRead()
 	go client.heartbeat()
 }
 
@@ -80,27 +77,35 @@ func (client *Client) Close() {
 	close(client.waitingReqs)
 }
 
-func (client *Client) handleConnectionError(err error) error {
-	err1 := client.conn.Close()
-	if err1 != nil {
-		if opErr, ok := err1.(*net.OpError); ok {
-			if opErr.Err.Error() != "use of closed network connection" {
-				return err1
-			}
+func (client *Client) reconnect() {
+	_ = client.conn.Close() // ignore possible errors from repeated closes
+
+	var conn net.Conn
+	for i := 0; i < 3; i++ {
+		var err error
+		conn, err = net.Dial("tcp", client.addr)
+		if err != nil {
+			logger.Error("reconnect error: " + err.Error())
+			time.Sleep(time.Second)
+			continue
 		} else {
-			return err1
+			break
 		}
 	}
-	conn, err1 := net.Dial("tcp", client.addr)
-	if err1 != nil {
-		logger.Error(err1)
-		return err1
+	if conn == nil { // reach max retry, abort
+		client.Close()
+		return
 	}
 	client.conn = conn
-	go func() {
-		_ = client.handleRead()
-	}()
-	return nil
+	//
+	close(client.waitingReqs)
+	for req := range client.waitingReqs {
+		req.err = errors.New("connection closed")
+		req.waiting.Done()
+	}
+	client.waitingReqs = make(chan *request, chanSize)
+	// restart handle read
+	go client.handleRead()
 }
 
 func (client *Client) heartbeat() {
@@ -155,14 +160,14 @@ func (client *Client) doRequest(req *request) {
 	}
 	re := protocol.MakeMultiBulkReply(req.args)
 	bytes := re.ToBytes()
-	_, err := client.conn.Write(bytes)
-	i := 0
-	for err != nil && i < 3 {
-		err = client.handleConnectionError(err)
-		if err == nil {
-			_, err = client.conn.Write(bytes)
+	var err error
+	for i := 0; i < 3; i++ { // only retry, waiting for handleRead
+		_, err = client.conn.Write(bytes)
+		if err == nil ||
+			(!strings.Contains(err.Error(), "timeout") && // only retry timeout
+				!strings.Contains(err.Error(), "deadline exceeded")) {
+			break
 		}
-		i++
 	}
 	if err == nil {
 		client.waitingReqs <- req
@@ -189,14 +194,13 @@ func (client *Client) finishRequest(reply redis.Reply) {
 	}
 }
 
-func (client *Client) handleRead() error {
+func (client *Client) handleRead() {
 	ch := parser.ParseStream(client.conn)
 	for payload := range ch {
 		if payload.Err != nil {
-			client.finishRequest(protocol.MakeErrReply(payload.Err.Error()))
-			continue
+			client.reconnect()
+			return
 		}
 		client.finishRequest(payload.Data)
 	}
-	return nil
 }

redis/client/client_test.go

@@ -1,10 +1,12 @@
 package client
 
 import (
+	"bytes"
 	"github.com/hdt3213/godis/lib/logger"
 	"github.com/hdt3213/godis/redis/protocol"
 	"strconv"
 	"testing"
+	"time"
 )
 
 func TestClient(t *testing.T) {
@@ -104,3 +106,36 @@ func TestClient(t *testing.T) {
 
 	client.Close()
 }
+
+func TestReconnect(t *testing.T) {
+	logger.Setup(&logger.Settings{
+		Path:       "logs",
+		Name:       "godis",
+		Ext:        ".log",
+		TimeFormat: "2006-01-02",
+	})
+	client, err := MakeClient("localhost:6379")
+	if err != nil {
+		t.Error(err)
+	}
+	client.Start()
+
+	_ = client.conn.Close()
+	time.Sleep(time.Second) // wait for reconnecting
+	success := false
+	for i := 0; i < 3; i++ {
+		result := client.Send([][]byte{
+			[]byte("PING"),
+		})
+		if bytes.Equal(result.ToBytes(), []byte("+PONG\r\n")) {
+			success = true
+			break
+		}
+	}
+	if !success {
+		t.Error("reconnect error")
+	}
+	//var wg sync.WaitGroup
+	//wg.Add(1)
+	//wg.Wait()
+}