renamenx in cluster

cluster/commands/rename.go

@@ -9,8 +9,12 @@ import (
 
 func init() {
 	core.RegisterCmd("rename_", execRenameInLocal)
+	core.RegisterCmd("renamenx_", execRenameNxInLocal)
 	core.RegisterCmd("rename", execRename)
+	core.RegisterCmd("renamenx", execRenameNx)
 	core.RegisterPrepareFunc("RenameFrom", prepareRenameFrom)
+	core.RegisterPrepareFunc("RenameNxTo", prepareRenameNxTo)
+
 }
 
 func execRenameInLocal(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
@@ -18,6 +22,11 @@ func execRenameInLocal(cluster *core.Cluster, c redis.Connection, cmdLine CmdLin
 	return cluster.LocalExec(c, cmdLine)
 }
 
+func execRenameNxInLocal(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
+	cmdLine[0] = []byte("renamenx")
+	return cluster.LocalExec(c, cmdLine)
+}
+
 func execRename(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
 	if len(cmdLine) != 3 {
 		return protocol.MakeArgNumErrReply("rename")
@@ -33,7 +42,7 @@ func execRename(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redi
 		return cluster.Relay(srcNode, c, cmdLine)
 	}
 	routeMap := RouteMap{
-		srcNode: {src},
+		srcNode:    {src},
 		targetNode: {target},
 	}
 
@@ -58,10 +67,10 @@ func execRename(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redi
 		return targetPrepareResp
 	}
 
-	// commit 
+	// commit
 	commitCmd := utils.ToCmdLine("commit", txID)
 	for node := range routeMap {
-		reply := cluster.Relay(node, c,commitCmd )
+		reply := cluster.Relay(node, c, commitCmd)
 		if err := protocol.Try2ErrorReply(reply); err != nil {
 			requestRollback(cluster, c, txID, routeMap)
 			return protocol.MakeErrReply("commit failed: " + err.Error())
@@ -70,6 +79,61 @@ func execRename(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redi
 	return protocol.MakeOkReply()
 }
 
+func execRenameNx(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
+	if len(cmdLine) != 3 {
+		return protocol.MakeArgNumErrReply("rename")
+	}
+	src := string(cmdLine[1])
+	target := string(cmdLine[2])
+	srcSlot := cluster.GetSlot(src)
+	srcNode := cluster.PickNode(srcSlot)
+	targetSlot := cluster.GetSlot(target)
+	targetNode := cluster.PickNode(targetSlot)
+	if srcNode == targetNode {
+		cmdLine[0] = []byte("rename")
+		return cluster.Relay(srcNode, c, cmdLine)
+	}
+	routeMap := RouteMap{
+		srcNode:    {src},
+		targetNode: {target},
+	}
+
+	txID := utils.RandString(10)
+	srcPrepareResp := cluster.Relay(srcNode, c, utils.ToCmdLine("Prepare", txID, "RenameFrom", src))
+	if protocol.IsErrorReply(srcPrepareResp) {
+		// rollback src node
+		requestRollback(cluster, c, txID, map[string][]string{srcNode: {src}})
+		return srcPrepareResp
+	}
+	srcPrepareResult, ok := srcPrepareResp.(*protocol.MultiBulkReply)
+	if !ok || len(srcPrepareResult.Args) < 2 {
+		requestRollback(cluster, c, txID, map[string][]string{srcNode: {src}})
+		return protocol.MakeErrReply("ERR invalid prepare response")
+	}
+	// prepare rename to
+	targetPrepareResp := cluster.Relay(targetNode, c, utils.ToCmdLine3("Prepare", []byte(txID),
+		[]byte("RenameNxTo"), []byte(target), srcPrepareResult.Args[0], srcPrepareResult.Args[1]))
+	if res, ok := targetPrepareResp.(protocol.ErrorReply); ok {
+		// rollback src node
+		requestRollback(cluster, c, txID, routeMap)
+		if res.Error() == keyExistsErr {
+			return protocol.MakeIntReply(0)
+		}
+		return res
+	}
+
+	// commit
+	commitCmd := utils.ToCmdLine("commit", txID)
+	for node := range routeMap {
+		reply := cluster.Relay(node, c, commitCmd)
+		if err := protocol.Try2ErrorReply(reply); err != nil {
+			requestRollback(cluster, c, txID, routeMap)
+			return protocol.MakeErrReply("commit failed: " + err.Error())
+		}
+	}
+	return protocol.MakeIntReply(1)
+}
+
 // prepareRenameFrom is prepare-function for RenameFrom
 func prepareRenameFrom(cluster *core.Cluster, conn redis.Connection, cmdLine CmdLine) redis.Reply {
 	if len(cmdLine) != 2 {
@@ -85,4 +149,18 @@ func prepareRenameFrom(cluster *core.Cluster, conn redis.Connection, cmdLine Cmd
 		return protocol.MakeErrReply("ERR no such key")
 	}
 	return cluster.LocalExecWithinLock(conn, utils.ToCmdLine2("DumpKey", key))
-}
+}
+
+const keyExistsErr = "key exists"
+
+func prepareRenameNxTo(cluster *core.Cluster, conn redis.Connection, cmdLine CmdLine) redis.Reply {
+	if len(cmdLine) != 4 {
+		return protocol.MakeArgNumErrReply("RenameNxTo")
+	}
+	key := string(cmdLine[1])
+	exists := cluster.LocalExists([]string{key})
+	if len(exists) > 0 {
+		return protocol.MakeErrReply(keyExistsErr)
+	}
+	return protocol.MakeOkReply()
+}

cluster/commands/rename_test.go

@@ -26,3 +26,25 @@ func TestRename(t *testing.T) {
 	res = node1.Exec(c, utils.ToCmdLine("get", "2"))
 	asserts.AssertBulkReply(t, res, "1")
 }
+
+func TestRenameNx(t *testing.T) {
+	id1 := "1"
+	id2 := "2"
+	nodes := core.MakeTestCluster([]string{id1, id2})
+	node1 := nodes[id1]
+	c := connection.NewFakeConn()
+	core.RegisterDefaultCmd("set")
+	core.RegisterDefaultCmd("get")
+	node1.Exec(c, utils.ToCmdLine("set", "1", "1"))
+
+	// 1, 2 will be routed to node1 and node2, see MakeTestCluster
+	res := execRenameNx(node1, c, utils.ToCmdLine("rename", "1", "2"))
+	asserts.AssertIntReply(t, res, 1)
+
+	res = node1.Exec(c, utils.ToCmdLine("get", "2"))
+	asserts.AssertBulkReply(t, res, "1")
+
+	node1.Exec(c, utils.ToCmdLine("set", "3", "3"))
+	res = execRenameNx(node1, c, utils.ToCmdLine("rename", "2", "3"))
+	asserts.AssertIntReply(t, res, 0)
+}

cluster/core/tcc.go

@@ -74,7 +74,10 @@ func execPrepare(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.Re
 	} else {
 		result = protocol.MakeOkReply()
 	}
-
+	if protocol.IsErrorReply(result) {
+		// prepare for rollback
+		cluster.db.RWUnLocks(0, tx.writeKeys, tx.readKeys)
+	}
 	return result
 }
 
@@ -145,6 +148,8 @@ func execRollback(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.R
 var prepareFuncs = make(map[string]CmdFunc)
 
 // RegisterCmd add tcc preparing validator
+// prepareFunc will be executed within lock
+// If prepareFunc returns an error reply, the transaction should be rolledback-
 func RegisterPrepareFunc(name string, fn CmdFunc) {
 	name = strings.ToLower(name)
 	prepareFuncs[name] = fn