support rename in cluster

cluster/commands/mset.go

@@ -123,7 +123,7 @@ func execMGet(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.
 	for node, ret := range nodeResults {
 		nodeCmdLine := cmdLineMap[node]
 		result := ret.(*protocol.MultiBulkReply)
-		if len(result.Args) != len(nodeCmdLine) - 1 {
+		if len(result.Args) != len(nodeCmdLine)-1 {
 			return protocol.MakeErrReply("wrong response from node " + node)
 		}
 		for i := 1; i < len(nodeCmdLine); i++ {
@@ -143,12 +143,12 @@ func execMGet(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.
 const someKeysExistsErr = "Some Keys Exists"
 
 func init() {
-	core.RegisterPreCheck("msetnx", msetNxPrecheck)
+	core.RegisterPrepareFunc("msetnx", msetNxPrecheck)
 }
 
 func msetNxPrecheck(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
 	var keys []string
-	for i := 1; i < len(cmdLine); i+=2 {
+	for i := 1; i < len(cmdLine); i += 2 {
 		keys = append(keys, string(cmdLine[i]))
 	}
 	exists := cluster.LocalExists(keys)

cluster/commands/rename.go

@@ -0,0 +1,88 @@
+package commands
+
+import (
+	"github.com/hdt3213/godis/cluster/core"
+	"github.com/hdt3213/godis/interface/redis"
+	"github.com/hdt3213/godis/lib/utils"
+	"github.com/hdt3213/godis/redis/protocol"
+)
+
+func init() {
+	core.RegisterCmd("rename_", execRenameInLocal)
+	core.RegisterCmd("rename", execRename)
+	core.RegisterPrepareFunc("RenameFrom", prepareRenameFrom)
+}
+
+func execRenameInLocal(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
+	cmdLine[0] = []byte("rename")
+	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")
+	}
+	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("RenameTo"), []byte(target), srcPrepareResult.Args[0], srcPrepareResult.Args[1]))
+	if protocol.IsErrorReply(targetPrepareResp) {
+		// rollback src node
+		requestRollback(cluster, c, txID, routeMap)
+		return targetPrepareResp
+	}
+
+	// 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.MakeOkReply()
+}
+
+// prepareRenameFrom is prepare-function for RenameFrom
+func prepareRenameFrom(cluster *core.Cluster, conn redis.Connection, cmdLine CmdLine) redis.Reply {
+	if len(cmdLine) != 2 {
+		return protocol.MakeArgNumErrReply("RenameFrom")
+	}
+	key := string(cmdLine[1])
+	existResp := cluster.LocalExec(conn, utils.ToCmdLine("Exists", key))
+	if protocol.IsErrorReply(existResp) {
+		return existResp
+	}
+	existIntResp := existResp.(*protocol.IntReply)
+	if existIntResp.Code == 0 {
+		return protocol.MakeErrReply("ERR no such key")
+	}
+	return cluster.LocalExecWithinLock(conn, utils.ToCmdLine2("DumpKey", key))
+}

cluster/commands/rename_test.go

@@ -0,0 +1,28 @@
+package commands
+
+import (
+	"testing"
+
+	"github.com/hdt3213/godis/cluster/core"
+	"github.com/hdt3213/godis/lib/utils"
+	"github.com/hdt3213/godis/redis/connection"
+	"github.com/hdt3213/godis/redis/protocol/asserts"
+)
+
+func TestRename(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 := execRename(node1, c, utils.ToCmdLine("rename", "1", "2"))
+	asserts.AssertStatusReply(t, res, "OK")
+
+	res = node1.Exec(c, utils.ToCmdLine("get", "2"))
+	asserts.AssertBulkReply(t, res, "1")
+}

cluster/core/tcc.go

@@ -60,22 +60,22 @@ func execPrepare(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.Re
 	cluster.transactions.txs[txId] = tx
 	cluster.transactions.mu.Unlock()
 
-	// pre-execute check
-	validator := preChecks[string(realCmdLine[0])]
-	if validator != nil {
-		validateResult := validator(cluster, c, realCmdLine)
-		if protocol.IsErrorReply(validateResult) {
-			return validateResult
-		}
-	}
-
 	// prepare lock and undo locks
 	tx.writeKeys, tx.readKeys = database.GetRelatedKeys(realCmdLine)
 	cluster.db.RWLocks(0, tx.writeKeys, tx.readKeys)
 	tx.undoLogs = cluster.db.GetUndoLogs(0, realCmdLine)
 	tx.realCmdLine = realCmdLine
 
-	return protocol.MakeOkReply()
+	// execute prepare func
+	prepareFunc := prepareFuncs[strings.ToLower(string(realCmdLine[0]))]
+	var result redis.Reply
+	if prepareFunc != nil {
+		result = prepareFunc(cluster, c, realCmdLine)
+	} else {
+		result = protocol.MakeOkReply()
+	}
+
+	return result
 }
 
 func execCommit(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
@@ -142,13 +142,10 @@ func execRollback(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.R
 	return protocol.MakeOkReply()
 }
 
-// PreCheckFunc do validation during tcc preparing period
-type PreCheckFunc func(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply
-
-var preChecks = make(map[string]PreCheckFunc)
+var prepareFuncs = make(map[string]CmdFunc)
 
 // RegisterCmd add tcc preparing validator
-func RegisterPreCheck(name string, fn PreCheckFunc) {
+func RegisterPrepareFunc(name string, fn CmdFunc) {
 	name = strings.ToLower(name)
-	preChecks[name] = fn
+	prepareFuncs[name] = fn
 }

cluster/core/utils.go

@@ -39,6 +39,11 @@ func (cluster *Cluster) LocalExec(c redis.Connection, cmdLine [][]byte) redis.Re
 	return cluster.db.Exec(c, cmdLine)
 }
 
+// LocalExec executes command at local node
+func (cluster *Cluster) LocalExecWithinLock(c redis.Connection, cmdLine [][]byte) redis.Reply {
+	return cluster.db.ExecWithLock(c, cmdLine)
+}
+
 // GetPartitionKey extract hashtag
 func GetPartitionKey(key string) string {
 	beg := strings.Index(key, "{")