tcc rename

database/cluster_helper.go

@@ -0,0 +1,91 @@
+package database
+
+import (
+	"github.com/hdt3213/godis/aof"
+	"github.com/hdt3213/godis/interface/redis"
+	"github.com/hdt3213/godis/redis/parser"
+	"github.com/hdt3213/godis/redis/protocol"
+)
+
+// execExistIn returns existing key in given keys
+// example: ExistIn key1 key2 key3..., returns [key1, key2]
+// custom command for MSetNX tcc transaction
+func execExistIn(db *DB, args [][]byte) redis.Reply {
+	var result [][]byte
+	for _, arg := range args {
+		key := string(arg)
+		_, exists := db.GetEntity(key)
+		if exists {
+			result = append(result, []byte(key))
+		}
+	}
+	if len(result) == 0 {
+		return protocol.MakeEmptyMultiBulkReply()
+	}
+	return protocol.MakeMultiBulkReply(result)
+}
+
+// execDumpKey returns redis serialization protocol data of given key (see aof.EntityToCmd)
+func execDumpKey(db *DB, args [][]byte) redis.Reply {
+	key := string(args[0])
+	entity, ok := db.GetEntity(key)
+	if !ok {
+		return protocol.MakeEmptyMultiBulkReply()
+	}
+	dumpCmd := aof.EntityToCmd(key, entity)
+	ttlCmd := toTTLCmd(db, key)
+	resp := protocol.MakeMultiBulkReply([][]byte{
+		dumpCmd.ToBytes(),
+		ttlCmd.ToBytes(),
+	})
+	return resp
+}
+
+// execRenameFrom exactly the same as execDel, used for cluster.Rename
+func execRenameFrom(db *DB, args [][]byte) redis.Reply {
+	key := string(args[0])
+	db.Remove(key)
+	return protocol.MakeOkReply()
+}
+
+// execRenameTo accepts result of execDumpKey and load the dumped key
+// args format: key dumpCmd ttlCmd
+// execRenameTo may be partially successful, do not use it without transaction
+func execRenameTo(db *DB, args [][]byte) redis.Reply {
+	key := args[0]
+	dumpRawCmd, err := parser.ParseOne(args[1])
+	if err != nil {
+		return protocol.MakeErrReply("illegal dump cmd: " + err.Error())
+	}
+	dumpCmd, ok := dumpRawCmd.(*protocol.MultiBulkReply)
+	if !ok {
+		return protocol.MakeErrReply("dump cmd is not multi bulk reply")
+	}
+	dumpCmd.Args[1] = key // change key
+	ttlRawCmd, err := parser.ParseOne(args[2])
+	if err != nil {
+		return protocol.MakeErrReply("illegal ttl cmd: " + err.Error())
+	}
+	ttlCmd, ok := ttlRawCmd.(*protocol.MultiBulkReply)
+	if !ok {
+		return protocol.MakeErrReply("ttl cmd is not multi bulk reply")
+	}
+	ttlCmd.Args[1] = key
+	db.Remove(string(key))
+	dumpResult := db.execWithLock(dumpCmd.Args)
+	if protocol.IsErrorReply(dumpResult) {
+		return dumpResult
+	}
+	ttlResult := db.execWithLock(ttlCmd.Args)
+	if protocol.IsErrorReply(ttlResult) {
+		return ttlResult
+	}
+	return protocol.MakeOkReply()
+}
+
+func init() {
+	RegisterCommand("DumpKey", execDumpKey, writeAllKeys, undoDel, 2)
+	RegisterCommand("ExistIn", execExistIn, readAllKeys, nil, -1)
+	RegisterCommand("RenameFrom", execRenameFrom, readFirstKey, nil, 2)
+	RegisterCommand("RenameTo", execRenameTo, writeFirstKey, rollbackFirstKey, 4)
+}