refactor command table

router.go

@@ -1,102 +1,23 @@
 package godis
 
-func makeRouter() map[string]cmdFunc {
-	routerMap := make(map[string]cmdFunc)
-	routerMap["ping"] = Ping
+import "strings"
 
-	routerMap["del"] = Del
-	routerMap["expire"] = Expire
-	routerMap["expireat"] = ExpireAt
-	routerMap["pexpire"] = PExpire
-	routerMap["pexpireat"] = PExpireAt
-	routerMap["ttl"] = TTL
-	routerMap["pttl"] = PTTL
-	routerMap["persist"] = Persist
-	routerMap["exists"] = Exists
-	routerMap["type"] = Type
-	routerMap["rename"] = Rename
-	routerMap["renamenx"] = RenameNx
+var cmdTable = make(map[string]*command)
 
-	routerMap["set"] = Set
-	routerMap["setnx"] = SetNX
-	routerMap["setex"] = SetEX
-	routerMap["psetex"] = PSetEX
-	routerMap["mset"] = MSet
-	routerMap["mget"] = MGet
-	routerMap["msetnx"] = MSetNX
-	routerMap["get"] = Get
-	routerMap["getset"] = GetSet
-	routerMap["incr"] = Incr
-	routerMap["incrby"] = IncrBy
-	routerMap["incrbyfloat"] = IncrByFloat
-	routerMap["decr"] = Decr
-	routerMap["decrby"] = DecrBy
-
-	routerMap["lpush"] = LPush
-	routerMap["lpushx"] = LPushX
-	routerMap["rpush"] = RPush
-	routerMap["rpushx"] = RPushX
-	routerMap["lpop"] = LPop
-	routerMap["rpop"] = RPop
-	routerMap["rpoplpush"] = RPopLPush
-	routerMap["lrem"] = LRem
-	routerMap["llen"] = LLen
-	routerMap["lindex"] = LIndex
-	routerMap["lset"] = LSet
-	routerMap["lrange"] = LRange
-
-	routerMap["hset"] = HSet
-	routerMap["hsetnx"] = HSetNX
-	routerMap["hget"] = HGet
-	routerMap["hexists"] = HExists
-	routerMap["hdel"] = HDel
-	routerMap["hlen"] = HLen
-	routerMap["hmget"] = HMGet
-	routerMap["hmset"] = HMSet
-	routerMap["hkeys"] = HKeys
-	routerMap["hvals"] = HVals
-	routerMap["hgetall"] = HGetAll
-	routerMap["hincrby"] = HIncrBy
-	routerMap["hincrbyfloat"] = HIncrByFloat
-
-	routerMap["sadd"] = SAdd
-	routerMap["sismember"] = SIsMember
-	routerMap["srem"] = SRem
-	routerMap["scard"] = SCard
-	routerMap["smembers"] = SMembers
-	routerMap["sinter"] = SInter
-	routerMap["sinterstore"] = SInterStore
-	routerMap["sunion"] = SUnion
-	routerMap["sunionstore"] = SUnionStore
-	routerMap["sdiff"] = SDiff
-	routerMap["sdiffstore"] = SDiffStore
-	routerMap["srandmember"] = SRandMember
-
-	routerMap["zadd"] = ZAdd
-	routerMap["zscore"] = ZScore
-	routerMap["zincrby"] = ZIncrBy
-	routerMap["zrank"] = ZRank
-	routerMap["zcount"] = ZCount
-	routerMap["zrevrank"] = ZRevRank
-	routerMap["zcard"] = ZCard
-	routerMap["zrange"] = ZRange
-	routerMap["zrevrange"] = ZRevRange
-	routerMap["zrangebyscore"] = ZRangeByScore
-	routerMap["zrevrangebyscore"] = ZRevRangeByScore
-	routerMap["zrem"] = ZRem
-	routerMap["zremrangebyscore"] = ZRemRangeByScore
-	routerMap["zremrangebyrank"] = ZRemRangeByRank
-
-	routerMap["geoadd"] = GeoAdd
-	routerMap["geopos"] = GeoPos
-	routerMap["geodist"] = GeoDist
-	routerMap["geohash"] = GeoHash
-	routerMap["georadius"] = GeoRadius
-	routerMap["georadiusbymember"] = GeoRadiusByMember
-
-	routerMap["flushdb"] = FlushDB
-	routerMap["flushall"] = FlushAll
-	routerMap["keys"] = Keys
-
-	return routerMap
+type command struct {
+	executor ExecFunc
+	prepare  PreFunc // return related keys and rollback command
+	arity    int     // allow number of args, arity < 0 means len(args) >= -arity
+}
+
+// RegisterCommand registers a new command
+// arity means allowed number of cmdArgs, arity < 0 means len(args) >= -arity.
+// for example: the arity of `get` is 2, `mget` is -2
+func RegisterCommand(name string, executor ExecFunc, prepare PreFunc, arity int) {
+	name = strings.ToLower(name)
+	cmdTable[name] = &command{
+		executor: executor,
+		prepare:  prepare,
+		arity:    arity,
+	}
 }