提供array和hashtable的存储引擎层的二进制安全支持，把入口函数修改为接收参数长度，将strlen、strcmp、strcpy替换。

kvs_rw_tools.h

@@ -25,7 +25,7 @@ int kvs_write_u32(uint8_t **pp, const uint8_t *end, uint32_t v);
 #define KVS_MAX_CMDS_PER_CALL 	64
 // 1MB
 #define KVS_MAX_RESPONSE 		(1024u * 1024u)
-#define KVS_MAX_ARGC 			64
+#define KVS_MAX_ARGC 			4
 #define KVS_MAX_ARGLEN			(1024u * 1024u)
 #define KVS_MAX_CMD_BYTES 		(4u * 1024u * 1024u)
 
@@ -37,6 +37,30 @@ enum {
 	KVS_STATUS_BADREQ = 4
 };
 
+enum {
+	KVS_CMD_START = 0,
+	// array
+	KVS_CMD_SET = KVS_CMD_START,
+	KVS_CMD_GET,
+	KVS_CMD_DEL,
+	KVS_CMD_MOD,
+	KVS_CMD_EXIST,
+	// rbtree
+	KVS_CMD_RSET,
+	KVS_CMD_RGET,
+	KVS_CMD_RDEL,
+	KVS_CMD_RMOD,
+	KVS_CMD_REXIST,
+	// hash
+	KVS_CMD_HSET,
+	KVS_CMD_HGET,
+	KVS_CMD_HDEL,
+	KVS_CMD_HMOD,
+	KVS_CMD_HEXIST,
+	
+	KVS_CMD_COUNT,
+};
+
 typedef enum {
 	KVS_OK = 1,
 	KVS_NEED_MORE = 0,