Scripting: luaRedisGenericCommand() fast path for buffer-only replies.

When the reply is only contained in the client static output buffer, use
a fast path avoiding the dynamic allocation of an SDS string to
concatenate the client reply objects.
This commit is contained in:
antirez 2014-05-05 22:14:23 +02:00
parent 8226be61ec
commit 0ef4f44c5a

View File

@ -306,13 +306,21 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
/* Convert the result of the Redis command into a suitable Lua type.
* The first thing we need is to create a single string from the client
* output buffers. */
reply = sdsnewlen(c->buf,c->bufpos);
c->bufpos = 0;
while(listLength(c->reply)) {
robj *o = listNodeValue(listFirst(c->reply));
if (listLength(c->reply) == 0 && c->bufpos < REDIS_REPLY_CHUNK_BYTES) {
/* This is a fast path for the common case of a reply inside the
* client static buffer. Don't create an SDS string but just use
* the client buffer directly. */
c->buf[c->bufpos] = '\0';
reply = c->buf;
} else {
reply = sdsnewlen(c->buf,c->bufpos);
c->bufpos = 0;
while(listLength(c->reply)) {
robj *o = listNodeValue(listFirst(c->reply));
reply = sdscatlen(reply,o->ptr,sdslen(o->ptr));
listDelNode(c->reply,listFirst(c->reply));
reply = sdscatlen(reply,o->ptr,sdslen(o->ptr));
listDelNode(c->reply,listFirst(c->reply));
}
}
if (raise_error && reply[0] != '-') raise_error = 0;
redisProtocolToLuaType(lua,reply);
@ -322,7 +330,7 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
(reply[0] == '*' && reply[1] != '-')) {
luaSortArray(lua);
}
sdsfree(reply);
if (reply != c->buf) sdsfree(reply);
c->reply_bytes = 0;
cleanup: