c->reply_bytes += zmalloc_size_sds(o->ptr);
}
}
asyncCloseClientOnOutputBufferLimitReached(c);
}把robj对象加载reply列表中，并且改变reply的byte大小，最后还调用了一个asyncCloseClientOnOutputBufferLimitReached(c);方法，这个方法我是在这个文件的最底部找到的，一开始还真不知道什么意思，作用就是当添加完数据后，当客户端的输出缓冲的大小超出限制时，会被异步关闭:
/* Asynchronously close a client if soft or hard limit is reached on the
* output buffer size. The caller can check if the client will be closed
* checking if the client REDIS_CLOSE_ASAP flag is set.
*
* Note: we need to close the client asynchronously because this function is
* called from contexts where the client can't be freed safely, i.e. from the
* lower level functions pushing data inside the client output buffers. */
/* 异步的关闭Client，如果缓冲区中的软限制或是硬限制已经到达的时候，缓冲区超出限制的结果会导致释放不安全， */
void asyncCloseClientOnOutputBufferLimitReached(redisClient *c) {
redisAssert(c->reply_bytes < ULONG_MAX-(1024*64));
if (c->reply_bytes == 0 || c->flags & REDIS_CLOSE_ASAP) return;
if (checkClientOutputBufferLimits(c)) {
sds client = catClientInfoString(sdsempty(),c);
freeClientAsync(c);
redisLog(REDIS_WARNING,"Client %s scheduled to be closed ASAP for overcoming of output buffer limits.", client);
sdsfree(client);
}
}
在addReply方法调用的时候，有时是需要一个前提的，我说的是在写数据事件发生的时候，你得先对写的文件创建一个监听事件：
/* 在回复中添加Sds字符串 */
void addReplySds(redisClient *c, sds s) {
//在调用添加操作之前，都要先执行prepareClientToWrite(c)，设置文件事件的写事件
if (prepareClientToWrite(c) != REDIS_OK) {
/* The caller expects the sds to be free'd. */
sdsfree(s);
return;
}
if (_addReplyToBuffer(c,s,sdslen(s)) == REDIS_OK) {
sdsfree(s);
} else {
/* This method free's the sds when it is no longer needed. */
_addReplySdsToList(c,s);
}
}在这个prepareClientToWrite()里面是干嘛的呢？
/* This function is called every time we are going to transmit new data
* to the client. The behavior is the following:
*
* If the client should receive new data (normal clients will) the function
* returns REDIS_OK, and make sure to install the write handler in our event
* loop so that when the socket is writable new data gets written.
*
* If the client should not receive new data, because it is a fake client,
* a master, a slave not yet online, or because the setup of the write handler
* failed, the function returns REDIS_ERR.
*
* Typically gets called every time a reply is built, before adding more
* data to the clients output buffers. If the function returns REDIS_ERR no
* data should be appended to the output buffers. */
/* 此方法将会被调用于Client准备接受新数据之前调用，在fileEvent为客户端设定writer的handler处理事件 */
int prepareClientToWrite(redisClient *c) {
if (c->flags & REDIS_LUA_CLIENT) return REDIS_OK;
if ((c->flags & REDIS_MASTER) &&
!(c->flags & REDIS_MASTER_FORCE_REPLY)) return REDIS_ERR;
if (c->fd <= 0) return REDIS_ERR; /* Fake client */
if (c->bufpos == 0 && listLength(c->reply) == 0 &&
(c->replstate == REDIS_REPL_NONE ||
c->replstate == REDIS_REPL_ONLINE) &&
//在这里创建写的文件事件
aeCreateFileEvent(server.el, c->fd, AE_WRITABLE,
sendReplyToClient, c) == AE_ERR) return REDIS_ERR;
return REDIS_OK;
}
在addReply的方法里提到了一个addReplyBulk类型方法，Bulk的中文意思为大块的，说明addReplyBulk添加的都是一些比较大块的数据，找一个方法看看：
/* Add a Redis Object as a bulk reply */
/* 将一个obj的数据，拆分成大块数据的添加 */
void addReplyBulk(redisClient *c, robj *obj) {
//reply添加长度
addReplyBulkLen(c,obj);
//reply添加对象
addReply(c,obj);
addReply(c,shared.crlf);
}将原本一个robj的数据拆分成可3个普通的addReply的方法调用。就变成了数据量变大了的数据。大数据的回复一个比较不好的地方是到时解析的时候或者是Data的复制的时候会比较耗时。在networking的方法里还提供了freeClient()的操作:
/* 释放freeClient，要