void redisAsyncHandleWrite(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
int done = 0;
// 连接创建失败？？？
if (!(c->flags & REDIS_CONNECTED)) {
/* Abort connect was not successful. */
if (__redisAsyncHandleConnect(ac) != REDIS_OK)
return;
// 再尝试检测 flag
/* Try again later when the context is still not connected. */
if (!(c->flags & REDIS_CONNECTED))
return;
}
if (redisBufferWrite(c,&done) == REDIS_ERR) {
__redisAsyncDisconnect(ac);
} else {
/* Continue writing when not done, stop writing otherwise */
// 当缓冲区中还有数据待发送时，会再次注册写事件
if (!done)
_EL_ADD_WRITE(ac);
// 当缓冲区中没有数据待发送时，会再次注册写事件
else
_EL_DEL_WRITE(ac);
/* Always schedule reads after writes */
_EL_ADD_READ(ac);
}
}
void redisAsyncHandleWrite(redisAsyncContext *ac) {
redisContext *c = &(ac->c);
int done = 0;
int status;
if (!(c->flags & REDIS_CONNECTED)) {
/* Abort connect was not successful. */
if (__redisAsyncHandleConnect(ac) != REDIS_OK)
return;
/* Try again later when the context is still not connected. */
if (!(c->flags & REDIS_CONNECTED))
return;
}
pthread_mutex_lock(&ac->lock);
status = redisBufferWrite(c,&done);
pthread_mutex_unlock(&ac->lock);
if (status == REDIS_ERR) {
__redisAsyncDisconnect(ac);
} else {
/* Continue writing when not done, stop writing otherwise */
if (!done)
_EL_ADD_WRITE(ac);
else
_EL_DEL_WRITE(ac);
/* Always schedule reads after writes */
_EL_ADD_READ(ac);
}
}
/* Helper function for the redisAsyncCommand* family of functions. Writes a
* formatted command to the output buffer and registers the provided callback
* function with the context. */
static int __redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, char *cmd, size_t len) {
redisContext *c = &(ac->c);
redisCallback cb;
int pvariant, hasnext;
char *cstr, *astr;
size_t clen, alen;
char *p;
sds sname;
/* Don't accept new commands when the connection is about to be closed. */
if (c->flags & (REDIS_DISCONNECTING | REDIS_FREEING)) return REDIS_ERR;
/* Setup callback */
cb.fn = fn;
cb.privdata = privdata;
/* Find out which command will be appended. */
p = nextArgument(cmd,&cstr,&clen);
assert(p != NULL);
hasnext = (p[0] == '$');
pvariant = (tolower(cstr[0]) == 'p') ? 1 : 0;
cstr += pvariant;
clen -= pvariant;
if (hasnext && strncasecmp(cstr,"subscribe\r\n",11) == 0) {
c->flags |= REDIS_SUBSCRIBED;
/* Add every channel/pattern to the list of subscription callbacks. */
while ((p = nextArgument(p,&astr,&alen)) != NULL) {
sname = sdsnewlen(astr,alen);
if (pvariant)
dictReplace(ac->sub.patterns,sname,&cb);
else
dictReplace(ac->sub.channels,sname,&cb);
}
} else if (strncasecmp(cstr,"unsubscribe\r\n",13) == 0) {
/* It is only useful to call (P)UNSUBSCRIBE when the context is
* subscribed to one or more channels or patterns. */
if (!(c->flags & REDIS_SUBSCRIBED)) return REDIS_ERR;
/* (P)UNSUBSCRIBE does not have its own response: every channel or
* pattern that is unsubscribed will receive a message. This means we
* should not append a callback function for this command. */
} else {
if (c->flags & REDIS_SUBSCRIBED)
/* This will likely result in an error reply, but it needs to be
* received and passed to the callback. */
__redisPushCallback(&ac->sub.invalid,&cb);
else
__redisPushCallback(&ac->replies,&cb);
}
__redisAppendCommand(c,cmd,len);
/* Always schedule a write when the write buffer is non-empty */
_EL_ADD_WRITE(ac);
return REDIS_OK;
}
int redisAsyncSetConnectCallback(redisAsyncContext *ac, redisConnectCallback *fn) {
if (ac->onConnect == NULL) {
ac->onConnect = fn;
/* The common way to detect an established connection is to wait for
* the first write event to be fired. This assumes the related event
* library functions are already set. */
_EL_ADD_WRITE(ac);
return REDIS_OK;
}
return REDIS_ERR;
}
int redisAsyncHandleWriteComplete(redisAsyncContext *ac, int written) {
redisContext *c = &(ac->c);
int done = 0;
int rc;
rc = redisBufferWriteDone(c, written, &done);
if (rc == REDIS_ERR) {
__redisAsyncDisconnect(ac);
} else {
/* Continue writing when not done, stop writing otherwise */
if (!done)
_EL_ADD_WRITE(ac);
else
_EL_DEL_WRITE(ac);
/* Always schedule reads after writes */
_EL_ADD_READ(ac);
}
return REDIS_OK;
}