/* Set a client in blocking mode for the specified key, with the specified
* timeout */
void blockForKeys(redisClient *c, robj **keys, int numkeys, mstime_t timeout, robj *target) {
dictEntry *de;
list *l;
int j;
c->bpop.timeout = timeout;
c->bpop.target = target;
if (target != NULL) incrRefCount(target);
for (j = 0; j < numkeys; j++) {
/* If the key already exists in the dict ignore it. */
if (dictAdd(c->bpop.keys,keys[j],NULL) != DICT_OK) continue;
incrRefCount(keys[j]);
redisDb *db = &(c->db)[keyHashSlot(keys[j]->ptr, sdslen(keys[j]->ptr))];
/* And in the other "side", to map keys -> clients */
de = dictFind(db->blocking_keys,keys[j]);
if (de == NULL) {
int retval;
/* For every key we take a list of clients blocked for it */
l = listCreate();
retval = dictAdd(db->blocking_keys,keys[j],l);
incrRefCount(keys[j]);
redisAssertWithInfo(c,keys[j],retval == DICT_OK);
} else {
l = dictGetVal(de);
}
listAddNodeTail(l,c);
}
blockClient(c,REDIS_BLOCKED_LIST);
}
void readQueryFromClient(aeEventLoop *el, int fd, httpClient *c) {
char buf[CCACHE_IOBUF_LEN];
int nread;
nread = read(fd, buf, CCACHE_IOBUF_LEN);
if (nread == -1) {
if (errno == EAGAIN) { /* try again */
nread = 0;
} else {
ulog(CCACHE_VERBOSE, "Reading from client: %s",strerror(errno));
freeClient(c);
return;
}
} else if (nread == 0) {
ulog(CCACHE_VERBOSE, "End of client request");
freeClient(c);
return;
}
if (nread>0) {
printf("Read Request: %.2lf \n", (double)(clock()));
c->lastinteraction = time(NULL);
listMoveNodeToTail(el->clients,c->elNode);
/* NOTICE: nread or nread-1 */
switch(requestParse(c->req,buf,buf+nread)){
case parse_not_completed:
break;
case parse_completed:
{
int handle_result = requestHandle(c->req,c->rep,el->cache,c);
if(handle_result == HANDLER_BLOCK){
blockClient(el,c);
}
else {
if (_installWriteEvent(el, c) != CCACHE_OK) return;
printf("Install Write: %.2lf\n", (double)(clock()));
/* For HANDLE_OK there is nothing to do */
if(handle_result == HANDLER_ERR) requestHandleError(c->req,c->rep);
}
break;
}
case parse_error:
if (_installWriteEvent(el, c) != CCACHE_OK) {
return;
}
requestHandleError(c->req,c->rep);
break;
default:
break;
};
}
}
/* Set a client in blocking mode for the specified key (list or stream), with
* the specified timeout. The 'type' argument is BLOCKED_LIST or BLOCKED_STREAM
* depending on the kind of operation we are waiting for an empty key in
* order to awake the client. The client is blocked for all the 'numkeys'
* keys as in the 'keys' argument. When we block for stream keys, we also
* provide an array of streamID structures: clients will be unblocked only
* when items with an ID greater or equal to the specified one is appended
* to the stream. */
void blockForKeys(client *c, int btype, robj **keys, int numkeys, mstime_t timeout, robj *target, streamID *ids) {
dictEntry *de;
list *l;
int j;
c->bpop.timeout = timeout;
c->bpop.target = target;
if (target != NULL) incrRefCount(target);
for (j = 0; j < numkeys; j++) {
/* The value associated with the key name in the bpop.keys dictionary
* is NULL for lists, or the stream ID for streams. */
void *key_data = NULL;
if (btype == BLOCKED_STREAM) {
key_data = zmalloc(sizeof(streamID));
memcpy(key_data,ids+j,sizeof(streamID));
}
/* If the key already exists in the dictionary ignore it. */
if (dictAdd(c->bpop.keys,keys[j],key_data) != DICT_OK) {
zfree(key_data);
continue;
}
incrRefCount(keys[j]);
/* And in the other "side", to map keys -> clients */
de = dictFind(c->db->blocking_keys,keys[j]);
if (de == NULL) {
int retval;
/* For every key we take a list of clients blocked for it */
l = listCreate();
retval = dictAdd(c->db->blocking_keys,keys[j],l);
incrRefCount(keys[j]);
serverAssertWithInfo(c,keys[j],retval == DICT_OK);
} else {
l = dictGetVal(de);
}
listAddNodeTail(l,c);
}
blockClient(c,btype);
}
// keys是一个key的数组，个数为numkeys个
// timeout保存超时时间
// target保存解除阻塞时的key对象，用于BRPOPLPUSH函数
// 根据给定的key将client阻塞
void blockForKeys(client *c, robj **keys, int numkeys, mstime_t timeout, robj *target) {
dictEntry *de;
list *l;
int j;
//设置超时时间和target
c->bpop.timeout = timeout;
c->bpop.target = target;
//增加target的引用计数
if (target != NULL) incrRefCount(target);
//将当前client的numkeys个key设置为阻塞
for (j = 0; j < numkeys; j++) {
/* If the key already exists in the dict ignore it. */
//bpop.keys记录所有造成client阻塞的键
//将要阻塞的键放入bpop.keys字典中
if (dictAdd(c->bpop.keys,keys[j],NULL) != DICT_OK) continue;
//当前的key引用计数加1
incrRefCount(keys[j]);
/* And in the other "side", to map keys -> clients */
//db->blocking_keys是一个字典，字典的键为bpop.keys中的一个键，值是一个列表，保存着所有被该键阻塞的client
//当前造成client被阻塞的键有没有当前的key
de = dictFind(c->db->blocking_keys,keys[j]);
if (de == NULL) { //没有当前的key，添加进去
int retval;
/* For every key we take a list of clients blocked for it */
//创建一个列表
l = listCreate();
//将造成阻塞的键和列表添加到db->blocking_keys字典中
retval = dictAdd(c->db->blocking_keys,keys[j],l);
incrRefCount(keys[j]);
serverAssertWithInfo(c,keys[j],retval == DICT_OK);
} else { //如果已经有了，则当前key的值保存起来，值是一个列表
l = dictGetVal(de);
}
listAddNodeTail(l,c); //将当前client加入到阻塞的client的列表
}
blockClient(c,BLOCKED_LIST); //阻塞client
}