//解阻塞一个正在阻塞中的client
void unblockClientWaitingData(client *c) {
dictEntry *de;
dictIterator *di;
list *l;
serverAssertWithInfo(c,NULL,dictSize(c->bpop.keys) != 0);
//创建一个字典的迭代器，指向的是造成client阻塞的键所组成的字典
di = dictGetIterator(c->bpop.keys);
/* The client may wait for multiple keys, so unblock it for every key. */
//因为client可能被多个key所阻塞，所以要遍历所有的键
while((de = dictNext(di)) != NULL) {
robj *key = dictGetKey(de); //获得key对象
/* Remove this client from the list of clients waiting for this key. */
//根据key找到对应的列表类型值，值保存着被阻塞的client，从中找c->db->blocking_keys中寻找
l = dictFetchValue(c->db->blocking_keys,key);
serverAssertWithInfo(c,key,l != NULL);
// 将阻塞的client从列表中移除
listDelNode(l,listSearchKey(l,c));
/* If the list is empty we need to remove it to avoid wasting memory */
//如果当前列表为空了，则从c->db->blocking_keys中将key删除
if (listLength(l) == 0)
dictDelete(c->db->blocking_keys,key);
}
dictReleaseIterator(di); //释放迭代器
/* Cleanup the client structure */
//清空bpop.keys的所有节点
dictEmpty(c->bpop.keys,NULL);
//如果保存有新添加的元素，则应该释放
if (c->bpop.target) {
decrRefCount(c->bpop.target);
c->bpop.target = NULL;
}
}
/* Unblock a client that's waiting in a blocking operation such as BLPOP.
* You should never call this function directly, but unblockClient() instead. */
void unblockClientWaitingData(client *c) {
dictEntry *de;
dictIterator *di;
list *l;
serverAssertWithInfo(c,NULL,dictSize(c->bpop.keys) != 0);
di = dictGetIterator(c->bpop.keys);
/* The client may wait for multiple keys, so unblock it for every key. */
while((de = dictNext(di)) != NULL) {
robj *key = dictGetKey(de);
/* Remove this client from the list of clients waiting for this key. */
l = dictFetchValue(c->db->blocking_keys,key);
serverAssertWithInfo(c,key,l != NULL);
listDelNode(l,listSearchKey(l,c));
/* If the list is empty we need to remove it to avoid wasting memory */
if (listLength(l) == 0)
dictDelete(c->db->blocking_keys,key);
}
dictReleaseIterator(di);
/* Cleanup the client structure */
dictEmpty(c->bpop.keys,NULL);
if (c->bpop.target) {
decrRefCount(c->bpop.target);
c->bpop.target = NULL;
}
}
/* Create a quicklist from a single ziplist */
void listTypeConvert(robj *subject, int enc) {
serverAssertWithInfo(NULL,subject,subject->type==OBJ_LIST);
serverAssertWithInfo(NULL,subject,subject->encoding==OBJ_ENCODING_ZIPLIST);
if (enc == OBJ_ENCODING_QUICKLIST) {
size_t zlen = server.list_max_ziplist_size;
int depth = server.list_compress_depth;
subject->ptr = quicklistCreateFromZiplist(zlen, depth, subject->ptr);
subject->encoding = OBJ_ENCODING_QUICKLIST;
} else {
serverPanic("Unsupported list conversion");
}
}
// 取消客户端对所有的键的监视，清理 EXEC dirty 标识状态由调用者决定
void unwatchAllKeys(client *c) {
listIter li;
listNode *ln;
// 如果客户端没有监视key则直接返回
if (listLength(c->watched_keys) == 0) return;
listRewind(c->watched_keys,&li);
// 遍历客户端监视的key
while((ln = listNext(&li))) {
list *clients;
watchedKey *wk;
/* Lookup the watched key -> clients list and remove the client
* from the list */
wk = listNodeValue(ln);
// 从数据库中的watched_keys字典中查找出监视key的client
clients = dictFetchValue(wk->db->watched_keys, wk->key);
serverAssertWithInfo(c,NULL,clients != NULL);
// 从client的链表中删除当前client节点
listDelNode(clients,listSearchKey(clients,c));
/* Kill the entry at all if this was the only client */
// 如果client链表为空，标识给key没有被监视
if (listLength(clients) == 0)
// 从数据库的watched_keys中删除该key
dictDelete(wk->db->watched_keys, wk->key);
/* Remove this watched key from the client->watched list */
// 从客户端的watched_keys中删除该节点
listDelNode(c->watched_keys,ln);
decrRefCount(wk->key);
zfree(wk);
}
}
/* Unwatch all the keys watched by this client. To clean the EXEC dirty
* flag is up to the caller.
*
* 清空WATCH的键, 而清空EXEC脏标识的任务由调用者完成 */
void unwatchAllKeys(client *c) {
listIter li;
listNode *ln;
/* 释放监控的键 */
if (listLength(c->watched_keys) == 0) return;
listRewind(c->watched_keys,&li);
while((ln = listNext(&li))) {
list *clients;
watchedKey *wk;
/* Lookup the watched key -> clients list and remove the client
* from the list */
wk = listNodeValue(ln);
clients = dictFetchValue(wk->db->watched_keys, wk->key);
serverAssertWithInfo(c,NULL,clients != NULL);
listDelNode(clients,listSearchKey(clients,c));
/* Kill the entry at all if this was the only client */
if (listLength(clients) == 0)
dictDelete(wk->db->watched_keys, wk->key);
/* Remove this watched key from the client->watched list */
listDelNode(c->watched_keys,ln);
decrRefCount(wk->key);
zfree(wk);
}
}
//从对象中将字符串值转换为long double并存储在target中
int getLongDoubleFromObject(robj *o, long double *target) {
long double value;
char *eptr;
if (o == NULL) { //对象不存在
value = 0;
} else {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
//如果是字符串编码的两种类型
if (sdsEncodedObject(o)) {
errno = 0;
value = strtold(o->ptr, &eptr); //将字符串转换为long double类型
if (isspace(((char*)o->ptr)[0]) || eptr[0] != '\0' ||
errno == ERANGE || isnan(value)) //转换失败返回-1
return C_ERR;
} else if (o->encoding == OBJ_ENCODING_INT) { //整数编码
value = (long)o->ptr; //保存整数值
} else {
serverPanic("Unknown string encoding");
}
}
*target = value; //将值存到传入参数中，返回0成功
return C_OK;
}
/* Set a client in blocking mode for the specified key, with the specified
* timeout */
void blockForKeys(client *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]);
/* 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,BLOCKED_LIST);
}
void brpoplpushCommand(client *c) {
mstime_t timeout;
if (getTimeoutFromObjectOrReply(c,c->argv[3],&timeout,UNIT_SECONDS)
!= C_OK) return;
robj *key = lookupKeyWrite(c->db, c->argv[1]);
if (key == NULL) {
if (c->flags & CLIENT_MULTI) {
/* Blocking against an empty list in a multi state
* returns immediately. */
addReply(c, shared.nullbulk);
} else {
/* The list is empty and the client blocks. */
blockForKeys(c, c->argv + 1, 1, timeout, c->argv[2]);
}
} else {
if (key->type != OBJ_LIST) {
addReply(c, shared.wrongtypeerr);
} else {
/* The list exists and has elements, so
* the regular rpoplpushCommand is executed. */
serverAssertWithInfo(c,key,listTypeLength(key) > 0);
rpoplpushCommand(c);
}
}
}
int getDoubleFromObject(robj *o, double *target) {
double value;
char *eptr;
if (o == NULL) {
value = 0;
} else {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
if (sdsEncodedObject(o)) {
errno = 0;
value = strtod(o->ptr, &eptr);
if (isspace(((char*)o->ptr)[0]) ||
eptr[0] != '\0' ||
(errno == ERANGE &&
(value == HUGE_VAL || value == -HUGE_VAL || value == 0)) ||
errno == EINVAL ||
isnan(value))
return C_ERR;
} else if (o->encoding == OBJ_ENCODING_INT) {
value = (long)o->ptr;
} else {
serverPanic("Unknown string encoding");
}
}
*target = value;
return C_OK;
}
/* Convert the set to specified encoding. The resulting dict (when converting
* to a hash table) is presized to hold the number of elements in the original
* set. */
void setTypeConvert(robj *setobj, int enc) {
setTypeIterator *si;
serverAssertWithInfo(NULL,setobj,setobj->type == OBJ_SET &&
setobj->encoding == OBJ_ENCODING_INTSET);
if (enc == OBJ_ENCODING_HT) {
int64_t intele;
dict *d = dictCreate(&setDictType,NULL);
sds element;
/* Presize the dict to avoid rehashing */
dictExpand(d,intsetLen(setobj->ptr));
/* To add the elements we extract integers and create redis objects */
si = setTypeInitIterator(setobj);
while (setTypeNext(si,&element,&intele) != -1) {
element = sdsfromlonglong(intele);
serverAssert(dictAdd(d,element,NULL) == DICT_OK);
}
setTypeReleaseIterator(si);
setobj->encoding = OBJ_ENCODING_HT;
zfree(setobj->ptr);
setobj->ptr = d;
} else {
serverPanic("Unsupported set conversion");
}
}
int compareStringObjectsWithFlags(robj *a, robj *b, int flags) {
serverAssertWithInfo(NULL,a,a->type == OBJ_STRING && b->type == OBJ_STRING);
char bufa[128], bufb[128], *astr, *bstr;
size_t alen, blen, minlen;
if (a == b) return 0;
if (sdsEncodedObject(a)) {
astr = a->ptr;
alen = sdslen(astr);
} else {
alen = ll2string(bufa,sizeof(bufa),(long) a->ptr);
astr = bufa;
}
if (sdsEncodedObject(b)) {
bstr = b->ptr;
blen = sdslen(bstr);
} else {
blen = ll2string(bufb,sizeof(bufb),(long) b->ptr);
bstr = bufb;
}
if (flags & REDIS_COMPARE_COLL) {
return strcoll(astr,bstr);
} else {
int cmp;
minlen = (alen < blen) ? alen : blen;
cmp = memcmp(astr,bstr,minlen);
if (cmp == 0) return alen-blen;
return cmp;
}
}
/* Add the key to the DB. It's up to the caller to increment the reference
* counter of the value if needed.
*
* The program is aborted if the key already exists. */
void dbAdd(redisDb *db, robj *key, robj *val) {
sds copy = sdsdup(key->ptr);
int retval = dictAdd(db->dict, copy, val);
serverAssertWithInfo(NULL,key,retval == C_OK);
if (val->type == OBJ_LIST) signalListAsReady(db, key);
if (server.cluster_enabled) slotToKeyAdd(key);
}
size_t stringObjectLen(robj *o) {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
if (sdsEncodedObject(o)) {
return sdslen(o->ptr);
} else {
return sdigits10((long)o->ptr);
}
}
/* Compare the given object with the entry at the current position. */
int listTypeEqual(listTypeEntry *entry, robj *o) {
if (entry->li->encoding == OBJ_ENCODING_QUICKLIST) {
serverAssertWithInfo(NULL,o,sdsEncodedObject(o));
return quicklistCompare(entry->entry.zi,o->ptr,sdslen(o->ptr));
} else {
serverPanic("Unknown list encoding");
}
}
/* Return the amount of memory used by the sds string at object->ptr
* for a string object. */
size_t getStringObjectSdsUsedMemory(robj *o) {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
switch(o->encoding) {
case OBJ_ENCODING_RAW: return sdsZmallocSize(o->ptr);
case OBJ_ENCODING_EMBSTR: return dmalloc_size(o)-sizeof(robj);
default: return 0; /* Just integer encoding for now. */
}
}
void setExpire(redisDb *db, robj *key, long long when) {
dictEntry *kde, *de;
/* Reuse the sds from the main dict in the expire dict */
kde = dictFind(db->dict,key->ptr);
serverAssertWithInfo(NULL,key,kde != NULL);
de = dictReplaceRaw(db->expires,dictGetKey(kde));
dictSetSignedIntegerVal(de,when);
}
//转换ZIPLIST编码类型为quicklist类型，enc指定OBJ_ENCODING_QUICKLIST
void listTypeConvert(robj *subject, int enc) {
//确保subject的类型为列表类型，且编码为ziplist类型
serverAssertWithInfo(NULL,subject,subject->type==OBJ_LIST);
serverAssertWithInfo(NULL,subject,subject->encoding==OBJ_ENCODING_ZIPLIST);
//对制定enc编码为quicklist类型操作
if (enc == OBJ_ENCODING_QUICKLIST) {
//以下两行都是由配置文件制定的参数
size_t zlen = server.list_max_ziplist_size; //最大ziplist大小
int depth = server.list_compress_depth; //压缩深度
//创建一个quicklist并将ptr指向的entry追加在quicklist末尾
subject->ptr = quicklistCreateFromZiplist(zlen, depth, subject->ptr);
//设置新的编码类型为OBJ_ENCODING_QUICKLIST
subject->encoding = OBJ_ENCODING_QUICKLIST;
} else {
serverPanic("Unsupported list conversion");
}
}
int isObjectRepresentableAsLongLong(robj *o, long long *llval) {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
if (o->encoding == OBJ_ENCODING_INT) {
if (llval) *llval = (long) o->ptr;
return C_OK;
} else {
return string2ll(o->ptr,sdslen(o->ptr),llval) ? C_OK : C_ERR;
}
}
//返回字符串对象的字符串长度
size_t stringObjectLen(robj *o) {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
//如果是字符串编码的两种类型
if (sdsEncodedObject(o)) {
return sdslen(o->ptr);
} else { //如果是整数编码类型
return sdigits10((long)o->ptr); //计算出整数值的位数返回
}
}
//判断对象的ptr指向的值能否转换为long long类型，如果可以保存在llval中
int isObjectRepresentableAsLongLong(robj *o, long long *llval) {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
if (o->encoding == OBJ_ENCODING_INT) { //如果本身就是整数
if (llval) *llval = (long) o->ptr;
return C_OK; //成功返回0
} else {
//字符串转换为longlong类型，成功返回0，失败返回-1
return string2ll(o->ptr,sdslen(o->ptr),llval) ? C_OK : C_ERR;
}
}
void debugCommand(client *c) {
if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
*((char*)-1) = 'x';
} else if (!strcasecmp(c->argv[1]->ptr,"oom")) {
void *ptr = zmalloc(ULONG_MAX); /* Should trigger an out of memory. */
zfree(ptr);
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"assert")) {
if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);
serverAssertWithInfo(c,c->argv[0],1 == 2);
} else if (!strcasecmp(c->argv[1]->ptr,"flushall")) {
flushServerData();
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
flushServerData();
if (loadAppendOnlyFile(server.aof_filename) != C_OK) {
addReply(c,shared.err);
return;
}
serverLog(LL_WARNING,"Append Only File loaded by DEBUG LOADAOF");
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
double dtime = strtod(c->argv[2]->ptr,NULL);
long long utime = dtime*1000000;
struct timespec tv;
tv.tv_sec = utime / 1000000;
tv.tv_nsec = (utime % 1000000) * 1000;
nanosleep(&tv, NULL);
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"error") && c->argc == 3) {
sds errstr = sdsnewlen("-",1);
errstr = sdscatsds(errstr,c->argv[2]->ptr);
errstr = sdsmapchars(errstr,"\n\r"," ",2); /* no newlines in errors. */
errstr = sdscatlen(errstr,"\r\n",2);
addReplySds(c,errstr);
} else if (!strcasecmp(c->argv[1]->ptr,"structsize") && c->argc == 2) {
sds sizes = sdsempty();
sizes = sdscatprintf(sizes,"bits:%d ",(sizeof(void*) == 8)?64:32);
sizes = sdscatprintf(sizes,"job:%d ", (int)sizeof(job));
sizes = sdscatprintf(sizes,"queue:%d ", (int)sizeof(queue));
sizes = sdscatprintf(sizes,"robj:%d ",(int)sizeof(robj));
sizes = sdscatprintf(sizes,"dictentry:%d ",(int)sizeof(dictEntry));
sizes = sdscatprintf(sizes,"sdshdr5:%d ",(int)sizeof(struct sdshdr5));
sizes = sdscatprintf(sizes,"sdshdr8:%d ",(int)sizeof(struct sdshdr8));
sizes = sdscatprintf(sizes,"sdshdr16:%d ",(int)sizeof(struct sdshdr16));
sizes = sdscatprintf(sizes,"sdshdr32:%d ",(int)sizeof(struct sdshdr32));
sizes = sdscatprintf(sizes,"sdshdr64:%d ",(int)sizeof(struct sdshdr64));
addReplyBulkSds(c,sizes);
} else {
addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",
(char*)c->argv[1]->ptr);
}
}
//比较列表类型的entry结构与对象的entry节点的值是否等，相等返回1
int listTypeEqual(listTypeEntry *entry, robj *o) {
//对列表对象编码为quicklist类型操作
if (entry->li->encoding == OBJ_ENCODING_QUICKLIST) {
//确保objptr的编码类型是简单动态字符串类型的RAW或EMBSTR
serverAssertWithInfo(NULL,o,sdsEncodedObject(o));
//比较listTypeEntry结构中的entry值和给定的对象的值
return quicklistCompare(entry->entry.zi,o->ptr,sdslen(o->ptr));
} else {
serverPanic("Unknown list encoding");
}
}
/* Return the expire time of the specified key, or -1 if no expire
* is associated with this key (i.e. the key is non volatile) */
long long getExpire(redisDb *db, robj *key) {
dictEntry *de;
/* No expire? return ASAP */
if (dictSize(db->expires) == 0 ||
(de = dictFind(db->expires,key->ptr)) == NULL) return -1;
/* The entry was found in the expire dict, this means it should also
* be present in the main dict (safety check). */
serverAssertWithInfo(NULL,key,dictFind(db->dict,key->ptr) != NULL);
return dictGetSignedIntegerVal(de);
}
/* Unsubscribe a client from a channel. Returns 1 if the operation succeeded, or
* 0 if the client was not subscribed to the specified channel. */
int smempubsubUnsubscribeChannel(client *c, robj *channel, int notify)
{
dictEntry *de;
list *clients;
listNode *ln;
int retval = 0;
/* Remove the channel from the client -> channels hash table */
incrRefCount(channel); /* channel may be just a pointer to the same object
we have in the hash tables. Protect it... */
if (dictDelete(c->smempubsub_channels,channel) == DICT_OK) {
retval = 1;
/* Remove the client from the channel -> clients list hash table */
de = dictFind(server.smempubsub_channels,channel);
serverAssertWithInfo(c,NULL,de != NULL);
clients = dictGetVal(de);
ln = listSearchKey(clients,c);
serverAssertWithInfo(c,NULL,ln != NULL);
listDelNode(clients,ln);
if (listLength(clients) == 0) {
/* Free the list and associated hash entry at all if this was
* the latest client, so that it will be possible to abuse
* Redis PUBSUB creating millions of channels. */
dictDelete(server.smempubsub_channels,channel);
}
}
/* Notify the client */
if (notify) {
addReply(c,shared.mbulkhdr[3]);
addReply(c,shared.unsubscribebulk);
addReplyBulk(c,channel);
addReplyLongLong(c,dictSize(c->smempubsub_channels));
}
decrRefCount(channel); /* it is finally safe to release it */
return retval;
}
/* This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT
* and PEXPIREAT. Because the commad second argument may be relative or absolute
* the "basetime" argument is used to signal what the base time is (either 0
* for *AT variants of the command, or the current time for relative expires).
*
* unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for
* the argv[2] parameter. The basetime is always specified in milliseconds. */
void expireGenericCommand(client *c, long long basetime, int unit) {
robj *key = c->argv[1], *param = c->argv[2];
long long when; /* unix time in milliseconds when the key will expire. */
if (getLongLongFromObjectOrReply(c, param, &when, NULL) != C_OK)
return;
if (unit == UNIT_SECONDS) when *= 1000;
when += basetime;
/* No key, return zero. */
if (lookupKeyWrite(c->db,key) == NULL) {
addReply(c,shared.czero);
return;
}
/* EXPIRE with negative TTL, or EXPIREAT with a timestamp into the past
* should never be executed as a DEL when load the AOF or in the context
* of a slave instance.
*
* Instead we take the other branch of the IF statement setting an expire
* (possibly in the past) and wait for an explicit DEL from the master. */
if (when <= mstime() && !server.loading && !server.masterhost) {
robj *aux;
serverAssertWithInfo(c,key,dbDelete(c->db,key));
server.dirty++;
/* Replicate/AOF this as an explicit DEL. */
aux = createStringObject("DEL",3);
rewriteClientCommandVector(c,2,aux,key);
decrRefCount(aux);
signalModifiedKey(c->db,key);
notifyKeyspaceEvent(NOTIFY_GENERIC,"del",key,c->db->id);
addReply(c, shared.cone);
return;
} else {
setExpire(c->db,key,when);
addReply(c,shared.cone);
signalModifiedKey(c->db,key);
notifyKeyspaceEvent(NOTIFY_GENERIC,"expire",key,c->db->id);
server.dirty++;
return;
}
}
int getLongLongFromObject(robj *o, long long *target) {
long long value;
if (o == NULL) {
value = 0;
} else {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
if (sdsEncodedObject(o)) {
if (string2ll(o->ptr,sdslen(o->ptr),&value) == 0) return C_ERR;
} else if (o->encoding == OBJ_ENCODING_INT) {
value = (long)o->ptr;
} else {
serverPanic("Unknown string encoding");
}
}
if (target) *target = value;
return C_OK;
}
/* 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
}
//从对象中将字符串值转换为long long并存储在target中
int getLongLongFromObject(robj *o, long long *target) {
long long value;
if (o == NULL) { //对象不存在
value = 0;
} else {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
//如果是字符串编码的两种类型
if (sdsEncodedObject(o)) {
//转换失败发送-1，成功保存值到value中
if (string2ll(o->ptr,sdslen(o->ptr),&value) == 0) return C_ERR;
} else if (o->encoding == OBJ_ENCODING_INT) { //整型编码
value = (long)o->ptr; //保存整数值
} else {
serverPanic("Unknown string encoding");
}
}
if (target) *target = value; //将值存到传入参数中，返回0成功
return C_OK;
}
int getLongLongFromObject(robj *o, long long *target) {
long long value;
char *eptr;
if (o == NULL) {
value = 0;
} else {
serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
if (sdsEncodedObject(o)) {
errno = 0;
value = strtoll(o->ptr, &eptr, 10);
if (isspace(((char*)o->ptr)[0]) || eptr[0] != '\0' ||
errno == ERANGE)
return VR_ERROR;
} else if (o->encoding == OBJ_ENCODING_INT) {
value = (long)o->ptr;
} else {
serverPanic("Unknown string encoding");
}
}
if (target) *target = value;
return VR_OK;
}
