void popGenericCommand(redisClient *c, int where) {
robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk);
if (o == NULL || checkType(c,o,REDIS_LIST)) return;
robj *value = listTypePop(o,where);
if (value == NULL) {
addReply(c,shared.nullbulk);
} else {
addReplyBulk(c,value);
decrRefCount(value);
if (listTypeLength(o) == 0) dbDelete(c->db,c->argv[1]);
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
}
}
void srandmemberCommand(redisClient *c) {
robj *set, *ele;
int64_t llele;
int encoding;
if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,set,REDIS_SET)) return;
encoding = setTypeRandomElement(set,&ele,&llele);
if (encoding == REDIS_ENCODING_INTSET) {
addReplyBulkLongLong(c,llele);
} else {
addReplyBulk(c,ele);
}
}
/* Blocking RPOP/LPOP */
void blockingPopGenericCommand(redisClient *c, int where) {
robj *o;
time_t timeout;
int j;
for (j = 1; j < c->argc-1; j++) {
o = lookupKeyWrite(c->db,c->argv[j]);
if (o != NULL) {
if (o->type != REDIS_LIST) {
addReply(c,shared.wrongtypeerr);
return;
} else {
if (listTypeLength(o) != 0) {
/* If the list contains elements fall back to the usual
* non-blocking POP operation */
robj *argv[2], **orig_argv;
int orig_argc;
/* We need to alter the command arguments before to call
* popGenericCommand() as the command takes a single key. */
orig_argv = c->argv;
orig_argc = c->argc;
argv[1] = c->argv[j];
c->argv = argv;
c->argc = 2;
/* Also the return value is different, we need to output
* the multi bulk reply header and the key name. The
* "real" command will add the last element (the value)
* for us. If this souds like an hack to you it's just
* because it is... */
addReplySds(c,sdsnew("*2\r\n"));
addReplyBulk(c,argv[1]);
popGenericCommand(c,where);
/* Fix the client structure with the original stuff */
c->argv = orig_argv;
c->argc = orig_argc;
return;
}
}
}
}
/* If the list is empty or the key does not exists we must block */
timeout = strtol(c->argv[c->argc-1]->ptr,NULL,10);
if (timeout > 0) timeout += time(NULL);
blockForKeys(c,c->argv+1,c->argc-2,timeout);
}
void rpoplpushHandlePush(redisClient *c, robj *dstkey, robj *dstobj, robj *value) {
if (!handleClientsWaitingListPush(c,dstkey,value)) {
/* Create the list if the key does not exist */
if (!dstobj) {
dstobj = createZiplistObject();
dbAdd(c->db,dstkey,dstobj);
} else {
touchWatchedKey(c->db,dstkey);
server.dirty++;
}
listTypePush(dstobj,value,REDIS_HEAD);
}
/* Always send the pushed value to the client. */
addReplyBulk(c,value);
}
/* 退订频道，即取消客户端对某频道的订阅。如果操作成功返回1，如果该客户端没有订阅该频道则返回0 */
int pubsubUnsubscribeChannel(redisClient *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... */
// 将频道从客户端client -> channels字典中移除，如果移除成功，说明客户端的确订阅了该频道
if (dictDelete(c->pubsub_channels,channel) == DICT_OK) {
retval = 1;
/* Remove the client from the channel -> clients list hash table */
/* 将客户端从server.pubsub_channels字典中移除 */
// 找到订阅该频道的客户端链表
de = dictFind(server.pubsub_channels,channel);
redisAssertWithInfo(c,NULL,de != NULL);
clients = dictGetVal(de);
// 在链表中查找该客户端
ln = listSearchKey(clients,c);
redisAssertWithInfo(c,NULL,ln != NULL);
// 移除客户端
listDelNode(clients,ln);
// 如果订阅该频道的客户端链表为空，则删除之
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.pubsub_channels,channel);
}
}
/* Notify the client */
// 回复客户端
if (notify) {
addReply(c,shared.mbulkhdr[3]);
addReply(c,shared.unsubscribebulk);
// 被退订的客户端
addReplyBulk(c,channel);
// 客户端仍在订阅的频道和模式数量
addReplyLongLong(c,dictSize(c->pubsub_channels)+
listLength(c->pubsub_patterns));
}
decrRefCount(channel); /* it is finally safe to release it */
return retval;
}
void mgetCommand(redisClient *c) {
int j;
addReplyMultiBulkLen(c,c->argc-1);
for (j = 1; j < c->argc; j++) {
robj *o = lookupKeyRead(c->db,c->argv[j]);
if (o == NULL) {
addReply(c,shared.nullbulk);
} else {
if (o->type != REDIS_STRING) {
addReply(c,shared.nullbulk);
} else {
addReplyBulk(c,o);
}
}
}
}
void mgetCommand(redisClient *c) {
int j;
addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",c->argc-1));
for (j = 1; j < c->argc; j++) {
robj *o = lookupKeyRead(c->db,c->argv[j]);
if (o == NULL) {
addReply(c,shared.nullbulk);
} else {
if (o->type != REDIS_STRING) {
addReply(c,shared.nullbulk);
} else {
addReplyBulk(c,o);
}
}
}
}
/* Subscribe a client to a pattern. Returns 1 if the operation succeeded, or 0 if the client was already subscribed to that pattern.
*
* 设置客户端 c 订阅模式 pattern 。
*
* 订阅成功返回 1 ，如果客户端已经订阅了该模式，那么返回 0 。
*/
int pubsubSubscribePattern(redisClient *c, robj *pattern) {
int retval = 0;
// 在链表中查找模式，看客户端是否已经订阅了这个模式
// 这里为什么不像 channel 那样，用字典来进行检测呢？
// 虽然 pattern 的数量一般来说并不多
if (listSearchKey(c->pubsub_patterns,pattern) == NULL) {
// 如果没有的话，执行以下代码
retval = 1;
pubsubPattern *pat;
// 将 pattern 添加到 c->pubsub_patterns 链表中
listAddNodeTail(c->pubsub_patterns,pattern);
incrRefCount(pattern);
// 创建并设置新的 pubsubPattern 结构
pat = zmalloc(sizeof(*pat));
pat->pattern = getDecodedObject(pattern);
pat->client = c;
// 添加到末尾
listAddNodeTail(server.pubsub_patterns,pat);
}
/* Notify the client */
// 回复客户端。
// 示例：
// redis 127.0.0.1:6379> PSUBSCRIBE xxx*
// Reading messages... (press Ctrl-C to quit)
// 1) "psubscribe"
// 2) "xxx*"
// 3) (integer) 1
addReply(c,shared.mbulkhdr[3]);
// 回复 "psubscribe" 字符串
addReply(c,shared.psubscribebulk);
// 回复被订阅的模式
addReplyBulk(c,pattern);
// 回复客户端订阅的频道和模式的总数
addReplyLongLong(c,dictSize(c->pubsub_channels)+listLength(c->pubsub_patterns));
return retval;
}
static void condSelectReply(fr_t *fr, aobj *akey, void *rrow, long *card) {
uchar hit = 0;
if (fr->nowc) hit = 1;
else hit = passFilters(fr->btr, akey, rrow,
fr->w->flist, fr->w->tmatch);
if (hit) {
*card = *card + 1;
if (fr->cstar) return; /* just counting */
robj *r = outputRow(fr->btr, rrow, fr->qcols, fr->cmatchs,
akey, fr->w->tmatch, 0);
if (fr->q->qed) addRow2OBList(fr->ll, fr->w, fr->btr, r, fr->ofree,
rrow, akey);
else addReplyBulk(fr->c, r);
decrRefCount(r);
}
}
int getGenericCommand(redisClient *c) {
robj *o;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL) {
printf("1\n");
return REDIS_OK;
}
if (o->type != REDIS_STRING) {
printf("2\n");
addReply(c,shared.wrongtypeerr);
return REDIS_ERR;
} else {
printf("3\n");
addReplyBulk(c,o);
return REDIS_OK;
}
}
/* The SLOWLOG command. Implements all the subcommands needed to handle the
* Redis slow log. */
void slowlogCommand(redisClient *c) {
if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"reset")) {
slowlogReset();
addReply(c,shared.ok);
} else if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"len")) {
addReplyLongLong(c,listLength(server.slowlog));
} else if ((c->argc == 2 || c->argc == 3) &&
!strcasecmp(c->argv[1]->ptr,"get"))
{
#ifdef _WIN64
long long count = 10, sent = 0;
#else
long count = 10, sent = 0;
#endif
listIter li;
void *totentries;
listNode *ln;
slowlogEntry *se;
if (c->argc == 3 &&
getLongFromObjectOrReply(c,c->argv[2],&count,NULL) != REDIS_OK)
return;
listRewind(server.slowlog,&li);
totentries = addDeferredMultiBulkLength(c);
while(count-- && (ln = listNext(&li))) {
int j;
se = ln->value;
addReplyMultiBulkLen(c,4);
addReplyLongLong(c,se->id);
addReplyLongLong(c,se->time);
addReplyLongLong(c,se->duration);
addReplyMultiBulkLen(c,se->argc);
for (j = 0; j < se->argc; j++)
addReplyBulk(c,se->argv[j]);
sent++;
}
setDeferredMultiBulkLength(c,totentries,sent);
} else {
addReplyError(c,
"Unknown SLOWLOG subcommand or wrong # of args. Try GET, RESET, LEN.");
}
}
static bool nonRelIndRespHandler(redisClient *c,
void *x,
robj *key,
long *card,
int b, /* variable ignored */
int n) { /* variable ignored */
x = 0; b = 0; n = 0; /* compiler warnings */
if (NriFlag == PIPE_ONE_LINER_FLAG) {
char *s = key->ptr;
robj *r = _createStringObject(s + 1); /* +1 skips '+','-',':' */
decrRefCount(key);
key = r;
}
addReplyBulk(c, key);
decrRefCount(key);
*card = *card + 1;
CurrCard++;
return 1;
}
/* COMMAND <subcommand> <args> */
void commandCommand(client *c) {
dictIterator *di;
dictEntry *de;
if (c->argc == 1) {
addReplyMultiBulkLen(c, dictSize(server.commands));
di = dictGetIterator(server.commands);
while ((de = dictNext(di)) != NULL) {
addReplyCommand(c, dictGetVal(de));
}
dictReleaseIterator(di);
} else if (!strcasecmp(c->argv[1]->ptr, "info")) {
int i;
addReplyMultiBulkLen(c, c->argc-2);
for (i = 2; i < c->argc; i++) {
addReplyCommand(c, dictFetchValue(server.commands, c->argv[i]->ptr));
}
} else if (!strcasecmp(c->argv[1]->ptr, "count") && c->argc == 2) {
addReplyLongLong(c, dictSize(server.commands));
} else if (!strcasecmp(c->argv[1]->ptr,"getkeys") && c->argc >= 3) {
struct redisCommand *cmd = lookupCommand(c->argv[2]->ptr);
int *keys, numkeys, j;
if (!cmd) {
addReplyErrorFormat(c,"Invalid command specified");
return;
} else if ((cmd->arity > 0 && cmd->arity != c->argc-2) ||
((c->argc-2) < -cmd->arity))
{
addReplyError(c,"Invalid number of arguments specified for command");
return;
}
keys = getKeysFromCommand(cmd,c->argv+2,c->argc-2,&numkeys);
addReplyMultiBulkLen(c,numkeys);
for (j = 0; j < numkeys; j++) addReplyBulk(c,c->argv[keys[j]+2]);
getKeysFreeResult(keys);
} else {
addReplyError(c, "Unknown subcommand or wrong number of arguments.");
return;
}
}
void spopCommand(redisClient *c) {
robj *set, *ele;
int64_t llele;
int encoding;
if ((set = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,set,REDIS_SET)) return;
encoding = setTypeRandomElement(set,&ele,&llele);
if (encoding == REDIS_ENCODING_INTSET) {
addReplyBulkLongLong(c,llele);
set->ptr = intsetRemove(set->ptr,llele,NULL);
} else {
addReplyBulk(c,ele);
setTypeRemove(set,ele);
}
if (setTypeSize(set) == 0) dbDelete(c->db,c->argv[1]);
touchWatchedKey(c->db,c->argv[1]);
server.dirty++;
}
int getGenericCommand(redisClient *c) {
robj *o;
#ifdef AUTH_FEATURE
if (authCheckPathOrReply(c, c->argv[1]) == REDIS_ERR) {
return REDIS_ERR;
}
#endif
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL)
return REDIS_OK;
if (o->type != REDIS_STRING) {
addReply(c,shared.wrongtypeerr);
return REDIS_ERR;
} else {
addReplyBulk(c,o);
return REDIS_OK;
}
}
/* Subscribe a client to a pattern. Returns 1 if the operation succeeded, or 0 if the client was already subscribed to that pattern. */
int pubsubSubscribePattern(redisClient *c, robj *pattern) {
int retval = 0;
if (listSearchKey(c->pubsub_patterns,pattern) == NULL) {
retval = 1;
pubsubPattern *pat;
listAddNodeTail(c->pubsub_patterns,pattern);
incrRefCount(pattern);
pat = zmalloc(sizeof(*pat));
pat->pattern = getDecodedObject(pattern);
pat->client = c;
listAddNodeTail(server.pubsub_patterns,pat);
}
/* Notify the client */
addReply(c,shared.mbulkhdr[3]);
addReply(c,shared.psubscribebulk);
addReplyBulk(c,pattern);
addReplyLongLong(c,dictSize(c->pubsub_channels)+listLength(c->pubsub_patterns));
return retval;
}
/* Unsubscribe a client from a channel. Returns 1 if the operation succeeded, or
* 0 if the client was not subscribed to the specified channel.
*
* 取消客户端 c 对模式 pattern 的订阅。
*
* 取消成功返回 1 ，因为客户端未订阅 pattern 而造成取消失败，返回 0 。
*/
int pubsubUnsubscribePattern(redisClient *c, robj *pattern, int notify) {
listNode *ln;
pubsubPattern pat;
int retval = 0;
incrRefCount(pattern); /* Protect the object. May be the same we remove */
// 先确认一下，客户端是否订阅了这个模式
if ((ln = listSearchKey(c->pubsub_patterns,pattern)) != NULL) {
retval = 1;
// 将模式从客户端的订阅列表中删除
listDelNode(c->pubsub_patterns,ln);
// 设置 pubsubPattern 结构
pat.client = c;
pat.pattern = pattern;
// 在服务器中查找
ln = listSearchKey(server.pubsub_patterns,&pat);
listDelNode(server.pubsub_patterns,ln);
}
/* Notify the client */
// 回复客户端
if (notify) {
addReply(c,shared.mbulkhdr[3]);
// "punsubscribe" 字符串
addReply(c,shared.punsubscribebulk);
// 被退订的模式
addReplyBulk(c,pattern);
// 退订频道之后客户端仍在订阅的频道和模式的总数
addReplyLongLong(c,dictSize(c->pubsub_channels)+
listLength(c->pubsub_patterns));
}
decrRefCount(pattern);
return retval;
}
//将一个value推入到列表头部，被rpoplpushCommand调用
void rpoplpushHandlePush(client *c, robj *dstkey, robj *dstobj, robj *value) {
/* Create the list if the key does not exist */
//如果目标dstkey不存在
if (!dstobj) {
//创建一个quicklist对象
dstobj = createQuicklistObject();
//设置ziplist的最大长度和压缩程度
quicklistSetOptions(dstobj->ptr, server.list_max_ziplist_size,
server.list_compress_depth);
//将key添加到数据库中
dbAdd(c->db,dstkey,dstobj);
}
//当数据库的键被改动，则会调用该函数发送信号
signalModifiedKey(c->db,dstkey);
//将vlaue推入到列表的头部
listTypePush(dstobj,value,LIST_HEAD);
//发送"lpush"时间通知
notifyKeyspaceEvent(NOTIFY_LIST,"lpush",dstkey,c->db->id);
/* Always send the pushed value to the client. */
//将value值发送给client
addReplyBulk(c,value);
}
void popGenericCommand(redisClient *c, int where) {
robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk);
if (o == NULL || checkType(c,o,REDIS_LIST)) return;
robj *value = listTypePop(o,where);
if (value == NULL) {
addReply(c,shared.nullbulk);
} else {
char *event = (where == REDIS_HEAD) ? "lpop" : "rpop";
addReplyBulk(c,value);
decrRefCount(value);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,c->argv[1],c->db->id);
if (listTypeLength(o) == 0) {
notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",
c->argv[1],c->db->id);
dbDelete(c->db,c->argv[1]);
}
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
}
}
void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
//propagateExpire删除超时key，或者propagate函数分发同步客户端写操作时会调用这里。
//将这条指令发送给所有的slaves，放到其缓冲里面以待发送。
listNode *ln;
listIter li;
int j;
listRewind(slaves,&li);//获取slaves的第一个节点
while((ln = listNext(&li))) {
redisClient *slave = ln->value;
//下面不发送给这个slave，那么数据怎么办? 后面记着了的。这个状态的客户端是个从库，并且sync后rdb还没有开始，没必要为其追加写操作日志。
/* Don't feed slaves that are still waiting for BGSAVE to start */
if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START) continue;
/* Feed slaves that are waiting for the initial SYNC (so these commands
* are queued in the output buffer until the initial SYNC completes),
* or are already in sync with the master. */
if (slave->slaveseldb != dictid) {
robj *selectcmd;
if (dictid >= 0 && dictid < REDIS_SHARED_SELECT_CMDS) {
selectcmd = shared.select[dictid];
incrRefCount(selectcmd);
} else {
selectcmd = createObject(REDIS_STRING,
sdscatprintf(sdsempty(),"select %d\r\n",dictid));
}
addReply(slave,selectcmd);//追加一条选择db的指令给当前这个slave
decrRefCount(selectcmd);
slave->slaveseldb = dictid;
}
addReplyMultiBulkLen(slave,argc);//增加参数数目指令
for (j = 0; j < argc; j++) //一个个将参数追加到slave上面去。
addReplyBulk(slave,argv[j]);
}
}
void lrangeCommand(redisClient *c) {
robj *o, *value;
int start = atoi(c->argv[2]->ptr);
int end = atoi(c->argv[3]->ptr);
int llen;
int rangelen, j;
listTypeEntry entry;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
|| checkType(c,o,REDIS_LIST)) return;
llen = listTypeLength(o);
/* convert negative indexes */
if (start < 0) start = llen+start;
if (end < 0) end = llen+end;
if (start < 0) start = 0;
/* Invariant: start >= 0, so this test will be true when end < 0.
* The range is empty when start > end or start >= length. */
if (start > end || start >= llen) {
addReply(c,shared.emptymultibulk);
return;
}
if (end >= llen) end = llen-1;
rangelen = (end-start)+1;
/* Return the result in form of a multi-bulk reply */
addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",rangelen));
listTypeIterator *li = listTypeInitIterator(o,start,REDIS_TAIL);
for (j = 0; j < rangelen; j++) {
redisAssert(listTypeNext(li,&entry));
value = listTypeGet(&entry);
addReplyBulk(c,value);
decrRefCount(value);
}
listTypeReleaseIterator(li);
}
/* 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;
}
void keysCommand(client *c) {
dictIterator *di;
dictEntry *de;
sds pattern = c->argv[1]->ptr;
int plen = sdslen(pattern), allkeys;
unsigned long numkeys = 0;
void *replylen = addDeferredMultiBulkLength(c);
di = dictGetSafeIterator(server.counters);
allkeys = (pattern[0] == '*' && pattern[1] == '\0');
while((de = dictNext(di)) != NULL) {
sds key = dictGetKey(de);
robj *keyobj;
if (allkeys || stringmatchlen(pattern,plen,key,sdslen(key),0)) {
keyobj = createStringObject(key,sdslen(key));
addReplyBulk(c,keyobj);
numkeys++;
decrRefCount(keyobj);
}
}
dictReleaseIterator(di);
setDeferredMultiBulkLength(c,replylen,numkeys);
}
void sunionDiffGenericCommand(redisClient *c, robj **setkeys, int setnum, robj *dstkey, int op) {
robj **sets = zmalloc(sizeof(robj*)*setnum);
setTypeIterator *si;
robj *ele, *dstset = NULL;
int j, cardinality = 0;
int diff_algo = 1;
for (j = 0; j < setnum; j++) {
robj *setobj = dstkey ?
lookupKeyWrite(c->db,setkeys[j]) :
lookupKeyRead(c->db,setkeys[j]);
if (!setobj) {
sets[j] = NULL;
continue;
}
if (checkType(c,setobj,REDIS_SET)) {
zfree(sets);
return;
}
sets[j] = setobj;
}
/* Select what DIFF algorithm to use.
*
* Algorithm 1 is O(N*M) where N is the size of the element first set
* and M the total number of sets.
*
* Algorithm 2 is O(N) where N is the total number of elements in all
* the sets.
*
* We compute what is the best bet with the current input here. */
if (op == REDIS_OP_DIFF && sets[0]) {
long long algo_one_work = 0, algo_two_work = 0;
for (j = 0; j < setnum; j++) {
if (sets[j] == NULL) continue;
algo_one_work += setTypeSize(sets[0]);
algo_two_work += setTypeSize(sets[j]);
}
/* Algorithm 1 has better constant times and performs less operations
* if there are elements in common. Give it some advantage. */
algo_one_work /= 2;
diff_algo = (algo_one_work <= algo_two_work) ? 1 : 2;
if (diff_algo == 1 && setnum > 1) {
/* With algorithm 1 it is better to order the sets to subtract
* by decreasing size, so that we are more likely to find
* duplicated elements ASAP. */
qsort(sets+1,setnum-1,sizeof(robj*),
qsortCompareSetsByRevCardinality);
}
}
/* We need a temp set object to store our union. If the dstkey
* is not NULL (that is, we are inside an SUNIONSTORE operation) then
* this set object will be the resulting object to set into the target key*/
dstset = createIntsetObject();
if (op == REDIS_OP_UNION) {
/* Union is trivial, just add every element of every set to the
* temporary set. */
for (j = 0; j < setnum; j++) {
if (!sets[j]) continue; /* non existing keys are like empty sets */
si = setTypeInitIterator(sets[j]);
while((ele = setTypeNextObject(si)) != NULL) {
if (setTypeAdd(dstset,ele)) cardinality++;
decrRefCount(ele);
}
setTypeReleaseIterator(si);
}
} else if (op == REDIS_OP_DIFF && sets[0] && diff_algo == 1) {
/* DIFF Algorithm 1:
*
* We perform the diff by iterating all the elements of the first set,
* and only adding it to the target set if the element does not exist
* into all the other sets.
*
* This way we perform at max N*M operations, where N is the size of
* the first set, and M the number of sets. */
si = setTypeInitIterator(sets[0]);
while((ele = setTypeNextObject(si)) != NULL) {
for (j = 1; j < setnum; j++) {
if (!sets[j]) continue; /* no key is an empty set. */
if (sets[j] == sets[0]) break; /* same set! */
if (setTypeIsMember(sets[j],ele)) break;
}
if (j == setnum) {
/* There is no other set with this element. Add it. */
setTypeAdd(dstset,ele);
cardinality++;
}
decrRefCount(ele);
}
setTypeReleaseIterator(si);
} else if (op == REDIS_OP_DIFF && sets[0] && diff_algo == 2) {
/* DIFF Algorithm 2:
*
* Add all the elements of the first set to the auxiliary set.
* Then remove all the elements of all the next sets from it.
*
* This is O(N) where N is the sum of all the elements in every
* set. */
for (j = 0; j < setnum; j++) {
if (!sets[j]) continue; /* non existing keys are like empty sets */
si = setTypeInitIterator(sets[j]);
while((ele = setTypeNextObject(si)) != NULL) {
if (j == 0) {
if (setTypeAdd(dstset,ele)) cardinality++;
} else {
if (setTypeRemove(dstset,ele)) cardinality--;
}
decrRefCount(ele);
}
setTypeReleaseIterator(si);
/* Exit if result set is empty as any additional removal
* of elements will have no effect. */
if (cardinality == 0) break;
}
}
/* Output the content of the resulting set, if not in STORE mode */
if (!dstkey) {
addReplyMultiBulkLen(c,cardinality);
si = setTypeInitIterator(dstset);
while((ele = setTypeNextObject(si)) != NULL) {
addReplyBulk(c,ele);
decrRefCount(ele);
}
setTypeReleaseIterator(si);
decrRefCount(dstset);
} else {
/* If we have a target key where to store the resulting set
* create this key with the result set inside */
int deleted = dbDelete(c->db,dstkey);
if (setTypeSize(dstset) > 0) {
dbAdd(c->db,dstkey,dstset);
addReplyLongLong(c,setTypeSize(dstset));
notifyKeyspaceEvent(REDIS_NOTIFY_SET,
op == REDIS_OP_UNION ? "sunionstore" : "sdiffstore",
dstkey,c->db->id);
} else {
decrRefCount(dstset);
addReply(c,shared.czero);
if (deleted)
notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",
dstkey,c->db->id);
}
signalModifiedKey(c->db,dstkey);
server.dirty++;
}
zfree(sets);
}
/* The SORT command is the most complex command in Redis. Warning: this code
* is optimized for speed and a bit less for readability */
void sortCommand(redisClient *c) {
list *operations;
unsigned int outputlen = 0;
int desc = 0, alpha = 0;
long limit_start = 0, limit_count = -1, start, end;
int j, dontsort = 0, vectorlen;
int getop = 0; /* GET operation counter */
int int_convertion_error = 0;
robj *sortval, *sortby = NULL, *storekey = NULL;
redisSortObject *vector; /* Resulting vector to sort */
/* Lookup the key to sort. It must be of the right types */
sortval = lookupKeyRead(c->db,c->argv[1]);
if (sortval && sortval->type != REDIS_SET && sortval->type != REDIS_LIST &&
sortval->type != REDIS_ZSET)
{
addReply(c,shared.wrongtypeerr);
return;
}
/* Create a list of operations to perform for every sorted element.
* Operations can be GET/DEL/INCR/DECR */
operations = listCreate();
listSetFreeMethod(operations,zfree);
j = 2;
/* Now we need to protect sortval incrementing its count, in the future
* SORT may have options able to overwrite/delete keys during the sorting
* and the sorted key itself may get destroied */
if (sortval)
incrRefCount(sortval);
else
sortval = createListObject();
/* The SORT command has an SQL-alike syntax, parse it */
while(j < c->argc) {
int leftargs = c->argc-j-1;
if (!strcasecmp(c->argv[j]->ptr,"asc")) {
desc = 0;
} else if (!strcasecmp(c->argv[j]->ptr,"desc")) {
desc = 1;
} else if (!strcasecmp(c->argv[j]->ptr,"alpha")) {
alpha = 1;
} else if (!strcasecmp(c->argv[j]->ptr,"limit") && leftargs >= 2) {
if ((getLongFromObjectOrReply(c, c->argv[j+1], &limit_start, NULL) != REDIS_OK) ||
(getLongFromObjectOrReply(c, c->argv[j+2], &limit_count, NULL) != REDIS_OK)) return;
j+=2;
} else if (!strcasecmp(c->argv[j]->ptr,"store") && leftargs >= 1) {
storekey = c->argv[j+1];
j++;
} else if (!strcasecmp(c->argv[j]->ptr,"by") && leftargs >= 1) {
sortby = c->argv[j+1];
/* If the BY pattern does not contain '*', i.e. it is constant,
* we don't need to sort nor to lookup the weight keys. */
if (strchr(c->argv[j+1]->ptr,'*') == NULL) dontsort = 1;
j++;
} else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
listAddNodeTail(operations,createSortOperation(
REDIS_SORT_GET,c->argv[j+1]));
getop++;
j++;
} else {
decrRefCount(sortval);
listRelease(operations);
addReply(c,shared.syntaxerr);
return;
}
j++;
}
/* If we have STORE we need to force sorting for deterministic output
* and replication. We use alpha sorting since this is guaranteed to
* work with any input. */
if (storekey && dontsort) {
dontsort = 0;
alpha = 1;
sortby = NULL;
}
/* Destructively convert encoded sorted sets for SORT. */
if (sortval->type == REDIS_ZSET)
zsetConvert(sortval, REDIS_ENCODING_SKIPLIST);
/* Load the sorting vector with all the objects to sort */
switch(sortval->type) {
case REDIS_LIST: vectorlen = listTypeLength(sortval); break;
case REDIS_SET: vectorlen = setTypeSize(sortval); break;
case REDIS_ZSET: vectorlen = dictSize(((zset*)sortval->ptr)->dict); break;
default: vectorlen = 0; redisPanic("Bad SORT type"); /* Avoid GCC warning */
}
vector = zmalloc(sizeof(redisSortObject)*vectorlen);
j = 0;
if (sortval->type == REDIS_LIST) {
listTypeIterator *li = listTypeInitIterator(sortval,0,REDIS_TAIL);
listTypeEntry entry;
while(listTypeNext(li,&entry)) {
vector[j].obj = listTypeGet(&entry);
vector[j].u.score = 0;
vector[j].u.cmpobj = NULL;
j++;
}
listTypeReleaseIterator(li);
} else if (sortval->type == REDIS_SET) {
setTypeIterator *si = setTypeInitIterator(sortval);
robj *ele;
while((ele = setTypeNextObject(si)) != NULL) {
vector[j].obj = ele;
vector[j].u.score = 0;
vector[j].u.cmpobj = NULL;
j++;
}
setTypeReleaseIterator(si);
} else if (sortval->type == REDIS_ZSET) {
dict *set = ((zset*)sortval->ptr)->dict;
dictIterator *di;
dictEntry *setele;
di = dictGetIterator(set);
while((setele = dictNext(di)) != NULL) {
vector[j].obj = dictGetKey(setele);
vector[j].u.score = 0;
vector[j].u.cmpobj = NULL;
j++;
}
dictReleaseIterator(di);
} else {
redisPanic("Unknown type");
}
redisAssertWithInfo(c,sortval,j == vectorlen);
/* Now it's time to load the right scores in the sorting vector */
if (dontsort == 0) {
for (j = 0; j < vectorlen; j++) {
robj *byval;
if (sortby) {
/* lookup value to sort by */
byval = lookupKeyByPattern(c->db,sortby,vector[j].obj);
if (!byval) continue;
} else {
/* use object itself to sort by */
byval = vector[j].obj;
}
if (alpha) {
if (sortby) vector[j].u.cmpobj = getDecodedObject(byval);
} else {
if (byval->encoding == REDIS_ENCODING_RAW) {
char *eptr;
vector[j].u.score = strtod(byval->ptr,&eptr);
if (eptr[0] != '\0' || errno == ERANGE ||
isnan(vector[j].u.score))
{
int_convertion_error = 1;
}
} else if (byval->encoding == REDIS_ENCODING_INT) {
/* Don't need to decode the object if it's
* integer-encoded (the only encoding supported) so
* far. We can just cast it */
vector[j].u.score = (long)byval->ptr;
} else {
redisAssertWithInfo(c,sortval,1 != 1);
}
}
/* when the object was retrieved using lookupKeyByPattern,
* its refcount needs to be decreased. */
if (sortby) {
decrRefCount(byval);
}
}
}
/* We are ready to sort the vector... perform a bit of sanity check
* on the LIMIT option too. We'll use a partial version of quicksort. */
start = (limit_start < 0) ? 0 : limit_start;
end = (limit_count < 0) ? vectorlen-1 : start+limit_count-1;
if (start >= vectorlen) {
start = vectorlen-1;
end = vectorlen-2;
}
if (end >= vectorlen) end = vectorlen-1;
server.sort_dontsort = dontsort;
if (dontsort == 0) {
server.sort_desc = desc;
server.sort_alpha = alpha;
server.sort_bypattern = sortby ? 1 : 0;
if (sortby && (start != 0 || end != vectorlen-1))
pqsort(vector,vectorlen,sizeof(redisSortObject),sortCompare, start,end);
else
qsort(vector,vectorlen,sizeof(redisSortObject),sortCompare);
}
/* Send command output to the output buffer, performing the specified
* GET/DEL/INCR/DECR operations if any. */
outputlen = getop ? getop*(end-start+1) : end-start+1;
if (int_convertion_error) {
addReplyError(c,"One or more scores can't be converted into double");
} else if (storekey == NULL) {
/* STORE option not specified, sent the sorting result to client */
addReplyMultiBulkLen(c,outputlen);
for (j = start; j <= end; j++) {
listNode *ln;
listIter li;
if (!getop) addReplyBulk(c,vector[j].obj);
listRewind(operations,&li);
while((ln = listNext(&li))) {
redisSortOperation *sop = ln->value;
robj *val = lookupKeyByPattern(c->db,sop->pattern,
vector[j].obj);
if (sop->type == REDIS_SORT_GET) {
if (!val) {
addReply(c,shared.nullbulk);
} else {
addReplyBulk(c,val);
decrRefCount(val);
}
} else {
/* Always fails */
redisAssertWithInfo(c,sortval,sop->type == REDIS_SORT_GET);
}
}
}
} else {
robj *sobj = createZiplistObject();
/* STORE option specified, set the sorting result as a List object */
for (j = start; j <= end; j++) {
listNode *ln;
listIter li;
if (!getop) {
listTypePush(sobj,vector[j].obj,REDIS_TAIL);
} else {
listRewind(operations,&li);
while((ln = listNext(&li))) {
redisSortOperation *sop = ln->value;
robj *val = lookupKeyByPattern(c->db,sop->pattern,
vector[j].obj);
if (sop->type == REDIS_SORT_GET) {
if (!val) val = createStringObject("",0);
/* listTypePush does an incrRefCount, so we should take care
* care of the incremented refcount caused by either
* lookupKeyByPattern or createStringObject("",0) */
listTypePush(sobj,val,REDIS_TAIL);
decrRefCount(val);
} else {
/* Always fails */
redisAssertWithInfo(c,sortval,sop->type == REDIS_SORT_GET);
}
}
}
}
if (outputlen) {
setKey(c->db,storekey,sobj);
server.dirty += outputlen;
} else if (dbDelete(c->db,storekey)) {
signalModifiedKey(c->db,storekey);
server.dirty++;
}
decrRefCount(sobj);
addReplyLongLong(c,outputlen);
}
/* Cleanup */
if (sortval->type == REDIS_LIST || sortval->type == REDIS_SET)
for (j = 0; j < vectorlen; j++)
decrRefCount(vector[j].obj);
decrRefCount(sortval);
listRelease(operations);
for (j = 0; j < vectorlen; j++) {
if (alpha && vector[j].u.cmpobj)
decrRefCount(vector[j].u.cmpobj);
}
zfree(vector);
}
/* This command implements ZRANGEBYSCORE, ZREVRANGEBYSCORE and ZCOUNT.
* If "justcount", only the number of elements in the range is returned. */
void genericZrangebyscoreCommand(redisClient *c, int reverse, int justcount) {
zrangespec range;
robj *o, *emptyreply;
zset *zsetobj;
zskiplist *zsl;
zskiplistNode *ln;
int offset = 0, limit = -1;
int withscores = 0;
unsigned long rangelen = 0;
void *replylen = NULL;
/* Parse the range arguments. */
if (zslParseRange(c->argv[2],c->argv[3],&range) != REDIS_OK) {
addReplyError(c,"min or max is not a double");
return;
}
/* Parse optional extra arguments. Note that ZCOUNT will exactly have
* 4 arguments, so we'll never enter the following code path. */
if (c->argc > 4) {
int remaining = c->argc - 4;
int pos = 4;
while (remaining) {
if (remaining >= 1 && !strcasecmp(c->argv[pos]->ptr,"withscores")) {
pos++; remaining--;
withscores = 1;
} else if (remaining >= 3 && !strcasecmp(c->argv[pos]->ptr,"limit")) {
offset = atoi(c->argv[pos+1]->ptr);
limit = atoi(c->argv[pos+2]->ptr);
pos += 3; remaining -= 3;
} else {
addReply(c,shared.syntaxerr);
return;
}
}
}
/* Ok, lookup the key and get the range */
emptyreply = justcount ? shared.czero : shared.emptymultibulk;
if ((o = lookupKeyReadOrReply(c,c->argv[1],emptyreply)) == NULL ||
checkType(c,o,REDIS_ZSET)) return;
zsetobj = o->ptr;
zsl = zsetobj->zsl;
/* If reversed, assume the elements are sorted from high to low score. */
ln = zslFirstWithScore(zsl,range.min);
if (reverse) {
/* If range.min is out of range, ln will be NULL and we need to use
* the tail of the skiplist as first node of the range. */
if (ln == NULL) ln = zsl->tail;
/* zslFirstWithScore returns the first element with where with
* score >= range.min, so backtrack to make sure the element we use
* here has score <= range.min. */
while (ln && ln->score > range.min) ln = ln->backward;
/* Move to the right element according to the range spec. */
if (range.minex) {
/* Find last element with score < range.min */
while (ln && ln->score == range.min) ln = ln->backward;
} else {
/* Find last element with score <= range.min */
while (ln && ln->level[0].forward &&
ln->level[0].forward->score == range.min)
ln = ln->level[0].forward;
}
} else {
if (range.minex) {
/* Find first element with score > range.min */
while (ln && ln->score == range.min) ln = ln->level[0].forward;
}
}
/* No "first" element in the specified interval. */
if (ln == NULL) {
addReply(c,emptyreply);
return;
}
/* We don't know in advance how many matching elements there
* are in the list, so we push this object that will represent
* the multi-bulk length in the output buffer, and will "fix"
* it later */
if (!justcount)
replylen = addDeferredMultiBulkLength(c);
/* If there is an offset, just traverse the number of elements without
* checking the score because that is done in the next loop. */
while(ln && offset--) {
if (reverse)
ln = ln->backward;
else
ln = ln->level[0].forward;
}
while (ln && limit--) {
/* Check if this this element is in range. */
if (reverse) {
if (range.maxex) {
/* Element should have score > range.max */
if (ln->score <= range.max) break;
} else {
/* Element should have score >= range.max */
if (ln->score < range.max) break;
}
} else {
if (range.maxex) {
/* Element should have score < range.max */
if (ln->score >= range.max) break;
} else {
/* Element should have score <= range.max */
if (ln->score > range.max) break;
}
}
/* Do our magic */
rangelen++;
if (!justcount) {
addReplyBulk(c,ln->obj);
if (withscores)
addReplyDouble(c,ln->score);
}
if (reverse)
ln = ln->backward;
else
ln = ln->level[0].forward;
}
if (justcount) {
addReplyLongLong(c,(long)rangelen);
} else {
setDeferredMultiBulkLength(c,replylen,
withscores ? (rangelen*2) : rangelen);
}
}
void zrangeGenericCommand(redisClient *c, int reverse) {
robj *o;
long start;
long end;
int withscores = 0;
int llen;
int rangelen, j;
zset *zsetobj;
zskiplist *zsl;
zskiplistNode *ln;
robj *ele;
if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
(getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
if (c->argc == 5 && !strcasecmp(c->argv[4]->ptr,"withscores")) {
withscores = 1;
} else if (c->argc >= 5) {
addReply(c,shared.syntaxerr);
return;
}
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
|| checkType(c,o,REDIS_ZSET)) return;
zsetobj = o->ptr;
zsl = zsetobj->zsl;
llen = zsl->length;
/* convert negative indexes */
if (start < 0) start = llen+start;
if (end < 0) end = llen+end;
if (start < 0) start = 0;
/* Invariant: start >= 0, so this test will be true when end < 0.
* The range is empty when start > end or start >= length. */
if (start > end || start >= llen) {
addReply(c,shared.emptymultibulk);
return;
}
if (end >= llen) end = llen-1;
rangelen = (end-start)+1;
/* check if starting point is trivial, before searching
* the element in log(N) time */
if (reverse) {
ln = start == 0 ? zsl->tail : zslGetElementByRank(zsl, llen-start);
} else {
ln = start == 0 ?
zsl->header->level[0].forward : zslGetElementByRank(zsl, start+1);
}
/* Return the result in form of a multi-bulk reply */
addReplyMultiBulkLen(c,withscores ? (rangelen*2) : rangelen);
for (j = 0; j < rangelen; j++) {
ele = ln->obj;
addReplyBulk(c,ele);
if (withscores)
addReplyDouble(c,ln->score);
ln = reverse ? ln->backward : ln->level[0].forward;
}
}
void sunionDiffGenericCommand(redisClient *c, robj **setkeys, int setnum, robj *dstkey, int op) {
robj **sets = zmalloc(sizeof(robj*)*setnum);
setTypeIterator *si;
robj *ele, *dstset = NULL;
int j, cardinality = 0;
for (j = 0; j < setnum; j++) {
robj *setobj = dstkey ?
lookupKeyWrite(c->db,setkeys[j]) :
lookupKeyRead(c->db,setkeys[j]);
if (!setobj) {
sets[j] = NULL;
continue;
}
if (checkType(c,setobj,REDIS_SET)) {
zfree(sets);
return;
}
sets[j] = setobj;
}
/* We need a temp set object to store our union. If the dstkey
* is not NULL (that is, we are inside an SUNIONSTORE operation) then
* this set object will be the resulting object to set into the target key*/
dstset = createIntsetObject();
/* Iterate all the elements of all the sets, add every element a single
* time to the result set */
for (j = 0; j < setnum; j++) {
if (op == REDIS_OP_DIFF && j == 0 && !sets[j]) break; /* result set is empty */
if (!sets[j]) continue; /* non existing keys are like empty sets */
si = setTypeInitIterator(sets[j]);
while((ele = setTypeNextObject(si)) != NULL) {
if (op == REDIS_OP_UNION || j == 0) {
if (setTypeAdd(dstset,ele)) {
cardinality++;
}
} else if (op == REDIS_OP_DIFF) {
if (setTypeRemove(dstset,ele)) {
cardinality--;
}
}
decrRefCount(ele);
}
setTypeReleaseIterator(si);
/* Exit when result set is empty. */
if (op == REDIS_OP_DIFF && cardinality == 0) break;
}
/* Output the content of the resulting set, if not in STORE mode */
if (!dstkey) {
addReplyMultiBulkLen(c,cardinality);
si = setTypeInitIterator(dstset);
while((ele = setTypeNextObject(si)) != NULL) {
addReplyBulk(c,ele);
decrRefCount(ele);
}
setTypeReleaseIterator(si);
decrRefCount(dstset);
} else {
/* If we have a target key where to store the resulting set
* create this key with the result set inside */
dbDelete(c->db,dstkey);
if (setTypeSize(dstset) > 0) {
dbAdd(c->db,dstkey,dstset);
addReplyLongLong(c,setTypeSize(dstset));
} else {
decrRefCount(dstset);
addReply(c,shared.czero);
}
touchWatchedKey(c->db,dstkey);
server.dirty++;
}
zfree(sets);
}
void sinterGenericCommand(redisClient *c, robj **setkeys, unsigned long setnum, robj *dstkey) {
robj **sets = zmalloc(sizeof(robj*)*setnum);
setTypeIterator *si;
robj *eleobj, *dstset = NULL;
int64_t intobj;
void *replylen = NULL;
unsigned long j, cardinality = 0;
int encoding;
for (j = 0; j < setnum; j++) {
robj *setobj = dstkey ?
lookupKeyWrite(c->db,setkeys[j]) :
lookupKeyRead(c->db,setkeys[j]);
if (!setobj) {
zfree(sets);
if (dstkey) {
if (dbDelete(c->db,dstkey)) {
touchWatchedKey(c->db,dstkey);
server.dirty++;
}
addReply(c,shared.czero);
} else {
addReply(c,shared.emptymultibulk);
}
return;
}
if (checkType(c,setobj,REDIS_SET)) {
zfree(sets);
return;
}
sets[j] = setobj;
}
/* Sort sets from the smallest to largest, this will improve our
* algorithm's performace */
qsort(sets,setnum,sizeof(robj*),qsortCompareSetsByCardinality);
/* The first thing we should output is the total number of elements...
* since this is a multi-bulk write, but at this stage we don't know
* the intersection set size, so we use a trick, append an empty object
* to the output list and save the pointer to later modify it with the
* right length */
if (!dstkey) {
replylen = addDeferredMultiBulkLength(c);
} else {
/* If we have a target key where to store the resulting set
* create this key with an empty set inside */
dstset = createIntsetObject();
}
/* Iterate all the elements of the first (smallest) set, and test
* the element against all the other sets, if at least one set does
* not include the element it is discarded */
si = setTypeInitIterator(sets[0]);
while((encoding = setTypeNext(si,&eleobj,&intobj)) != -1) {
for (j = 1; j < setnum; j++) {
if (encoding == REDIS_ENCODING_INTSET) {
/* intset with intset is simple... and fast */
if (sets[j]->encoding == REDIS_ENCODING_INTSET &&
!intsetFind((intset*)sets[j]->ptr,intobj))
{
break;
/* in order to compare an integer with an object we
* have to use the generic function, creating an object
* for this */
} else if (sets[j]->encoding == REDIS_ENCODING_HT) {
eleobj = createStringObjectFromLongLong(intobj);
if (!setTypeIsMember(sets[j],eleobj)) {
decrRefCount(eleobj);
break;
}
decrRefCount(eleobj);
}
} else if (encoding == REDIS_ENCODING_HT) {
/* Optimization... if the source object is integer
* encoded AND the target set is an intset, we can get
* a much faster path. */
if (eleobj->encoding == REDIS_ENCODING_INT &&
sets[j]->encoding == REDIS_ENCODING_INTSET &&
!intsetFind((intset*)sets[j]->ptr,(long)eleobj->ptr))
{
break;
/* else... object to object check is easy as we use the
* type agnostic API here. */
} else if (!setTypeIsMember(sets[j],eleobj)) {
break;
}
}
}
/* Only take action when all sets contain the member */
if (j == setnum) {
if (!dstkey) {
if (encoding == REDIS_ENCODING_HT)
addReplyBulk(c,eleobj);
else
addReplyBulkLongLong(c,intobj);
cardinality++;
} else {
if (encoding == REDIS_ENCODING_INTSET) {
eleobj = createStringObjectFromLongLong(intobj);
setTypeAdd(dstset,eleobj);
decrRefCount(eleobj);
} else {
setTypeAdd(dstset,eleobj);
}
}
}
}
setTypeReleaseIterator(si);
if (dstkey) {
/* Store the resulting set into the target, if the intersection
* is not an empty set. */
dbDelete(c->db,dstkey);
if (setTypeSize(dstset) > 0) {
dbAdd(c->db,dstkey,dstset);
addReplyLongLong(c,setTypeSize(dstset));
} else {
decrRefCount(dstset);
addReply(c,shared.czero);
}
touchWatchedKey(c->db,dstkey);
server.dirty++;
} else {
setDeferredMultiBulkLength(c,replylen,cardinality);
}
zfree(sets);
}
/* This command implements SCAN, HSCAN and SSCAN commands.
* If object 'o' is passed, then it must be a Hash or Set object, otherwise
* if 'o' is NULL the command will operate on the dictionary associated with
* the current database.
*
* When 'o' is not NULL the function assumes that the first argument in
* the client arguments vector is a key so it skips it before iterating
* in order to parse options.
*
* In the case of a Hash object the function returns both the field and value
* of every element on the Hash. */
void scanGenericCommand(client *c, robj *o, unsigned long cursor) {
int i, j;
list *keys = listCreate();
listNode *node, *nextnode;
long count = 10;
sds pat = NULL;
int patlen = 0, use_pattern = 0;
dict *ht;
/* Object must be NULL (to iterate keys names), or the type of the object
* must be Set, Sorted Set, or Hash. */
serverAssert(o == NULL || o->type == OBJ_SET || o->type == OBJ_HASH ||
o->type == OBJ_ZSET);
/* Set i to the first option argument. The previous one is the cursor. */
i = (o == NULL) ? 2 : 3; /* Skip the key argument if needed. */
/* Step 1: Parse options. */
while (i < c->argc) {
j = c->argc - i;
if (!strcasecmp(c->argv[i]->ptr, "count") && j >= 2) {
if (getLongFromObjectOrReply(c, c->argv[i+1], &count, NULL)
!= C_OK)
{
goto cleanup;
}
if (count < 1) {
addReply(c,shared.syntaxerr);
goto cleanup;
}
i += 2;
} else if (!strcasecmp(c->argv[i]->ptr, "match") && j >= 2) {
pat = c->argv[i+1]->ptr;
patlen = sdslen(pat);
/* The pattern always matches if it is exactly "*", so it is
* equivalent to disabling it. */
use_pattern = !(pat[0] == '*' && patlen == 1);
i += 2;
} else {
addReply(c,shared.syntaxerr);
goto cleanup;
}
}
/* Step 2: Iterate the collection.
*
* Note that if the object is encoded with a ziplist, intset, or any other
* representation that is not a hash table, we are sure that it is also
* composed of a small number of elements. So to avoid taking state we
* just return everything inside the object in a single call, setting the
* cursor to zero to signal the end of the iteration. */
/* Handle the case of a hash table. */
ht = NULL;
if (o == NULL) {
ht = c->db->dict;
} else if (o->type == OBJ_SET && o->encoding == OBJ_ENCODING_HT) {
ht = o->ptr;
} else if (o->type == OBJ_HASH && o->encoding == OBJ_ENCODING_HT) {
ht = o->ptr;
count *= 2; /* We return key / value for this type. */
} else if (o->type == OBJ_ZSET && o->encoding == OBJ_ENCODING_SKIPLIST) {
zset *zs = o->ptr;
ht = zs->dict;
count *= 2; /* We return key / value for this type. */
}
if (ht) {
void *privdata[2];
/* We set the max number of iterations to ten times the specified
* COUNT, so if the hash table is in a pathological state (very
* sparsely populated) we avoid to block too much time at the cost
* of returning no or very few elements. */
long maxiterations = count*10;
/* We pass two pointers to the callback: the list to which it will
* add new elements, and the object containing the dictionary so that
* it is possible to fetch more data in a type-dependent way. */
privdata[0] = keys;
privdata[1] = o;
do {
cursor = dictScan(ht, cursor, scanCallback, privdata);
} while (cursor &&
maxiterations-- &&
listLength(keys) < (unsigned long)count);
} else if (o->type == OBJ_SET) {
int pos = 0;
int64_t ll;
while(intsetGet(o->ptr,pos++,&ll))
listAddNodeTail(keys,createStringObjectFromLongLong(ll));
cursor = 0;
} else if (o->type == OBJ_HASH || o->type == OBJ_ZSET) {
unsigned char *p = ziplistIndex(o->ptr,0);
unsigned char *vstr;
unsigned int vlen;
long long vll;
while(p) {
ziplistGet(p,&vstr,&vlen,&vll);
listAddNodeTail(keys,
(vstr != NULL) ? createStringObject((char*)vstr,vlen) :
createStringObjectFromLongLong(vll));
p = ziplistNext(o->ptr,p);
}
cursor = 0;
} else {
serverPanic("Not handled encoding in SCAN.");
}
/* Step 3: Filter elements. */
node = listFirst(keys);
while (node) {
robj *kobj = listNodeValue(node);
nextnode = listNextNode(node);
int filter = 0;
/* Filter element if it does not match the pattern. */
if (!filter && use_pattern) {
if (sdsEncodedObject(kobj)) {
if (!stringmatchlen(pat, patlen, kobj->ptr, sdslen(kobj->ptr), 0))
filter = 1;
} else {
char buf[LONG_STR_SIZE];
int len;
serverAssert(kobj->encoding == OBJ_ENCODING_INT);
len = ll2string(buf,sizeof(buf),(long)kobj->ptr);
if (!stringmatchlen(pat, patlen, buf, len, 0)) filter = 1;
}
}
/* Filter element if it is an expired key. */
if (!filter && o == NULL && expireIfNeeded(c->db, kobj)) filter = 1;
/* Remove the element and its associted value if needed. */
if (filter) {
decrRefCount(kobj);
listDelNode(keys, node);
}
/* If this is a hash or a sorted set, we have a flat list of
* key-value elements, so if this element was filtered, remove the
* value, or skip it if it was not filtered: we only match keys. */
if (o && (o->type == OBJ_ZSET || o->type == OBJ_HASH)) {
node = nextnode;
nextnode = listNextNode(node);
if (filter) {
kobj = listNodeValue(node);
decrRefCount(kobj);
listDelNode(keys, node);
}
}
node = nextnode;
}
/* Step 4: Reply to the client. */
addReplyMultiBulkLen(c, 2);
addReplyBulkLongLong(c,cursor);
addReplyMultiBulkLen(c, listLength(keys));
while ((node = listFirst(keys)) != NULL) {
robj *kobj = listNodeValue(node);
addReplyBulk(c, kobj);
decrRefCount(kobj);
listDelNode(keys, node);
}
cleanup:
listSetFreeMethod(keys,decrRefCountVoid);
listRelease(keys);
}