void lindexCommand(client *c) {
robj *o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk);
if (o == NULL || checkType(c,o,OBJ_LIST)) return;
long index;
robj *value = NULL;
if ((getLongFromObjectOrReply(c, c->argv[2], &index, NULL) != C_OK))
return;
if (o->encoding == OBJ_ENCODING_QUICKLIST) {
quicklistEntry entry;
if (quicklistIndex(o->ptr, index, &entry)) {
if (entry.value) {
value = createStringObject((char*)entry.value,entry.sz);
} else {
value = createStringObjectFromLongLong(entry.longval);
}
addReplyBulk(c,value);
decrRefCount(value);
} else {
addReply(c,shared.nullbulk);
}
} else {
serverPanic("Unknown list encoding");
}
}
void zrankGenericCommand(redisClient *c, int reverse) {
robj *o;
zset *zs;
zskiplist *zsl;
dictEntry *de;
unsigned long rank;
double *score;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,o,REDIS_ZSET)) return;
zs = o->ptr;
zsl = zs->zsl;
c->argv[2] = tryObjectEncoding(c->argv[2]);
de = dictFind(zs->dict,c->argv[2]);
if (!de) {
addReply(c,shared.nullbulk);
return;
}
score = dictGetEntryVal(de);
rank = zslGetRank(zsl, *score, c->argv[2]);
if (rank) {
if (reverse) {
addReplyLongLong(c, zsl->length - rank);
} else {
addReplyLongLong(c, rank-1);
}
} else {
addReply(c,shared.nullbulk);
}
}
// LINDEX key index
// LINDEX命令的实现
void lindexCommand(client *c) {
//以读操作取出key对象的value值
robj *o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk);
//如果key没找到或value对象不是列表类型则直接返回
if (o == NULL || checkType(c,o,OBJ_LIST)) return;
long index;
robj *value = NULL;
//将index参数转换为long类型的整数，保存在index中
if ((getLongFromObjectOrReply(c, c->argv[2], &index, NULL) != C_OK))
return;
//只对编码为quicklist类型的value对象操作
if (o->encoding == OBJ_ENCODING_QUICKLIST) {
quicklistEntry entry;
//将下标为index的entry节点保存到entry中
if (quicklistIndex(o->ptr, index, &entry)) {
if (entry.value) { //如果vlaue是字符串类型
//创建一个字符串类型的对象，保存value值
value = createStringObject((char*)entry.value,entry.sz);
} else {
//将整型的value值转换为字符串类型并创建字符串类型的对象
value = createStringObjectFromLongLong(entry.longval);
}
addReplyBulk(c,value); //发送value对象
decrRefCount(value); //释放value对象
} else {
addReply(c,shared.nullbulk); //如果下标为index没找到，则发送空信息
}
} else {
serverPanic("Unknown list encoding"); //发送未知的列表编码类型
}
}
void srandmemberCommand(redisClient* c)
{
robj* set, *ele;
int64_t llele;
int encoding;
if (c->argc == 3) {
srandmemberWithCountCommand(c);
return;
} else if (c->argc > 3) {
addReply(c, shared.syntaxerr);
return;
}
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);
}
}
void lindexCommand(redisClient *c) {
robj *o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk);
if (o == NULL || checkType(c,o,REDIS_LIST)) return;
int index = atoi(c->argv[2]->ptr);
robj *value = NULL;
if (o->encoding == REDIS_ENCODING_ZIPLIST) {
unsigned char *p;
unsigned char *vstr;
unsigned int vlen;
long long vlong;
p = ziplistIndex(o->ptr,index);
if (ziplistGet(p,&vstr,&vlen,&vlong)) {
if (vstr) {
value = createStringObject((char*)vstr,vlen);
} else {
value = createStringObjectFromLongLong(vlong);
}
addReplyBulk(c,value);
decrRefCount(value);
} else {
addReply(c,shared.nullbulk);
}
} else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
listNode *ln = listIndex(o->ptr,index);
if (ln != NULL) {
value = listNodeValue(ln);
addReplyBulk(c,value);
} else {
addReply(c,shared.nullbulk);
}
} else {
redisPanic("Unknown list encoding");
}
}
void scardCommand(redisClient *c) {
robj *o;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,o,REDIS_SET)) return;
addReplyLongLong(c,setTypeSize(o));
}
// LLEN key
//LLEN命令实现
void llenCommand(client *c) {
//以读操作取出key大小的value值
robj *o = lookupKeyReadOrReply(c,c->argv[1],shared.czero);
//如果key没找到或value大小不是列表类型则直接返回
if (o == NULL || checkType(c,o,OBJ_LIST)) return;
//发送列表中的元素数量给client
addReplyLongLong(c,listTypeLength(o));
}
void lrangeCommand(redisClient *c) {
robj *o;
long start, end, llen, rangelen;
if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
(getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
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 */
addReplyMultiBulkLen(c,rangelen);
if (o->encoding == REDIS_ENCODING_ZIPLIST) {
unsigned char *p = ziplistIndex(o->ptr,start);
unsigned char *vstr;
unsigned int vlen;
long long vlong;
while(rangelen--) {
ziplistGet(p,&vstr,&vlen,&vlong);
if (vstr) {
addReplyBulkCBuffer(c,vstr,vlen);
} else {
addReplyBulkLongLong(c,vlong);
}
p = ziplistNext(o->ptr,p);
}
} else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
listNode *ln;
/* If we are nearest to the end of the list, reach the element
* starting from tail and going backward, as it is faster. */
if (start > llen/2) start -= llen;
ln = listIndex(o->ptr,start);
while(rangelen--) {
addReplyBulk(c,ln->value);
ln = ln->next;
}
} else {
redisPanic("List encoding is not LINKEDLIST nor ZIPLIST!");
}
}
// t_hash.c
void hgetCommand(client *c) {
robj *o;
// will invoke expireIfNeeded()
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,o,OBJ_HASH)) return;
addHashFieldToReply(c, o, c->argv[2]);
}
void sscanCommand(redisClient *c) {
robj *set;
unsigned long cursor;
if (parseScanCursorOrReply(c,c->argv[2],&cursor) == REDIS_ERR) return;
if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.emptyscan)) == NULL ||
checkType(c,set,REDIS_SET)) return;
scanGenericCommand(c,set,cursor);
}
void zcardCommand(redisClient *c) {
robj *o;
zset *zs;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,o,REDIS_ZSET)) return;
zs = o->ptr;
addReplyLongLong(c,zs->zsl->length);
}
void strlenCommand(redisClient *c) {
robj *o;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,o,REDIS_STRING)) return;
o = getDecodedObject(o);
addReplyLongLong(c,sdslen(o->ptr));
decrRefCount(o);
}
void sismemberCommand(client *c) {
robj *set;
if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,set,OBJ_SET)) return;
if (setTypeIsMember(set,c->argv[2]->ptr))
addReply(c,shared.cone);
else
addReply(c,shared.czero);
}
void pushxGenericCommand(redisClient *c, robj *refval, robj *val, int where) {
robj *subject;
listTypeIterator *iter;
listTypeEntry entry;
int inserted = 0;
int slotnum = keyHashSlot(c->argv[1]->ptr, sdslen(c->argv[1]->ptr));
if ((subject = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,subject,REDIS_LIST)) return;
if (refval != NULL) {
/* We're not sure if this value can be inserted yet, but we cannot
* convert the list inside the iterator. We don't want to loop over
* the list twice (once to see if the value can be inserted and once
* to do the actual insert), so we assume this value can be inserted
* and convert the ziplist to a regular list if necessary. */
listTypeTryConversion(subject,val);
/* Seek refval from head to tail */
iter = listTypeInitIterator(subject,0,REDIS_TAIL);
while (listTypeNext(iter,&entry)) {
if (listTypeEqual(&entry,refval)) {
listTypeInsert(&entry,val,where);
inserted = 1;
break;
}
}
listTypeReleaseIterator(iter);
if (inserted) {
/* Check if the length exceeds the ziplist length threshold. */
if (subject->encoding == REDIS_ENCODING_ZIPLIST &&
ziplistLen(subject->ptr) > server.list_max_ziplist_entries)
listTypeConvert(subject,REDIS_ENCODING_LINKEDLIST);
signalModifiedKey(c->db,c->argv[1],slotnum);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"linsert",
c->argv[1],c->db->id);
server.dirty++;
} else {
/* Notify client of a failed insert */
addReply(c,shared.cnegone);
return;
}
} else {
char *event = (where == REDIS_HEAD) ? "lpush" : "rpush";
listTypePush(subject,val,where);
signalModifiedKey(c->db,c->argv[1],slotnum);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,c->argv[1],c->db->id);
server.dirty++;
}
addReplyLongLong(c,listTypeLength(subject));
}
void sismemberCommand(redisClient *c) {
robj *set;
if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,set,REDIS_SET)) return;
c->argv[2] = tryObjectEncoding(c->argv[2]);
if (setTypeIsMember(set,c->argv[2]))
addReply(c,shared.cone);
else
addReply(c,shared.czero);
}
void pushxGenericCommand(redisClient *c, robj *refval, robj *val, int where) {
robj *subject;
listTypeIterator *iter;
listTypeEntry entry;
int inserted = 0;
if ((subject = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,subject,REDIS_LIST)) return;
if (refval != NULL) {
/* Note: we expect refval to be string-encoded because it is *not* the
* last argument of the multi-bulk LINSERT. */
redisAssertWithInfo(c,refval,refval->encoding == REDIS_ENCODING_RAW);
/* We're not sure if this value can be inserted yet, but we cannot
* convert the list inside the iterator. We don't want to loop over
* the list twice (once to see if the value can be inserted and once
* to do the actual insert), so we assume this value can be inserted
* and convert the ziplist to a regular list if necessary. */
listTypeTryConversion(subject,val);
/* Seek refval from head to tail */
iter = listTypeInitIterator(subject,0,REDIS_TAIL);
while (listTypeNext(iter,&entry)) {
if (listTypeEqual(&entry,refval)) {
listTypeInsert(&entry,val,where);
inserted = 1;
break;
}
}
listTypeReleaseIterator(iter);
if (inserted) {
/* Check if the length exceeds the ziplist length threshold. */
if (subject->encoding == REDIS_ENCODING_ZIPLIST &&
ziplistLen(subject->ptr) > server.list_max_ziplist_entries)
listTypeConvert(subject,REDIS_ENCODING_LINKEDLIST);
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
} else {
/* Notify client of a failed insert */
addReply(c,shared.cnegone);
return;
}
} else {
listTypePush(subject,val,where);
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
}
addReplyLongLong(c,listTypeLength(subject));
}
int getGenericCommand(client *c) {
robj *o;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL)
return C_OK;
if (o->type != OBJ_STRING) {
addReply(c,shared.wrongtypeerr);
return C_ERR;
} else {
addReplyBulk(c,o);
return C_OK;
}
}
int getGenericCommand(redisClient *c) {
robj *o;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL)
return REDIS_OK;
// 这里比的是type字段, 不是encoding.
if (o->type != REDIS_STRING) {
addReply(c,shared.wrongtypeerr);
return REDIS_ERR;
} else {
addReplyBulk(c,o);
return REDIS_OK;
}
}
void lrangeCommand(client *c) {
robj *o;
long start, end, llen, rangelen;
if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != C_OK) ||
(getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != C_OK)) return;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
|| checkType(c,o,OBJ_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 */
addReplyMultiBulkLen(c,rangelen);
if (o->encoding == OBJ_ENCODING_QUICKLIST) {
listTypeIterator *iter = listTypeInitIterator(o, start, LIST_TAIL);
while(rangelen--) {
listTypeEntry entry;
listTypeNext(iter, &entry);
quicklistEntry *qe = &entry.entry;
if (qe->value) {
addReplyBulkCBuffer(c,qe->value,qe->sz);
} else {
addReplyBulkLongLong(c,qe->longval);
}
}
listTypeReleaseIterator(iter);
} else {
serverPanic("List encoding is not QUICKLIST!");
}
}
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;
}
}
void zscoreCommand(redisClient *c) {
robj *o;
zset *zs;
dictEntry *de;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,o,REDIS_ZSET)) return;
zs = o->ptr;
de = dictFind(zs->dict,c->argv[2]);
if (!de) {
addReply(c,shared.nullbulk);
} else {
double *score = dictGetEntryVal(de);
addReplyDouble(c,*score);
}
}
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;
}
}
void getrangeCommand(client *c) {
robj *o;
long long start, end;
char *str, llbuf[32];
size_t strlen;
if (getLongLongFromObjectOrReply(c,c->argv[2],&start,NULL) != C_OK)
return;
if (getLongLongFromObjectOrReply(c,c->argv[3],&end,NULL) != C_OK)
return;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptybulk)) == NULL ||
checkType(c,o,OBJ_STRING)) return;
if (o->encoding == OBJ_ENCODING_INT) {
str = llbuf;
strlen = ll2string(llbuf,sizeof(llbuf),(long)o->ptr);
} else {
str = o->ptr;
strlen = sdslen(str);
}
/* Convert negative indexes */
if (start < 0 && end < 0 && start > end) {
addReply(c,shared.emptybulk);
return;
}
if (start < 0) start = strlen+start;
if (end < 0) end = strlen+end;
if (start < 0) start = 0;
if (end < 0) end = 0;
if ((unsigned long long)end >= strlen) end = strlen-1;
/* Precondition: end >= 0 && end < strlen, so the only condition where
* nothing can be returned is: start > end. */
if (start > end || strlen == 0) {
addReply(c,shared.emptybulk);
} else {
addReplyBulkCBuffer(c,(char*)str+start,end-start+1);
}
}
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);
}
void substrCommand(redisClient *c) {
robj *o;
long start = atoi(c->argv[2]->ptr);
long end = atoi(c->argv[3]->ptr);
size_t rangelen, strlen;
sds range;
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
checkType(c,o,REDIS_STRING)) return;
o = getDecodedObject(o);
strlen = sdslen(o->ptr);
/* convert negative indexes */
if (start < 0) start = strlen+start;
if (end < 0) end = strlen+end;
if (start < 0) start = 0;
if (end < 0) end = 0;
/* indexes sanity checks */
if (start > end || (size_t)start >= strlen) {
/* Out of range start or start > end result in null reply */
addReply(c,shared.nullbulk);
decrRefCount(o);
return;
}
if ((size_t)end >= strlen) end = strlen-1;
rangelen = (end-start)+1;
/* Return the result */
addReplySds(c,sdscatprintf(sdsempty(),"$%zu\r\n",rangelen));
range = sdsnewlen((char*)o->ptr+start,rangelen);
addReplySds(c,range);
addReply(c,shared.crlf);
decrRefCount(o);
}
void spopWithCountCommand(redisClient *c) {
long l;
unsigned long count, size;
robj *set;
/* Get the count argument */
if (getLongFromObjectOrReply(c,c->argv[2],&l,NULL) != REDIS_OK) return;
if (l >= 0) {
count = (unsigned) l;
} else {
addReply(c,shared.outofrangeerr);
return;
}
/* Make sure a key with the name inputted exists, and that it's type is
* indeed a set. Otherwise, return nil */
if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk))
== NULL || checkType(c,set,REDIS_SET)) return;
/* If count is zero, serve an empty multibulk ASAP to avoid special
* cases later. */
if (count == 0) {
addReply(c,shared.emptymultibulk);
return;
}
size = setTypeSize(set);
/* Generate an SPOP keyspace notification */
notifyKeyspaceEvent(REDIS_NOTIFY_SET,"spop",c->argv[1],c->db->id);
server.dirty += count;
/* CASE 1:
* The number of requested elements is greater than or equal to
* the number of elements inside the set: simply return the whole set. */
if (count >= size) {
/* We just return the entire set */
sunionDiffGenericCommand(c,c->argv+1,1,NULL,REDIS_OP_UNION);
/* Delete the set as it is now empty */
dbDelete(c->db,c->argv[1]);
notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",c->argv[1],c->db->id);
/* Propagate this command as an DEL operation */
rewriteClientCommandVector(c,2,shared.del,c->argv[1]);
signalModifiedKey(c->db,c->argv[1]);
server.dirty++;
return;
}
/* Case 2 and 3 require to replicate SPOP as a set of SERM commands.
* Prepare our replication argument vector. Also send the array length
* which is common to both the code paths. */
robj *propargv[3];
propargv[0] = createStringObject("SREM",4);
propargv[1] = c->argv[1];
addReplyMultiBulkLen(c,count);
/* Common iteration vars. */
robj *objele;
int encoding;
int64_t llele;
unsigned long remaining = size-count; /* Elements left after SPOP. */
/* If we are here, the number of requested elements is less than the
* number of elements inside the set. Also we are sure that count < size.
* Use two different strategies.
*
* CASE 2: The number of elements to return is small compared to the
* set size. We can just extract random elements and return them to
* the set. */
if (remaining*SPOP_MOVE_STRATEGY_MUL > count) {
while(count--) {
encoding = setTypeRandomElement(set,&objele,&llele);
if (encoding == REDIS_ENCODING_INTSET) {
objele = createStringObjectFromLongLong(llele);
} else {
incrRefCount(objele);
}
/* Return the element to the client and remove from the set. */
addReplyBulk(c,objele);
setTypeRemove(set,objele);
/* Replicate/AOF this command as an SREM operation */
propargv[2] = objele;
alsoPropagate(server.sremCommand,c->db->id,propargv,3,
REDIS_PROPAGATE_AOF|REDIS_PROPAGATE_REPL);
decrRefCount(objele);
}
} else {
/* CASE 3: The number of elements to return is very big, approaching
* the size of the set itself. After some time extracting random elements
* from such a set becomes computationally expensive, so we use
* a different strategy, we extract random elements that we don't
* want to return (the elements that will remain part of the set),
* creating a new set as we do this (that will be stored as the original
* set). Then we return the elements left in the original set and
* release it. */
robj *newset = NULL;
/* Create a new set with just the remaining elements. */
while(remaining--) {
encoding = setTypeRandomElement(set,&objele,&llele);
if (encoding == REDIS_ENCODING_INTSET) {
objele = createStringObjectFromLongLong(llele);
} else {
incrRefCount(objele);
}
if (!newset) newset = setTypeCreate(objele);
setTypeAdd(newset,objele);
setTypeRemove(set,objele);
decrRefCount(objele);
}
/* Assign the new set as the key value. */
incrRefCount(set); /* Protect the old set value. */
dbOverwrite(c->db,c->argv[1],newset);
/* Tranfer the old set to the client and release it. */
setTypeIterator *si;
si = setTypeInitIterator(set);
while((encoding = setTypeNext(si,&objele,&llele)) != -1) {
if (encoding == REDIS_ENCODING_INTSET) {
objele = createStringObjectFromLongLong(llele);
} else {
incrRefCount(objele);
}
addReplyBulk(c,objele);
/* Replicate/AOF this command as an SREM operation */
propargv[2] = objele;
alsoPropagate(server.sremCommand,c->db->id,propargv,3,
REDIS_PROPAGATE_AOF|REDIS_PROPAGATE_REPL);
decrRefCount(objele);
}
setTypeReleaseIterator(si);
decrRefCount(set);
}
/* Don't propagate the command itself even if we incremented the
* dirty counter. We don't want to propagate an SPOP command since
* we propagated the command as a set of SREMs operations using
* the alsoPropagate() API. */
decrRefCount(propargv[0]);
preventCommandPropagation(c);
}
void srandmemberWithCountCommand(redisClient *c) {
long l;
unsigned long count, size;
int uniq = 1;
robj *set, *ele;
int64_t llele;
int encoding;
dict *d;
if (getLongFromObjectOrReply(c,c->argv[2],&l,NULL) != REDIS_OK) return;
if (l >= 0) {
count = (unsigned) l;
} else {
/* A negative count means: return the same elements multiple times
* (i.e. don't remove the extracted element after every extraction). */
count = -l;
uniq = 0;
}
if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk))
== NULL || checkType(c,set,REDIS_SET)) return;
size = setTypeSize(set);
/* If count is zero, serve it ASAP to avoid special cases later. */
if (count == 0) {
addReply(c,shared.emptymultibulk);
return;
}
/* CASE 1: The count was negative, so the extraction method is just:
* "return N random elements" sampling the whole set every time.
* This case is trivial and can be served without auxiliary data
* structures. */
if (!uniq) {
addReplyMultiBulkLen(c,count);
while(count--) {
encoding = setTypeRandomElement(set,&ele,&llele);
if (encoding == REDIS_ENCODING_INTSET) {
addReplyBulkLongLong(c,llele);
} else {
addReplyBulk(c,ele);
}
}
return;
}
/* CASE 2:
* The number of requested elements is greater than the number of
* elements inside the set: simply return the whole set. */
if (count >= size) {
sunionDiffGenericCommand(c,c->argv+1,1,NULL,REDIS_OP_UNION);
return;
}
/* For CASE 3 and CASE 4 we need an auxiliary dictionary. */
d = dictCreate(&setDictType,NULL);
/* CASE 3:
* The number of elements inside the set is not greater than
* SRANDMEMBER_SUB_STRATEGY_MUL times the number of requested elements.
* In this case we create a set from scratch with all the elements, and
* subtract random elements to reach the requested number of elements.
*
* This is done because if the number of requsted elements is just
* a bit less than the number of elements in the set, the natural approach
* used into CASE 3 is highly inefficient. */
if (count*SRANDMEMBER_SUB_STRATEGY_MUL > size) {
setTypeIterator *si;
/* Add all the elements into the temporary dictionary. */
si = setTypeInitIterator(set);
while((encoding = setTypeNext(si,&ele,&llele)) != -1) {
int retval = DICT_ERR;
if (encoding == REDIS_ENCODING_INTSET) {
retval = dictAdd(d,createStringObjectFromLongLong(llele),NULL);
} else if (ele->encoding == REDIS_ENCODING_RAW) {
retval = dictAdd(d,dupStringObject(ele),NULL);
} else if (ele->encoding == REDIS_ENCODING_INT) {
retval = dictAdd(d,
createStringObjectFromLongLong((long)ele->ptr),NULL);
}
redisAssert(retval == DICT_OK);
}
setTypeReleaseIterator(si);
redisAssert(dictSize(d) == size);
/* Remove random elements to reach the right count. */
while(size > count) {
dictEntry *de;
de = dictGetRandomKey(d);
dictDelete(d,dictGetKey(de));
size--;
}
}
/* CASE 4: We have a big set compared to the requested number of elements.
* In this case we can simply get random elements from the set and add
* to the temporary set, trying to eventually get enough unique elements
* to reach the specified count. */
else {
unsigned long added = 0;
while(added < count) {
encoding = setTypeRandomElement(set,&ele,&llele);
if (encoding == REDIS_ENCODING_INTSET) {
ele = createStringObjectFromLongLong(llele);
} else if (ele->encoding == REDIS_ENCODING_RAW) {
ele = dupStringObject(ele);
} else if (ele->encoding == REDIS_ENCODING_INT) {
ele = createStringObjectFromLongLong((long)ele->ptr);
}
/* Try to add the object to the dictionary. If it already exists
* free it, otherwise increment the number of objects we have
* in the result dictionary. */
if (dictAdd(d,ele,NULL) == DICT_OK)
added++;
else
decrRefCount(ele);
}
}
/* CASE 3 & 4: send the result to the user. */
{
dictIterator *di;
dictEntry *de;
addReplyMultiBulkLen(c,count);
di = dictGetIterator(d);
while((de = dictNext(di)) != NULL)
addReplyBulk(c,dictGetKey(de));
dictReleaseIterator(di);
dictRelease(d);
}
}
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 llenCommand(redisClient *c) {
robj *o = lookupKeyReadOrReply(c,c->argv[1],shared.czero);
if (o == NULL || checkType(c,o,REDIS_LIST)) return;
addReplyLongLong(c,listTypeLength(o));
}
/* 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);
}
}
