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#include "redis.h"
/*-----------------------------------------------------------------------------
* Set Commands
*----------------------------------------------------------------------------*/
/* Factory method to return a set that *can* hold "value". When the object has
* an integer-encodable value, an intset will be returned. Otherwise a regular
* hash table. */
robj *setTypeCreate(robj *value) {
if (isObjectRepresentableAsLongLong(value,NULL) == REDIS_OK)
return createIntsetObject();
return createSetObject();
}
int setTypeAdd(robj *subject, robj *value) {
long long llval;
if (subject->encoding == REDIS_ENCODING_HT) {
if (dictAdd(subject->ptr,value,NULL) == DICT_OK) {
incrRefCount(value);
return 1;
}
} else if (subject->encoding == REDIS_ENCODING_INTSET) {
if (isObjectRepresentableAsLongLong(value,&llval) == REDIS_OK) {
uint8_t success = 0;
subject->ptr = intsetAdd(subject->ptr,llval,&success);
if (success) {
/* Convert to regular set when the intset contains
* too many entries. */
if (intsetLen(subject->ptr) > server.set_max_intset_entries)
setTypeConvert(subject,REDIS_ENCODING_HT);
return 1;
}
} else {
/* Failed to get integer from object, convert to regular set. */
setTypeConvert(subject,REDIS_ENCODING_HT);
/* The set *was* an intset and this value is not integer
* encodable, so dictAdd should always work. */
redisAssert(dictAdd(subject->ptr,value,NULL) == DICT_OK);
incrRefCount(value);
return 1;
}
} else {
redisPanic("Unknown set encoding");
}
return 0;
}
int setTypeRemove(robj *setobj, robj *value) {
long long llval;
if (setobj->encoding == REDIS_ENCODING_HT) {
if (dictDelete(setobj->ptr,value) == DICT_OK) {
if (htNeedsResize(setobj->ptr)) dictResize(setobj->ptr);
return 1;
}
} else if (setobj->encoding == REDIS_ENCODING_INTSET) {
if (isObjectRepresentableAsLongLong(value,&llval) == REDIS_OK) {
int success;
setobj->ptr = intsetRemove(setobj->ptr,llval,&success);
if (success) return 1;
}
} else {
redisPanic("Unknown set encoding");
}
return 0;
}
int setTypeIsMember(robj *subject, robj *value) {
long long llval;
if (subject->encoding == REDIS_ENCODING_HT) {
return dictFind((dict*)subject->ptr,value) != NULL;
} else if (subject->encoding == REDIS_ENCODING_INTSET) {
if (isObjectRepresentableAsLongLong(value,&llval) == REDIS_OK) {
return intsetFind((intset*)subject->ptr,llval);
}
} else {
redisPanic("Unknown set encoding");
}
return 0;
}
setTypeIterator *setTypeInitIterator(robj *subject) {
setTypeIterator *si = zmalloc(sizeof(setTypeIterator));
si->subject = subject;
si->encoding = subject->encoding;
if (si->encoding == REDIS_ENCODING_HT) {
si->di = dictGetIterator(subject->ptr);
} else if (si->encoding == REDIS_ENCODING_INTSET) {
si->ii = 0;
} else {
redisPanic("Unknown set encoding");
}
return si;
}
void setTypeReleaseIterator(setTypeIterator *si) {
if (si->encoding == REDIS_ENCODING_HT)
dictReleaseIterator(si->di);
zfree(si);
}
/* Move to the next entry in the set. Returns the object at the current
* position.
*
* Since set elements can be internally be stored as redis objects or
* simple arrays of integers, setTypeNext returns the encoding of the
* set object you are iterating, and will populate the appropriate pointer
* (eobj) or (llobj) accordingly.
*
* When there are no longer elements -1 is returned.
* Returned objects ref count is not incremented, so this function is
* copy on write friendly. */
int setTypeNext(setTypeIterator *si, robj **objele, int64_t *llele) {
if (si->encoding == REDIS_ENCODING_HT) {
dictEntry *de = dictNext(si->di);
if (de == NULL) return -1;
*objele = dictGetEntryKey(de);
} else if (si->encoding == REDIS_ENCODING_INTSET) {
if (!intsetGet(si->subject->ptr,si->ii++,llele))
return -1;
}
return si->encoding;
}
/* The not copy on write friendly version but easy to use version
* of setTypeNext() is setTypeNextObject(), returning new objects
* or incrementing the ref count of returned objects. So if you don't
* retain a pointer to this object you should call decrRefCount() against it.
*
* This function is the way to go for write operations where COW is not
* an issue as the result will be anyway of incrementing the ref count. */
robj *setTypeNextObject(setTypeIterator *si) {
int64_t intele;
robj *objele;
int encoding;
encoding = setTypeNext(si,&objele,&intele);
switch(encoding) {
case -1: return NULL;
case REDIS_ENCODING_INTSET:
return createStringObjectFromLongLong(intele);
case REDIS_ENCODING_HT:
incrRefCount(objele);
return objele;
default:
redisPanic("Unsupported encoding");
}
return NULL; /* just to suppress warnings */
}
/* Return random element from a non empty set.
* The returned element can be a int64_t value if the set is encoded
* as an "intset" blob of integers, or a redis object if the set
* is a regular set.
*
* The caller provides both pointers to be populated with the right
* object. The return value of the function is the object->encoding
* field of the object and is used by the caller to check if the
* int64_t pointer or the redis object pointere was populated.
*
* When an object is returned (the set was a real set) the ref count
* of the object is not incremented so this function can be considered
* copy on write friendly. */
int setTypeRandomElement(robj *setobj, robj **objele, int64_t *llele) {
if (setobj->encoding == REDIS_ENCODING_HT) {
dictEntry *de = dictGetRandomKey(setobj->ptr);
*objele = dictGetEntryKey(de);
} else if (setobj->encoding == REDIS_ENCODING_INTSET) {
*llele = intsetRandom(setobj->ptr);
} else {
redisPanic("Unknown set encoding");
}
return setobj->encoding;
}
unsigned long setTypeSize(robj *subject) {
if (subject->encoding == REDIS_ENCODING_HT) {
return dictSize((dict*)subject->ptr);
} else if (subject->encoding == REDIS_ENCODING_INTSET) {
return intsetLen((intset*)subject->ptr);
} else {
redisPanic("Unknown set encoding");
}
}
/* Convert the set to specified encoding. The resulting dict (when converting
* to a hashtable) is presized to hold the number of elements in the original
* set. */
void setTypeConvert(robj *setobj, int enc) {
setTypeIterator *si;
redisAssert(setobj->type == REDIS_SET &&
setobj->encoding == REDIS_ENCODING_INTSET);
if (enc == REDIS_ENCODING_HT) {
int64_t intele;
dict *d = dictCreate(&setDictType,NULL);
robj *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,NULL,&intele) != -1) {
element = createStringObjectFromLongLong(intele);
redisAssert(dictAdd(d,element,NULL) == DICT_OK);
}
setTypeReleaseIterator(si);
setobj->encoding = REDIS_ENCODING_HT;
zfree(setobj->ptr);
setobj->ptr = d;
} else {
redisPanic("Unsupported set conversion");
}
}
void saddCommand(redisClient *c) {
robj *set;
int j, added = 0;
set = lookupKeyWrite(c->db,c->argv[1]);
if (set == NULL) {
set = setTypeCreate(c->argv[2]);
dbAdd(c->db,c->argv[1],set);
} else {
if (set->type != REDIS_SET) {
addReply(c,shared.wrongtypeerr);
return;
}
}
for (j = 2; j < c->argc; j++) {
c->argv[j] = tryObjectEncoding(c->argv[j]);
if (setTypeAdd(set,c->argv[j])) added++;
}
if (added) signalModifiedKey(c->db,c->argv[1]);
server.dirty += added;
addReplyLongLong(c,added);
}
void sremCommand(redisClient *c) {
robj *set;
int j, deleted = 0;
if ((set = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
checkType(c,set,REDIS_SET)) return;
for (j = 2; j < c->argc; j++) {
if (setTypeRemove(set,c->argv[j])) {
deleted++;
if (setTypeSize(set) == 0) {
dbDelete(c->db,c->argv[1]);
break;
}
}
}
if (deleted) {
signalModifiedKey(c->db,c->argv[1]);
server.dirty += deleted;
}
addReplyLongLong(c,deleted);
}
void smoveCommand(redisClient *c) {
robj *srcset, *dstset, *ele;
srcset = lookupKeyWrite(c->db,c->argv[1]);
dstset = lookupKeyWrite(c->db,c->argv[2]);
ele = c->argv[3] = tryObjectEncoding(c->argv[3]);
/* If the source key does not exist return 0 */
if (srcset == NULL) {
addReply(c,shared.czero);
return;
}
/* If the source key has the wrong type, or the destination key
* is set and has the wrong type, return with an error. */
if (checkType(c,srcset,REDIS_SET) ||
(dstset && checkType(c,dstset,REDIS_SET))) return;
/* If srcset and dstset are equal, SMOVE is a no-op */
if (srcset == dstset) {
addReply(c,shared.cone);
return;
}
/* If the element cannot be removed from the src set, return 0. */
if (!setTypeRemove(srcset,ele)) {
addReply(c,shared.czero);
return;
}
/* Remove the src set from the database when empty */
if (setTypeSize(srcset) == 0) dbDelete(c->db,c->argv[1]);
signalModifiedKey(c->db,c->argv[1]);
signalModifiedKey(c->db,c->argv[2]);
server.dirty++;
/* Create the destination set when it doesn't exist */
if (!dstset) {
dstset = setTypeCreate(ele);
dbAdd(c->db,c->argv[2],dstset);
}
/* An extra key has changed when ele was successfully added to dstset */
if (setTypeAdd(dstset,ele)) server.dirty++;
addReply(c,shared.cone);
}
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 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));
}
void spopCommand(redisClient *c) {
robj *set, *ele, *aux;
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) {
ele = createStringObjectFromLongLong(llele);
set->ptr = intsetRemove(set->ptr,llele,NULL);
} else {
incrRefCount(ele);
setTypeRemove(set,ele);
}
/* Replicate/AOF this command as an SREM operation */
aux = createStringObject("SREM",4);
rewriteClientCommandVector(c,3,aux,c->argv[1],ele);
decrRefCount(ele);
decrRefCount(aux);
addReplyBulk(c,ele);
if (setTypeSize(set) == 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);
}
}
int qsortCompareSetsByCardinality(const void *s1, const void *s2) {
return setTypeSize(*(robj**)s1)-setTypeSize(*(robj**)s2);
}
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)) {
signalModifiedKey(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 (sets[j] == sets[0]) continue;
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);
}
signalModifiedKey(c->db,dstkey);
server.dirty++;
} else {
setDeferredMultiBulkLength(c,replylen,cardinality);
}
zfree(sets);
}
void sinterCommand(redisClient *c) {
sinterGenericCommand(c,c->argv+1,c->argc-1,NULL);
}
void sinterstoreCommand(redisClient *c) {
sinterGenericCommand(c,c->argv+2,c->argc-2,c->argv[1]);
}
#define REDIS_OP_UNION 0
#define REDIS_OP_DIFF 1
#define REDIS_OP_INTER 2
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);
}
signalModifiedKey(c->db,dstkey);
server.dirty++;
}
zfree(sets);
}
void sunionCommand(redisClient *c) {
sunionDiffGenericCommand(c,c->argv+1,c->argc-1,NULL,REDIS_OP_UNION);
}
void sunionstoreCommand(redisClient *c) {
sunionDiffGenericCommand(c,c->argv+2,c->argc-2,c->argv[1],REDIS_OP_UNION);
}
void sdiffCommand(redisClient *c) {
sunionDiffGenericCommand(c,c->argv+1,c->argc-1,NULL,REDIS_OP_DIFF);
}
void sdiffstoreCommand(redisClient *c) {
sunionDiffGenericCommand(c,c->argv+2,c->argc-2,c->argv[1],REDIS_OP_DIFF);
}
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