X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/af4e866dbb1455a50d51b3d5f46832f1a36e2080..aa9a61ccd7cc1ffa1441ef74edd9d51954fc7896:/src/t_set.c

diff --git a/src/t_set.c b/src/t_set.c
index 808ef268..3cf1cf00 100644
--- a/src/t_set.c
+++ b/src/t_set.c
@@ -4,12 +4,225 @@
  * 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. */
+            redisAssertWithInfo(NULL,value,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 = dictGetKey(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 = dictGetKey(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;
+    redisAssertWithInfo(NULL,setobj,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);
+            redisAssertWithInfo(NULL,element,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 = createSetObject();
+        set = setTypeCreate(c->argv[2]);
         dbAdd(c->db,c->argv[1],set);
     } else {
         if (set->type != REDIS_SET) {
@@ -17,64 +230,82 @@ void saddCommand(redisClient *c) {
             return;
         }
     }
-    if (dictAdd(set->ptr,c->argv[2],NULL) == DICT_OK) {
-        incrRefCount(c->argv[2]);
-        server.dirty++;
-        addReply(c,shared.cone);
-    } else {
-        addReply(c,shared.czero);
+
+    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;
 
-    if (dictDelete(set->ptr,c->argv[2]) == DICT_OK) {
-        server.dirty++;
-        if (htNeedsResize(set->ptr)) dictResize(set->ptr);
-        if (dictSize((dict*)set->ptr) == 0) dbDelete(c->db,c->argv[1]);
-        addReply(c,shared.cone);
-    } else {
-        addReply(c,shared.czero);
+    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;
-
+    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 it's of the wrong type
-     * raise an error */
-    if (srcset == NULL || srcset->type != REDIS_SET) {
-        addReply(c, srcset ? shared.wrongtypeerr : shared.czero);
+    /* If the source key does not exist return 0 */
+    if (srcset == NULL) {
+        addReply(c,shared.czero);
         return;
     }
-    /* Error if the destination key is not a set as well */
-    if (dstset && dstset->type != REDIS_SET) {
-        addReply(c,shared.wrongtypeerr);
+
+    /* 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;
     }
-    /* Remove the element from the source set */
-    if (dictDelete(srcset->ptr,c->argv[3]) == DICT_ERR) {
-        /* Key not found in the src set! return zero */
+
+    /* If the element cannot be removed from the src set, return 0. */
+    if (!setTypeRemove(srcset,ele)) {
         addReply(c,shared.czero);
         return;
     }
-    if (dictSize((dict*)srcset->ptr) == 0 && srcset != dstset)
-        dbDelete(c->db,c->argv[1]);
+
+    /* 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++;
-    /* Add the element to the destination set */
+
+    /* Create the destination set when it doesn't exist */
     if (!dstset) {
-        dstset = createSetObject();
+        dstset = setTypeCreate(ele);
         dbAdd(c->db,c->argv[2],dstset);
     }
-    if (dictAdd(dstset->ptr,c->argv[3],NULL) == DICT_OK)
-        incrRefCount(c->argv[3]);
+
+    /* An extra key has changed when ele was successfully added to dstset */
+    if (setTypeAdd(dstset,ele)) server.dirty++;
     addReply(c,shared.cone);
 }
 
@@ -84,7 +315,8 @@ void sismemberCommand(redisClient *c) {
     if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,set,REDIS_SET)) return;
 
-    if (dictFind(set->ptr,c->argv[2]))
+    c->argv[2] = tryObjectEncoding(c->argv[2]);
+    if (setTypeIsMember(set,c->argv[2]))
         addReply(c,shared.cone);
     else
         addReply(c,shared.czero);
@@ -92,93 +324,97 @@ void sismemberCommand(redisClient *c) {
 
 void scardCommand(redisClient *c) {
     robj *o;
-    dict *s;
 
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
         checkType(c,o,REDIS_SET)) return;
 
-    s = o->ptr;
-    addReplyUlong(c,dictSize(s));
+    addReplyLongLong(c,setTypeSize(o));
 }
 
 void spopCommand(redisClient *c) {
-    robj *set;
-    dictEntry *de;
+    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;
 
-    de = dictGetRandomKey(set->ptr);
-    if (de == NULL) {
-        addReply(c,shared.nullbulk);
+    encoding = setTypeRandomElement(set,&ele,&llele);
+    if (encoding == REDIS_ENCODING_INTSET) {
+        ele = createStringObjectFromLongLong(llele);
+        set->ptr = intsetRemove(set->ptr,llele,NULL);
     } else {
-        robj *ele = dictGetEntryKey(de);
-
-        addReplyBulk(c,ele);
-        dictDelete(set->ptr,ele);
-        if (htNeedsResize(set->ptr)) dictResize(set->ptr);
-        if (dictSize((dict*)set->ptr) == 0) dbDelete(c->db,c->argv[1]);
-        server.dirty++;
+        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;
-    dictEntry *de;
+    robj *set, *ele;
+    int64_t llele;
+    int encoding;
 
     if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
         checkType(c,set,REDIS_SET)) return;
 
-    de = dictGetRandomKey(set->ptr);
-    if (de == NULL) {
-        addReply(c,shared.nullbulk);
+    encoding = setTypeRandomElement(set,&ele,&llele);
+    if (encoding == REDIS_ENCODING_INTSET) {
+        addReplyBulkLongLong(c,llele);
     } else {
-        robj *ele = dictGetEntryKey(de);
-
         addReplyBulk(c,ele);
     }
 }
 
 int qsortCompareSetsByCardinality(const void *s1, const void *s2) {
-    dict **d1 = (void*) s1, **d2 = (void*) s2;
-
-    return dictSize(*d1)-dictSize(*d2);
+    return setTypeSize(*(robj**)s1)-setTypeSize(*(robj**)s2);
 }
 
-void sinterGenericCommand(redisClient *c, robj **setskeys, unsigned long setsnum, robj *dstkey) {
-    dict **dv = zmalloc(sizeof(dict*)*setsnum);
-    dictIterator *di;
-    dictEntry *de;
-    robj *lenobj = NULL, *dstset = NULL;
+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 < setsnum; j++) {
-        robj *setobj;
-
-        setobj = dstkey ?
-                    lookupKeyWrite(c->db,setskeys[j]) :
-                    lookupKeyRead(c->db,setskeys[j]);
+    for (j = 0; j < setnum; j++) {
+        robj *setobj = dstkey ?
+            lookupKeyWrite(c->db,setkeys[j]) :
+            lookupKeyRead(c->db,setkeys[j]);
         if (!setobj) {
-            zfree(dv);
+            zfree(sets);
             if (dstkey) {
-                if (dbDelete(c->db,dstkey))
+                if (dbDelete(c->db,dstkey)) {
+                    signalModifiedKey(c->db,dstkey);
                     server.dirty++;
+                }
                 addReply(c,shared.czero);
             } else {
                 addReply(c,shared.emptymultibulk);
             }
             return;
         }
-        if (setobj->type != REDIS_SET) {
-            zfree(dv);
-            addReply(c,shared.wrongtypeerr);
+        if (checkType(c,setobj,REDIS_SET)) {
+            zfree(sets);
             return;
         }
-        dv[j] = setobj->ptr;
+        sets[j] = setobj;
     }
     /* Sort sets from the smallest to largest, this will improve our
      * algorithm's performace */
-    qsort(dv,setsnum,sizeof(dict*),qsortCompareSetsByCardinality);
+    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
@@ -186,54 +422,92 @@ void sinterGenericCommand(redisClient *c, robj **setskeys, unsigned long setsnum
      * to the output list and save the pointer to later modify it with the
      * right length */
     if (!dstkey) {
-        lenobj = createObject(REDIS_STRING,NULL);
-        addReply(c,lenobj);
-        decrRefCount(lenobj);
+        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 = createSetObject();
+        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 */
-    di = dictGetIterator(dv[0]);
-
-    while((de = dictNext(di)) != NULL) {
-        robj *ele;
+    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;
+                }
+            }
+        }
 
-        for (j = 1; j < setsnum; j++)
-            if (dictFind(dv[j],dictGetEntryKey(de)) == NULL) break;
-        if (j != setsnum)
-            continue; /* at least one set does not contain the member */
-        ele = dictGetEntryKey(de);
-        if (!dstkey) {
-            addReplyBulk(c,ele);
-            cardinality++;
-        } else {
-            dictAdd(dstset->ptr,ele,NULL);
-            incrRefCount(ele);
+        /* 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);
+                }
+            }
         }
     }
-    dictReleaseIterator(di);
+    setTypeReleaseIterator(si);
 
     if (dstkey) {
         /* Store the resulting set into the target, if the intersection
          * is not an empty set. */
         dbDelete(c->db,dstkey);
-        if (dictSize((dict*)dstset->ptr) > 0) {
+        if (setTypeSize(dstset) > 0) {
             dbAdd(c->db,dstkey,dstset);
-            addReplyLongLong(c,dictSize((dict*)dstset->ptr));
+            addReplyLongLong(c,setTypeSize(dstset));
         } else {
             decrRefCount(dstset);
             addReply(c,shared.czero);
         }
+        signalModifiedKey(c->db,dstkey);
         server.dirty++;
     } else {
-        lenobj->ptr = sdscatprintf(sdsempty(),"*%lu\r\n",cardinality);
+        setDeferredMultiBulkLength(c,replylen,cardinality);
     }
-    zfree(dv);
+    zfree(sets);
 }
 
 void sinterCommand(redisClient *c) {
@@ -244,92 +518,86 @@ void sinterstoreCommand(redisClient *c) {
     sinterGenericCommand(c,c->argv+2,c->argc-2,c->argv[1]);
 }
 
-void sunionDiffGenericCommand(redisClient *c, robj **setskeys, int setsnum, robj *dstkey, int op) {
-    dict **dv = zmalloc(sizeof(dict*)*setsnum);
-    dictIterator *di;
-    dictEntry *de;
-    robj *dstset = NULL;
-    int j, cardinality = 0;
+#define REDIS_OP_UNION 0
+#define REDIS_OP_DIFF 1
+#define REDIS_OP_INTER 2
 
-    for (j = 0; j < setsnum; j++) {
-        robj *setobj;
+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;
 
-        setobj = dstkey ?
-                    lookupKeyWrite(c->db,setskeys[j]) :
-                    lookupKeyRead(c->db,setskeys[j]);
+    for (j = 0; j < setnum; j++) {
+        robj *setobj = dstkey ?
+            lookupKeyWrite(c->db,setkeys[j]) :
+            lookupKeyRead(c->db,setkeys[j]);
         if (!setobj) {
-            dv[j] = NULL;
+            sets[j] = NULL;
             continue;
         }
-        if (setobj->type != REDIS_SET) {
-            zfree(dv);
-            addReply(c,shared.wrongtypeerr);
+        if (checkType(c,setobj,REDIS_SET)) {
+            zfree(sets);
             return;
         }
-        dv[j] = setobj->ptr;
+        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 = createSetObject();
+    dstset = createIntsetObject();
 
     /* Iterate all the elements of all the sets, add every element a single
      * time to the result set */
-    for (j = 0; j < setsnum; j++) {
-        if (op == REDIS_OP_DIFF && j == 0 && !dv[j]) break; /* result set is empty */
-        if (!dv[j]) continue; /* non existing keys are like empty sets */
+    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 */
 
-        di = dictGetIterator(dv[j]);
-
-        while((de = dictNext(di)) != NULL) {
-            robj *ele;
-
-            /* dictAdd will not add the same element multiple times */
-            ele = dictGetEntryKey(de);
+        si = setTypeInitIterator(sets[j]);
+        while((ele = setTypeNextObject(si)) != NULL) {
             if (op == REDIS_OP_UNION || j == 0) {
-                if (dictAdd(dstset->ptr,ele,NULL) == DICT_OK) {
-                    incrRefCount(ele);
+                if (setTypeAdd(dstset,ele)) {
                     cardinality++;
                 }
             } else if (op == REDIS_OP_DIFF) {
-                if (dictDelete(dstset->ptr,ele) == DICT_OK) {
+                if (setTypeRemove(dstset,ele)) {
                     cardinality--;
                 }
             }
+            decrRefCount(ele);
         }
-        dictReleaseIterator(di);
+        setTypeReleaseIterator(si);
 
-        /* result set is empty? Exit asap. */
+        /* 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) {
-        addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",cardinality));
-        di = dictGetIterator(dstset->ptr);
-        while((de = dictNext(di)) != NULL) {
-            robj *ele;
-
-            ele = dictGetEntryKey(de);
+        addReplyMultiBulkLen(c,cardinality);
+        si = setTypeInitIterator(dstset);
+        while((ele = setTypeNextObject(si)) != NULL) {
             addReplyBulk(c,ele);
+            decrRefCount(ele);
         }
-        dictReleaseIterator(di);
+        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 (dictSize((dict*)dstset->ptr) > 0) {
+        if (setTypeSize(dstset) > 0) {
             dbAdd(c->db,dstkey,dstset);
-            addReplyLongLong(c,dictSize((dict*)dstset->ptr));
+            addReplyLongLong(c,setTypeSize(dstset));
         } else {
             decrRefCount(dstset);
             addReply(c,shared.czero);
         }
+        signalModifiedKey(c->db,dstkey);
         server.dirty++;
     }
-    zfree(dv);
+    zfree(sets);
 }
 
 void sunionCommand(redisClient *c) {