X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/cc4c964b33ac108c9541e31eb2e2420addf9a82e..9c21b72bb9b7844b22b60f63af37aa30dd78f898:/src/t_zset.c

diff --git a/src/t_zset.c b/src/t_zset.c
index 3c9ede1c..4812709e 100644
--- a/src/t_zset.c
+++ b/src/t_zset.c
@@ -17,7 +17,7 @@
 /* This skiplist implementation is almost a C translation of the original
  * algorithm described by William Pugh in "Skip Lists: A Probabilistic
  * Alternative to Balanced Trees", modified in three ways:
- * a) this implementation allows for repeated values.
+ * a) this implementation allows for repeated scores.
  * b) the comparison is not just by key (our 'score') but by satellite data.
  * c) there is a back pointer, so it's a doubly linked list with the back
  * pointers being only at "level 1". This allows to traverse the list
@@ -64,6 +64,10 @@ void zslFree(zskiplist *zsl) {
     zfree(zsl);
 }
 
+/* Returns a random level for the new skiplist node we are going to create.
+ * The return value of this function is between 1 and ZSKIPLIST_MAXLEVEL
+ * (both inclusive), with a powerlaw-alike distribution where higher
+ * levels are less likely to be returned. */
 int zslRandomLevel(void) {
     int level = 1;
     while ((random()&0xFFFF) < (ZSKIPLIST_P * 0xFFFF))
@@ -76,6 +80,7 @@ zskiplistNode *zslInsert(zskiplist *zsl, double score, robj *obj) {
     unsigned int rank[ZSKIPLIST_MAXLEVEL];
     int i, level;
 
+    redisAssert(!isnan(score));
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
         /* store rank that is crossed to reach the insert position */
@@ -174,12 +179,6 @@ int zslDelete(zskiplist *zsl, double score, robj *obj) {
     return 0; /* not found */
 }
 
-/* Struct to hold a inclusive/exclusive range spec. */
-typedef struct {
-    double min, max;
-    int minex, maxex; /* are min or max exclusive? */
-} zrangespec;
-
 static int zslValueGteMin(double value, zrangespec *spec) {
     return spec->minex ? (value > spec->min) : (value >= spec->min);
 }
@@ -188,10 +187,6 @@ static int zslValueLteMax(double value, zrangespec *spec) {
     return spec->maxex ? (value < spec->max) : (value <= spec->max);
 }
 
-static int zslValueInRange(double value, zrangespec *spec) {
-    return zslValueGteMin(value,spec) && zslValueLteMax(value,spec);
-}
-
 /* Returns if there is a part of the zset is in range. */
 int zslIsInRange(zskiplist *zsl, zrangespec *range) {
     zskiplistNode *x;
@@ -226,10 +221,12 @@ zskiplistNode *zslFirstInRange(zskiplist *zsl, zrangespec range) {
                 x = x->level[i].forward;
     }
 
-    /* The tail is in range, so the previous block should always return a
-     * node that is non-NULL and the last one to be out of range. */
+    /* This is an inner range, so the next node cannot be NULL. */
     x = x->level[0].forward;
-    redisAssert(x != NULL && zslValueInRange(x->score,&range));
+    redisAssert(x != NULL);
+
+    /* Check if score <= max. */
+    if (!zslValueLteMax(x->score,&range)) return NULL;
     return x;
 }
 
@@ -250,9 +247,11 @@ zskiplistNode *zslLastInRange(zskiplist *zsl, zrangespec range) {
                 x = x->level[i].forward;
     }
 
-    /* The header is in range, so the previous block should always return a
-     * node that is non-NULL and in range. */
-    redisAssert(x != NULL && zslValueInRange(x->score,&range));
+    /* This is an inner range, so this node cannot be NULL. */
+    redisAssert(x != NULL);
+
+    /* Check if score >= min. */
+    if (!zslValueGteMin(x->score,&range)) return NULL;
     return x;
 }
 
@@ -449,9 +448,7 @@ int zzlCompareElements(unsigned char *eptr, unsigned char *cstr, unsigned int cl
     return cmp;
 }
 
-unsigned int zzlLength(robj *zobj) {
-    unsigned char *zl = zobj->ptr;
-    redisAssert(zobj->encoding == REDIS_ENCODING_ZIPLIST);
+unsigned int zzlLength(unsigned char *zl) {
     return ziplistLen(zl)/2;
 }
 
@@ -505,7 +502,7 @@ int zzlIsInRange(unsigned char *zl, zrangespec *range) {
         return 0;
 
     p = ziplistIndex(zl,-1); /* Last score. */
-    redisAssert(p != NULL);
+    if (p == NULL) return 0; /* Empty sorted set */
     score = zzlGetScore(p);
     if (!zslValueGteMin(score,range))
         return 0;
@@ -521,8 +518,7 @@ int zzlIsInRange(unsigned char *zl, zrangespec *range) {
 
 /* Find pointer to the first element contained in the specified range.
  * Returns NULL when no element is contained in the range. */
-unsigned char *zzlFirstInRange(robj *zobj, zrangespec range) {
-    unsigned char *zl = zobj->ptr;
+unsigned char *zzlFirstInRange(unsigned char *zl, zrangespec range) {
     unsigned char *eptr = ziplistIndex(zl,0), *sptr;
     double score;
 
@@ -534,8 +530,12 @@ unsigned char *zzlFirstInRange(robj *zobj, zrangespec range) {
         redisAssert(sptr != NULL);
 
         score = zzlGetScore(sptr);
-        if (zslValueGteMin(score,&range))
-            return eptr;
+        if (zslValueGteMin(score,&range)) {
+            /* Check if score <= max. */
+            if (zslValueLteMax(score,&range))
+                return eptr;
+            return NULL;
+        }
 
         /* Move to next element. */
         eptr = ziplistNext(zl,sptr);
@@ -546,8 +546,7 @@ unsigned char *zzlFirstInRange(robj *zobj, zrangespec range) {
 
 /* Find pointer to the last element contained in the specified range.
  * Returns NULL when no element is contained in the range. */
-unsigned char *zzlLastInRange(robj *zobj, zrangespec range) {
-    unsigned char *zl = zobj->ptr;
+unsigned char *zzlLastInRange(unsigned char *zl, zrangespec range) {
     unsigned char *eptr = ziplistIndex(zl,-2), *sptr;
     double score;
 
@@ -559,8 +558,12 @@ unsigned char *zzlLastInRange(robj *zobj, zrangespec range) {
         redisAssert(sptr != NULL);
 
         score = zzlGetScore(sptr);
-        if (zslValueLteMax(score,&range))
-            return eptr;
+        if (zslValueLteMax(score,&range)) {
+            /* Check if score >= min. */
+            if (zslValueGteMin(score,&range))
+                return eptr;
+            return NULL;
+        }
 
         /* Move to previous element by moving to the score of previous element.
          * When this returns NULL, we know there also is no element. */
@@ -574,14 +577,13 @@ unsigned char *zzlLastInRange(robj *zobj, zrangespec range) {
     return NULL;
 }
 
-unsigned char *zzlFind(robj *zobj, robj *ele, double *score) {
-    unsigned char *zl = zobj->ptr;
+unsigned char *zzlFind(unsigned char *zl, robj *ele, double *score) {
     unsigned char *eptr = ziplistIndex(zl,0), *sptr;
 
     ele = getDecodedObject(ele);
     while (eptr != NULL) {
         sptr = ziplistNext(zl,eptr);
-        redisAssert(sptr != NULL);
+        redisAssertWithInfo(NULL,ele,sptr != NULL);
 
         if (ziplistCompare(eptr,ele->ptr,sdslen(ele->ptr))) {
             /* Matching element, pull out score. */
@@ -600,25 +602,22 @@ unsigned char *zzlFind(robj *zobj, robj *ele, double *score) {
 
 /* Delete (element,score) pair from ziplist. Use local copy of eptr because we
  * don't want to modify the one given as argument. */
-int zzlDelete(robj *zobj, unsigned char *eptr) {
-    unsigned char *zl = zobj->ptr;
+unsigned char *zzlDelete(unsigned char *zl, unsigned char *eptr) {
     unsigned char *p = eptr;
 
     /* TODO: add function to ziplist API to delete N elements from offset. */
     zl = ziplistDelete(zl,&p);
     zl = ziplistDelete(zl,&p);
-    zobj->ptr = zl;
-    return REDIS_OK;
+    return zl;
 }
 
-int zzlInsertAt(robj *zobj, robj *ele, double score, unsigned char *eptr) {
-    unsigned char *zl = zobj->ptr;
+unsigned char *zzlInsertAt(unsigned char *zl, unsigned char *eptr, robj *ele, double score) {
     unsigned char *sptr;
     char scorebuf[128];
     int scorelen;
-    int offset;
+    size_t offset;
 
-    redisAssert(ele->encoding == REDIS_ENCODING_RAW);
+    redisAssertWithInfo(NULL,ele,ele->encoding == REDIS_ENCODING_RAW);
     scorelen = d2string(scorebuf,sizeof(scorebuf),score);
     if (eptr == NULL) {
         zl = ziplistPush(zl,ele->ptr,sdslen(ele->ptr),ZIPLIST_TAIL);
@@ -630,37 +629,35 @@ int zzlInsertAt(robj *zobj, robj *ele, double score, unsigned char *eptr) {
         eptr = zl+offset;
 
         /* Insert score after the element. */
-        redisAssert((sptr = ziplistNext(zl,eptr)) != NULL);
+        redisAssertWithInfo(NULL,ele,(sptr = ziplistNext(zl,eptr)) != NULL);
         zl = ziplistInsert(zl,sptr,(unsigned char*)scorebuf,scorelen);
     }
 
-    zobj->ptr = zl;
-    return REDIS_OK;
+    return zl;
 }
 
 /* Insert (element,score) pair in ziplist. This function assumes the element is
  * not yet present in the list. */
-int zzlInsert(robj *zobj, robj *ele, double score) {
-    unsigned char *zl = zobj->ptr;
+unsigned char *zzlInsert(unsigned char *zl, robj *ele, double score) {
     unsigned char *eptr = ziplistIndex(zl,0), *sptr;
     double s;
 
     ele = getDecodedObject(ele);
     while (eptr != NULL) {
         sptr = ziplistNext(zl,eptr);
-        redisAssert(sptr != NULL);
+        redisAssertWithInfo(NULL,ele,sptr != NULL);
         s = zzlGetScore(sptr);
 
         if (s > score) {
             /* First element with score larger than score for element to be
              * inserted. This means we should take its spot in the list to
              * maintain ordering. */
-            zzlInsertAt(zobj,ele,score,eptr);
+            zl = zzlInsertAt(zl,eptr,ele,score);
             break;
         } else if (s == score) {
             /* Ensure lexicographical ordering for elements. */
             if (zzlCompareElements(eptr,ele->ptr,sdslen(ele->ptr)) > 0) {
-                zzlInsertAt(zobj,ele,score,eptr);
+                zl = zzlInsertAt(zl,eptr,ele,score);
                 break;
             }
         }
@@ -671,21 +668,21 @@ int zzlInsert(robj *zobj, robj *ele, double score) {
 
     /* Push on tail of list when it was not yet inserted. */
     if (eptr == NULL)
-        zzlInsertAt(zobj,ele,score,NULL);
+        zl = zzlInsertAt(zl,NULL,ele,score);
 
     decrRefCount(ele);
-    return REDIS_OK;
+    return zl;
 }
 
-unsigned long zzlDeleteRangeByScore(robj *zobj, zrangespec range) {
-    unsigned char *zl = zobj->ptr;
+unsigned char *zzlDeleteRangeByScore(unsigned char *zl, zrangespec range, unsigned long *deleted) {
     unsigned char *eptr, *sptr;
     double score;
-    unsigned long deleted = 0;
+    unsigned long num = 0;
 
-    eptr = zzlFirstInRange(zobj,range);
-    if (eptr == NULL) return deleted;
+    if (deleted != NULL) *deleted = 0;
 
+    eptr = zzlFirstInRange(zl,range);
+    if (eptr == NULL) return zl;
 
     /* When the tail of the ziplist is deleted, eptr will point to the sentinel
      * byte and ziplistNext will return NULL. */
@@ -695,33 +692,35 @@ unsigned long zzlDeleteRangeByScore(robj *zobj, zrangespec range) {
             /* Delete both the element and the score. */
             zl = ziplistDelete(zl,&eptr);
             zl = ziplistDelete(zl,&eptr);
-            deleted++;
+            num++;
         } else {
             /* No longer in range. */
             break;
         }
     }
 
-    return deleted;
+    if (deleted != NULL) *deleted = num;
+    return zl;
 }
 
 /* Delete all the elements with rank between start and end from the skiplist.
  * Start and end are inclusive. Note that start and end need to be 1-based */
-unsigned long zzlDeleteRangeByRank(robj *zobj, unsigned int start, unsigned int end) {
+unsigned char *zzlDeleteRangeByRank(unsigned char *zl, unsigned int start, unsigned int end, unsigned long *deleted) {
     unsigned int num = (end-start)+1;
-    zobj->ptr = ziplistDeleteRange(zobj->ptr,2*(start-1),2*num);
-    return num;
+    if (deleted) *deleted = num;
+    zl = ziplistDeleteRange(zl,2*(start-1),2*num);
+    return zl;
 }
 
 /*-----------------------------------------------------------------------------
  * Common sorted set API
  *----------------------------------------------------------------------------*/
 
-int zsLength(robj *zobj) {
+unsigned int zsetLength(robj *zobj) {
     int length = -1;
     if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
-        length = zzlLength(zobj);
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+        length = zzlLength(zobj->ptr);
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         length = ((zset*)zobj->ptr)->zsl->length;
     } else {
         redisPanic("Unknown sorted set encoding");
@@ -729,7 +728,7 @@ int zsLength(robj *zobj) {
     return length;
 }
 
-void zsConvert(robj *zobj, int encoding) {
+void zsetConvert(robj *zobj, int encoding) {
     zset *zs;
     zskiplistNode *node, *next;
     robj *ele;
@@ -743,7 +742,7 @@ void zsConvert(robj *zobj, int encoding) {
         unsigned int vlen;
         long long vlong;
 
-        if (encoding != REDIS_ENCODING_RAW)
+        if (encoding != REDIS_ENCODING_SKIPLIST)
             redisPanic("Unknown target encoding");
 
         zs = zmalloc(sizeof(*zs));
@@ -751,13 +750,13 @@ void zsConvert(robj *zobj, int encoding) {
         zs->zsl = zslCreate();
 
         eptr = ziplistIndex(zl,0);
-        redisAssert(eptr != NULL);
+        redisAssertWithInfo(NULL,zobj,eptr != NULL);
         sptr = ziplistNext(zl,eptr);
-        redisAssert(sptr != NULL);
+        redisAssertWithInfo(NULL,zobj,sptr != NULL);
 
         while (eptr != NULL) {
             score = zzlGetScore(sptr);
-            redisAssert(ziplistGet(eptr,&vstr,&vlen,&vlong));
+            redisAssertWithInfo(NULL,zobj,ziplistGet(eptr,&vstr,&vlen,&vlong));
             if (vstr == NULL)
                 ele = createStringObjectFromLongLong(vlong);
             else
@@ -765,15 +764,15 @@ void zsConvert(robj *zobj, int encoding) {
 
             /* Has incremented refcount since it was just created. */
             node = zslInsert(zs->zsl,score,ele);
-            redisAssert(dictAdd(zs->dict,ele,&node->score) == DICT_OK);
+            redisAssertWithInfo(NULL,zobj,dictAdd(zs->dict,ele,&node->score) == DICT_OK);
             incrRefCount(ele); /* Added to dictionary. */
             zzlNext(zl,&eptr,&sptr);
         }
 
         zfree(zobj->ptr);
         zobj->ptr = zs;
-        zobj->encoding = REDIS_ENCODING_RAW;
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+        zobj->encoding = REDIS_ENCODING_SKIPLIST;
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         unsigned char *zl = ziplistNew();
 
         if (encoding != REDIS_ENCODING_ZIPLIST)
@@ -787,13 +786,9 @@ void zsConvert(robj *zobj, int encoding) {
         zfree(zs->zsl->header);
         zfree(zs->zsl);
 
-        /* Immediately store pointer to ziplist in object because it will
-         * change because of reallocations when pushing to the ziplist. */
-        zobj->ptr = zl;
-
         while (node) {
             ele = getDecodedObject(node->obj);
-            redisAssert(zzlInsertAt(zobj,ele,node->score,NULL) == REDIS_OK);
+            zl = zzlInsertAt(zl,NULL,ele,node->score);
             decrRefCount(ele);
 
             next = node->level[0].forward;
@@ -802,6 +797,7 @@ void zsConvert(robj *zobj, int encoding) {
         }
 
         zfree(zs);
+        zobj->ptr = zl;
         zobj->encoding = REDIS_ENCODING_ZIPLIST;
     } else {
         redisPanic("Unknown sorted set encoding");
@@ -819,11 +815,29 @@ void zaddGenericCommand(redisClient *c, int incr) {
     robj *ele;
     robj *zobj;
     robj *curobj;
-    double score, curscore = 0.0;
+    double score = 0, *scores, curscore = 0.0;
+    int j, elements = (c->argc-2)/2;
+    int added = 0;
 
-    if (getDoubleFromObjectOrReply(c,c->argv[2],&score,NULL) != REDIS_OK)
+    if (c->argc % 2) {
+        addReply(c,shared.syntaxerr);
         return;
+    }
 
+    /* Start parsing all the scores, we need to emit any syntax error
+     * before executing additions to the sorted set, as the command should
+     * either execute fully or nothing at all. */
+    scores = zmalloc(sizeof(double)*elements);
+    for (j = 0; j < elements; j++) {
+        if (getDoubleFromObjectOrReply(c,c->argv[2+j*2],&scores[j],NULL)
+            != REDIS_OK)
+        {
+            zfree(scores);
+            return;
+        }
+    }
+
+    /* Lookup the key and create the sorted set if does not exist. */
     zobj = lookupKeyWrite(c->db,key);
     if (zobj == NULL) {
         if (server.zset_max_ziplist_entries == 0 ||
@@ -837,111 +851,105 @@ void zaddGenericCommand(redisClient *c, int incr) {
     } else {
         if (zobj->type != REDIS_ZSET) {
             addReply(c,shared.wrongtypeerr);
+            zfree(scores);
             return;
         }
     }
 
-    if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
-        unsigned char *eptr;
-
-        /* Prefer non-encoded element when dealing with ziplists. */
-        ele = c->argv[3];
-        if ((eptr = zzlFind(zobj,ele,&curscore)) != NULL) {
-            if (incr) {
-                score += curscore;
-                if (isnan(score)) {
-                    addReplyError(c,nanerr);
-                    /* Don't need to check if the sorted set is empty, because
-                     * we know it has at least one element. */
-                    return;
+    for (j = 0; j < elements; j++) {
+        score = scores[j];
+
+        if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
+            unsigned char *eptr;
+
+            /* Prefer non-encoded element when dealing with ziplists. */
+            ele = c->argv[3+j*2];
+            if ((eptr = zzlFind(zobj->ptr,ele,&curscore)) != NULL) {
+                if (incr) {
+                    score += curscore;
+                    if (isnan(score)) {
+                        addReplyError(c,nanerr);
+                        /* Don't need to check if the sorted set is empty
+                         * because we know it has at least one element. */
+                        zfree(scores);
+                        return;
+                    }
                 }
-            }
 
-            /* Remove and re-insert when score changed. */
-            if (score != curscore) {
-                redisAssert(zzlDelete(zobj,eptr) == REDIS_OK);
-                redisAssert(zzlInsert(zobj,ele,score) == REDIS_OK);
+                /* Remove and re-insert when score changed. */
+                if (score != curscore) {
+                    zobj->ptr = zzlDelete(zobj->ptr,eptr);
+                    zobj->ptr = zzlInsert(zobj->ptr,ele,score);
+
+                    signalModifiedKey(c->db,key);
+                    server.dirty++;
+                }
+            } else {
+                /* Optimize: check if the element is too large or the list
+                 * becomes too long *before* executing zzlInsert. */
+                zobj->ptr = zzlInsert(zobj->ptr,ele,score);
+                if (zzlLength(zobj->ptr) > server.zset_max_ziplist_entries)
+                    zsetConvert(zobj,REDIS_ENCODING_SKIPLIST);
+                if (sdslen(ele->ptr) > server.zset_max_ziplist_value)
+                    zsetConvert(zobj,REDIS_ENCODING_SKIPLIST);
 
                 signalModifiedKey(c->db,key);
                 server.dirty++;
+                if (!incr) added++;
             }
-
-            if (incr) /* ZINCRBY */
-                addReplyDouble(c,score);
-            else /* ZADD */
-                addReply(c,shared.czero);
-        } else {
-            /* Optimize: check if the element is too large or the list becomes
-             * too long *before* executing zzlInsert. */
-            redisAssert(zzlInsert(zobj,ele,score) == REDIS_OK);
-            if (zzlLength(zobj) > server.zset_max_ziplist_entries)
-                zsConvert(zobj,REDIS_ENCODING_RAW);
-            if (sdslen(ele->ptr) > server.zset_max_ziplist_value)
-                zsConvert(zobj,REDIS_ENCODING_RAW);
-
-            signalModifiedKey(c->db,key);
-            server.dirty++;
-
-            if (incr) /* ZINCRBY */
-                addReplyDouble(c,score);
-            else /* ZADD */
-                addReply(c,shared.cone);
-        }
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
-        zset *zs = zobj->ptr;
-        zskiplistNode *znode;
-        dictEntry *de;
-
-        ele = c->argv[3] = tryObjectEncoding(c->argv[3]);
-        de = dictFind(zs->dict,ele);
-        if (de != NULL) {
-            curobj = dictGetEntryKey(de);
-            curscore = *(double*)dictGetEntryVal(de);
-
-            if (incr) {
-                score += curscore;
-                if (isnan(score)) {
-                    addReplyError(c,nanerr);
-                    /* Don't need to check if the sorted set is empty, because
-                     * we know it has at least one element. */
-                    return;
+        } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
+            zset *zs = zobj->ptr;
+            zskiplistNode *znode;
+            dictEntry *de;
+
+            ele = c->argv[3+j*2] = tryObjectEncoding(c->argv[3+j*2]);
+            de = dictFind(zs->dict,ele);
+            if (de != NULL) {
+                curobj = dictGetKey(de);
+                curscore = *(double*)dictGetVal(de);
+
+                if (incr) {
+                    score += curscore;
+                    if (isnan(score)) {
+                        addReplyError(c,nanerr);
+                        /* Don't need to check if the sorted set is empty
+                         * because we know it has at least one element. */
+                        zfree(scores);
+                        return;
+                    }
                 }
-            }
 
-            /* Remove and re-insert when score changed. We can safely delete
-             * the key object from the skiplist, since the dictionary still has
-             * a reference to it. */
-            if (score != curscore) {
-                redisAssert(zslDelete(zs->zsl,curscore,curobj));
-                znode = zslInsert(zs->zsl,score,curobj);
-                incrRefCount(curobj); /* Re-inserted in skiplist. */
-                dictGetEntryVal(de) = &znode->score; /* Update score ptr. */
+                /* Remove and re-insert when score changed. We can safely
+                 * delete the key object from the skiplist, since the
+                 * dictionary still has a reference to it. */
+                if (score != curscore) {
+                    redisAssertWithInfo(c,curobj,zslDelete(zs->zsl,curscore,curobj));
+                    znode = zslInsert(zs->zsl,score,curobj);
+                    incrRefCount(curobj); /* Re-inserted in skiplist. */
+                    dictGetVal(de) = &znode->score; /* Update score ptr. */
+
+                    signalModifiedKey(c->db,key);
+                    server.dirty++;
+                }
+            } else {
+                znode = zslInsert(zs->zsl,score,ele);
+                incrRefCount(ele); /* Inserted in skiplist. */
+                redisAssertWithInfo(c,NULL,dictAdd(zs->dict,ele,&znode->score) == DICT_OK);
+                incrRefCount(ele); /* Added to dictionary. */
 
                 signalModifiedKey(c->db,key);
                 server.dirty++;
+                if (!incr) added++;
             }
-
-            if (incr) /* ZINCRBY */
-                addReplyDouble(c,score);
-            else /* ZADD */
-                addReply(c,shared.czero);
         } else {
-            znode = zslInsert(zs->zsl,score,ele);
-            incrRefCount(ele); /* Inserted in skiplist. */
-            redisAssert(dictAdd(zs->dict,ele,&znode->score) == DICT_OK);
-            incrRefCount(ele); /* Added to dictionary. */
-
-            signalModifiedKey(c->db,key);
-            server.dirty++;
-
-            if (incr) /* ZINCRBY */
-                addReplyDouble(c,score);
-            else /* ZADD */
-                addReply(c,shared.cone);
+            redisPanic("Unknown sorted set encoding");
         }
-    } else {
-        redisPanic("Unknown sorted set encoding");
     }
+    zfree(scores);
+    if (incr) /* ZINCRBY */
+        addReplyDouble(c,score);
+    else /* ZADD */
+        addReplyLongLong(c,added);
 }
 
 void zaddCommand(redisClient *c) {
@@ -954,8 +962,8 @@ void zincrbyCommand(redisClient *c) {
 
 void zremCommand(redisClient *c) {
     robj *key = c->argv[1];
-    robj *ele = c->argv[2];
     robj *zobj;
+    int deleted = 0, j;
 
     if ((zobj = lookupKeyWriteOrReply(c,key,shared.czero)) == NULL ||
         checkType(c,zobj,REDIS_ZSET)) return;
@@ -963,39 +971,48 @@ void zremCommand(redisClient *c) {
     if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
         unsigned char *eptr;
 
-        if ((eptr = zzlFind(zobj,ele,NULL)) != NULL) {
-            redisAssert(zzlDelete(zobj,eptr) == REDIS_OK);
-            if (zzlLength(zobj) == 0) dbDelete(c->db,key);
-        } else {
-            addReply(c,shared.czero);
-            return;
+        for (j = 2; j < c->argc; j++) {
+            if ((eptr = zzlFind(zobj->ptr,c->argv[j],NULL)) != NULL) {
+                deleted++;
+                zobj->ptr = zzlDelete(zobj->ptr,eptr);
+                if (zzlLength(zobj->ptr) == 0) {
+                    dbDelete(c->db,key);
+                    break;
+                }
+            }
         }
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         zset *zs = zobj->ptr;
         dictEntry *de;
         double score;
 
-        de = dictFind(zs->dict,ele);
-        if (de != NULL) {
-            /* Delete from the skiplist */
-            score = *(double*)dictGetEntryVal(de);
-            redisAssert(zslDelete(zs->zsl,score,ele));
-
-            /* Delete from the hash table */
-            dictDelete(zs->dict,ele);
-            if (htNeedsResize(zs->dict)) dictResize(zs->dict);
-            if (dictSize(zs->dict) == 0) dbDelete(c->db,key);
-        } else {
-            addReply(c,shared.czero);
-            return;
+        for (j = 2; j < c->argc; j++) {
+            de = dictFind(zs->dict,c->argv[j]);
+            if (de != NULL) {
+                deleted++;
+
+                /* Delete from the skiplist */
+                score = *(double*)dictGetVal(de);
+                redisAssertWithInfo(c,c->argv[j],zslDelete(zs->zsl,score,c->argv[j]));
+
+                /* Delete from the hash table */
+                dictDelete(zs->dict,c->argv[j]);
+                if (htNeedsResize(zs->dict)) dictResize(zs->dict);
+                if (dictSize(zs->dict) == 0) {
+                    dbDelete(c->db,key);
+                    break;
+                }
+            }
         }
     } else {
         redisPanic("Unknown sorted set encoding");
     }
 
-    signalModifiedKey(c->db,key);
-    server.dirty++;
-    addReply(c,shared.cone);
+    if (deleted) {
+        signalModifiedKey(c->db,key);
+        server.dirty += deleted;
+    }
+    addReplyLongLong(c,deleted);
 }
 
 void zremrangebyscoreCommand(redisClient *c) {
@@ -1006,7 +1023,7 @@ void zremrangebyscoreCommand(redisClient *c) {
 
     /* Parse the range arguments. */
     if (zslParseRange(c->argv[2],c->argv[3],&range) != REDIS_OK) {
-        addReplyError(c,"min or max is not a double");
+        addReplyError(c,"min or max is not a float");
         return;
     }
 
@@ -1014,8 +1031,9 @@ void zremrangebyscoreCommand(redisClient *c) {
         checkType(c,zobj,REDIS_ZSET)) return;
 
     if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
-        deleted = zzlDeleteRangeByScore(zobj,range);
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+        zobj->ptr = zzlDeleteRangeByScore(zobj->ptr,range,&deleted);
+        if (zzlLength(zobj->ptr) == 0) dbDelete(c->db,key);
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         zset *zs = zobj->ptr;
         deleted = zslDeleteRangeByScore(zs->zsl,range,zs->dict);
         if (htNeedsResize(zs->dict)) dictResize(zs->dict);
@@ -1044,7 +1062,7 @@ void zremrangebyrankCommand(redisClient *c) {
         checkType(c,zobj,REDIS_ZSET)) return;
 
     /* Sanitize indexes. */
-    llen = zsLength(zobj);
+    llen = zsetLength(zobj);
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;
@@ -1059,8 +1077,9 @@ void zremrangebyrankCommand(redisClient *c) {
 
     if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
         /* Correct for 1-based rank. */
-        deleted = zzlDeleteRangeByRank(zobj,start+1,end+1);
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+        zobj->ptr = zzlDeleteRangeByRank(zobj->ptr,start+1,end+1,&deleted);
+        if (zzlLength(zobj->ptr) == 0) dbDelete(c->db,key);
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         zset *zs = zobj->ptr;
 
         /* Correct for 1-based rank. */
@@ -1077,22 +1096,336 @@ void zremrangebyrankCommand(redisClient *c) {
 }
 
 typedef struct {
-    dict *dict;
+    robj *subject;
+    int type; /* Set, sorted set */
+    int encoding;
     double weight;
+
+    union {
+        /* Set iterators. */
+        union _iterset {
+            struct {
+                intset *is;
+                int ii;
+            } is;
+            struct {
+                dict *dict;
+                dictIterator *di;
+                dictEntry *de;
+            } ht;
+        } set;
+
+        /* Sorted set iterators. */
+        union _iterzset {
+            struct {
+                unsigned char *zl;
+                unsigned char *eptr, *sptr;
+            } zl;
+            struct {
+                zset *zs;
+                zskiplistNode *node;
+            } sl;
+        } zset;
+    } iter;
 } zsetopsrc;
 
-int qsortCompareZsetopsrcByCardinality(const void *s1, const void *s2) {
-    zsetopsrc *d1 = (void*) s1, *d2 = (void*) s2;
-    unsigned long size1, size2;
-    size1 = d1->dict ? dictSize(d1->dict) : 0;
-    size2 = d2->dict ? dictSize(d2->dict) : 0;
-    return size1 - size2;
+
+/* Use dirty flags for pointers that need to be cleaned up in the next
+ * iteration over the zsetopval. The dirty flag for the long long value is
+ * special, since long long values don't need cleanup. Instead, it means that
+ * we already checked that "ell" holds a long long, or tried to convert another
+ * representation into a long long value. When this was successful,
+ * OPVAL_VALID_LL is set as well. */
+#define OPVAL_DIRTY_ROBJ 1
+#define OPVAL_DIRTY_LL 2
+#define OPVAL_VALID_LL 4
+
+/* Store value retrieved from the iterator. */
+typedef struct {
+    int flags;
+    unsigned char _buf[32]; /* Private buffer. */
+    robj *ele;
+    unsigned char *estr;
+    unsigned int elen;
+    long long ell;
+    double score;
+} zsetopval;
+
+typedef union _iterset iterset;
+typedef union _iterzset iterzset;
+
+void zuiInitIterator(zsetopsrc *op) {
+    if (op->subject == NULL)
+        return;
+
+    if (op->type == REDIS_SET) {
+        iterset *it = &op->iter.set;
+        if (op->encoding == REDIS_ENCODING_INTSET) {
+            it->is.is = op->subject->ptr;
+            it->is.ii = 0;
+        } else if (op->encoding == REDIS_ENCODING_HT) {
+            it->ht.dict = op->subject->ptr;
+            it->ht.di = dictGetIterator(op->subject->ptr);
+            it->ht.de = dictNext(it->ht.di);
+        } else {
+            redisPanic("Unknown set encoding");
+        }
+    } else if (op->type == REDIS_ZSET) {
+        iterzset *it = &op->iter.zset;
+        if (op->encoding == REDIS_ENCODING_ZIPLIST) {
+            it->zl.zl = op->subject->ptr;
+            it->zl.eptr = ziplistIndex(it->zl.zl,0);
+            if (it->zl.eptr != NULL) {
+                it->zl.sptr = ziplistNext(it->zl.zl,it->zl.eptr);
+                redisAssert(it->zl.sptr != NULL);
+            }
+        } else if (op->encoding == REDIS_ENCODING_SKIPLIST) {
+            it->sl.zs = op->subject->ptr;
+            it->sl.node = it->sl.zs->zsl->header->level[0].forward;
+        } else {
+            redisPanic("Unknown sorted set encoding");
+        }
+    } else {
+        redisPanic("Unsupported type");
+    }
+}
+
+void zuiClearIterator(zsetopsrc *op) {
+    if (op->subject == NULL)
+        return;
+
+    if (op->type == REDIS_SET) {
+        iterset *it = &op->iter.set;
+        if (op->encoding == REDIS_ENCODING_INTSET) {
+            REDIS_NOTUSED(it); /* skip */
+        } else if (op->encoding == REDIS_ENCODING_HT) {
+            dictReleaseIterator(it->ht.di);
+        } else {
+            redisPanic("Unknown set encoding");
+        }
+    } else if (op->type == REDIS_ZSET) {
+        iterzset *it = &op->iter.zset;
+        if (op->encoding == REDIS_ENCODING_ZIPLIST) {
+            REDIS_NOTUSED(it); /* skip */
+        } else if (op->encoding == REDIS_ENCODING_SKIPLIST) {
+            REDIS_NOTUSED(it); /* skip */
+        } else {
+            redisPanic("Unknown sorted set encoding");
+        }
+    } else {
+        redisPanic("Unsupported type");
+    }
+}
+
+int zuiLength(zsetopsrc *op) {
+    if (op->subject == NULL)
+        return 0;
+
+    if (op->type == REDIS_SET) {
+        iterset *it = &op->iter.set;
+        if (op->encoding == REDIS_ENCODING_INTSET) {
+            return intsetLen(it->is.is);
+        } else if (op->encoding == REDIS_ENCODING_HT) {
+            return dictSize(it->ht.dict);
+        } else {
+            redisPanic("Unknown set encoding");
+        }
+    } else if (op->type == REDIS_ZSET) {
+        iterzset *it = &op->iter.zset;
+        if (op->encoding == REDIS_ENCODING_ZIPLIST) {
+            return zzlLength(it->zl.zl);
+        } else if (op->encoding == REDIS_ENCODING_SKIPLIST) {
+            return it->sl.zs->zsl->length;
+        } else {
+            redisPanic("Unknown sorted set encoding");
+        }
+    } else {
+        redisPanic("Unsupported type");
+    }
+}
+
+/* Check if the current value is valid. If so, store it in the passed structure
+ * and move to the next element. If not valid, this means we have reached the
+ * end of the structure and can abort. */
+int zuiNext(zsetopsrc *op, zsetopval *val) {
+    if (op->subject == NULL)
+        return 0;
+
+    if (val->flags & OPVAL_DIRTY_ROBJ)
+        decrRefCount(val->ele);
+
+    memset(val,0,sizeof(zsetopval));
+
+    if (op->type == REDIS_SET) {
+        iterset *it = &op->iter.set;
+        if (op->encoding == REDIS_ENCODING_INTSET) {
+            int64_t ell;
+
+            if (!intsetGet(it->is.is,it->is.ii,&ell))
+                return 0;
+            val->ell = ell;
+            val->score = 1.0;
+
+            /* Move to next element. */
+            it->is.ii++;
+        } else if (op->encoding == REDIS_ENCODING_HT) {
+            if (it->ht.de == NULL)
+                return 0;
+            val->ele = dictGetKey(it->ht.de);
+            val->score = 1.0;
+
+            /* Move to next element. */
+            it->ht.de = dictNext(it->ht.di);
+        } else {
+            redisPanic("Unknown set encoding");
+        }
+    } else if (op->type == REDIS_ZSET) {
+        iterzset *it = &op->iter.zset;
+        if (op->encoding == REDIS_ENCODING_ZIPLIST) {
+            /* No need to check both, but better be explicit. */
+            if (it->zl.eptr == NULL || it->zl.sptr == NULL)
+                return 0;
+            redisAssert(ziplistGet(it->zl.eptr,&val->estr,&val->elen,&val->ell));
+            val->score = zzlGetScore(it->zl.sptr);
+
+            /* Move to next element. */
+            zzlNext(it->zl.zl,&it->zl.eptr,&it->zl.sptr);
+        } else if (op->encoding == REDIS_ENCODING_SKIPLIST) {
+            if (it->sl.node == NULL)
+                return 0;
+            val->ele = it->sl.node->obj;
+            val->score = it->sl.node->score;
+
+            /* Move to next element. */
+            it->sl.node = it->sl.node->level[0].forward;
+        } else {
+            redisPanic("Unknown sorted set encoding");
+        }
+    } else {
+        redisPanic("Unsupported type");
+    }
+    return 1;
+}
+
+int zuiLongLongFromValue(zsetopval *val) {
+    if (!(val->flags & OPVAL_DIRTY_LL)) {
+        val->flags |= OPVAL_DIRTY_LL;
+
+        if (val->ele != NULL) {
+            if (val->ele->encoding == REDIS_ENCODING_INT) {
+                val->ell = (long)val->ele->ptr;
+                val->flags |= OPVAL_VALID_LL;
+            } else if (val->ele->encoding == REDIS_ENCODING_RAW) {
+                if (string2ll(val->ele->ptr,sdslen(val->ele->ptr),&val->ell))
+                    val->flags |= OPVAL_VALID_LL;
+            } else {
+                redisPanic("Unsupported element encoding");
+            }
+        } else if (val->estr != NULL) {
+            if (string2ll((char*)val->estr,val->elen,&val->ell))
+                val->flags |= OPVAL_VALID_LL;
+        } else {
+            /* The long long was already set, flag as valid. */
+            val->flags |= OPVAL_VALID_LL;
+        }
+    }
+    return val->flags & OPVAL_VALID_LL;
+}
+
+robj *zuiObjectFromValue(zsetopval *val) {
+    if (val->ele == NULL) {
+        if (val->estr != NULL) {
+            val->ele = createStringObject((char*)val->estr,val->elen);
+        } else {
+            val->ele = createStringObjectFromLongLong(val->ell);
+        }
+        val->flags |= OPVAL_DIRTY_ROBJ;
+    }
+    return val->ele;
+}
+
+int zuiBufferFromValue(zsetopval *val) {
+    if (val->estr == NULL) {
+        if (val->ele != NULL) {
+            if (val->ele->encoding == REDIS_ENCODING_INT) {
+                val->elen = ll2string((char*)val->_buf,sizeof(val->_buf),(long)val->ele->ptr);
+                val->estr = val->_buf;
+            } else if (val->ele->encoding == REDIS_ENCODING_RAW) {
+                val->elen = sdslen(val->ele->ptr);
+                val->estr = val->ele->ptr;
+            } else {
+                redisPanic("Unsupported element encoding");
+            }
+        } else {
+            val->elen = ll2string((char*)val->_buf,sizeof(val->_buf),val->ell);
+            val->estr = val->_buf;
+        }
+    }
+    return 1;
+}
+
+/* Find value pointed to by val in the source pointer to by op. When found,
+ * return 1 and store its score in target. Return 0 otherwise. */
+int zuiFind(zsetopsrc *op, zsetopval *val, double *score) {
+    if (op->subject == NULL)
+        return 0;
+
+    if (op->type == REDIS_SET) {
+        iterset *it = &op->iter.set;
+
+        if (op->encoding == REDIS_ENCODING_INTSET) {
+            if (zuiLongLongFromValue(val) && intsetFind(it->is.is,val->ell)) {
+                *score = 1.0;
+                return 1;
+            } else {
+                return 0;
+            }
+        } else if (op->encoding == REDIS_ENCODING_HT) {
+            zuiObjectFromValue(val);
+            if (dictFind(it->ht.dict,val->ele) != NULL) {
+                *score = 1.0;
+                return 1;
+            } else {
+                return 0;
+            }
+        } else {
+            redisPanic("Unknown set encoding");
+        }
+    } else if (op->type == REDIS_ZSET) {
+        iterzset *it = &op->iter.zset;
+        zuiObjectFromValue(val);
+
+        if (op->encoding == REDIS_ENCODING_ZIPLIST) {
+            if (zzlFind(it->zl.zl,val->ele,score) != NULL) {
+                /* Score is already set by zzlFind. */
+                return 1;
+            } else {
+                return 0;
+            }
+        } else if (op->encoding == REDIS_ENCODING_SKIPLIST) {
+            dictEntry *de;
+            if ((de = dictFind(it->sl.zs->dict,val->ele)) != NULL) {
+                *score = *(double*)dictGetVal(de);
+                return 1;
+            } else {
+                return 0;
+            }
+        } else {
+            redisPanic("Unknown sorted set encoding");
+        }
+    } else {
+        redisPanic("Unsupported type");
+    }
+}
+
+int zuiCompareByCardinality(const void *s1, const void *s2) {
+    return zuiLength((zsetopsrc*)s1) - zuiLength((zsetopsrc*)s2);
 }
 
 #define REDIS_AGGR_SUM 1
 #define REDIS_AGGR_MIN 2
 #define REDIS_AGGR_MAX 3
-#define zunionInterDictValue(_e) (dictGetEntryVal(_e) == NULL ? 1.0 : *(double*)dictGetEntryVal(_e))
+#define zunionInterDictValue(_e) (dictGetVal(_e) == NULL ? 1.0 : *(double*)dictGetVal(_e))
 
 inline static void zunionInterAggregate(double *target, double val, int aggregate) {
     if (aggregate == REDIS_AGGR_SUM) {
@@ -1112,18 +1445,22 @@ inline static void zunionInterAggregate(double *target, double val, int aggregat
 }
 
 void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
-    int i, j, setnum;
+    int i, j;
+    long setnum;
     int aggregate = REDIS_AGGR_SUM;
     zsetopsrc *src;
+    zsetopval zval;
+    robj *tmp;
+    unsigned int maxelelen = 0;
     robj *dstobj;
     zset *dstzset;
     zskiplistNode *znode;
-    dictIterator *di;
-    dictEntry *de;
     int touched = 0;
 
     /* expect setnum input keys to be given */
-    setnum = atoi(c->argv[2]->ptr);
+    if ((getLongFromObjectOrReply(c, c->argv[2], &setnum, NULL) != REDIS_OK))
+        return;
+
     if (setnum < 1) {
         addReplyError(c,
             "at least 1 input key is needed for ZUNIONSTORE/ZINTERSTORE");
@@ -1137,24 +1474,24 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
     }
 
     /* read keys to be used for input */
-    src = zmalloc(sizeof(zsetopsrc) * setnum);
+    src = zcalloc(sizeof(zsetopsrc) * setnum);
     for (i = 0, j = 3; i < setnum; i++, j++) {
         robj *obj = lookupKeyWrite(c->db,c->argv[j]);
-        if (!obj) {
-            src[i].dict = NULL;
-        } else {
-            if (obj->type == REDIS_ZSET) {
-                src[i].dict = ((zset*)obj->ptr)->dict;
-            } else if (obj->type == REDIS_SET) {
-                src[i].dict = (obj->ptr);
-            } else {
+        if (obj != NULL) {
+            if (obj->type != REDIS_ZSET && obj->type != REDIS_SET) {
                 zfree(src);
                 addReply(c,shared.wrongtypeerr);
                 return;
             }
+
+            src[i].subject = obj;
+            src[i].type = obj->type;
+            src[i].encoding = obj->encoding;
+        } else {
+            src[i].subject = NULL;
         }
 
-        /* default all weights to 1 */
+        /* Default all weights to 1. */
         src[i].weight = 1.0;
     }
 
@@ -1167,7 +1504,7 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
                 j++; remaining--;
                 for (i = 0; i < setnum; i++, j++, remaining--) {
                     if (getDoubleFromObjectOrReply(c,c->argv[j],&src[i].weight,
-                            "weight value is not a double") != REDIS_OK)
+                            "weight value is not a float") != REDIS_OK)
                     {
                         zfree(src);
                         return;
@@ -1195,95 +1532,122 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
         }
     }
 
+    for (i = 0; i < setnum; i++)
+        zuiInitIterator(&src[i]);
+
     /* sort sets from the smallest to largest, this will improve our
      * algorithm's performance */
-    qsort(src,setnum,sizeof(zsetopsrc),qsortCompareZsetopsrcByCardinality);
+    qsort(src,setnum,sizeof(zsetopsrc),zuiCompareByCardinality);
 
     dstobj = createZsetObject();
     dstzset = dstobj->ptr;
+    memset(&zval, 0, sizeof(zval));
 
     if (op == REDIS_OP_INTER) {
-        /* skip going over all entries if the smallest zset is NULL or empty */
-        if (src[0].dict && dictSize(src[0].dict) > 0) {
-            /* precondition: as src[0].dict is non-empty and the zsets are ordered
-             * from small to large, all src[i > 0].dict are non-empty too */
-            di = dictGetIterator(src[0].dict);
-            while((de = dictNext(di)) != NULL) {
+        /* Skip everything if the smallest input is empty. */
+        if (zuiLength(&src[0]) > 0) {
+            /* Precondition: as src[0] is non-empty and the inputs are ordered
+             * by size, all src[i > 0] are non-empty too. */
+            while (zuiNext(&src[0],&zval)) {
                 double score, value;
 
-                score = src[0].weight * zunionInterDictValue(de);
+                score = src[0].weight * zval.score;
+                if (isnan(score)) score = 0;
+
                 for (j = 1; j < setnum; j++) {
-                    dictEntry *other = dictFind(src[j].dict,dictGetEntryKey(de));
-                    if (other) {
-                        value = src[j].weight * zunionInterDictValue(other);
+                    /* It is not safe to access the zset we are
+                     * iterating, so explicitly check for equal object. */
+                    if (src[j].subject == src[0].subject) {
+                        value = zval.score*src[j].weight;
+                        zunionInterAggregate(&score,value,aggregate);
+                    } else if (zuiFind(&src[j],&zval,&value)) {
+                        value *= src[j].weight;
                         zunionInterAggregate(&score,value,aggregate);
                     } else {
                         break;
                     }
                 }
 
-                /* Only continue when present in every source dict. */
+                /* Only continue when present in every input. */
                 if (j == setnum) {
-                    robj *o = dictGetEntryKey(de);
-                    znode = zslInsert(dstzset->zsl,score,o);
-                    incrRefCount(o); /* added to skiplist */
-                    dictAdd(dstzset->dict,o,&znode->score);
-                    incrRefCount(o); /* added to dictionary */
+                    tmp = zuiObjectFromValue(&zval);
+                    znode = zslInsert(dstzset->zsl,score,tmp);
+                    incrRefCount(tmp); /* added to skiplist */
+                    dictAdd(dstzset->dict,tmp,&znode->score);
+                    incrRefCount(tmp); /* added to dictionary */
+
+                    if (tmp->encoding == REDIS_ENCODING_RAW)
+                        if (sdslen(tmp->ptr) > maxelelen)
+                            maxelelen = sdslen(tmp->ptr);
                 }
             }
-            dictReleaseIterator(di);
         }
     } else if (op == REDIS_OP_UNION) {
         for (i = 0; i < setnum; i++) {
-            if (!src[i].dict) continue;
+            if (zuiLength(&src[i]) == 0)
+                continue;
 
-            di = dictGetIterator(src[i].dict);
-            while((de = dictNext(di)) != NULL) {
+            while (zuiNext(&src[i],&zval)) {
                 double score, value;
 
-                /* skip key when already processed */
-                if (dictFind(dstzset->dict,dictGetEntryKey(de)) != NULL)
+                /* Skip key when already processed */
+                if (dictFind(dstzset->dict,zuiObjectFromValue(&zval)) != NULL)
                     continue;
 
-                /* initialize score */
-                score = src[i].weight * zunionInterDictValue(de);
+                /* Initialize score */
+                score = src[i].weight * zval.score;
+                if (isnan(score)) score = 0;
 
-                /* because the zsets are sorted by size, its only possible
-                 * for sets at larger indices to hold this entry */
+                /* Because the inputs are sorted by size, it's only possible
+                 * for sets at larger indices to hold this element. */
                 for (j = (i+1); j < setnum; j++) {
-                    dictEntry *other = dictFind(src[j].dict,dictGetEntryKey(de));
-                    if (other) {
-                        value = src[j].weight * zunionInterDictValue(other);
+                    /* It is not safe to access the zset we are
+                     * iterating, so explicitly check for equal object. */
+                    if(src[j].subject == src[i].subject) {
+                        value = zval.score*src[j].weight;
+                        zunionInterAggregate(&score,value,aggregate);
+                    } else if (zuiFind(&src[j],&zval,&value)) {
+                        value *= src[j].weight;
                         zunionInterAggregate(&score,value,aggregate);
                     }
                 }
 
-                robj *o = dictGetEntryKey(de);
-                znode = zslInsert(dstzset->zsl,score,o);
-                incrRefCount(o); /* added to skiplist */
-                dictAdd(dstzset->dict,o,&znode->score);
-                incrRefCount(o); /* added to dictionary */
+                tmp = zuiObjectFromValue(&zval);
+                znode = zslInsert(dstzset->zsl,score,tmp);
+                incrRefCount(zval.ele); /* added to skiplist */
+                dictAdd(dstzset->dict,tmp,&znode->score);
+                incrRefCount(zval.ele); /* added to dictionary */
+
+                if (tmp->encoding == REDIS_ENCODING_RAW)
+                    if (sdslen(tmp->ptr) > maxelelen)
+                        maxelelen = sdslen(tmp->ptr);
             }
-            dictReleaseIterator(di);
         }
     } else {
-        /* unknown operator */
-        redisAssert(op == REDIS_OP_INTER || op == REDIS_OP_UNION);
+        redisPanic("Unknown operator");
     }
 
+    for (i = 0; i < setnum; i++)
+        zuiClearIterator(&src[i]);
+
     if (dbDelete(c->db,dstkey)) {
         signalModifiedKey(c->db,dstkey);
         touched = 1;
         server.dirty++;
     }
     if (dstzset->zsl->length) {
+        /* Convert to ziplist when in limits. */
+        if (dstzset->zsl->length <= server.zset_max_ziplist_entries &&
+            maxelelen <= server.zset_max_ziplist_value)
+                zsetConvert(dstobj,REDIS_ENCODING_ZIPLIST);
+
         dbAdd(c->db,dstkey,dstobj);
-        addReplyLongLong(c, dstzset->zsl->length);
+        addReplyLongLong(c,zsetLength(dstobj));
         if (!touched) signalModifiedKey(c->db,dstkey);
         server.dirty++;
     } else {
         decrRefCount(dstobj);
-        addReply(c, shared.czero);
+        addReply(c,shared.czero);
     }
     zfree(src);
 }
@@ -1319,7 +1683,7 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
          || checkType(c,zobj,REDIS_ZSET)) return;
 
     /* Sanitize indexes. */
-    llen = zsLength(zobj);
+    llen = zsetLength(zobj);
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;
@@ -1348,12 +1712,12 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
         else
             eptr = ziplistIndex(zl,2*start);
 
-        redisAssert(eptr != NULL);
+        redisAssertWithInfo(c,zobj,eptr != NULL);
         sptr = ziplistNext(zl,eptr);
 
         while (rangelen--) {
-            redisAssert(eptr != NULL && sptr != NULL);
-            redisAssert(ziplistGet(eptr,&vstr,&vlen,&vlong));
+            redisAssertWithInfo(c,zobj,eptr != NULL && sptr != NULL);
+            redisAssertWithInfo(c,zobj,ziplistGet(eptr,&vstr,&vlen,&vlong));
             if (vstr == NULL)
                 addReplyBulkLongLong(c,vlong);
             else
@@ -1368,7 +1732,7 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
                 zzlNext(zl,&eptr,&sptr);
         }
 
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         zset *zs = zobj->ptr;
         zskiplist *zsl = zs->zsl;
         zskiplistNode *ln;
@@ -1386,7 +1750,7 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
         }
 
         while(rangelen--) {
-            redisAssert(ln != NULL);
+            redisAssertWithInfo(c,zobj,ln != NULL);
             ele = ln->obj;
             addReplyBulk(c,ele);
             if (withscores)
@@ -1406,13 +1770,12 @@ void zrevrangeCommand(redisClient *c) {
     zrangeGenericCommand(c,1);
 }
 
-/* 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) {
+/* This command implements ZRANGEBYSCORE, ZREVRANGEBYSCORE. */
+void genericZrangebyscoreCommand(redisClient *c, int reverse) {
     zrangespec range;
     robj *key = c->argv[1];
-    robj *emptyreply, *zobj;
-    int offset = 0, limit = -1;
+    robj *zobj;
+    long offset = 0, limit = -1;
     int withscores = 0;
     unsigned long rangelen = 0;
     void *replylen = NULL;
@@ -1428,7 +1791,7 @@ void genericZrangebyscoreCommand(redisClient *c, int reverse, int justcount) {
     }
 
     if (zslParseRange(c->argv[minidx],c->argv[maxidx],&range) != REDIS_OK) {
-        addReplyError(c,"min or max is not a double");
+        addReplyError(c,"min or max is not a float");
         return;
     }
 
@@ -1443,8 +1806,8 @@ void genericZrangebyscoreCommand(redisClient *c, int reverse, int justcount) {
                 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);
+                if ((getLongFromObjectOrReply(c, c->argv[pos+1], &offset, NULL) != REDIS_OK) ||
+                    (getLongFromObjectOrReply(c, c->argv[pos+2], &limit, NULL) != REDIS_OK)) return;
                 pos += 3; remaining -= 3;
             } else {
                 addReply(c,shared.syntaxerr);
@@ -1454,8 +1817,7 @@ void genericZrangebyscoreCommand(redisClient *c, int reverse, int justcount) {
     }
 
     /* Ok, lookup the key and get the range */
-    emptyreply = justcount ? shared.czero : shared.emptymultibulk;
-    if ((zobj = lookupKeyReadOrReply(c,key,emptyreply)) == NULL ||
+    if ((zobj = lookupKeyReadOrReply(c,key,shared.emptymultibulk)) == NULL ||
         checkType(c,zobj,REDIS_ZSET)) return;
 
     if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
@@ -1467,34 +1829,36 @@ void genericZrangebyscoreCommand(redisClient *c, int reverse, int justcount) {
         double score;
 
         /* If reversed, get the last node in range as starting point. */
-        if (reverse)
-            eptr = zzlLastInRange(zobj,range);
-        else
-            eptr = zzlFirstInRange(zobj,range);
+        if (reverse) {
+            eptr = zzlLastInRange(zl,range);
+        } else {
+            eptr = zzlFirstInRange(zl,range);
+        }
 
         /* No "first" element in the specified interval. */
         if (eptr == NULL) {
-            addReply(c,emptyreply);
+            addReply(c, shared.emptymultibulk);
             return;
         }
 
         /* Get score pointer for the first element. */
-        redisAssert(eptr != NULL);
+        redisAssertWithInfo(c,zobj,eptr != NULL);
         sptr = ziplistNext(zl,eptr);
 
         /* 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);
+        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 (eptr && offset--)
-            if (reverse)
+        while (eptr && offset--) {
+            if (reverse) {
                 zzlPrev(zl,&eptr,&sptr);
-            else
+            } else {
                 zzlNext(zl,&eptr,&sptr);
+            }
+        }
 
         while (eptr && limit--) {
             score = zzlGetScore(sptr);
@@ -1506,52 +1870,59 @@ void genericZrangebyscoreCommand(redisClient *c, int reverse, int justcount) {
                 if (!zslValueLteMax(score,&range)) break;
             }
 
-            /* Do our magic */
+            /* We know the element exists, so ziplistGet should always succeed */
+            redisAssertWithInfo(c,zobj,ziplistGet(eptr,&vstr,&vlen,&vlong));
+
             rangelen++;
-            if (!justcount) {
-                redisAssert(ziplistGet(eptr,&vstr,&vlen,&vlong));
-                if (vstr == NULL)
-                    addReplyBulkLongLong(c,vlong);
-                else
-                    addReplyBulkCBuffer(c,vstr,vlen);
-
-                if (withscores)
-                    addReplyDouble(c,score);
+            if (vstr == NULL) {
+                addReplyBulkLongLong(c,vlong);
+            } else {
+                addReplyBulkCBuffer(c,vstr,vlen);
+            }
+
+            if (withscores) {
+                addReplyDouble(c,score);
             }
 
             /* Move to next node */
-            if (reverse)
+            if (reverse) {
                 zzlPrev(zl,&eptr,&sptr);
-            else
+            } else {
                 zzlNext(zl,&eptr,&sptr);
+            }
         }
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         zset *zs = zobj->ptr;
         zskiplist *zsl = zs->zsl;
         zskiplistNode *ln;
 
         /* If reversed, get the last node in range as starting point. */
-        if (reverse)
+        if (reverse) {
             ln = zslLastInRange(zsl,range);
-        else
+        } else {
             ln = zslFirstInRange(zsl,range);
+        }
 
         /* No "first" element in the specified interval. */
         if (ln == NULL) {
-            addReply(c,emptyreply);
+            addReply(c, shared.emptymultibulk);
             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);
+        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--)
-            ln = reverse ? ln->backward : ln->level[0].forward;
+        while (ln && offset--) {
+            if (reverse) {
+                ln = ln->backward;
+            } else {
+                ln = ln->level[0].forward;
+            }
+        }
 
         while (ln && limit--) {
             /* Abort when the node is no longer in range. */
@@ -1561,39 +1932,114 @@ void genericZrangebyscoreCommand(redisClient *c, int reverse, int justcount) {
                 if (!zslValueLteMax(ln->score,&range)) break;
             }
 
-            /* Do our magic */
             rangelen++;
-            if (!justcount) {
-                addReplyBulk(c,ln->obj);
-                if (withscores)
-                    addReplyDouble(c,ln->score);
+            addReplyBulk(c,ln->obj);
+
+            if (withscores) {
+                addReplyDouble(c,ln->score);
             }
 
             /* Move to next node */
-            ln = reverse ? ln->backward : ln->level[0].forward;
+            if (reverse) {
+                ln = ln->backward;
+            } else {
+                ln = ln->level[0].forward;
+            }
         }
     } else {
         redisPanic("Unknown sorted set encoding");
     }
 
-    if (justcount) {
-        addReplyLongLong(c,(long)rangelen);
-    } else {
-        if (withscores) rangelen *= 2;
-        setDeferredMultiBulkLength(c,replylen,rangelen);
+    if (withscores) {
+        rangelen *= 2;
     }
+
+    setDeferredMultiBulkLength(c, replylen, rangelen);
 }
 
 void zrangebyscoreCommand(redisClient *c) {
-    genericZrangebyscoreCommand(c,0,0);
+    genericZrangebyscoreCommand(c,0);
 }
 
 void zrevrangebyscoreCommand(redisClient *c) {
-    genericZrangebyscoreCommand(c,1,0);
+    genericZrangebyscoreCommand(c,1);
 }
 
 void zcountCommand(redisClient *c) {
-    genericZrangebyscoreCommand(c,0,1);
+    robj *key = c->argv[1];
+    robj *zobj;
+    zrangespec range;
+    int count = 0;
+
+    /* Parse the range arguments */
+    if (zslParseRange(c->argv[2],c->argv[3],&range) != REDIS_OK) {
+        addReplyError(c,"min or max is not a float");
+        return;
+    }
+
+    /* Lookup the sorted set */
+    if ((zobj = lookupKeyReadOrReply(c, key, shared.czero)) == NULL ||
+        checkType(c, zobj, REDIS_ZSET)) return;
+
+    if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
+        unsigned char *zl = zobj->ptr;
+        unsigned char *eptr, *sptr;
+        double score;
+
+        /* Use the first element in range as the starting point */
+        eptr = zzlFirstInRange(zl,range);
+
+        /* No "first" element */
+        if (eptr == NULL) {
+            addReply(c, shared.czero);
+            return;
+        }
+
+        /* First element is in range */
+        sptr = ziplistNext(zl,eptr);
+        score = zzlGetScore(sptr);
+        redisAssertWithInfo(c,zobj,zslValueLteMax(score,&range));
+
+        /* Iterate over elements in range */
+        while (eptr) {
+            score = zzlGetScore(sptr);
+
+            /* Abort when the node is no longer in range. */
+            if (!zslValueLteMax(score,&range)) {
+                break;
+            } else {
+                count++;
+                zzlNext(zl,&eptr,&sptr);
+            }
+        }
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
+        zset *zs = zobj->ptr;
+        zskiplist *zsl = zs->zsl;
+        zskiplistNode *zn;
+        unsigned long rank;
+
+        /* Find first element in range */
+        zn = zslFirstInRange(zsl, range);
+
+        /* Use rank of first element, if any, to determine preliminary count */
+        if (zn != NULL) {
+            rank = zslGetRank(zsl, zn->score, zn->obj);
+            count = (zsl->length - (rank - 1));
+
+            /* Find last element in range */
+            zn = zslLastInRange(zsl, range);
+
+            /* Use rank of last element, if any, to determine the actual count */
+            if (zn != NULL) {
+                rank = zslGetRank(zsl, zn->score, zn->obj);
+                count -= (zsl->length - rank);
+            }
+        }
+    } else {
+        redisPanic("Unknown sorted set encoding");
+    }
+
+    addReplyLongLong(c, count);
 }
 
 void zcardCommand(redisClient *c) {
@@ -1603,7 +2049,7 @@ void zcardCommand(redisClient *c) {
     if ((zobj = lookupKeyReadOrReply(c,key,shared.czero)) == NULL ||
         checkType(c,zobj,REDIS_ZSET)) return;
 
-    addReplyLongLong(c,zsLength(zobj));
+    addReplyLongLong(c,zsetLength(zobj));
 }
 
 void zscoreCommand(redisClient *c) {
@@ -1615,18 +2061,18 @@ void zscoreCommand(redisClient *c) {
         checkType(c,zobj,REDIS_ZSET)) return;
 
     if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
-        if (zzlFind(zobj,c->argv[2],&score) != NULL)
+        if (zzlFind(zobj->ptr,c->argv[2],&score) != NULL)
             addReplyDouble(c,score);
         else
             addReply(c,shared.nullbulk);
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         zset *zs = zobj->ptr;
         dictEntry *de;
 
         c->argv[2] = tryObjectEncoding(c->argv[2]);
         de = dictFind(zs->dict,c->argv[2]);
         if (de != NULL) {
-            score = *(double*)dictGetEntryVal(de);
+            score = *(double*)dictGetVal(de);
             addReplyDouble(c,score);
         } else {
             addReply(c,shared.nullbulk);
@@ -1645,17 +2091,17 @@ void zrankGenericCommand(redisClient *c, int reverse) {
 
     if ((zobj = lookupKeyReadOrReply(c,key,shared.nullbulk)) == NULL ||
         checkType(c,zobj,REDIS_ZSET)) return;
-    llen = zsLength(zobj);
+    llen = zsetLength(zobj);
 
-    redisAssert(ele->encoding == REDIS_ENCODING_RAW);
+    redisAssertWithInfo(c,ele,ele->encoding == REDIS_ENCODING_RAW);
     if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
         unsigned char *zl = zobj->ptr;
         unsigned char *eptr, *sptr;
 
         eptr = ziplistIndex(zl,0);
-        redisAssert(eptr != NULL);
+        redisAssertWithInfo(c,zobj,eptr != NULL);
         sptr = ziplistNext(zl,eptr);
-        redisAssert(sptr != NULL);
+        redisAssertWithInfo(c,zobj,sptr != NULL);
 
         rank = 1;
         while(eptr != NULL) {
@@ -1673,7 +2119,7 @@ void zrankGenericCommand(redisClient *c, int reverse) {
         } else {
             addReply(c,shared.nullbulk);
         }
-    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {
         zset *zs = zobj->ptr;
         zskiplist *zsl = zs->zsl;
         dictEntry *de;
@@ -1682,9 +2128,9 @@ void zrankGenericCommand(redisClient *c, int reverse) {
         ele = c->argv[2] = tryObjectEncoding(c->argv[2]);
         de = dictFind(zs->dict,ele);
         if (de != NULL) {
-            score = *(double*)dictGetEntryVal(de);
+            score = *(double*)dictGetVal(de);
             rank = zslGetRank(zsl,score,ele);
-            redisAssert(rank); /* Existing elements always have a rank. */
+            redisAssertWithInfo(c,ele,rank); /* Existing elements always have a rank. */
             if (reverse)
                 addReplyLongLong(c,llen-rank);
             else