Reference zset score in zskiplistNode from dict entries

[redis.git] / src / t_zset.c

diff --git a/src/t_zset.c b/src/t_zset.c
index de32a8eedf7667c4795de5446dce9aa11c359bcb..3d9f612afd66eb96c9f2d40584627c9dd5a799b2 100644 (file)
--- a/src/t_zset.c
+++ b/src/t_zset.c
@@ -24,13 +24,7 @@
  * from tail to head, useful for ZREVRANGE. */
 
 zskiplistNode *zslCreateNode(int level, double score, robj *obj) {
  * from tail to head, useful for ZREVRANGE. */
 
 zskiplistNode *zslCreateNode(int level, double score, robj *obj) {

-    zskiplistNode *zn = zmalloc(sizeof(*zn));
-
-    zn->forward = zmalloc(sizeof(zskiplistNode*) * level);
-    if (level > 1)
-        zn->span = zmalloc(sizeof(unsigned int) * (level - 1));
-    else
-        zn->span = NULL;
+    zskiplistNode *zn = zmalloc(sizeof(*zn)+level*sizeof(struct zskiplistLevel));

     zn->score = score;
     zn->obj = obj;
     return zn;
     zn->score = score;
     zn->obj = obj;
     return zn;


@@ -45,11 +39,8 @@ zskiplist *zslCreate(void) {
     zsl->length = 0;
     zsl->header = zslCreateNode(ZSKIPLIST_MAXLEVEL,0,NULL);
     for (j = 0; j < ZSKIPLIST_MAXLEVEL; j++) {
     zsl->length = 0;
     zsl->header = zslCreateNode(ZSKIPLIST_MAXLEVEL,0,NULL);
     for (j = 0; j < ZSKIPLIST_MAXLEVEL; j++) {

-        zsl->header->forward[j] = NULL;
-
-        /* span has space for ZSKIPLIST_MAXLEVEL-1 elements */
-        if (j < ZSKIPLIST_MAXLEVEL-1)
-            zsl->header->span[j] = 0;
+        zsl->header->level[j].forward = NULL;
+        zsl->header->level[j].span = 0;

     }
     zsl->header->backward = NULL;
     zsl->tail = NULL;
     }
     zsl->header->backward = NULL;
     zsl->tail = NULL;


@@ -58,19 +49,15 @@ zskiplist *zslCreate(void) {
 
 void zslFreeNode(zskiplistNode *node) {
     decrRefCount(node->obj);
 
 void zslFreeNode(zskiplistNode *node) {
     decrRefCount(node->obj);

-    zfree(node->forward);
-    zfree(node->span);

     zfree(node);
 }
 
 void zslFree(zskiplist *zsl) {
     zfree(node);
 }
 
 void zslFree(zskiplist *zsl) {

-    zskiplistNode *node = zsl->header->forward[0], *next;
+    zskiplistNode *node = zsl->header->level[0].forward, *next;

 
 

-    zfree(zsl->header->forward);
-    zfree(zsl->header->span);

     zfree(zsl->header);
     while(node) {
     zfree(zsl->header);
     while(node) {

-        next = node->forward[0];
+        next = node->level[0].forward;

         zslFreeNode(node);
         node = next;
     }
         zslFreeNode(node);
         node = next;
     }


@@ -84,7 +71,7 @@ int zslRandomLevel(void) {
     return (level<ZSKIPLIST_MAXLEVEL) ? level : ZSKIPLIST_MAXLEVEL;
 }
 
     return (level<ZSKIPLIST_MAXLEVEL) ? level : ZSKIPLIST_MAXLEVEL;
 }
 

-void zslInsert(zskiplist *zsl, double score, robj *obj) {
+zskiplistNode *zslInsert(zskiplist *zsl, double score, robj *obj) {

     zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
     unsigned int rank[ZSKIPLIST_MAXLEVEL];
     int i, level;
     zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
     unsigned int rank[ZSKIPLIST_MAXLEVEL];
     int i, level;


@@ -93,13 +80,12 @@ void zslInsert(zskiplist *zsl, double score, robj *obj) {
     for (i = zsl->level-1; i >= 0; i--) {
         /* store rank that is crossed to reach the insert position */
         rank[i] = i == (zsl->level-1) ? 0 : rank[i+1];
     for (i = zsl->level-1; i >= 0; i--) {
         /* store rank that is crossed to reach the insert position */
         rank[i] = i == (zsl->level-1) ? 0 : rank[i+1];

-
-        while (x->forward[i] &&
-            (x->forward[i]->score < score ||
-                (x->forward[i]->score == score &&
-                compareStringObjects(x->forward[i]->obj,obj) < 0))) {
-            rank[i] += i > 0 ? x->span[i-1] : 1;
-            x = x->forward[i];
+        while (x->level[i].forward &&
+            (x->level[i].forward->score < score ||
+                (x->level[i].forward->score == score &&
+                compareStringObjects(x->level[i].forward->obj,obj) < 0))) {
+            rank[i] += x->level[i].span;
+            x = x->level[i].forward;

         }
         update[i] = x;
     }
         }
         update[i] = x;
     }


@@ -112,56 +98,51 @@ void zslInsert(zskiplist *zsl, double score, robj *obj) {
         for (i = zsl->level; i < level; i++) {
             rank[i] = 0;
             update[i] = zsl->header;
         for (i = zsl->level; i < level; i++) {
             rank[i] = 0;
             update[i] = zsl->header;

-            update[i]->span[i-1] = zsl->length;
+            update[i]->level[i].span = zsl->length;

         }
         zsl->level = level;
     }
     x = zslCreateNode(level,score,obj);
     for (i = 0; i < level; i++) {
         }
         zsl->level = level;
     }
     x = zslCreateNode(level,score,obj);
     for (i = 0; i < level; i++) {

-        x->forward[i] = update[i]->forward[i];
-        update[i]->forward[i] = x;
+        x->level[i].forward = update[i]->level[i].forward;
+        update[i]->level[i].forward = x;

 
         /* update span covered by update[i] as x is inserted here */
 
         /* update span covered by update[i] as x is inserted here */

-        if (i > 0) {
-            x->span[i-1] = update[i]->span[i-1] - (rank[0] - rank[i]);
-            update[i]->span[i-1] = (rank[0] - rank[i]) + 1;
-        }
+        x->level[i].span = update[i]->level[i].span - (rank[0] - rank[i]);
+        update[i]->level[i].span = (rank[0] - rank[i]) + 1;

     }
 
     /* increment span for untouched levels */
     for (i = level; i < zsl->level; i++) {
     }
 
     /* increment span for untouched levels */
     for (i = level; i < zsl->level; i++) {

-        update[i]->span[i-1]++;
+        update[i]->level[i].span++;

     }
 
     x->backward = (update[0] == zsl->header) ? NULL : update[0];
     }
 
     x->backward = (update[0] == zsl->header) ? NULL : update[0];

-    if (x->forward[0])
-        x->forward[0]->backward = x;
+    if (x->level[0].forward)
+        x->level[0].forward->backward = x;

     else
         zsl->tail = x;
     zsl->length++;
     else
         zsl->tail = x;
     zsl->length++;

+    return x;

 }
 
 /* Internal function used by zslDelete, zslDeleteByScore and zslDeleteByRank */
 void zslDeleteNode(zskiplist *zsl, zskiplistNode *x, zskiplistNode **update) {
     int i;
     for (i = 0; i < zsl->level; i++) {
 }
 
 /* Internal function used by zslDelete, zslDeleteByScore and zslDeleteByRank */
 void zslDeleteNode(zskiplist *zsl, zskiplistNode *x, zskiplistNode **update) {
     int i;
     for (i = 0; i < zsl->level; i++) {

-        if (update[i]->forward[i] == x) {
-            if (i > 0) {
-                update[i]->span[i-1] += x->span[i-1] - 1;
-            }
-            update[i]->forward[i] = x->forward[i];
+        if (update[i]->level[i].forward == x) {
+            update[i]->level[i].span += x->level[i].span - 1;
+            update[i]->level[i].forward = x->level[i].forward;

         } else {
         } else {

-            /* invariant: i > 0, because update[0]->forward[0]
-             * is always equal to x */
-            update[i]->span[i-1] -= 1;
+            update[i]->level[i].span -= 1;

         }
     }
         }
     }

-    if (x->forward[0]) {
-        x->forward[0]->backward = x->backward;
+    if (x->level[0].forward) {
+        x->level[0].forward->backward = x->backward;

     } else {
         zsl->tail = x->backward;
     }
     } else {
         zsl->tail = x->backward;
     }

-    while(zsl->level > 1 && zsl->header->forward[zsl->level-1] == NULL)
+    while(zsl->level > 1 && zsl->header->level[zsl->level-1].forward == NULL)

         zsl->level--;
     zsl->length--;
 }
         zsl->level--;
     zsl->length--;
 }


@@ -173,16 +154,16 @@ int zslDelete(zskiplist *zsl, double score, robj *obj) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {

-        while (x->forward[i] &&
-            (x->forward[i]->score < score ||
-                (x->forward[i]->score == score &&
-                compareStringObjects(x->forward[i]->obj,obj) < 0)))
-            x = x->forward[i];
+        while (x->level[i].forward &&
+            (x->level[i].forward->score < score ||
+                (x->level[i].forward->score == score &&
+                compareStringObjects(x->level[i].forward->obj,obj) < 0)))
+            x = x->level[i].forward;

         update[i] = x;
     }
     /* We may have multiple elements with the same score, what we need
      * is to find the element with both the right score and object. */
         update[i] = x;
     }
     /* We may have multiple elements with the same score, what we need
      * is to find the element with both the right score and object. */

-    x = x->forward[0];
+    x = x->level[0].forward;

     if (x && score == x->score && equalStringObjects(x->obj,obj)) {
         zslDeleteNode(zsl, x, update);
         zslFreeNode(x);
     if (x && score == x->score && equalStringObjects(x->obj,obj)) {
         zslDeleteNode(zsl, x, update);
         zslFreeNode(x);


@@ -204,16 +185,16 @@ unsigned long zslDeleteRangeByScore(zskiplist *zsl, double min, double max, dict
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {

-        while (x->forward[i] && x->forward[i]->score < min)
-            x = x->forward[i];
+        while (x->level[i].forward && x->level[i].forward->score < min)
+            x = x->level[i].forward;

         update[i] = x;
     }
     /* We may have multiple elements with the same score, what we need
      * is to find the element with both the right score and object. */
         update[i] = x;
     }
     /* We may have multiple elements with the same score, what we need
      * is to find the element with both the right score and object. */

-    x = x->forward[0];
+    x = x->level[0].forward;

     while (x && x->score <= max) {
     while (x && x->score <= max) {

-        zskiplistNode *next = x->forward[0];
-        zslDeleteNode(zsl, x, update);
+        zskiplistNode *next = x->level[0].forward;
+        zslDeleteNode(zsl,x,update);

         dictDelete(dict,x->obj);
         zslFreeNode(x);
         removed++;
         dictDelete(dict,x->obj);
         zslFreeNode(x);
         removed++;


@@ -231,18 +212,18 @@ unsigned long zslDeleteRangeByRank(zskiplist *zsl, unsigned int start, unsigned
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {

-        while (x->forward[i] && (traversed + (i > 0 ? x->span[i-1] : 1)) < start) {
-            traversed += i > 0 ? x->span[i-1] : 1;
-            x = x->forward[i];
+        while (x->level[i].forward && (traversed + x->level[i].span) < start) {
+            traversed += x->level[i].span;
+            x = x->level[i].forward;

         }
         update[i] = x;
     }
 
     traversed++;
         }
         update[i] = x;
     }
 
     traversed++;

-    x = x->forward[0];
+    x = x->level[0].forward;

     while (x && traversed <= end) {
     while (x && traversed <= end) {

-        zskiplistNode *next = x->forward[0];
-        zslDeleteNode(zsl, x, update);
+        zskiplistNode *next = x->level[0].forward;
+        zslDeleteNode(zsl,x,update);

         dictDelete(dict,x->obj);
         zslFreeNode(x);
         removed++;
         dictDelete(dict,x->obj);
         zslFreeNode(x);
         removed++;


@@ -260,12 +241,12 @@ zskiplistNode *zslFirstWithScore(zskiplist *zsl, double score) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {

-        while (x->forward[i] && x->forward[i]->score < score)
-            x = x->forward[i];
+        while (x->level[i].forward && x->level[i].forward->score < score)
+            x = x->level[i].forward;

     }
     /* We may have multiple elements with the same score, what we need
      * is to find the element with both the right score and object. */
     }
     /* We may have multiple elements with the same score, what we need
      * is to find the element with both the right score and object. */

-    return x->forward[0];
+    return x->level[0].forward;

 }
 
 /* Find the rank for an element by both score and key.
 }
 
 /* Find the rank for an element by both score and key.


@@ -279,12 +260,12 @@ unsigned long zslistTypeGetRank(zskiplist *zsl, double score, robj *o) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {

-        while (x->forward[i] &&
-            (x->forward[i]->score < score ||
-                (x->forward[i]->score == score &&
-                compareStringObjects(x->forward[i]->obj,o) <= 0))) {
-            rank += i > 0 ? x->span[i-1] : 1;
-            x = x->forward[i];
+        while (x->level[i].forward &&
+            (x->level[i].forward->score < score ||
+                (x->level[i].forward->score == score &&
+                compareStringObjects(x->level[i].forward->obj,o) <= 0))) {
+            rank += x->level[i].span;
+            x = x->level[i].forward;

         }
 
         /* x might be equal to zsl->header, so test if obj is non-NULL */
         }
 
         /* x might be equal to zsl->header, so test if obj is non-NULL */


@@ -303,10 +284,10 @@ zskiplistNode* zslistTypeGetElementByRank(zskiplist *zsl, unsigned long rank) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {

-        while (x->forward[i] && (traversed + (i>0 ? x->span[i-1] : 1)) <= rank)
+        while (x->level[i].forward && (traversed + x->level[i].span) <= rank)

         {
         {

-            traversed += i > 0 ? x->span[i-1] : 1;
-            x = x->forward[i];
+            traversed += x->level[i].span;
+            x = x->level[i].forward;

         }
         if (traversed == rank) {
             return x;
         }
         if (traversed == rank) {
             return x;


@@ -319,18 +300,11 @@ zskiplistNode* zslistTypeGetElementByRank(zskiplist *zsl, unsigned long rank) {
  * Sorted set commands 
  *----------------------------------------------------------------------------*/
 
  * Sorted set commands 
  *----------------------------------------------------------------------------*/
 

-/* This generic command implements both ZADD and ZINCRBY.
- * scoreval is the score if the operation is a ZADD (doincrement == 0) or
- * the increment if the operation is a ZINCRBY (doincrement == 1). */
-void zaddGenericCommand(redisClient *c, robj *key, robj *ele, double scoreval, int doincrement) {
+/* This generic command implements both ZADD and ZINCRBY. */
+void zaddGenericCommand(redisClient *c, robj *key, robj *ele, double score, int incr) {

     robj *zsetobj;
     zset *zs;
     robj *zsetobj;
     zset *zs;

-    double *score;
-
-    if (isnan(scoreval)) {
-        addReplySds(c,sdsnew("-ERR provide score is Not A Number (nan)\r\n"));
-        return;
-    }
+    zskiplistNode *znode;

 
     zsetobj = lookupKeyWrite(c->db,key);
     if (zsetobj == NULL) {
 
     zsetobj = lookupKeyWrite(c->db,key);
     if (zsetobj == NULL) {


@@ -344,70 +318,73 @@ void zaddGenericCommand(redisClient *c, robj *key, robj *ele, double scoreval, i
     }
     zs = zsetobj->ptr;
 
     }
     zs = zsetobj->ptr;
 

-    /* Ok now since we implement both ZADD and ZINCRBY here the code
-     * needs to handle the two different conditions. It's all about setting
-     * '*score', that is, the new score to set, to the right value. */
-    score = zmalloc(sizeof(double));
-    if (doincrement) {
-        dictEntry *de;
-
+    /* Since both ZADD and ZINCRBY are implemented here, we need to increment
+     * the score first by the current score if ZINCRBY is called. */
+    if (incr) {

         /* Read the old score. If the element was not present starts from 0 */
         /* Read the old score. If the element was not present starts from 0 */

-        de = dictFind(zs->dict,ele);
-        if (de) {
-            double *oldscore = dictGetEntryVal(de);
-            *score = *oldscore + scoreval;
-        } else {
-            *score = scoreval;
-        }
-        if (isnan(*score)) {
+        dictEntry *de = dictFind(zs->dict,ele);
+        if (de != NULL)
+            score += *(double*)dictGetEntryVal(de);
+
+        if (isnan(score)) {

             addReplySds(c,
             addReplySds(c,

-                sdsnew("-ERR resulting score is Not A Number (nan)\r\n"));
-            zfree(score);
+                sdsnew("-ERR resulting score is not a number (NaN)\r\n"));

             /* Note that we don't need to check if the zset may be empty and
              * should be removed here, as we can only obtain Nan as score if
              * there was already an element in the sorted set. */
             return;
         }
             /* Note that we don't need to check if the zset may be empty and
              * should be removed here, as we can only obtain Nan as score if
              * there was already an element in the sorted set. */
             return;
         }

-    } else {
-        *score = scoreval;

     }
 
     }
 

-    /* What follows is a simple remove and re-insert operation that is common
-     * to both ZADD and ZINCRBY... */
-    if (dictAdd(zs->dict,ele,score) == DICT_OK) {
-        /* case 1: New element */
+    /* We need to remove and re-insert the element when it was already present
+     * in the dictionary, to update the skiplist. Note that we delay adding a
+     * pointer to the score because we want to reference the score in the
+     * skiplist node. */
+    if (dictAdd(zs->dict,ele,NULL) == DICT_OK) {
+        dictEntry *de;
+
+        /* New element */

         incrRefCount(ele); /* added to hash */
         incrRefCount(ele); /* added to hash */

-        zslInsert(zs->zsl,*score,ele);
+        znode = zslInsert(zs->zsl,score,ele);

         incrRefCount(ele); /* added to skiplist */
         incrRefCount(ele); /* added to skiplist */

+
+        /* Update the score in the dict entry */
+        de = dictFind(zs->dict,ele);
+        redisAssert(de != NULL);
+        dictGetEntryVal(de) = &znode->score;
+        touchWatchedKey(c->db,c->argv[1]);

         server.dirty++;
         server.dirty++;

-        if (doincrement)
-            addReplyDouble(c,*score);
+        if (incr)
+            addReplyDouble(c,score);

         else
             addReply(c,shared.cone);
     } else {
         dictEntry *de;
         else
             addReply(c,shared.cone);
     } else {
         dictEntry *de;

-        double *oldscore;
+        robj *curobj;
+        double *curscore;
+        int deleted;

 
 

-        /* case 2: Score update operation */
+        /* Update score */

         de = dictFind(zs->dict,ele);
         redisAssert(de != NULL);
         de = dictFind(zs->dict,ele);
         redisAssert(de != NULL);

-        oldscore = dictGetEntryVal(de);
-        if (*score != *oldscore) {
-            int deleted;
+        curobj = dictGetEntryKey(de);
+        curscore = dictGetEntryVal(de);

 
 

-            /* Remove and insert the element in the skip list with new score */
-            deleted = zslDelete(zs->zsl,*oldscore,ele);
+        /* When the score is updated, reuse the existing string object to
+         * prevent extra alloc/dealloc of strings on ZINCRBY. */
+        if (score != *curscore) {
+            deleted = zslDelete(zs->zsl,*curscore,curobj);

             redisAssert(deleted != 0);
             redisAssert(deleted != 0);

-            zslInsert(zs->zsl,*score,ele);
-            incrRefCount(ele);
-            /* Update the score in the hash table */
-            dictReplace(zs->dict,ele,score);
+            znode = zslInsert(zs->zsl,score,curobj);
+            incrRefCount(curobj);
+
+            /* Update the score in the current dict entry */
+            dictGetEntryVal(de) = &znode->score;
+            touchWatchedKey(c->db,c->argv[1]);

             server.dirty++;
             server.dirty++;

-        } else {
-            zfree(score);

         }
         }

-        if (doincrement)
-            addReplyDouble(c,*score);
+        if (incr)
+            addReplyDouble(c,score);

         else
             addReply(c,shared.czero);
     }
         else
             addReply(c,shared.czero);
     }


@@ -415,15 +392,13 @@ void zaddGenericCommand(redisClient *c, robj *key, robj *ele, double scoreval, i
 
 void zaddCommand(redisClient *c) {
     double scoreval;
 
 void zaddCommand(redisClient *c) {
     double scoreval;

-
-    if (getDoubleFromObjectOrReply(c, c->argv[2], &scoreval, NULL) != REDIS_OK) return;
+    if (getDoubleFromObjectOrReply(c,c->argv[2],&scoreval,NULL) != REDIS_OK) return;

     zaddGenericCommand(c,c->argv[1],c->argv[3],scoreval,0);
 }
 
 void zincrbyCommand(redisClient *c) {
     double scoreval;
     zaddGenericCommand(c,c->argv[1],c->argv[3],scoreval,0);
 }
 
 void zincrbyCommand(redisClient *c) {
     double scoreval;

-
-    if (getDoubleFromObjectOrReply(c, c->argv[2], &scoreval, NULL) != REDIS_OK) return;
+    if (getDoubleFromObjectOrReply(c,c->argv[2],&scoreval,NULL) != REDIS_OK) return;

     zaddGenericCommand(c,c->argv[1],c->argv[3],scoreval,1);
 }
 
     zaddGenericCommand(c,c->argv[1],c->argv[3],scoreval,1);
 }
 


@@ -431,7 +406,7 @@ void zremCommand(redisClient *c) {
     robj *zsetobj;
     zset *zs;
     dictEntry *de;
     robj *zsetobj;
     zset *zs;
     dictEntry *de;

-    double *oldscore;
+    double curscore;

     int deleted;
 
     if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
     int deleted;
 
     if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||


@@ -444,14 +419,15 @@ void zremCommand(redisClient *c) {
         return;
     }
     /* Delete from the skiplist */
         return;
     }
     /* Delete from the skiplist */

-    oldscore = dictGetEntryVal(de);
-    deleted = zslDelete(zs->zsl,*oldscore,c->argv[2]);
+    curscore = *(double*)dictGetEntryVal(de);
+    deleted = zslDelete(zs->zsl,curscore,c->argv[2]);

     redisAssert(deleted != 0);
 
     /* Delete from the hash table */
     dictDelete(zs->dict,c->argv[2]);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
     if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);
     redisAssert(deleted != 0);
 
     /* Delete from the hash table */
     dictDelete(zs->dict,c->argv[2]);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
     if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);

+    touchWatchedKey(c->db,c->argv[1]);

     server.dirty++;
     addReply(c,shared.cone);
 }
     server.dirty++;
     addReply(c,shared.cone);
 }


@@ -473,6 +449,7 @@ void zremrangebyscoreCommand(redisClient *c) {
     deleted = zslDeleteRangeByScore(zs->zsl,min,max,zs->dict);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
     if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);
     deleted = zslDeleteRangeByScore(zs->zsl,min,max,zs->dict);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
     if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);

+    if (deleted) touchWatchedKey(c->db,c->argv[1]);

     server.dirty += deleted;
     addReplyLongLong(c,deleted);
 }
     server.dirty += deleted;
     addReplyLongLong(c,deleted);
 }


@@ -497,9 +474,9 @@ void zremrangebyrankCommand(redisClient *c) {
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;

-    if (end < 0) end = 0;

 
 

-    /* indexes sanity checks */
+    /* Invariant: start >= 0, so this test will be true when end < 0.
+     * The range is empty when start > end or start >= length. */

     if (start > end || start >= llen) {
         addReply(c,shared.czero);
         return;
     if (start > end || start >= llen) {
         addReply(c,shared.czero);
         return;


@@ -511,6 +488,7 @@ void zremrangebyrankCommand(redisClient *c) {
     deleted = zslDeleteRangeByRank(zs->zsl,start+1,end+1,zs->dict);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
     if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);
     deleted = zslDeleteRangeByRank(zs->zsl,start+1,end+1,zs->dict);
     if (htNeedsResize(zs->dict)) dictResize(zs->dict);
     if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);

+    if (deleted) touchWatchedKey(c->db,c->argv[1]);

     server.dirty += deleted;
     addReplyLongLong(c, deleted);
 }
     server.dirty += deleted;
     addReplyLongLong(c, deleted);
 }


@@ -536,6 +514,10 @@ int qsortCompareZsetopsrcByCardinality(const void *s1, const void *s2) {
 inline static void zunionInterAggregate(double *target, double val, int aggregate) {
     if (aggregate == REDIS_AGGR_SUM) {
         *target = *target + val;
 inline static void zunionInterAggregate(double *target, double val, int aggregate) {
     if (aggregate == REDIS_AGGR_SUM) {
         *target = *target + val;

+        /* The result of adding two doubles is NaN when one variable
+         * is +inf and the other is -inf. When these numbers are added,
+         * we maintain the convention of the result being 0.0. */
+        if (isnan(*target)) *target = 0.0;

     } else if (aggregate == REDIS_AGGR_MIN) {
         *target = val < *target ? val : *target;
     } else if (aggregate == REDIS_AGGR_MAX) {
     } else if (aggregate == REDIS_AGGR_MIN) {
         *target = val < *target ? val : *target;
     } else if (aggregate == REDIS_AGGR_MAX) {


@@ -552,8 +534,10 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
     zsetopsrc *src;
     robj *dstobj;
     zset *dstzset;
     zsetopsrc *src;
     robj *dstobj;
     zset *dstzset;

+    zskiplistNode *znode;

     dictIterator *di;
     dictEntry *de;
     dictIterator *di;
     dictEntry *de;

+    int touched = 0;

 
     /* expect setnum input keys to be given */
     setnum = atoi(c->argv[2]->ptr);
 
     /* expect setnum input keys to be given */
     setnum = atoi(c->argv[2]->ptr);


@@ -598,8 +582,12 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
             if (remaining >= (setnum + 1) && !strcasecmp(c->argv[j]->ptr,"weights")) {
                 j++; remaining--;
                 for (i = 0; i < setnum; i++, j++, remaining--) {
             if (remaining >= (setnum + 1) && !strcasecmp(c->argv[j]->ptr,"weights")) {
                 j++; remaining--;
                 for (i = 0; i < setnum; i++, j++, remaining--) {

-                    if (getDoubleFromObjectOrReply(c, c->argv[j], &src[i].weight, NULL) != REDIS_OK)
+                    if (getDoubleFromObjectOrReply(c,c->argv[j],&src[i].weight,
+                            "weight value is not a double") != REDIS_OK)
+                    {
+                        zfree(src);

                         return;
                         return;

+                    }

                 }
             } else if (remaining >= 2 && !strcasecmp(c->argv[j]->ptr,"aggregate")) {
                 j++; remaining--;
                 }
             } else if (remaining >= 2 && !strcasecmp(c->argv[j]->ptr,"aggregate")) {
                 j++; remaining--;


@@ -655,10 +643,10 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
                     zfree(score);
                 } else {
                     robj *o = dictGetEntryKey(de);
                     zfree(score);
                 } else {
                     robj *o = dictGetEntryKey(de);

-                    dictAdd(dstzset->dict,o,score);
-                    incrRefCount(o); /* added to dictionary */
-                    zslInsert(dstzset->zsl,*score,o);
+                    znode = zslInsert(dstzset->zsl,*score,o);

                     incrRefCount(o); /* added to skiplist */
                     incrRefCount(o); /* added to skiplist */

+                    dictAdd(dstzset->dict,o,&znode->score);
+                    incrRefCount(o); /* added to dictionary */

                 }
             }
             dictReleaseIterator(di);
                 }
             }
             dictReleaseIterator(di);


@@ -686,10 +674,10 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
                 }
 
                 robj *o = dictGetEntryKey(de);
                 }
 
                 robj *o = dictGetEntryKey(de);

-                dictAdd(dstzset->dict,o,score);
-                incrRefCount(o); /* added to dictionary */
-                zslInsert(dstzset->zsl,*score,o);
+                znode = zslInsert(dstzset->zsl,*score,o);

                 incrRefCount(o); /* added to skiplist */
                 incrRefCount(o); /* added to skiplist */

+                dictAdd(dstzset->dict,o,&znode->score);
+                incrRefCount(o); /* added to dictionary */

             }
             dictReleaseIterator(di);
         }
             }
             dictReleaseIterator(di);
         }


@@ -698,10 +686,15 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
         redisAssert(op == REDIS_OP_INTER || op == REDIS_OP_UNION);
     }
 
         redisAssert(op == REDIS_OP_INTER || op == REDIS_OP_UNION);
     }
 

-    dbDelete(c->db,dstkey);
+    if (dbDelete(c->db,dstkey)) {
+        touchWatchedKey(c->db,dstkey);
+        touched = 1;
+        server.dirty++;
+    }

     if (dstzset->zsl->length) {
         dbAdd(c->db,dstkey,dstobj);
         addReplyLongLong(c, dstzset->zsl->length);
     if (dstzset->zsl->length) {
         dbAdd(c->db,dstkey,dstobj);
         addReplyLongLong(c, dstzset->zsl->length);

+        if (!touched) touchWatchedKey(c->db,dstkey);

         server.dirty++;
     } else {
         decrRefCount(dstobj);
         server.dirty++;
     } else {
         decrRefCount(dstobj);


@@ -750,11 +743,10 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;
     if (start < 0) start = llen+start;
     if (end < 0) end = llen+end;
     if (start < 0) start = 0;

-    if (end < 0) end = 0;

 
 

-    /* indexes sanity checks */
+    /* Invariant: start >= 0, so this test will be true when end < 0.
+     * The range is empty when start > end or start >= length. */

     if (start > end || start >= llen) {
     if (start > end || start >= llen) {

-        /* Out of range start or start > end result in empty list */

         addReply(c,shared.emptymultibulk);
         return;
     }
         addReply(c,shared.emptymultibulk);
         return;
     }


@@ -767,7 +759,7 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
         ln = start == 0 ? zsl->tail : zslistTypeGetElementByRank(zsl, llen-start);
     } else {
         ln = start == 0 ?
         ln = start == 0 ? zsl->tail : zslistTypeGetElementByRank(zsl, llen-start);
     } else {
         ln = start == 0 ?

-            zsl->header->forward[0] : zslistTypeGetElementByRank(zsl, start+1);
+            zsl->header->level[0].forward : zslistTypeGetElementByRank(zsl, start+1);

     }
 
     /* Return the result in form of a multi-bulk reply */
     }
 
     /* Return the result in form of a multi-bulk reply */


@@ -778,7 +770,7 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
         addReplyBulk(c,ele);
         if (withscores)
             addReplyDouble(c,ln->score);
         addReplyBulk(c,ele);
         if (withscores)
             addReplyDouble(c,ln->score);

-        ln = reverse ? ln->backward : ln->forward[0];
+        ln = reverse ? ln->backward : ln->level[0].forward;

     }
 }
 
     }
 }
 


@@ -861,7 +853,7 @@ void genericZrangebyscoreCommand(redisClient *c, int justcount) {
             /* Get the first node with the score >= min, or with
              * score > min if 'minex' is true. */
             ln = zslFirstWithScore(zsl,min);
             /* Get the first node with the score >= min, or with
              * score > min if 'minex' is true. */
             ln = zslFirstWithScore(zsl,min);

-            while (minex && ln && ln->score == min) ln = ln->forward[0];
+            while (minex && ln && ln->score == min) ln = ln->level[0].forward;

 
             if (ln == NULL) {
                 /* No element matching the speciifed interval */
 
             if (ln == NULL) {
                 /* No element matching the speciifed interval */


@@ -882,7 +874,7 @@ void genericZrangebyscoreCommand(redisClient *c, int justcount) {
             while(ln && (maxex ? (ln->score < max) : (ln->score <= max))) {
                 if (offset) {
                     offset--;
             while(ln && (maxex ? (ln->score < max) : (ln->score <= max))) {
                 if (offset) {
                     offset--;

-                    ln = ln->forward[0];
+                    ln = ln->level[0].forward;

                     continue;
                 }
                 if (limit == 0) break;
                     continue;
                 }
                 if (limit == 0) break;


@@ -892,7 +884,7 @@ void genericZrangebyscoreCommand(redisClient *c, int justcount) {
                     if (withscores)
                         addReplyDouble(c,ln->score);
                 }
                     if (withscores)
                         addReplyDouble(c,ln->score);
                 }

-                ln = ln->forward[0];
+                ln = ln->level[0].forward;

                 rangelen++;
                 if (limit > 0) limit--;
             }
                 rangelen++;
                 if (limit > 0) limit--;
             }