Helpers to move around in encoded sorted set

[redis.git] / src / t_zset.c

diff --git a/src/t_zset.c b/src/t_zset.c
index d944e92329fca9d8f8f0033216dbf7f0ae631706..8665aa143483354903a799810e7d9c50c0a04f06 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);


@@ -193,33 +174,119 @@ int zslDelete(zskiplist *zsl, double score, robj *obj) {
     return 0; /* not found */
 }
 
     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);
+}
+
+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;
+
+    /* Test for ranges that will always be empty. */
+    if (range->min > range->max ||
+            (range->min == range->max && (range->minex || range->maxex)))
+        return 0;
+    x = zsl->tail;
+    if (x == NULL || !zslValueGteMin(x->score,range))
+        return 0;
+    x = zsl->header->level[0].forward;
+    if (x == NULL || !zslValueLteMax(x->score,range))
+        return 0;
+    return 1;
+}
+
+/* Find the first node that is contained in the specified range.
+ * Returns NULL when no element is contained in the range. */
+zskiplistNode *zslFirstInRange(zskiplist *zsl, zrangespec range) {
+    zskiplistNode *x;
+    int i;
+
+    /* If everything is out of range, return early. */
+    if (!zslIsInRange(zsl,&range)) return NULL;
+
+    x = zsl->header;
+    for (i = zsl->level-1; i >= 0; i--) {
+        /* Go forward while *OUT* of range. */
+        while (x->level[i].forward &&
+            !zslValueGteMin(x->level[i].forward->score,&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. */
+    x = x->level[0].forward;
+    redisAssert(x != NULL && zslValueInRange(x->score,&range));
+    return x;
+}
+
+/* Find the last node that is contained in the specified range.
+ * Returns NULL when no element is contained in the range. */
+zskiplistNode *zslLastInRange(zskiplist *zsl, zrangespec range) {
+    zskiplistNode *x;
+    int i;
+
+    /* If everything is out of range, return early. */
+    if (!zslIsInRange(zsl,&range)) return NULL;
+
+    x = zsl->header;
+    for (i = zsl->level-1; i >= 0; i--) {
+        /* Go forward while *IN* range. */
+        while (x->level[i].forward &&
+            zslValueLteMax(x->level[i].forward->score,&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));
+    return x;
+}
+

 /* Delete all the elements with score between min and max from the skiplist.
  * Min and mx are inclusive, so a score >= min || score <= max is deleted.
  * Note that this function takes the reference to the hash table view of the
  * sorted set, in order to remove the elements from the hash table too. */
 /* Delete all the elements with score between min and max from the skiplist.
  * Min and mx are inclusive, so a score >= min || score <= max is deleted.
  * Note that this function takes the reference to the hash table view of the
  * sorted set, in order to remove the elements from the hash table too. */

-unsigned long zslDeleteRangeByScore(zskiplist *zsl, double min, double max, dict *dict) {
+unsigned long zslDeleteRangeByScore(zskiplist *zsl, zrangespec range, dict *dict) {

     zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
     unsigned long removed = 0;
     int i;
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
     zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
     unsigned long removed = 0;
     int 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 && (range.minex ?
+            x->level[i].forward->score <= range.min :
+            x->level[i].forward->score < range.min))
+                x = x->level[i].forward;

         update[i] = x;
     }
         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];
-    while (x && x->score <= max) {
-        zskiplistNode *next = x->forward[0];
-        zslDeleteNode(zsl, x, update);
+
+    /* Current node is the last with score < or <= min. */
+    x = x->level[0].forward;
+
+    /* Delete nodes while in range. */
+    while (x && (range.maxex ? x->score < range.max : x->score <= range.max)) {
+        zskiplistNode *next = x->level[0].forward;
+        zslDeleteNode(zsl,x,update);

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

-    return removed; /* not found */
+    return removed;

 }
 
 /* Delete all the elements with rank between start and end from the skiplist.
 }
 
 /* Delete all the elements with rank between start and end from the skiplist.


@@ -231,18 +298,18 @@ 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++;


@@ -252,39 +319,23 @@ unsigned long zslDeleteRangeByRank(zskiplist *zsl, unsigned int start, unsigned
     return removed;
 }
 
     return removed;
 }
 

-/* Find the first node having a score equal or greater than the specified one.
- * Returns NULL if there is no match. */
-zskiplistNode *zslFirstWithScore(zskiplist *zsl, double score) {
-    zskiplistNode *x;
-    int 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];
-    }
-    /* 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];
-}
-

 /* Find the rank for an element by both score and key.
  * Returns 0 when the element cannot be found, rank otherwise.
  * Note that the rank is 1-based due to the span of zsl->header to the
  * first element. */
 /* Find the rank for an element by both score and key.
  * Returns 0 when the element cannot be found, rank otherwise.
  * Note that the rank is 1-based due to the span of zsl->header to the
  * first element. */

-unsigned long zslistTypeGetRank(zskiplist *zsl, double score, robj *o) {
+unsigned long zslGetRank(zskiplist *zsl, double score, robj *o) {

     zskiplistNode *x;
     unsigned long rank = 0;
     int i;
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
     zskiplistNode *x;
     unsigned long rank = 0;
     int 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 */


@@ -296,17 +347,17 @@ unsigned long zslistTypeGetRank(zskiplist *zsl, double score, robj *o) {
 }
 
 /* Finds an element by its rank. The rank argument needs to be 1-based. */
 }
 
 /* Finds an element by its rank. The rank argument needs to be 1-based. */

-zskiplistNode* zslistTypeGetElementByRank(zskiplist *zsl, unsigned long rank) {
+zskiplistNode* zslGetElementByRank(zskiplist *zsl, unsigned long rank) {

     zskiplistNode *x;
     unsigned long traversed = 0;
     int i;
 
     x = zsl->header;
     for (i = zsl->level-1; i >= 0; i--) {
     zskiplistNode *x;
     unsigned long traversed = 0;
     int 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;


@@ -315,181 +366,593 @@ zskiplistNode* zslistTypeGetElementByRank(zskiplist *zsl, unsigned long rank) {
     return NULL;
 }
 
     return NULL;
 }
 

+/* Populate the rangespec according to the objects min and max. */
+static int zslParseRange(robj *min, robj *max, zrangespec *spec) {
+    char *eptr;
+    spec->minex = spec->maxex = 0;
+
+    /* Parse the min-max interval. If one of the values is prefixed
+     * by the "(" character, it's considered "open". For instance
+     * ZRANGEBYSCORE zset (1.5 (2.5 will match min < x < max
+     * ZRANGEBYSCORE zset 1.5 2.5 will instead match min <= x <= max */
+    if (min->encoding == REDIS_ENCODING_INT) {
+        spec->min = (long)min->ptr;
+    } else {
+        if (((char*)min->ptr)[0] == '(') {
+            spec->min = strtod((char*)min->ptr+1,&eptr);
+            if (eptr[0] != '\0' || isnan(spec->min)) return REDIS_ERR;
+            spec->minex = 1;
+        } else {
+            spec->min = strtod((char*)min->ptr,&eptr);
+            if (eptr[0] != '\0' || isnan(spec->min)) return REDIS_ERR;
+        }
+    }
+    if (max->encoding == REDIS_ENCODING_INT) {
+        spec->max = (long)max->ptr;
+    } else {
+        if (((char*)max->ptr)[0] == '(') {
+            spec->max = strtod((char*)max->ptr+1,&eptr);
+            if (eptr[0] != '\0' || isnan(spec->max)) return REDIS_ERR;
+            spec->maxex = 1;
+        } else {
+            spec->max = strtod((char*)max->ptr,&eptr);
+            if (eptr[0] != '\0' || isnan(spec->max)) return REDIS_ERR;
+        }
+    }
+
+    return REDIS_OK;
+}
+

 /*-----------------------------------------------------------------------------
 /*-----------------------------------------------------------------------------

- * Sorted set commands 
+ * Ziplist-backed sorted set API

  *----------------------------------------------------------------------------*/
 
  *----------------------------------------------------------------------------*/
 

-/* 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) {
-    robj *zsetobj;
-    zset *zs;
-    double *score;
+double zzlGetScore(unsigned char *sptr) {
+    unsigned char *vstr;
+    unsigned int vlen;
+    long long vlong;
+    char buf[128];
+    double score;

 
 

-    zsetobj = lookupKeyWrite(c->db,key);
-    if (zsetobj == NULL) {
-        zsetobj = createZsetObject();
-        dbAdd(c->db,key,zsetobj);
+    redisAssert(sptr != NULL);
+    redisAssert(ziplistGet(sptr,&vstr,&vlen,&vlong));
+
+    if (vstr) {
+        memcpy(buf,vstr,vlen);
+        buf[vlen] = '\0';
+        score = strtod(buf,NULL);

     } else {
     } else {

-        if (zsetobj->type != REDIS_ZSET) {
-            addReply(c,shared.wrongtypeerr);
-            return;
+        score = vlong;
+    }
+
+    return score;
+}
+
+/* Compare element in sorted set with given element. */
+int zzlCompareElements(unsigned char *eptr, unsigned char *cstr, unsigned int clen) {
+    unsigned char *vstr;
+    unsigned int vlen;
+    long long vlong;
+    unsigned char vbuf[32];
+    int minlen, cmp;
+
+    redisAssert(ziplistGet(eptr,&vstr,&vlen,&vlong));
+    if (vstr == NULL) {
+        /* Store string representation of long long in buf. */
+        vlen = ll2string((char*)vbuf,sizeof(vbuf),vlong);
+        vstr = vbuf;
+    }
+
+    minlen = (vlen < clen) ? vlen : clen;
+    cmp = memcmp(vstr,cstr,minlen);
+    if (cmp == 0) return vlen-clen;
+    return cmp;
+}
+
+unsigned int zzlLength(robj *zobj) {
+    unsigned char *zl = zobj->ptr;
+    return ziplistLen(zl)/2;
+}
+
+/* Move to next entry based on the values in eptr and sptr. Both are set to
+ * NULL when there is no next entry. */
+void zzlNext(unsigned char *zl, unsigned char **eptr, unsigned char **sptr) {
+    unsigned char *_eptr, *_sptr;
+    redisAssert(*eptr != NULL && *sptr != NULL);
+
+    _eptr = ziplistNext(zl,*sptr);
+    if (_eptr != NULL) {
+        _sptr = ziplistNext(zl,_eptr);
+        redisAssert(_sptr != NULL);
+    } else {
+        /* No next entry. */
+        _sptr = NULL;
+    }
+
+    *eptr = _eptr;
+    *sptr = _sptr;
+}
+
+/* Move to the previous entry based on the values in eptr and sptr. Both are
+ * set to NULL when there is no next entry. */
+void zzlPrev(unsigned char *zl, unsigned char **eptr, unsigned char **sptr) {
+    unsigned char *_eptr, *_sptr;
+    redisAssert(*eptr != NULL && *sptr != NULL);
+
+    _sptr = ziplistPrev(zl,*eptr);
+    if (_sptr != NULL) {
+        _eptr = ziplistPrev(zl,_sptr);
+        redisAssert(_eptr != NULL);
+    } else {
+        /* No previous entry. */
+        _eptr = NULL;
+    }
+
+    *eptr = _eptr;
+    *sptr = _sptr;
+}
+
+/* Returns if there is a part of the zset is in range. Should only be used
+ * internally by zzlFirstInRange and zzlLastInRange. */
+int zzlIsInRange(unsigned char *zl, zrangespec *range) {
+    unsigned char *p;
+    double score;
+
+    /* Test for ranges that will always be empty. */
+    if (range->min > range->max ||
+            (range->min == range->max && (range->minex || range->maxex)))
+        return 0;
+
+    p = ziplistIndex(zl,-1); /* Last score. */
+    redisAssert(p != NULL);
+    score = zzlGetScore(p);
+    if (!zslValueGteMin(score,range))
+        return 0;
+
+    p = ziplistIndex(zl,1); /* First score. */
+    redisAssert(p != NULL);
+    score = zzlGetScore(p);
+    if (!zslValueLteMax(score,range))
+        return 0;
+
+    return 1;
+}
+
+/* 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 *eptr = ziplistIndex(zl,0), *sptr;
+    double score;
+
+    /* If everything is out of range, return early. */
+    if (!zzlIsInRange(zl,&range)) return NULL;
+
+    while (eptr != NULL) {
+        sptr = ziplistNext(zl,eptr);
+        redisAssert(sptr != NULL);
+
+        score = zzlGetScore(sptr);
+        if (zslValueGteMin(score,&range))
+            return eptr;
+
+        /* Move to next element. */
+        eptr = ziplistNext(zl,sptr);
+    }
+
+    return NULL;
+}
+
+/* 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 *eptr = ziplistIndex(zl,-2), *sptr;
+    double score;
+
+    /* If everything is out of range, return early. */
+    if (!zzlIsInRange(zl,&range)) return NULL;
+
+    while (eptr != NULL) {
+        sptr = ziplistNext(zl,eptr);
+        redisAssert(sptr != NULL);
+
+        score = zzlGetScore(sptr);
+        if (zslValueLteMax(score,&range))
+            return eptr;
+
+        /* Move to previous element by moving to the score of previous element.
+         * When this returns NULL, we know there also is no element. */
+        sptr = ziplistPrev(zl,eptr);
+        if (sptr != NULL)
+            redisAssert((eptr = ziplistPrev(zl,sptr)) != NULL);
+        else
+            eptr = NULL;
+    }
+
+    return NULL;
+}
+
+unsigned char *zzlFind(robj *zobj, robj *ele, double *score) {
+    unsigned char *zl = zobj->ptr;
+    unsigned char *eptr = ziplistIndex(zl,0), *sptr;
+
+    ele = getDecodedObject(ele);
+    while (eptr != NULL) {
+        sptr = ziplistNext(zl,eptr);
+        redisAssert(sptr != NULL);
+
+        if (ziplistCompare(eptr,ele->ptr,sdslen(ele->ptr))) {
+            /* Matching element, pull out score. */
+            if (score != NULL) *score = zzlGetScore(sptr);
+            decrRefCount(ele);
+            return eptr;

         }
         }

+
+        /* Move to next element. */
+        eptr = ziplistNext(zl,sptr);

     }
     }

-    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;
+    decrRefCount(ele);
+    return NULL;
+}

 
 

-        /* 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;
+/* 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 *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;
+}
+
+int zzlInsertAt(robj *zobj, robj *ele, double score, unsigned char *eptr) {
+    unsigned char *zl = zobj->ptr;
+    unsigned char *sptr;
+    char scorebuf[128];
+    int scorelen;
+    int offset;
+
+    redisAssert(ele->encoding == REDIS_ENCODING_RAW);
+    scorelen = d2string(scorebuf,sizeof(scorebuf),score);
+    if (eptr == NULL) {
+        zl = ziplistPush(zl,ele->ptr,sdslen(ele->ptr),ZIPLIST_TAIL);
+        zl = ziplistPush(zl,(unsigned char*)scorebuf,scorelen,ZIPLIST_TAIL);
+    } else {
+        /* Keep offset relative to zl, as it might be re-allocated. */
+        offset = eptr-zl;
+        zl = ziplistInsert(zl,eptr,ele->ptr,sdslen(ele->ptr));
+        eptr = zl+offset;
+
+        /* Insert score after the element. */
+        redisAssert((sptr = ziplistNext(zl,eptr)) != NULL);
+        zl = ziplistInsert(zl,sptr,(unsigned char*)scorebuf,scorelen);
+    }
+
+    zobj->ptr = zl;
+    return REDIS_OK;
+}
+
+/* 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 *eptr = ziplistIndex(zl,0), *sptr;
+    double s;
+
+    ele = getDecodedObject(ele);
+    while (eptr != NULL) {
+        sptr = ziplistNext(zl,eptr);
+        redisAssert(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);
+            break;
+        } else if (s == score) {
+            /* Ensure lexicographical ordering for elements. */
+            if (zzlCompareElements(eptr,ele->ptr,sdslen(ele->ptr)) < 0) {
+                zzlInsertAt(zobj,ele,score,eptr);
+                break;
+            }

         }
         }

-        if (isnan(*score)) {
-            addReplyError(c,"resulting score is not a number (NaN)");
-            zfree(score);
-            /* 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;
+
+        /* Move to next element. */
+        eptr = ziplistNext(zl,sptr);
+    }
+
+    /* Push on tail of list when it was not yet inserted. */
+    if (eptr == NULL)
+        zzlInsertAt(zobj,ele,score,NULL);
+
+    decrRefCount(ele);
+    return REDIS_OK;
+}
+
+unsigned long zzlDeleteRangeByScore(robj *zobj, zrangespec range) {
+    unsigned char *zl = zobj->ptr;
+    unsigned char *eptr, *sptr;
+    double score;
+    unsigned long deleted = 0;
+
+    eptr = zzlFirstInRange(zobj,range);
+    if (eptr == NULL) return deleted;
+
+
+    /* When the tail of the ziplist is deleted, eptr will point to the sentinel
+     * byte and ziplistNext will return NULL. */
+    while ((sptr = ziplistNext(zl,eptr)) != NULL) {
+        score = zzlGetScore(sptr);
+        if (zslValueLteMax(score,&range)) {
+            /* Delete both the element and the score. */
+            zl = ziplistDelete(zl,&eptr);
+            zl = ziplistDelete(zl,&eptr);
+            deleted++;
+        } else {
+            /* No longer in range. */
+            break;

         }
         }

+    }
+
+    return deleted;
+}
+
+/* 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 int num = (end-start)+1;
+    zobj->ptr = ziplistDeleteRange(zobj->ptr,2*(start-1),2*num);
+    return num;
+}
+
+/*-----------------------------------------------------------------------------
+ * Common sorted set API
+ *----------------------------------------------------------------------------*/
+
+int zsLength(robj *zobj) {
+    int length = -1;
+    if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
+        length = zzlLength(zobj);
+    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+        length = ((zset*)zobj->ptr)->zsl->length;

     } else {
     } else {

-        *score = scoreval;
+        redisPanic("Unknown sorted set encoding");

     }
     }

+    return length;
+}

 
 

-    /* 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 */
-        incrRefCount(ele); /* added to hash */
-        zslInsert(zs->zsl,*score,ele);
-        incrRefCount(ele); /* added to skiplist */
-        touchWatchedKey(c->db,c->argv[1]);
-        server.dirty++;
-        if (doincrement)
-            addReplyDouble(c,*score);
-        else
-            addReply(c,shared.cone);
+/*-----------------------------------------------------------------------------
+ * Sorted set commands 
+ *----------------------------------------------------------------------------*/
+
+/* This generic command implements both ZADD and ZINCRBY. */
+void zaddGenericCommand(redisClient *c, int incr) {
+    static char *nanerr = "resulting score is not a number (NaN)";
+    robj *key = c->argv[1];
+    robj *ele;
+    robj *zobj;
+    robj *curobj;
+    double score, curscore = 0.0;
+
+    if (getDoubleFromObjectOrReply(c,c->argv[2],&score,NULL) != REDIS_OK)
+        return;
+
+    zobj = lookupKeyWrite(c->db,key);
+    if (zobj == NULL) {
+        zobj = createZsetZiplistObject();
+        dbAdd(c->db,key,zobj);

     } else {
     } else {

+        if (zobj->type != REDIS_ZSET) {
+            addReply(c,shared.wrongtypeerr);
+            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;
+                }
+            }
+
+            /* Remove and re-insert when score changed. */
+            if (score != curscore) {
+                redisAssert(zzlDelete(zobj,eptr) == REDIS_OK);
+                redisAssert(zzlInsert(zobj,ele,score) == REDIS_OK);
+
+                signalModifiedKey(c->db,key);
+                server.dirty++;
+            }
+
+            if (incr) /* ZINCRBY */
+                addReplyDouble(c,score);
+            else /* ZADD */
+                addReply(c,shared.czero);
+        } else {
+            redisAssert(zzlInsert(zobj,ele,score) == REDIS_OK);
+
+            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;
         dictEntry *de;

-        double *oldscore;

 
 

-        /* case 2: Score update operation */
+        ele = c->argv[3] = tryObjectEncoding(c->argv[3]);

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

-        redisAssert(de != NULL);
-        oldscore = dictGetEntryVal(de);
-        if (*score != *oldscore) {
-            int deleted;
-
-            /* Remove and insert the element in the skip list with new score */
-            deleted = zslDelete(zs->zsl,*oldscore,ele);
-            redisAssert(deleted != 0);
-            zslInsert(zs->zsl,*score,ele);
-            incrRefCount(ele);
-            /* Update the score in the hash table */
-            dictReplace(zs->dict,ele,score);
-            touchWatchedKey(c->db,c->argv[1]);
-            server.dirty++;
+        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;
+                }
+            }
+
+            /* 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. */
+
+                signalModifiedKey(c->db,key);
+                server.dirty++;
+            }
+
+            if (incr) /* ZINCRBY */
+                addReplyDouble(c,score);
+            else /* ZADD */
+                addReply(c,shared.czero);

         } else {
         } else {

-            zfree(score);
+            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);

         }
         }

-        if (doincrement)
-            addReplyDouble(c,*score);
-        else
-            addReply(c,shared.czero);
+    } else {
+        redisPanic("Unknown sorted set encoding");

     }
 }
 
 void zaddCommand(redisClient *c) {
     }
 }
 
 void zaddCommand(redisClient *c) {

-    double scoreval;
-    if (getDoubleFromObjectOrReply(c,c->argv[2],&scoreval,NULL) != REDIS_OK) return;
-    zaddGenericCommand(c,c->argv[1],c->argv[3],scoreval,0);
+    zaddGenericCommand(c,0);

 }
 
 void zincrbyCommand(redisClient *c) {
 }
 
 void zincrbyCommand(redisClient *c) {

-    double scoreval;
-    if (getDoubleFromObjectOrReply(c,c->argv[2],&scoreval,NULL) != REDIS_OK) return;
-    zaddGenericCommand(c,c->argv[1],c->argv[3],scoreval,1);
+    zaddGenericCommand(c,1);

 }
 
 void zremCommand(redisClient *c) {
 }
 
 void zremCommand(redisClient *c) {

-    robj *zsetobj;
-    zset *zs;
-    dictEntry *de;
-    double *oldscore;
-    int deleted;
+    robj *key = c->argv[1];
+    robj *ele = c->argv[2];
+    robj *zobj;

 
 

-    if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
-        checkType(c,zsetobj,REDIS_ZSET)) return;
+    if ((zobj = lookupKeyWriteOrReply(c,key,shared.czero)) == NULL ||
+        checkType(c,zobj,REDIS_ZSET)) return;

 
 

-    zs = zsetobj->ptr;
-    de = dictFind(zs->dict,c->argv[2]);
-    if (de == NULL) {
-        addReply(c,shared.czero);
-        return;
+    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;
+        }
+    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+        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;
+        }
+    } else {
+        redisPanic("Unknown sorted set encoding");

     }
     }

-    /* Delete from the skiplist */
-    oldscore = dictGetEntryVal(de);
-    deleted = zslDelete(zs->zsl,*oldscore,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]);
-    touchWatchedKey(c->db,c->argv[1]);
+    signalModifiedKey(c->db,key);

     server.dirty++;
     addReply(c,shared.cone);
 }
 
 void zremrangebyscoreCommand(redisClient *c) {
     server.dirty++;
     addReply(c,shared.cone);
 }
 
 void zremrangebyscoreCommand(redisClient *c) {

-    double min;
-    double max;
-    long deleted;
-    robj *zsetobj;
-    zset *zs;
+    robj *key = c->argv[1];
+    robj *zobj;
+    zrangespec range;
+    unsigned long deleted;
+
+    /* Parse the range arguments. */
+    if (zslParseRange(c->argv[2],c->argv[3],&range) != REDIS_OK) {
+        addReplyError(c,"min or max is not a double");
+        return;
+    }

 
 

-    if ((getDoubleFromObjectOrReply(c, c->argv[2], &min, NULL) != REDIS_OK) ||
-        (getDoubleFromObjectOrReply(c, c->argv[3], &max, NULL) != REDIS_OK)) return;
+    if ((zobj = lookupKeyWriteOrReply(c,key,shared.czero)) == NULL ||
+        checkType(c,zobj,REDIS_ZSET)) return;

 
 

-    if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
-        checkType(c,zsetobj,REDIS_ZSET)) return;
+    if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
+        deleted = zzlDeleteRangeByScore(zobj,range);
+    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+        zset *zs = zobj->ptr;
+        deleted = zslDeleteRangeByScore(zs->zsl,range,zs->dict);
+        if (htNeedsResize(zs->dict)) dictResize(zs->dict);
+        if (dictSize(zs->dict) == 0) dbDelete(c->db,key);
+    } else {
+        redisPanic("Unknown sorted set encoding");
+    }

 
 

-    zs = zsetobj->ptr;
-    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]);
+    if (deleted) signalModifiedKey(c->db,key);

     server.dirty += deleted;
     addReplyLongLong(c,deleted);
 }
 
 void zremrangebyrankCommand(redisClient *c) {
     server.dirty += deleted;
     addReplyLongLong(c,deleted);
 }
 
 void zremrangebyrankCommand(redisClient *c) {

+    robj *key = c->argv[1];
+    robj *zobj;

     long start;
     long end;
     int llen;
     long start;
     long end;
     int llen;

-    long deleted;
-    robj *zsetobj;
-    zset *zs;
+    unsigned long deleted;

 
     if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
         (getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
 
 
     if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
         (getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
 

-    if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
-        checkType(c,zsetobj,REDIS_ZSET)) return;
-    zs = zsetobj->ptr;
-    llen = zs->zsl->length;
+    if ((zobj = lookupKeyWriteOrReply(c,key,shared.czero)) == NULL ||
+        checkType(c,zobj,REDIS_ZSET)) return;

 
 

-    /* convert negative indexes */
+    /* Sanitize indexes. */
+    llen = zsLength(zobj);

     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;


@@ -502,14 +965,23 @@ void zremrangebyrankCommand(redisClient *c) {
     }
     if (end >= llen) end = llen-1;
 
     }
     if (end >= llen) end = llen-1;
 

-    /* increment start and end because zsl*Rank functions
-     * use 1-based rank */
-    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]);
+    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) {
+        zset *zs = zobj->ptr;
+
+        /* Correct for 1-based rank. */
+        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,key);
+    } else {
+        redisPanic("Unknown sorted set encoding");
+    }
+
+    if (deleted) signalModifiedKey(c->db,key);

     server.dirty += deleted;
     server.dirty += deleted;

-    addReplyLongLong(c, deleted);
+    addReplyLongLong(c,deleted);

 }
 
 typedef struct {
 }
 
 typedef struct {


@@ -553,6 +1025,7 @@ 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;
     int touched = 0;
     dictIterator *di;
     dictEntry *de;
     int touched = 0;


@@ -644,28 +1117,26 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
              * from small to large, all src[i > 0].dict are non-empty too */
             di = dictGetIterator(src[0].dict);
             while((de = dictNext(di)) != NULL) {
              * from small to large, all src[i > 0].dict are non-empty too */
             di = dictGetIterator(src[0].dict);
             while((de = dictNext(di)) != NULL) {

-                double *score = zmalloc(sizeof(double)), value;
-                *score = src[0].weight * zunionInterDictValue(de);
+                double score, value;

 
 

+                score = src[0].weight * zunionInterDictValue(de);

                 for (j = 1; j < setnum; j++) {
                     dictEntry *other = dictFind(src[j].dict,dictGetEntryKey(de));
                     if (other) {
                         value = src[j].weight * zunionInterDictValue(other);
                 for (j = 1; j < setnum; j++) {
                     dictEntry *other = dictFind(src[j].dict,dictGetEntryKey(de));
                     if (other) {
                         value = src[j].weight * zunionInterDictValue(other);

-                        zunionInterAggregate(score, value, aggregate);
+                        zunionInterAggregate(&score,value,aggregate);

                     } else {
                         break;
                     }
                 }
 
                     } else {
                         break;
                     }
                 }
 

-                /* skip entry when not present in every source dict */
-                if (j != setnum) {
-                    zfree(score);
-                } else {
+                /* Only continue when present in every source dict. */
+                if (j == setnum) {

                     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);


@@ -676,11 +1147,14 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
 
             di = dictGetIterator(src[i].dict);
             while((de = dictNext(di)) != NULL) {
 
             di = dictGetIterator(src[i].dict);
             while((de = dictNext(di)) != NULL) {

+                double score, value;
+

                 /* skip key when already processed */
                 /* skip key when already processed */

-                if (dictFind(dstzset->dict,dictGetEntryKey(de)) != NULL) continue;
+                if (dictFind(dstzset->dict,dictGetEntryKey(de)) != NULL)
+                    continue;

 
 

-                double *score = zmalloc(sizeof(double)), value;
-                *score = src[i].weight * zunionInterDictValue(de);
+                /* initialize score */
+                score = src[i].weight * zunionInterDictValue(de);

 
                 /* because the zsets are sorted by size, its only possible
                  * for sets at larger indices to hold this entry */
 
                 /* because the zsets are sorted by size, its only possible
                  * for sets at larger indices to hold this entry */


@@ -688,15 +1162,15 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
                     dictEntry *other = dictFind(src[j].dict,dictGetEntryKey(de));
                     if (other) {
                         value = src[j].weight * zunionInterDictValue(other);
                     dictEntry *other = dictFind(src[j].dict,dictGetEntryKey(de));
                     if (other) {
                         value = src[j].weight * zunionInterDictValue(other);

-                        zunionInterAggregate(score, value, aggregate);
+                        zunionInterAggregate(&score,value,aggregate);

                     }
                 }
 
                 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);
         }


@@ -706,14 +1180,14 @@ void zunionInterGenericCommand(redisClient *c, robj *dstkey, int op) {
     }
 
     if (dbDelete(c->db,dstkey)) {
     }
 
     if (dbDelete(c->db,dstkey)) {

-        touchWatchedKey(c->db,dstkey);
+        signalModifiedKey(c->db,dstkey);

         touched = 1;
         server.dirty++;
     }
     if (dstzset->zsl->length) {
         dbAdd(c->db,dstkey,dstobj);
         addReplyLongLong(c, dstzset->zsl->length);
         touched = 1;
         server.dirty++;
     }
     if (dstzset->zsl->length) {
         dbAdd(c->db,dstkey,dstobj);
         addReplyLongLong(c, dstzset->zsl->length);

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

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


@@ -731,16 +1205,13 @@ void zinterstoreCommand(redisClient *c) {
 }
 
 void zrangeGenericCommand(redisClient *c, int reverse) {
 }
 
 void zrangeGenericCommand(redisClient *c, int reverse) {

-    robj *o;
+    robj *key = c->argv[1];
+    robj *zobj;
+    int withscores = 0;

     long start;
     long end;
     long start;
     long end;

-    int withscores = 0;

     int llen;
     int llen;

-    int rangelen, j;
-    zset *zsetobj;
-    zskiplist *zsl;
-    zskiplistNode *ln;
-    robj *ele;
+    int rangelen;

 
     if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
         (getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;
 
     if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
         (getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;


@@ -752,13 +1223,11 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
         return;
     }
 
         return;
     }
 

-    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
-         || checkType(c,o,REDIS_ZSET)) return;
-    zsetobj = o->ptr;
-    zsl = zsetobj->zsl;
-    llen = zsl->length;
+    if ((zobj = lookupKeyReadOrReply(c,key,shared.emptymultibulk)) == NULL
+         || checkType(c,zobj,REDIS_ZSET)) return;

 
 

-    /* convert negative indexes */
+    /* Sanitize indexes. */
+    llen = zsLength(zobj);

     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;


@@ -772,23 +1241,68 @@ void zrangeGenericCommand(redisClient *c, int reverse) {
     if (end >= llen) end = llen-1;
     rangelen = (end-start)+1;
 
     if (end >= llen) end = llen-1;
     rangelen = (end-start)+1;
 

-    /* check if starting point is trivial, before searching
-     * the element in log(N) time */
-    if (reverse) {
-        ln = start == 0 ? zsl->tail : zslistTypeGetElementByRank(zsl, llen-start);
-    } else {
-        ln = start == 0 ?
-            zsl->header->forward[0] : zslistTypeGetElementByRank(zsl, start+1);
-    }
-

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

-    addReplyMultiBulkLen(c,withscores ? (rangelen*2) : rangelen);
-    for (j = 0; j < rangelen; j++) {
-        ele = ln->obj;
-        addReplyBulk(c,ele);
-        if (withscores)
-            addReplyDouble(c,ln->score);
-        ln = reverse ? ln->backward : ln->forward[0];
+    addReplyMultiBulkLen(c, withscores ? (rangelen*2) : rangelen);
+
+    if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {
+        unsigned char *zl = zobj->ptr;
+        unsigned char *eptr, *sptr;
+        unsigned char *vstr;
+        unsigned int vlen;
+        long long vlong;
+
+        if (reverse)
+            eptr = ziplistIndex(zl,-2-(2*start));
+        else
+            eptr = ziplistIndex(zl,2*start);
+
+        redisAssert(eptr != NULL);
+        sptr = ziplistNext(zl,eptr);
+
+        while (rangelen--) {
+            redisAssert(eptr != NULL && sptr != NULL);
+            redisAssert(ziplistGet(eptr,&vstr,&vlen,&vlong));
+            if (vstr == NULL)
+                addReplyBulkLongLong(c,vlong);
+            else
+                addReplyBulkCBuffer(c,vstr,vlen);
+
+            if (withscores)
+                addReplyDouble(c,zzlGetScore(sptr));
+
+            if (reverse)
+                zzlPrev(zl,&eptr,&sptr);
+            else
+                zzlNext(zl,&eptr,&sptr);
+        }
+
+    } else if (zobj->encoding == REDIS_ENCODING_RAW) {
+        zset *zs = zobj->ptr;
+        zskiplist *zsl = zs->zsl;
+        zskiplistNode *ln;
+        robj *ele;
+
+        /* Check if starting point is trivial, before doing log(N) lookup. */
+        if (reverse) {
+            ln = zsl->tail;
+            if (start > 0)
+                ln = zslGetElementByRank(zsl,llen-start);
+        } else {
+            ln = zsl->header->level[0].forward;
+            if (start > 0)
+                ln = zslGetElementByRank(zsl,start+1);
+        }
+
+        while(rangelen--) {
+            redisAssert(ln != NULL);
+            ele = ln->obj;
+            addReplyBulk(c,ele);
+            if (withscores)
+                addReplyDouble(c,ln->score);
+            ln = reverse ? ln->backward : ln->level[0].forward;
+        }
+    } else {
+        redisPanic("Unknown sorted set encoding");

     }
 }
 
     }
 }
 


@@ -800,125 +1314,125 @@ void zrevrangeCommand(redisClient *c) {
     zrangeGenericCommand(c,1);
 }
 
     zrangeGenericCommand(c,1);
 }
 

-/* This command implements both ZRANGEBYSCORE and ZCOUNT.
- * If justcount is non-zero, just the count is returned. */
-void genericZrangebyscoreCommand(redisClient *c, int justcount) {
-    robj *o;
-    double min, max;
-    int minex = 0, maxex = 0; /* are min or max exclusive? */
+/* This command implements ZRANGEBYSCORE, ZREVRANGEBYSCORE and ZCOUNT.
+ * If "justcount", only the number of elements in the range is returned. */
+void genericZrangebyscoreCommand(redisClient *c, int reverse, int justcount) {
+    zrangespec range;
+    robj *o, *emptyreply;
+    zset *zsetobj;
+    zskiplist *zsl;
+    zskiplistNode *ln;

     int offset = 0, limit = -1;
     int withscores = 0;
     int offset = 0, limit = -1;
     int withscores = 0;

-    int badsyntax = 0;
+    unsigned long rangelen = 0;
+    void *replylen = NULL;
+    int minidx, maxidx;

 
 

-    /* Parse the min-max interval. If one of the values is prefixed
-     * by the "(" character, it's considered "open". For instance
-     * ZRANGEBYSCORE zset (1.5 (2.5 will match min < x < max
-     * ZRANGEBYSCORE zset 1.5 2.5 will instead match min <= x <= max */
-    if (((char*)c->argv[2]->ptr)[0] == '(') {
-        min = strtod((char*)c->argv[2]->ptr+1,NULL);
-        minex = 1;
-    } else {
-        min = strtod(c->argv[2]->ptr,NULL);
-    }
-    if (((char*)c->argv[3]->ptr)[0] == '(') {
-        max = strtod((char*)c->argv[3]->ptr+1,NULL);
-        maxex = 1;
+    /* Parse the range arguments. */
+    if (reverse) {
+        /* Range is given as [max,min] */
+        maxidx = 2; minidx = 3;

     } else {
     } else {

-        max = strtod(c->argv[3]->ptr,NULL);
+        /* Range is given as [min,max] */
+        minidx = 2; maxidx = 3;

     }
 
     }
 

-    /* Parse "WITHSCORES": note that if the command was called with
-     * the name ZCOUNT then we are sure that c->argc == 4, so we'll never
-     * enter the following paths to parse WITHSCORES and LIMIT. */
-    if (c->argc == 5 || c->argc == 8) {
-        if (strcasecmp(c->argv[c->argc-1]->ptr,"withscores") == 0)
-            withscores = 1;
-        else
-            badsyntax = 1;
-    }
-    if (c->argc != (4 + withscores) && c->argc != (7 + withscores))
-        badsyntax = 1;
-    if (badsyntax) {
-        addReplyError(c,"wrong number of arguments for ZRANGEBYSCORE");
+    if (zslParseRange(c->argv[minidx],c->argv[maxidx],&range) != REDIS_OK) {
+        addReplyError(c,"min or max is not a double");

         return;
     }
 
         return;
     }
 

-    /* Parse "LIMIT" */
-    if (c->argc == (7 + withscores) && strcasecmp(c->argv[4]->ptr,"limit")) {
-        addReply(c,shared.syntaxerr);
-        return;
-    } else if (c->argc == (7 + withscores)) {
-        offset = atoi(c->argv[5]->ptr);
-        limit = atoi(c->argv[6]->ptr);
-        if (offset < 0) offset = 0;
+    /* Parse optional extra arguments. Note that ZCOUNT will exactly have
+     * 4 arguments, so we'll never enter the following code path. */
+    if (c->argc > 4) {
+        int remaining = c->argc - 4;
+        int pos = 4;
+
+        while (remaining) {
+            if (remaining >= 1 && !strcasecmp(c->argv[pos]->ptr,"withscores")) {
+                pos++; remaining--;
+                withscores = 1;
+            } else if (remaining >= 3 && !strcasecmp(c->argv[pos]->ptr,"limit")) {
+                offset = atoi(c->argv[pos+1]->ptr);
+                limit = atoi(c->argv[pos+2]->ptr);
+                pos += 3; remaining -= 3;
+            } else {
+                addReply(c,shared.syntaxerr);
+                return;
+            }
+        }

     }
 
     /* Ok, lookup the key and get the range */
     }
 
     /* Ok, lookup the key and get the range */

-    o = lookupKeyRead(c->db,c->argv[1]);
-    if (o == NULL) {
-        addReply(c,justcount ? shared.czero : shared.emptymultibulk);
+    emptyreply = justcount ? shared.czero : shared.emptymultibulk;
+    if ((o = lookupKeyReadOrReply(c,c->argv[1],emptyreply)) == NULL ||
+        checkType(c,o,REDIS_ZSET)) return;
+    zsetobj = o->ptr;
+    zsl = zsetobj->zsl;
+
+    /* If reversed, get the last node in range as starting point. */
+    if (reverse) {
+        ln = zslLastInRange(zsl,range);

     } else {
     } else {

-        if (o->type != REDIS_ZSET) {
-            addReply(c,shared.wrongtypeerr);
+        ln = zslFirstInRange(zsl,range);
+    }
+
+    /* No "first" element in the specified interval. */
+    if (ln == NULL) {
+        addReply(c,emptyreply);
+        return;
+    }
+
+    /* We don't know in advance how many matching elements there are in the
+     * list, so we push this object that will represent the multi-bulk length
+     * in the output buffer, and will "fix" it later */
+    if (!justcount)
+        replylen = addDeferredMultiBulkLength(c);
+
+    /* If there is an offset, just traverse the number of elements without
+     * checking the score because that is done in the next loop. */
+    while(ln && offset--) {
+        ln = reverse ? ln->backward : ln->level[0].forward;
+    }
+
+    while (ln && limit--) {
+        /* Abort when the node is no longer in range. */
+        if (reverse) {
+            if (!zslValueGteMin(ln->score,&range)) break;

         } else {
         } else {

-            zset *zsetobj = o->ptr;
-            zskiplist *zsl = zsetobj->zsl;
-            zskiplistNode *ln;
-            robj *ele;
-            void *replylen = NULL;
-            unsigned long rangelen = 0;
-
-            /* 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];
-
-            if (ln == NULL) {
-                /* No element matching the speciifed interval */
-                addReply(c,justcount ? shared.czero : shared.emptymultibulk);
-                return;
-            }
+            if (!zslValueLteMax(ln->score,&range)) break;
+        }

 
 

-            /* 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);
-
-            while(ln && (maxex ? (ln->score < max) : (ln->score <= max))) {
-                if (offset) {
-                    offset--;
-                    ln = ln->forward[0];
-                    continue;
-                }
-                if (limit == 0) break;
-                if (!justcount) {
-                    ele = ln->obj;
-                    addReplyBulk(c,ele);
-                    if (withscores)
-                        addReplyDouble(c,ln->score);
-                }
-                ln = ln->forward[0];
-                rangelen++;
-                if (limit > 0) limit--;
-            }
-            if (justcount) {
-                addReplyLongLong(c,(long)rangelen);
-            } else {
-                setDeferredMultiBulkLength(c,replylen,
-                     withscores ? (rangelen*2) : rangelen);
-            }
+        /* Do our magic */
+        rangelen++;
+        if (!justcount) {
+            addReplyBulk(c,ln->obj);
+            if (withscores)
+                addReplyDouble(c,ln->score);

         }
         }

+
+        /* Move to next node */
+        ln = reverse ? ln->backward : ln->level[0].forward;
+    }
+
+    if (justcount) {
+        addReplyLongLong(c,(long)rangelen);
+    } else {
+        setDeferredMultiBulkLength(c,replylen,
+             withscores ? (rangelen*2) : rangelen);

     }
 }
 
 void zrangebyscoreCommand(redisClient *c) {
     }
 }
 
 void zrangebyscoreCommand(redisClient *c) {

-    genericZrangebyscoreCommand(c,0);
+    genericZrangebyscoreCommand(c,0,0);
+}
+
+void zrevrangebyscoreCommand(redisClient *c) {
+    genericZrangebyscoreCommand(c,1,0);

 }
 
 void zcountCommand(redisClient *c) {
 }
 
 void zcountCommand(redisClient *c) {

-    genericZrangebyscoreCommand(c,1);
+    genericZrangebyscoreCommand(c,0,1);

 }
 
 void zcardCommand(redisClient *c) {
 }
 
 void zcardCommand(redisClient *c) {


@@ -941,6 +1455,7 @@ void zscoreCommand(redisClient *c) {
         checkType(c,o,REDIS_ZSET)) return;
 
     zs = o->ptr;
         checkType(c,o,REDIS_ZSET)) return;
 
     zs = o->ptr;

+    c->argv[2] = tryObjectEncoding(c->argv[2]);

     de = dictFind(zs->dict,c->argv[2]);
     if (!de) {
         addReply(c,shared.nullbulk);
     de = dictFind(zs->dict,c->argv[2]);
     if (!de) {
         addReply(c,shared.nullbulk);


@@ -964,6 +1479,7 @@ void zrankGenericCommand(redisClient *c, int reverse) {
 
     zs = o->ptr;
     zsl = zs->zsl;
 
     zs = o->ptr;
     zsl = zs->zsl;

+    c->argv[2] = tryObjectEncoding(c->argv[2]);

     de = dictFind(zs->dict,c->argv[2]);
     if (!de) {
         addReply(c,shared.nullbulk);
     de = dictFind(zs->dict,c->argv[2]);
     if (!de) {
         addReply(c,shared.nullbulk);


@@ -971,7 +1487,7 @@ void zrankGenericCommand(redisClient *c, int reverse) {
     }
 
     score = dictGetEntryVal(de);
     }
 
     score = dictGetEntryVal(de);

-    rank = zslistTypeGetRank(zsl, *score, c->argv[2]);
+    rank = zslGetRank(zsl, *score, c->argv[2]);

     if (rank) {
         if (reverse) {
             addReplyLongLong(c, zsl->length - rank);
     if (rank) {
         if (reverse) {
             addReplyLongLong(c, zsl->length - rank);