/* 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 zslDeleteRangeByRank(zskiplist *zsl, unsigned int start, unsigned int end, dict *dict) {
zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
unsigned long traversed = 0, removed = 0;
int i;
x = zsl->header;
for (i = zsl->level-1; i >= 0; 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++;
x = x->level[0].forward;
while (x && traversed <= end) {
zskiplistNode *next = x->level[0].forward;
zslDeleteNode(zsl,x,update);
dictDelete(dict,x->obj);
zslFreeNode(x);
removed++;
traversed++;
x = next;
}
return removed;
}
/* Delete an element with matching score/object from the skiplist. */
int zslDelete(zskiplist *zsl, double score, robj *obj) {
zskiplistNode *update[ZSKIPLIST_MAXLEVEL], *x;
int i;
x = zsl->header;
for (i = zsl->level-1; i >= 0; 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. */
x = x->level[0].forward;
if (x && score == x->score && equalStringObjects(x->obj,obj)) {
zslDeleteNode(zsl, x, update);
zslFreeNode(x);
return 1;
} else {
return 0; /* not found */
}
return 0; /* not found */
}
/* 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, 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--) {
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;
}
/* 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;
}
return removed;
}
/* 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) {
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];
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);
dictDelete(dict,x->obj);
zslFreeNode(x);
removed++;
x = next;
}
return removed; /* not found */
}