Function zslDeleteNode

src/t_zset.cpp:191–209

Internal function used by zslDelete, zslDeleteRangeByScore and * zslDeleteRangeByRank. */

/* Internal function used by zslDelete, zslDeleteRangeByScore and
 * zslDeleteRangeByRank. */
void zslDeleteNode(zskiplist *zsl, zskiplistNode *x, zskiplistNode **update) {
    int i;
    for (i = 0; i < zsl->level; 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 {
            update[i]->level(i)->span -= 1;
        }
    }
    if (x->level(0)->forward) {
        x->level(0)->forward->backward = x->backward;
    } else {
        zsl->tail = x->backward;
    }
    while(zsl->level > 1 && zsl->header->level(zsl->level-1)->forward == NULL)
        zsl->level--;
    zsl->length--;
}

/* Delete an element with matching score/element from the skiplist.
 * The function returns 1 if the node was found and deleted, otherwise