Function zsetInitScoreRange

app/redis-6.2.6/src/module.c:2773–2801

Helper function for RM_ZsetFirstInScoreRange() and RM_ZsetLastInScoreRange(). * Setup the sorted set iteration according to the specified score range * (see the functions calling it for more info). If 'first' is true the * first element in the range is used as a starting point for the iterator * otherwise the last. Return REDISMODULE_OK on success otherwise * REDISMODULE_ERR. */

 * otherwise the last. Return REDISMODULE_OK on success otherwise
 * REDISMODULE_ERR. */
int zsetInitScoreRange(RedisModuleKey *key, double min, double max, int minex, int maxex, int first) {
    if (!key->value || key->value->type != OBJ_ZSET) return REDISMODULE_ERR;

    RM_ZsetRangeStop(key);
    key->u.zset.type = REDISMODULE_ZSET_RANGE_SCORE;
    key->u.zset.er = 0;

    /* Setup the range structure used by the sorted set core implementation
     * in order to seek at the specified element. */
    zrangespec *zrs = &key->u.zset.rs;
    zrs->min = min;
    zrs->max = max;
    zrs->minex = minex;
    zrs->maxex = maxex;

    if (key->value->encoding == OBJ_ENCODING_ZIPLIST) {
        key->u.zset.current = first ? zzlFirstInRange(key->value->ptr,zrs) :
                                      zzlLastInRange(key->value->ptr,zrs);
    } else if (key->value->encoding == OBJ_ENCODING_SKIPLIST) {
        zset *zs = key->value->ptr;
        zskiplist *zsl = zs->zsl;
        key->u.zset.current = first ? zslFirstInRange(zsl,zrs) :
                                      zslLastInRange(zsl,zrs);
    } else {
        serverPanic("Unsupported zset encoding");
    }
    if (key->u.zset.current == NULL) key->u.zset.er = 1;
    return REDISMODULE_OK;
}

/* Setup a sorted set iterator seeking the first element in the specified
 * range. Returns REDISMODULE_OK if the iterator was correctly initialized