Function zzlLastInRange

src/t_zset.cpp:883–912

Find pointer to the last element contained in the specified range. * Returns NULL when no element is contained in the range. */

/* Find pointer to the last element contained in the specified range.
 * Returns NULL when no element is contained in the range. */
unsigned char *zzlLastInRange(unsigned char *zl, zrangespec *range) {
    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);
        serverAssert(sptr != NULL);

        score = zzlGetScore(sptr);
        if (zslValueLteMax(score,range)) {
            /* Check if score >= min. */
            if (zslValueGteMin(score,range))
                return eptr;
            return NULL;
        }

        /* 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)
            serverAssert((eptr = ziplistPrev(zl,sptr)) != NULL);
        else
            eptr = NULL;
    }

    return NULL;
}

int zzlLexValueGteMin(unsigned char *p, zlexrangespec *spec) {
    sds value = ziplistGetObject(p);