/* Update the sorted set according to its encoding. */

    if (zobj->encoding == OBJ_ENCODING_ZIPLIST) {

        unsigned char *eptr;

        if ((eptr = zzlFind(zobj->ptr,ele,&curscore)) != NULL) {

            /* NX? Return, same element already exists. */

            if (nx) {

                *flags |= ZADD_NOP;

                return 1;

            }

            /* Prepare the score for the increment if needed. */

            if (incr) {

                score += curscore;

                if (isnan(score)) {

                    *flags |= ZADD_NAN;

                    return 0;

                }

                if (newscore) *newscore = score;

            }

            /* Remove and re-insert when score changed. */

            if (score != curscore) {

                zobj->ptr = zzlDelete(zobj->ptr,eptr);

                zobj->ptr = zzlInsert(zobj->ptr,ele,score);

                *flags |= ZADD_UPDATED;

            }

            return 1;

        } else if (!xx) {

            /* Optimize: check if the element is too large or the list

             * becomes too long *before* executing zzlInsert. */

            zobj->ptr = zzlInsert(zobj->ptr,ele,score);

            if (zzlLength(zobj->ptr) > server.zset_max_ziplist_entries)

                zsetConvert(zobj,OBJ_ENCODING_SKIPLIST);

            if (sdslen(ele) > server.zset_max_ziplist_value)

                zsetConvert(zobj,OBJ_ENCODING_SKIPLIST);

            if (newscore) *newscore = score;

            *flags |= ZADD_ADDED;

            return 1;

        } else {

            *flags |= ZADD_NOP;

            return 1;

        }