Function sortGetKeys

app/redis-6.2.6/src/db.c:1722–1761

Helper function to extract keys from the SORT command. * * SORT ... STORE ... * * The first argument of SORT is always a key, however a list of options * follow in SQL-alike style. Here we parse just the minimum in order to * correctly identify keys in the "STORE" option. */

 * follow in SQL-alike style. Here we parse just the minimum in order to
 * correctly identify keys in the "STORE" option. */
int sortGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result) {
    int i, j, num, *keys, found_store = 0;
    UNUSED(cmd);

    num = 0;
    keys = getKeysPrepareResult(result, 2); /* Alloc 2 places for the worst case. */
    keys[num++] = 1; /* <sort-key> is always present. */

    /* Search for STORE option. By default we consider options to don't
     * have arguments, so if we find an unknown option name we scan the
     * next. However there are options with 1 or 2 arguments, so we
     * provide a list here in order to skip the right number of args. */
    struct {
        char *name;
        int skip;
    } skiplist[] = {
        {"limit", 2},
        {"get", 1},
        {"by", 1},
        {NULL, 0} /* End of elements. */
    };

    for (i = 2; i < argc; i++) {
        for (j = 0; skiplist[j].name != NULL; j++) {
            if (!strcasecmp(argv[i]->ptr,skiplist[j].name)) {
                i += skiplist[j].skip;
                break;
            } else if (!strcasecmp(argv[i]->ptr,"store") && i+1 < argc) {
                /* Note: we don't increment "num" here and continue the loop
                 * to be sure to process the *last* "STORE" option if multiple
                 * ones are provided. This is same behavior as SORT. */
                found_store = 1;
                keys[num] = i+1; /* <store-key> */
                break;
            }
        }
    }
    result->numkeys = num + found_store;
    return result->numkeys;
}

int migrateGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result) {
    int i, num, first, *keys;