Function RM_ListPop

app/redis-6.2.6/src/module.c:2581–2592

Pop an element from the list, and returns it as a module string object * that the user should be free with RM_FreeString() or by enabling * automatic memory. 'where' specifies if the element should be popped from * head or tail. The command returns NULL if: * * 1. The list is empty. * 2. The key was not open for writing. * 3. The key is not a list. */

 * 2. The key was not open for writing.
 * 3. The key is not a list. */
RedisModuleString *RM_ListPop(RedisModuleKey *key, int where) {
    if (!(key->mode & REDISMODULE_WRITE) ||
        key->value == NULL ||
        key->value->type != OBJ_LIST) return NULL;
    robj *ele = listTypePop(key->value,
        (where == REDISMODULE_LIST_HEAD) ? QUICKLIST_HEAD : QUICKLIST_TAIL);
    robj *decoded = getDecodedObject(ele);
    decrRefCount(ele);
    moduleDelKeyIfEmpty(key);
    autoMemoryAdd(key->ctx,REDISMODULE_AM_STRING,decoded);
    return decoded;
}

/* --------------------------------------------------------------------------
 * ## Key API for Sorted Set type