Function lsetCommand

app/redis-6.2.6/src/t_list.c:365–394

LSET */

/* LSET <key> <index> <element> */
void lsetCommand(client *c) {
    robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nokeyerr);
    if (o == NULL || checkType(c,o,OBJ_LIST)) return;
    long index;
    robj *value = c->argv[3];

    if (sdslen(value->ptr) > LIST_MAX_ITEM_SIZE) {
        addReplyError(c, "Element too large");
        return;
    }

    if ((getLongFromObjectOrReply(c, c->argv[2], &index, NULL) != C_OK))
        return;

    if (o->encoding == OBJ_ENCODING_QUICKLIST) {
        quicklist *ql = o->ptr;
        int replaced = quicklistReplaceAtIndex(ql, index,
                                               value->ptr, sdslen(value->ptr));
        if (!replaced) {
            addReplyErrorObject(c,shared.outofrangeerr);
        } else {
            addReply(c,shared.ok);
            signalModifiedKey(c,c->db,c->argv[1]);
            notifyKeyspaceEvent(NOTIFY_LIST,"lset",c->argv[1],c->db->id);
            server.dirty++;
        }
    } else {
        serverPanic("Unknown list encoding");
    }
}

/* A helper for replying with a list's range between the inclusive start and end
 * indexes as multi-bulk, with support for negative indexes. Note that start