Function expireGenericCommand

app/redis-6.2.6/src/expire.c:490–534

This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT * and PEXPIREAT. Because the command second argument may be relative or absolute * the "basetime" argument is used to signal what the base time is (either 0 * for *AT variants of the command, or the current time for relative expires). * * unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for * the argv[

 * unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for
 * the argv[2] parameter. The basetime is always specified in milliseconds. */
void expireGenericCommand(client *c, long long basetime, int unit) {
    robj *key = c->argv[1], *param = c->argv[2];
    long long when; /* unix time in milliseconds when the key will expire. */

    if (getLongLongFromObjectOrReply(c, param, &when, NULL) != C_OK)
        return;
    int negative_when = when < 0;
    if (unit == UNIT_SECONDS) when *= 1000;
    when += basetime;
    if (((when < 0) && !negative_when) || ((when-basetime > 0) && negative_when)) {
        /* EXPIRE allows negative numbers, but we can at least detect an
         * overflow by either unit conversion or basetime addition. */
        addReplyErrorFormat(c, "invalid expire time in %s", c->cmd->name);
        return;
    }
    /* No key, return zero. */
    if (lookupKeyWrite(c->db,key) == NULL) {
        addReply(c,shared.czero);
        return;
    }

    if (checkAlreadyExpired(when)) {
        robj *aux;

        int deleted = server.lazyfree_lazy_expire ? dbAsyncDelete(c->db,key) :
                                                    dbSyncDelete(c->db,key);
        serverAssertWithInfo(c,key,deleted);
        server.dirty++;

        /* Replicate/AOF this as an explicit DEL or UNLINK. */
        aux = server.lazyfree_lazy_expire ? shared.unlink : shared.del;
        rewriteClientCommandVector(c,2,aux,key);
        signalModifiedKey(c,c->db,key);
        notifyKeyspaceEvent(NOTIFY_GENERIC,"del",key,c->db->id);
        addReply(c, shared.cone);
        return;
    } else {
        setExpire(c,c->db,key,when);
        addReply(c,shared.cone);
        signalModifiedKey(c,c->db,key);
        notifyKeyspaceEvent(NOTIFY_GENERIC,"expire",key,c->db->id);
        server.dirty++;
        return;
    }
}

/* EXPIRE key seconds */
void expireCommand(client *c) {