Function setExpire

src/db.cpp:1864–1887

Set an expire to the specified key. If the expire is set in the context * of an user calling a command 'c' is the client, otherwise 'c' is set * to NULL. The 'when' parameter is the absolute unix time in milliseconds * after which the key will no longer be considered valid. */

 * to NULL. The 'when' parameter is the absolute unix time in milliseconds
 * after which the key will no longer be considered valid. */
void setExpire(client *c, redisDb *db, robj *key, robj *subkey, long long when) {
    serverAssert(GlobalLocksAcquired());

    /* Update TTL stats (exponential moving average) */
    /*  Note: We never have to update this on expiry since we reduce it by the current elapsed time here */
    mstime_t now;
    __atomic_load(&g_pserver->mstime, &now, __ATOMIC_ACQUIRE);
    db->avg_ttl -= (now - db->last_expire_set); // reduce the TTL by the time that has elapsed
    if (db->expireSize() == 0)
        db->avg_ttl = 0;
    else
        db->avg_ttl -= db->avg_ttl / db->expireSize(); // slide one entry out the window
    if (db->avg_ttl < 0)
        db->avg_ttl = 0;    // TTLs are never negative
    db->avg_ttl += (double)(when-now) / (db->expireSize()+1);    // add the new entry
    db->last_expire_set = now;

    /* Update the expire set */
    db->setExpire(key, subkey, when);

    int writable_slave = listLength(g_pserver->masters) && g_pserver->repl_slave_ro == 0 && !g_pserver->fActiveReplica;
    if (c && writable_slave && !(c->flags & CLIENT_MASTER))
        rememberSlaveKeyWithExpire(db,key);
}

redisDb::~redisDb()
{