Function keyIsExpired

src/db.cpp:2030–2069

Check if the key is expired. Note, this does not check subexpires */

/* Check if the key is expired. Note, this does not check subexpires */
int keyIsExpired(const redisDbPersistentDataSnapshot *db, robj *key) {
    /* Don't expire anything while loading. It will be done later. */
    if (g_pserver->loading) return 0;
    
    const expireEntry *pexpire = db->getExpire(key);
    mstime_t now;
    long long when;

    if (pexpire == nullptr) return 0; /* No expire for this key */

    if (!pexpire->FGetPrimaryExpire(&when))
        return 0;

    /* If we are in the context of a Lua script, we pretend that time is
     * blocked to when the Lua script started. This way a key can expire
     * only the first time it is accessed and not in the middle of the
     * script execution, making propagation to slaves / AOF consistent.
     * See issue #1525 on Github for more information. */
    if (g_pserver->lua_caller) {
        now = g_pserver->lua_time_snapshot;
    }
    /* If we are in the middle of a command execution, we still want to use
     * a reference time that does not change: in that case we just use the
     * cached time, that we update before each call in the call() function.
     * This way we avoid that commands such as RPOPLPUSH or similar, that
     * may re-open the same key multiple times, can invalidate an already
     * open object in a next call, if the next call will see the key expired,
     * while the first did not. */
    else if (serverTL->fixed_time_expire > 0) {
        __atomic_load(&g_pserver->mstime, &now, __ATOMIC_ACQUIRE);
    }
    /* For the other cases, we want to use the most fresh time we have. */
    else {
        now = mstime();
    }

    /* The key expired if the current (virtual or real) time is greater
     * than the expire time of the key. */
    return now > when;
}

/* This function is called when we are going to perform some operation
 * in a given key, but such key may be already logically expired even if