Function LFUDecrAndReturn

src/evict.cpp:329–336

If the object decrement time is reached decrement the LFU counter but * do not update LFU fields of the object, we update the access time * and counter in an explicit way when the object is really accessed. * And we will times halve the counter according to the times of * elapsed time than g_pserver->lfu_decay_time. * Return the object frequency counter. * * This function is used in order t

 * to fit: as we check for the candidate, we incrementally decrement the
 * counter of the scanned objects if needed. */
unsigned long LFUDecrAndReturn(robj_roptr o) {
    unsigned long ldt = o->lru >> 8;
    unsigned long counter = o->lru & 255;
    unsigned long num_periods = g_pserver->lfu_decay_time ? LFUTimeElapsed(ldt) / g_pserver->lfu_decay_time : 0;
    if (num_periods)
        counter = (num_periods > counter) ? 0 : counter - num_periods;
    return counter;
}

unsigned long getClientReplicationBacklogSharedUsage(client *c);