Function freeMemoryGetNotCountedMemory

src/evict.cpp:343–369

We don't want to count AOF buffers and slaves output buffers as * used memory: the eviction should use mostly data size. This function * returns the sum of AOF and slaves buffer. */

 * used memory: the eviction should use mostly data size. This function
 * returns the sum of AOF and slaves buffer. */
size_t freeMemoryGetNotCountedMemory(void) {
    serverAssert(GlobalLocksAcquired());
    size_t overhead = 0;
    int slaves = listLength(g_pserver->slaves);

    if (slaves) {
        listIter li;
        listNode *ln;

        listRewind(g_pserver->slaves,&li);
        while((ln = listNext(&li))) {
            client *replica = (client*)listNodeValue(ln);
            std::unique_lock<fastlock>(replica->lock);
            /* we don't wish to multiple count the replication backlog shared usage */
            overhead += (getClientOutputBufferMemoryUsage(replica) - getClientReplicationBacklogSharedUsage(replica));
        }
    }

    /* also don't count the replication backlog memory
     * that's where the replication clients get their memory from */
    overhead += g_pserver->repl_backlog_size - g_pserver->repl_backlog_config_size;

    if (g_pserver->aof_state != AOF_OFF) {
        overhead += sdsalloc(g_pserver->aof_buf)+aofRewriteBufferSize();
    }
    return overhead;
}

/* Get the memory status from the point of view of the maxmemory directive:
 * if the memory used is under the maxmemory setting then C_OK is returned.