namespace CurrentMemoryTracker
{
    using DB::current_thread;

    void alloc(Int64 size)
    {
        if (auto * memory_tracker = DB::CurrentThread::getMemoryTracker())
        {
            current_thread->untracked_memory += size;
            if (current_thread->untracked_memory > current_thread->untracked_memory_limit)
            {
                /// Zero untracked before track. If tracker throws out-of-limit we would be able to alloc up to untracked_memory_limit bytes
                /// more. It could be useful to enlarge Exception message in rethrow logic.
                Int64 tmp = current_thread->untracked_memory;
                current_thread->untracked_memory = 0;
                memory_tracker->alloc(tmp);
            }
        }
    }

    void free(Int64 size)
    {
        if (auto * memory_tracker = DB::CurrentThread::getMemoryTracker())
        {
            current_thread->untracked_memory -= size;
            if (current_thread->untracked_memory < -current_thread->untracked_memory_limit)
            {
                memory_tracker->free(-current_thread->untracked_memory);
                current_thread->untracked_memory = 0;
            }
        }
    }
}