private void TrimItems()
{
while (_lastFreqForItem.Count > TopKMax)
{
if (Topk.Count == 0)
{
break;
}
var last = Topk.LastOrDefault();
if (last.Value is Deque <ByteBuffer> deque)
{
var valueRemoved = deque.RemoveLast();
_lastFreqForItem.Remove(valueRemoved);
if (deque.IsEmpty())
{
Topk.Remove(last.Key);
}
}
else
{
Topk.Remove(last.Key);
_lastFreqForItem.Remove((ByteBuffer)last.Value);
}
}
}
public void Add(byte[] bytes, int count)
{
Hashes.Add(bytes, count);
if (Topk != null)
{
long frequency = Hashes.EstimateCount(bytes);
Topk.UpdateExpectIncreasing(bytes, frequency);
}
}
private void RemoveItemFromSorted(
long frequency,
ByteBuffer value)
{
var existing = Topk.Get(frequency);
if (existing is Deque <ByteBuffer> deque)
{
deque.Remove(value);
if (deque.IsEmpty())
{
Topk.Remove(frequency);
}
}
else if (existing != null)
{
Topk.Remove(frequency);
}
}
private void AddItemToSorted(
long frequency,
ByteBuffer value)
{
var existing = Topk.Get(frequency);
if (existing == null)
{
Topk.Put(frequency, value);
}
else if (existing is Deque <ByteBuffer> existingDeque)
{
existingDeque.Add(value);
}
else
{
Deque <ByteBuffer> deque = new ArrayDeque <ByteBuffer>(2);
deque.Add((ByteBuffer)existing);
deque.Add(value);
Topk.Put(frequency, deque);
}
}
public void UpdateExpectIncreasing(
byte[] value,
long frequency)
{
var filled = _lastFreqForItem.Count == TopKMax;
if (!filled)
{
var valueBuffer = new ByteBuffer(value);
UpdateInternal(valueBuffer, frequency);
}
else
{
var lastKey = Topk.Last().Key;
if (frequency > lastKey)
{
var valueBuffer = new ByteBuffer(value);
UpdateInternal(valueBuffer, frequency);
}
}
TrimItems();
}