public void Put(int key, int value)
{
if (_capacity < 1)
{
return;
}
if (_keyCache.TryGetValue(key, out var v))
{
v.Value = value;
SetFreq(v, true);
}
else
{
if (_capacity == _keyCache.Count)
{
var list = _freCache[_minFreq];
var r = list[0];
list.RemoveAt(0);
_keyCache.Remove(r.Key);
}
var item = new LFUItem {
Freq = 1, Key = key, Value = value
};
_keyCache[key] = item;
SetFreq(item, false);
_minFreq = 1;
}
}
private void SetFreq(LFUItem v, bool removeOld)
{
if (removeOld)
{
var oldList = _freCache[v.Freq];
oldList.Remove(v);
if (v.Freq == _minFreq && oldList.Count == 0)
{
_minFreq++;
}
v.Freq++;
}
if (!_freCache.TryGetValue(v.Freq, out var newList))
{
newList = new List <LFUItem>();
_freCache[v.Freq] = newList;
}
newList.Add(v);
}
