public TValue this[TKey key]
{
get
{
m_oCurrent = m_oMainDict[key];
if (m_oCurrent == m_oHead)
{
//do nothing
}
else if (m_oCurrent == m_oTail)
{
m_oTail = m_oCurrent.Next;
m_oTail.Prev = null;
m_oHead.Next = m_oCurrent;
m_oCurrent.Prev = m_oHead;
m_oCurrent.Next = null;
m_oHead = m_oCurrent;
}
else
{
m_oCurrent.Prev.Next = m_oCurrent.Next;
m_oCurrent.Next.Prev = m_oCurrent.Prev;
m_oHead.Next = m_oCurrent;
m_oCurrent.Prev = m_oHead;
m_oCurrent.Next = null;
m_oHead = m_oCurrent;
}
return(m_oCurrent.Value);
}
}
public LRUCache(int iSize)
{
m_iMaxItems = iSize;
m_oMainDict = new Dictionary <TKey, LRUNode <TKey, TValue> >();
m_oHead = null;
m_oTail = null;
}
public void Add(TKey key, TValue value)
{
if (m_oMainDict.Count >= m_iMaxItems)
{
//remove old
m_oMainDict.Remove(m_oTail.Key);
//reuse old
LRUNode <TKey, TValue> oNewNode = m_oTail;
oNewNode.Key = key;
oNewNode.Value = value;
m_oTail = m_oTail.Next;
m_oTail.Prev = null;
//add new
m_oHead.Next = oNewNode;
oNewNode.Prev = m_oHead;
oNewNode.Next = null;
m_oHead = oNewNode;
m_oMainDict.Add(key, oNewNode);
}
else
{
LRUNode <TKey, TValue> oNewNode = new LRUNode <TKey, TValue>(key, value);
if (m_oHead == null)
{
m_oHead = oNewNode;
m_oTail = oNewNode;
}
else
{
m_oHead.Next = oNewNode;
oNewNode.Prev = m_oHead;
m_oHead = oNewNode;
}
m_oMainDict.Add(key, oNewNode);
}
}