private void CheckExpirations(DateTime now, ref TTNode node)
{
if (node == null)
{
return;
}
if (node.ExpirationTime <= now)
{
// remove node and its left subtree
TTNode toRemove = node;
// put the right subtree into its place
node = node.rNode;
CheckExpirations(now, ref node);
//
ClearNode(toRemove, false);
ClearNode(toRemove.lNode, true);
}
else
{
CheckExpirations(now, ref node.lNode);
}
}
/// <summary>
/// Add the value into the specified sub-tree.
/// </summary>
/// <param name="key"></param>
/// <param name="value"></param>
/// <param name="expiration"></param>
/// <param name="node"></param>
private void Add(TKey key, TValue value, DateTime expiration, ref TTNode node, object parentLocker)
{
if (node == null)
{
lock (parentLocker)
if (node == null)
{
node = new TTNode(expiration);
}
}
if (expiration < node.ExpirationTime)
{
Add(key, value, expiration, ref node.lNode, node);
}
else if (expiration > node.ExpirationTime)
{
Add(key, value, expiration, ref node.rNode, node);
}
else
{
lock (node)
{
// add the item in to the current node
Items[key] = new DictionaryValue()
{
treeNode = node, listNode = node.AddFirst(new KeyValuePair <TKey, TValue>(key, value))
};
}
}
}
/// <summary>
/// Properly removes all items from the given tree node.
/// </summary>
/// <param name="node"></param>
private void ClearNode(TTNode node, bool wholeSubtree)
{
if (node == null)
{
return;
}
foreach (var x in node)
{
Items.Remove(x.Key);
}
if (wholeSubtree)
{
ClearNode(node.lNode, true);
ClearNode(node.rNode, true);
}
}
