public void RemoveAt(int index)
{
DoBaseWrite(() =>
{
WriteCollection.RemoveAt(index);
});
}
/// <summary>
///
/// </summary>
/// <param name="i"></param>
public void RemoveAt(int i)
{
var Item = this[i];
DoBaseWrite(() => WriteCollection.RemoveAt(i));
OnItemRemoved(Item);
OnItemsChanged();
}
// ************************************************************************
// Protected Methods
// ************************************************************************
#region Protected Methods
/// <summary>
/// Removes all items from the ICollection<T>.
/// </summary>
protected void DoBaseClear(Action action)
{
// Don't use BaseCollection.Clear(), it causes problems because it
// sends a reset event, and then the collection needs to be read out through
// an enumerator. Use RemoveAt instead until the collection is empty.
// Using remove from end after testing with this speed test:
//
// // speed test for using RemoveAt(int index);
// using System;
// using System.Collections.Generic;
// using System.Collections.ObjectModel;
// using System.Diagnostics;
//
// namespace ConsoleApplication1 {
// class Program {
// static void Main(string[] args) {
// var coll = new Collection<int>();
// for (int ix = 0; ix < 100000; ++ix) coll.Add(ix);
// var sw = Stopwatch.StartNew();
// while (coll.Count > 0) coll.RemoveAt(0);
// sw.Stop();
// Console.WriteLine("Removed from start {0}ms",sw.ElapsedMilliseconds);
// for (int ix = 0; ix < 100000; ++ix) coll.Add(ix);
// sw = Stopwatch.StartNew();
// while (coll.Count > 0) coll.RemoveAt(coll.Count - 1);
// Console.WriteLine("Removed from end {0}ms",sw.ElapsedMilliseconds);
// Console.ReadLine();
// }
// }
// }
//
// Output:
// Removed from start 4494ms
// Removed from end 3ms
// Need a special case of DoBaseWrite for a set changes to make sure that nothing else does a change
// while we are in the middle of doing a collection of changes.
_readWriteLock.TryEnterUpgradeableReadLock(Timeout.Infinite);
try {
_readWriteLock.TryEnterWriteLock(Timeout.Infinite);
action();
while (WriteCollection.Count > 0)
{
_newSnapshotRequired = true;
WriteCollection.RemoveAt(WriteCollection.Count - 1);
}
} finally {
if (_readWriteLock.IsWriteLockHeld)
{
_readWriteLock.ExitWriteLock();
}
_readWriteLock.ExitUpgradeableReadLock();
}
}
/// <summary>
/// Removes the element with the specified key from the IDictionary<TKey, TValue>.
/// </summary>
/// <param name="key">
/// The key of the element to remove.
/// </param>
/// <returns>
/// True if the element is successfully removed; otherwise, false. This method also returns false if key was not found in the original IDictionary<TKey, TValue>.
/// </returns>
public bool Remove(TKey key)
{
return(DoBaseWrite(() => {
DoubleLinkListIndexNode node;
if (_keyToIndex.TryGetValue(key, out node))
{
WriteCollection.RemoveAt(node.Index);
if (node == _lastNode)
{
_lastNode = node.Previous;
}
node.Remove();
}
return _keyToIndex.Remove(key);
}));
}
protected void DoBaseClear(Action action)
{
_readWriteLock.TryEnterUpgradeableReadLock(Timeout.Infinite);
try
{
_readWriteLock.TryEnterWriteLock(Timeout.Infinite);
action();
while (WriteCollection.Count > 0)
{
_newSnapshotRequired = true;
WriteCollection.RemoveAt(WriteCollection.Count - 1);
}
}
finally
{
if (_readWriteLock.IsWriteLockHeld)
{
_readWriteLock.ExitWriteLock();
}
_readWriteLock.ExitUpgradeableReadLock();
}
}
