/// <summary>
/// Recycles this instance of the <see cref="CollectionChangedEventArgs{T}"/> class.
/// </summary>
/// <remarks>
/// <para>
/// This method resets this instance and returns it to a resource pool if resource pooling is
/// enabled (see <see cref="ResourcePool.Enabled">ResourcePool.Enabled</see>).
/// </para>
/// </remarks>
public void Recycle()
{
Action = CollectionChangedAction.Add;
NewItemsIndex = -1;
NewItems.Clear();
OldItemsIndex = -1;
OldItems.Clear();
Pool.Recycle(this);
}
/// <summary>
/// Update the container buffer and item snapshots. Old (removed) items will be added to
/// <see cref="OldItems"/> and new items to <see cref="NewItems"/>.
/// </summary>
public void Update()
{
_container.TakeSnapshot();
_previousSegments = _currentSegments;
if (_previousData.Length != _currentData.Length)
{
Array.Resize(ref _previousData, _currentData.Length);
}
Buffer.BlockCopy(_currentData, 0, _previousData, 0, _currentData.Length);
_currentSegments = _container.GetAllocatedBytes(ref _currentData);
if (_currentData.Length != _previousData.Length) // buffer was resized (and replaced), update underlying buffer for all items
{
for (int i = 0; i < _items.Length; i++)
{
if (_items[i] == null)
{
continue;
}
_items[i].SetSnapshot(_currentData, i * _container.ItemSize, _container.ItemSize);
}
}
if (_previousMapping.Length != _currentMapping.Length)
{
Array.Resize(ref _previousMapping, _currentMapping.Length);
}
Buffer.BlockCopy(_currentMapping, 0, _previousMapping, 0, _currentMapping.Length * sizeof(int));
var count = _currentData.Length / _container.ItemSize;
var mr = new BufferMemoryReader(_currentData);
if (_currentMapping.Length != count)
{
Array.Resize(ref _currentMapping, count);
}
for (int i = 0; i <= _container.MaxIndex; i++)
{
_currentMapping[i] = mr.Read <int>(i * _container.ItemSize);
}
for (int i = _container.MaxIndex + 1; i < count; i++)
{
_currentMapping[i] = -1;
}
NewItems.Clear();
OldItems.Clear();
if (_items.Length != _container.Capacity)
{
Array.Resize(ref _items, _container.Capacity);
}
// Compare against previous where there is a value.
for (int i = 0; i < Math.Min(_previousMapping.Length, _currentMapping.Length); i++)
{
if (_currentMapping[i] != _previousMapping[i])
{
if (_previousMapping[i] != -1)
{
var item = CreatePreviousItem(i);
OnItemRemoved(i, item);
OldItems.Add(item);
}
if (_currentMapping[i] != -1 && _currentMapping[i] != 0) // NB: New item starts with ID 0
{
var item = CreateCurrentItem(i);
OnItemAdded(i, item);
NewItems.Add(item);
}
}
}
// Check expanded area.
for (int i = _previousMapping.Length; i < _currentMapping.Length; i++)
{
if (_currentMapping[i] != -1)
{
var item = CreateCurrentItem(i);
OnItemAdded(i, item);
NewItems.Add(item);
}
}
// Check reduced area.
for (int i = _currentMapping.Length; i < _previousMapping.Length; i++)
{
if (_previousMapping[i] != -1)
{
var item = CreatePreviousItem(i);
OnItemRemoved(i, item);
OldItems.Add(item);
}
}
}
private void ClearChanges()
{
NewItems.Clear();
DirtyItems.Clear();
DeletedItems.Clear();
}