Code:
/ Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / Orcas / QFE / wpf / src / Framework / System / Windows / Documents / TextElementCollectionHelper.cs / 1 / TextElementCollectionHelper.cs
//---------------------------------------------------------------------------- // // Copyright (C) Microsoft Corporation. All rights reserved. // // Description: Static methods for all TextElementCollectioninstances. // //--------------------------------------------------------------------------- namespace System.Windows.Documents { // This class maintains a static list of "clean" TextElementCollection // instances. Clean in this sense means guarantee not to have been // modified in a way that could invalidate their _indexCache members. // // The cache is a simple list of WeakReferences to collections. // The size of the list limits the number of collections // that can be used to modify content simultaneously with good IList // performance. The scenario we're concerned about is the parser, // which will allocate one collection for each scoping TextElement // in a document: // requires a minimum cache size of 3 to keep load times O(n). internal static class TextElementCollectionHelper { //------------------------------------------------------------------- // // Internal Methods // //------------------------------------------------------------------- #region Internal Methods // Invalidates any collection tracking parent's children. // Called by the TextContainer. internal static void MarkDirty(DependencyObject parent) { if (parent == null) { return; } lock (_cleanParentList) { for (int i = 0; i < _cleanParentList.Length; i++) { if (_cleanParentList[i] != null) { ParentCollectionPair pair = (ParentCollectionPair)_cleanParentList[i].Target; if (pair == null || pair.Parent == parent) { _cleanParentList[i] = null; } } } } } // Tags a parent/collection as synchronized. // Since we use a most-recently-used algorithm, it's useful // to call this any time a collection is touched, even if it is // only read. internal static void MarkClean(DependencyObject parent, object collection) { lock (_cleanParentList) { int firstFreeIndex; int index = GetCleanParentIndex(parent, collection, out firstFreeIndex); if (index == -1) { index = firstFreeIndex >= 0 ? firstFreeIndex : _cleanParentList.Length - 1; _cleanParentList[index] = new WeakReference(new ParentCollectionPair(parent, collection)); } TouchCleanParent(index); } } // Returns true if the parent/collection pair are clean. // Since we use a most-recently-used algorithm, it's useful // to call this any time a collection is touched, even if it is // only read. internal static bool IsCleanParent(DependencyObject parent, object collection) { int index = -1; lock (_cleanParentList) { int firstFreeIndex; index = GetCleanParentIndex(parent, collection, out firstFreeIndex); if (index >= 0) { TouchCleanParent(index); } } return (index >= 0); } #endregion Internal Methods //-------------------------------------------------------------------- // // Private Methods // //------------------------------------------------------------------- #region Private Methods // Moves an entry to the top of the most-recently-used list. // Caller must hold a lock on _cleanParentList! private static void TouchCleanParent(int index) { WeakReference parentReference = _cleanParentList[index]; // Shift preceding parents down, dropping the last parent. Array.Copy(_cleanParentList, 0, _cleanParentList, 1, index); // Put the mru parent at the head. _cleanParentList[0] = parentReference; } // Returns the index of an entry in the list, or -1 if not present. // Caller must hold a lock on _cleanParentList! private static int GetCleanParentIndex(DependencyObject parent, object collection, out int firstFreeIndex) { int index = -1; firstFreeIndex = -1; for (int i = 0; i < _cleanParentList.Length; i++) { if (_cleanParentList[i] == null) { if (firstFreeIndex == -1) { firstFreeIndex = i; } } else { ParentCollectionPair pair = (ParentCollectionPair)_cleanParentList[i].Target; if (pair == null) { // WeakReference is dead, remove it. _cleanParentList[i] = null; if (firstFreeIndex == -1) { firstFreeIndex = i; } } else if (pair.Parent == parent && pair.Collection == collection) { // Found a match. Keep going to clean up any dead WeakReferences // or set firstFreeIndex. index = i; } } } return index; } #endregion Private Methods //-------------------------------------------------------------------- // // Private Types // //-------------------------------------------------------------------- #region Private Types // A parent/collection entry. private class ParentCollectionPair { internal ParentCollectionPair(DependencyObject parent, object collection) { _parent = parent; _collection = collection; } internal DependencyObject Parent { get { return _parent; } } internal object Collection { get { return _collection; } } private readonly DependencyObject _parent; private readonly object _collection; } #endregion Private Types //------------------------------------------------------------------- // // Private Fields // //-------------------------------------------------------------------- #region Private Fields // Static list of clean parent/collection pairs. private static readonly WeakReference []_cleanParentList = new WeakReference[10]; #endregion Private Fields } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. //---------------------------------------------------------------------------- // // Copyright (C) Microsoft Corporation. All rights reserved. // // Description: Static methods for all TextElementCollection hello world instances. // //--------------------------------------------------------------------------- namespace System.Windows.Documents { // This class maintains a static list of "clean" TextElementCollection // instances. Clean in this sense means guarantee not to have been // modified in a way that could invalidate their _indexCache members. // // The cache is a simple list of WeakReferences to collections. // The size of the list limits the number of collections // that can be used to modify content simultaneously with good IList // performance. The scenario we're concerned about is the parser, // which will allocate one collection for each scoping TextElement // in a document: // requires a minimum cache size of 3 to keep load times O(n). internal static class TextElementCollectionHelper { //------------------------------------------------------------------- // // Internal Methods // //------------------------------------------------------------------- #region Internal Methods // Invalidates any collection tracking parent's children. // Called by the TextContainer. internal static void MarkDirty(DependencyObject parent) { if (parent == null) { return; } lock (_cleanParentList) { for (int i = 0; i < _cleanParentList.Length; i++) { if (_cleanParentList[i] != null) { ParentCollectionPair pair = (ParentCollectionPair)_cleanParentList[i].Target; if (pair == null || pair.Parent == parent) { _cleanParentList[i] = null; } } } } } // Tags a parent/collection as synchronized. // Since we use a most-recently-used algorithm, it's useful // to call this any time a collection is touched, even if it is // only read. internal static void MarkClean(DependencyObject parent, object collection) { lock (_cleanParentList) { int firstFreeIndex; int index = GetCleanParentIndex(parent, collection, out firstFreeIndex); if (index == -1) { index = firstFreeIndex >= 0 ? firstFreeIndex : _cleanParentList.Length - 1; _cleanParentList[index] = new WeakReference(new ParentCollectionPair(parent, collection)); } TouchCleanParent(index); } } // Returns true if the parent/collection pair are clean. // Since we use a most-recently-used algorithm, it's useful // to call this any time a collection is touched, even if it is // only read. internal static bool IsCleanParent(DependencyObject parent, object collection) { int index = -1; lock (_cleanParentList) { int firstFreeIndex; index = GetCleanParentIndex(parent, collection, out firstFreeIndex); if (index >= 0) { TouchCleanParent(index); } } return (index >= 0); } #endregion Internal Methods //-------------------------------------------------------------------- // // Private Methods // //------------------------------------------------------------------- #region Private Methods // Moves an entry to the top of the most-recently-used list. // Caller must hold a lock on _cleanParentList! private static void TouchCleanParent(int index) { WeakReference parentReference = _cleanParentList[index]; // Shift preceding parents down, dropping the last parent. Array.Copy(_cleanParentList, 0, _cleanParentList, 1, index); // Put the mru parent at the head. _cleanParentList[0] = parentReference; } // Returns the index of an entry in the list, or -1 if not present. // Caller must hold a lock on _cleanParentList! private static int GetCleanParentIndex(DependencyObject parent, object collection, out int firstFreeIndex) { int index = -1; firstFreeIndex = -1; for (int i = 0; i < _cleanParentList.Length; i++) { if (_cleanParentList[i] == null) { if (firstFreeIndex == -1) { firstFreeIndex = i; } } else { ParentCollectionPair pair = (ParentCollectionPair)_cleanParentList[i].Target; if (pair == null) { // WeakReference is dead, remove it. _cleanParentList[i] = null; if (firstFreeIndex == -1) { firstFreeIndex = i; } } else if (pair.Parent == parent && pair.Collection == collection) { // Found a match. Keep going to clean up any dead WeakReferences // or set firstFreeIndex. index = i; } } } return index; } #endregion Private Methods //-------------------------------------------------------------------- // // Private Types // //-------------------------------------------------------------------- #region Private Types // A parent/collection entry. private class ParentCollectionPair { internal ParentCollectionPair(DependencyObject parent, object collection) { _parent = parent; _collection = collection; } internal DependencyObject Parent { get { return _parent; } } internal object Collection { get { return _collection; } } private readonly DependencyObject _parent; private readonly object _collection; } #endregion Private Types //------------------------------------------------------------------- // // Private Fields // //-------------------------------------------------------------------- #region Private Fields // Static list of clean parent/collection pairs. private static readonly WeakReference []_cleanParentList = new WeakReference[10]; #endregion Private Fields } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. hello world
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- TableLayoutPanelCodeDomSerializer.cs
- PointConverter.cs
- ComponentGlyph.cs
- MemberPath.cs
- PositiveTimeSpanValidator.cs
- DbProviderSpecificTypePropertyAttribute.cs
- UdpTransportBindingElement.cs
- ExtensionSimplifierMarkupObject.cs
- DefaultTextStoreTextComposition.cs
- ListViewItemCollectionEditor.cs
- TextTreeRootTextBlock.cs
- ResponseBodyWriter.cs
- AccessControlEntry.cs
- GroupBoxAutomationPeer.cs
- StickyNote.cs
- MasterPageParser.cs
- UrlAuthorizationModule.cs
- RequestValidator.cs
- SeverityFilter.cs
- XMLSchema.cs
- WebPartVerbsEventArgs.cs
- FileSecurity.cs
- DragEventArgs.cs
- TextLineBreak.cs
- SpAudioStreamWrapper.cs
- EtwTrackingBehavior.cs
- GridEntryCollection.cs
- PointConverter.cs
- MonthCalendar.cs
- COM2IProvidePropertyBuilderHandler.cs
- NavigateEvent.cs
- Emitter.cs
- ScopelessEnumAttribute.cs
- KernelTypeValidation.cs
- NativeCompoundFileAPIs.cs
- ThreadAbortException.cs
- Latin1Encoding.cs
- StreamGeometry.cs
- GlobalId.cs
- HttpVersion.cs
- ConfigurationException.cs
- TraceContext.cs
- ColumnWidthChangingEvent.cs
- SubtreeProcessor.cs
- DbProviderSpecificTypePropertyAttribute.cs
- ReaderWriterLock.cs
- PrimarySelectionGlyph.cs
- TextEndOfLine.cs
- FontNamesConverter.cs
- TemplateXamlParser.cs
- HtmlElementCollection.cs
- EditorZone.cs
- Splitter.cs
- InternalsVisibleToAttribute.cs
- TreeNodeEventArgs.cs
- CryptoStream.cs
- ContentPlaceHolder.cs
- RtType.cs
- GroupDescription.cs
- ADMembershipProvider.cs
- FacetChecker.cs
- DbDataRecord.cs
- WebPartExportVerb.cs
- StateDesigner.CommentLayoutGlyph.cs
- PublisherMembershipCondition.cs
- CodeSubDirectory.cs
- SmiConnection.cs
- SubpageParaClient.cs
- ApplicationProxyInternal.cs
- ValueSerializer.cs
- UInt64Storage.cs
- MediaTimeline.cs
- DataGridPageChangedEventArgs.cs
- TextSimpleMarkerProperties.cs
- SizeChangedEventArgs.cs
- InfoCardX509Validator.cs
- DelegateTypeInfo.cs
- MatrixAnimationBase.cs
- SqlParameterCollection.cs
- Stroke.cs
- XmlSerializerAssemblyAttribute.cs
- ListViewItemEventArgs.cs
- AssemblyResolver.cs
- AddInProcess.cs
- RequestTimeoutManager.cs
- HMACRIPEMD160.cs
- ProfileSettings.cs
- AmbientProperties.cs
- WindowsListViewScroll.cs
- StreamInfo.cs
- StylusShape.cs
- EntityModelSchemaGenerator.cs
- DataPagerFieldCommandEventArgs.cs
- CngProvider.cs
- DotAtomReader.cs
- BrowserDefinition.cs
- EventLogPermissionAttribute.cs
- WebPartManager.cs
- HttpGetClientProtocol.cs
- Debugger.cs