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
- TreeNodeStyleCollection.cs
- PointAnimationBase.cs
- SqlAliaser.cs
- XsdBuilder.cs
- SignatureDescription.cs
- OleDbInfoMessageEvent.cs
- TransmissionStrategy.cs
- PropertyDescriptors.cs
- AdornerDecorator.cs
- TitleStyle.cs
- AsymmetricKeyExchangeFormatter.cs
- XamlRtfConverter.cs
- BindingExpressionBase.cs
- RootNamespaceAttribute.cs
- DbConnectionPoolGroupProviderInfo.cs
- DynamicUpdateCommand.cs
- AssemblyBuilderData.cs
- InputBindingCollection.cs
- HiddenFieldPageStatePersister.cs
- DocumentGridContextMenu.cs
- SqlBulkCopyColumnMapping.cs
- ShapeTypeface.cs
- PlainXmlSerializer.cs
- OwnerDrawPropertyBag.cs
- XmlMapping.cs
- PackagePartCollection.cs
- ContentPropertyAttribute.cs
- SqlFacetAttribute.cs
- DateTimeStorage.cs
- TextSegment.cs
- SqlDataSourceEnumerator.cs
- StreamReader.cs
- VolatileResourceManager.cs
- CompiledWorkflowDefinitionContext.cs
- Configuration.cs
- BinaryWriter.cs
- StrokeFIndices.cs
- WebExceptionStatus.cs
- HitTestParameters.cs
- LightweightCodeGenerator.cs
- SctClaimSerializer.cs
- RuntimeTrackingProfile.cs
- HttpWrapper.cs
- ListViewGroup.cs
- TextElementCollectionHelper.cs
- DescendantBaseQuery.cs
- _AuthenticationState.cs
- ColorTranslator.cs
- ControlPaint.cs
- RoleGroup.cs
- XhtmlConformanceSection.cs
- CompilerGeneratedAttribute.cs
- WebRequestModuleElementCollection.cs
- WSSecurityJan2004.cs
- Monitor.cs
- ValidatorCompatibilityHelper.cs
- LinqDataSourceDeleteEventArgs.cs
- StrokeCollectionDefaultValueFactory.cs
- PagerStyle.cs
- Context.cs
- MethodAccessException.cs
- FrugalList.cs
- AppDomainFactory.cs
- ISCIIEncoding.cs
- CodeDOMProvider.cs
- SslStream.cs
- BrowserCapabilitiesFactory.cs
- SystemIcmpV4Statistics.cs
- CommonProperties.cs
- MailWriter.cs
- XmlEncoding.cs
- CryptoApi.cs
- AssociatedControlConverter.cs
- NameValueConfigurationCollection.cs
- DataQuery.cs
- JoinCqlBlock.cs
- ToolStripDropDown.cs
- BackgroundFormatInfo.cs
- ChannelBinding.cs
- DateTimeUtil.cs
- SqlUtils.cs
- SByteConverter.cs
- _HeaderInfo.cs
- Single.cs
- PropertyBuilder.cs
- Encoder.cs
- InheritanceContextChangedEventManager.cs
- ReceiveContextCollection.cs
- SchemaImporterExtensionElementCollection.cs
- XmlEventCache.cs
- DataObjectMethodAttribute.cs
- XPathConvert.cs
- PeoplePickerWrapper.cs
- _FixedSizeReader.cs
- DeferrableContentConverter.cs
- SqlProviderManifest.cs
- Win32.cs
- EmbeddedMailObject.cs
- UnsafeNativeMethodsTablet.cs
- NavigationPropertySingletonExpression.cs