Code:
/ Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / whidbey / netfxsp / ndp / fx / src / Data / System / Data / ProviderBase / DbReferenceCollection.cs / 5 / DbReferenceCollection.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data.ProviderBase { using System; using System.Collections; using System.Diagnostics; internal abstract class DbReferenceCollection { #if ORACLE abstract public void Add(object value, int tag); abstract public void Notify(int message); abstract public void Remove(object value); #else private struct CollectionEntry { private int _tag; // information about the reference private WeakReference _weak; // the reference itself. public bool HasTarget { get { Debug.Assert((0 != _tag && null != _weak) || (null == _weak || !_weak.IsAlive), "0 tag with Target"); return ((0 != _tag) && null != _weak && _weak.IsAlive); } } public bool InUse { get { return (null != _weak); } } public int Tag { get { return _tag; } set { _tag = value; } } public object Target { get { if (0 != _tag) { return _weak.Target; } Debug.Assert(!_weak.IsAlive, "0 tag with Target"); return null; } set { if (null == _weak) { _weak = new WeakReference(value, false); } else { _weak.Target = value; } } } } private CollectionEntry[] _items; protected DbReferenceCollection() { _items = new CollectionEntry[5]; } abstract public void Add(object value, int tag); protected void AddItem(object value, int tag) { Debug.Assert(null != value && 0 != tag, "AddItem with null value or 0 tag"); CollectionEntry[] items = _items; for (int i = 0; i < items.Length; ++i) { if (!items[i].HasTarget) { items[i].Target = value; items[i].Tag = tag; Debug.Assert(items[i].HasTarget, "missing expected target"); return; } } int newlength = ((5 == items.Length) ? 15 : (items.Length + 15)); CollectionEntry[] jtems = new CollectionEntry[newlength]; for (int i = 0; i < items.Length; ++i) { jtems[i] = items[i]; } jtems[items.Length].Target = value; jtems[items.Length].Tag = tag; Debug.Assert(jtems[items.Length].HasTarget, "missing expected target"); _items = jtems; } internal IEnumerable Filter(int tag) { return new DbFilteredReferenceCollection (_items, tag); } public void Notify(int message) { CollectionEntry[] items = _items; for (int index = 0; index < items.Length; ++index) { if (items[index].InUse) { object value = items[index].Target; // checks tag & gets target if (null != value) { Debug.Assert(items[index].HasTarget, "missing expected target"); if (!NotifyItem(message, items[index].Tag, value)) { items[index].Tag = 0; items[index].Target = null; Debug.Assert(!items[index].HasTarget, "has unexpected target"); } } // else (0 == Tag) or !IsAlive } else { Debug.Assert(!items[index].HasTarget, "has unexpected target"); break; // we're done as soon as we find the first null in the list } } } abstract protected bool NotifyItem(int message, int tag, object value); public void Purge() { CollectionEntry[] items = _items; #if DEBUG for(int i = 0; i < items.Length; ++i) { Debug.Assert(!items[i].HasTarget, "unexpected target during purge"); } #endif if (100 < items.Length) { _items = new CollectionEntry[5]; // revert back to 5 items if we're really big... } } abstract public void Remove(object value); protected void RemoveItem(object value) { Debug.Assert(null != value, "RemoveItem with null"); CollectionEntry[] items = _items; for (int index = 0; index < items.Length; ++index) { if (items[index].InUse) { if (value == items[index].Target) { // checks tag & gets target items[index].Tag = 0; items[index].Target = null; Debug.Assert(!items[index].HasTarget, "has unexpected target"); break; } // else (0 == Tag) or !IsAlive or (value != Target) } else { break; // we're done as soon as we find the first null in the list } } } private struct DbFilteredReferenceCollection : IEnumerable { private readonly DbReferenceCollection.CollectionEntry[] _items; private readonly int _filterTag; internal DbFilteredReferenceCollection(DbReferenceCollection.CollectionEntry[] items, int filterTag) { _items = items; _filterTag = filterTag; } IEnumerator IEnumerable.GetEnumerator() { return new DbFilteredReferenceCollectionedEnumerator(_items, _filterTag); } private struct DbFilteredReferenceCollectionedEnumerator : IEnumerator { private readonly DbReferenceCollection.CollectionEntry[] _items; private readonly int _filterTag; private int _current; internal DbFilteredReferenceCollectionedEnumerator(DbReferenceCollection.CollectionEntry[] items, int filterTag) { _items = items; _filterTag = filterTag; _current = -1; } object IEnumerator.Current { get { return _items[_current].Target; } } bool IEnumerator.MoveNext() { while (++_current < _items.Length) { if (_items[_current].InUse) { if (_items[_current].Tag == _filterTag) { return true; } } else { break; } } return false; } void IEnumerator.Reset() { _current = -1; } } } #endif } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. //------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //----------------------------------------------------------------------------- namespace System.Data.ProviderBase { using System; using System.Collections; using System.Diagnostics; internal abstract class DbReferenceCollection { #if ORACLE abstract public void Add(object value, int tag); abstract public void Notify(int message); abstract public void Remove(object value); #else private struct CollectionEntry { private int _tag; // information about the reference private WeakReference _weak; // the reference itself. public bool HasTarget { get { Debug.Assert((0 != _tag && null != _weak) || (null == _weak || !_weak.IsAlive), "0 tag with Target"); return ((0 != _tag) && null != _weak && _weak.IsAlive); } } public bool InUse { get { return (null != _weak); } } public int Tag { get { return _tag; } set { _tag = value; } } public object Target { get { if (0 != _tag) { return _weak.Target; } Debug.Assert(!_weak.IsAlive, "0 tag with Target"); return null; } set { if (null == _weak) { _weak = new WeakReference(value, false); } else { _weak.Target = value; } } } } private CollectionEntry[] _items; protected DbReferenceCollection() { _items = new CollectionEntry[5]; } abstract public void Add(object value, int tag); protected void AddItem(object value, int tag) { Debug.Assert(null != value && 0 != tag, "AddItem with null value or 0 tag"); CollectionEntry[] items = _items; for (int i = 0; i < items.Length; ++i) { if (!items[i].HasTarget) { items[i].Target = value; items[i].Tag = tag; Debug.Assert(items[i].HasTarget, "missing expected target"); return; } } int newlength = ((5 == items.Length) ? 15 : (items.Length + 15)); CollectionEntry[] jtems = new CollectionEntry[newlength]; for (int i = 0; i < items.Length; ++i) { jtems[i] = items[i]; } jtems[items.Length].Target = value; jtems[items.Length].Tag = tag; Debug.Assert(jtems[items.Length].HasTarget, "missing expected target"); _items = jtems; } internal IEnumerable Filter(int tag) { return new DbFilteredReferenceCollection (_items, tag); } public void Notify(int message) { CollectionEntry[] items = _items; for (int index = 0; index < items.Length; ++index) { if (items[index].InUse) { object value = items[index].Target; // checks tag & gets target if (null != value) { Debug.Assert(items[index].HasTarget, "missing expected target"); if (!NotifyItem(message, items[index].Tag, value)) { items[index].Tag = 0; items[index].Target = null; Debug.Assert(!items[index].HasTarget, "has unexpected target"); } } // else (0 == Tag) or !IsAlive } else { Debug.Assert(!items[index].HasTarget, "has unexpected target"); break; // we're done as soon as we find the first null in the list } } } abstract protected bool NotifyItem(int message, int tag, object value); public void Purge() { CollectionEntry[] items = _items; #if DEBUG for(int i = 0; i < items.Length; ++i) { Debug.Assert(!items[i].HasTarget, "unexpected target during purge"); } #endif if (100 < items.Length) { _items = new CollectionEntry[5]; // revert back to 5 items if we're really big... } } abstract public void Remove(object value); protected void RemoveItem(object value) { Debug.Assert(null != value, "RemoveItem with null"); CollectionEntry[] items = _items; for (int index = 0; index < items.Length; ++index) { if (items[index].InUse) { if (value == items[index].Target) { // checks tag & gets target items[index].Tag = 0; items[index].Target = null; Debug.Assert(!items[index].HasTarget, "has unexpected target"); break; } // else (0 == Tag) or !IsAlive or (value != Target) } else { break; // we're done as soon as we find the first null in the list } } } private struct DbFilteredReferenceCollection : IEnumerable { private readonly DbReferenceCollection.CollectionEntry[] _items; private readonly int _filterTag; internal DbFilteredReferenceCollection(DbReferenceCollection.CollectionEntry[] items, int filterTag) { _items = items; _filterTag = filterTag; } IEnumerator IEnumerable.GetEnumerator() { return new DbFilteredReferenceCollectionedEnumerator(_items, _filterTag); } private struct DbFilteredReferenceCollectionedEnumerator : IEnumerator { private readonly DbReferenceCollection.CollectionEntry[] _items; private readonly int _filterTag; private int _current; internal DbFilteredReferenceCollectionedEnumerator(DbReferenceCollection.CollectionEntry[] items, int filterTag) { _items = items; _filterTag = filterTag; _current = -1; } object IEnumerator.Current { get { return _items[_current].Target; } } bool IEnumerator.MoveNext() { while (++_current < _items.Length) { if (_items[_current].InUse) { if (_items[_current].Tag == _filterTag) { return true; } } else { break; } } return false; } void IEnumerator.Reset() { _current = -1; } } } #endif } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu

This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- BindingRestrictions.cs
- FieldNameLookup.cs
- FileDialog_Vista.cs
- SystemNetworkInterface.cs
- SafeBitVector32.cs
- GridViewRow.cs
- MenuItem.cs
- FileCodeGroup.cs
- GridPatternIdentifiers.cs
- ConsumerConnectionPointCollection.cs
- SqlBulkCopyColumnMapping.cs
- TreeView.cs
- XsdDateTime.cs
- BlockUIContainer.cs
- LoginUtil.cs
- WebPartMinimizeVerb.cs
- DeferredTextReference.cs
- Mouse.cs
- RenderOptions.cs
- KeyToListMap.cs
- QuaternionValueSerializer.cs
- FontInfo.cs
- TypedReference.cs
- TargetException.cs
- DrawingContextDrawingContextWalker.cs
- filewebresponse.cs
- EmbeddedMailObject.cs
- FrameworkContextData.cs
- Empty.cs
- TextControl.cs
- DynamicUpdateCommand.cs
- GridViewPageEventArgs.cs
- Console.cs
- FlowNode.cs
- HijriCalendar.cs
- XmlUtil.cs
- GenericAuthenticationEventArgs.cs
- SqlBooleanMismatchVisitor.cs
- ColorDialog.cs
- SizeAnimation.cs
- WebPartConnectionsCloseVerb.cs
- SynchronizingStream.cs
- XPathSelectionIterator.cs
- WorkflowDesignerMessageFilter.cs
- HttpRawResponse.cs
- XhtmlBasicTextViewAdapter.cs
- WriteableBitmap.cs
- BrowserCapabilitiesCompiler.cs
- InboundActivityHelper.cs
- SecurityResources.cs
- BinaryUtilClasses.cs
- HostedElements.cs
- DataGridViewTextBoxColumn.cs
- BasicHttpMessageSecurityElement.cs
- UnsafeNativeMethods.cs
- webeventbuffer.cs
- DefaultHttpHandler.cs
- SafeNativeMethods.cs
- URLString.cs
- WebHttpBehavior.cs
- HttpStreamMessageEncoderFactory.cs
- RuleDefinitions.cs
- ComplexType.cs
- GestureRecognizer.cs
- UInt32.cs
- ToolboxItem.cs
- QueryReaderSettings.cs
- GridViewRowPresenterBase.cs
- ConfigurationSectionCollection.cs
- HelpProvider.cs
- InternalsVisibleToAttribute.cs
- BooleanAnimationUsingKeyFrames.cs
- QueueProcessor.cs
- ExportFileRequest.cs
- BooleanProjectedSlot.cs
- SourceFileInfo.cs
- DataGridViewComboBoxEditingControl.cs
- PathFigure.cs
- SoapExtensionReflector.cs
- MarkupWriter.cs
- EntityDataSourceDataSelection.cs
- FlowDocumentPage.cs
- UnauthorizedAccessException.cs
- COAUTHIDENTITY.cs
- Stylus.cs
- MediaPlayerState.cs
- DataTableMappingCollection.cs
- FloaterParaClient.cs
- DataGridViewComboBoxCell.cs
- XmlSchemaElement.cs
- TextDecoration.cs
- OleDbErrorCollection.cs
- CallbackHandler.cs
- Overlapped.cs
- MatrixKeyFrameCollection.cs
- ReadOnlyAttribute.cs
- SqlAliasesReferenced.cs
- updatecommandorderer.cs
- ApplicationBuildProvider.cs
- VirtualPath.cs