Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / ProviderBase / DbReferenceCollection.cs / 1305376 / 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
- ClientUtils.cs
- EnumConverter.cs
- MetadataExporter.cs
- CompilationLock.cs
- SequenceDesigner.cs
- DCSafeHandle.cs
- XmlName.cs
- CategoryNameCollection.cs
- PrintEvent.cs
- DataTrigger.cs
- HostProtectionException.cs
- OletxDependentTransaction.cs
- InvokeWebService.cs
- ImageMetadata.cs
- PackagingUtilities.cs
- MenuAdapter.cs
- TaiwanLunisolarCalendar.cs
- LogEntryHeaderDeserializer.cs
- _ShellExpression.cs
- ChangeDirector.cs
- PageCodeDomTreeGenerator.cs
- mansign.cs
- IdentityNotMappedException.cs
- OperatorExpressions.cs
- FacetDescriptionElement.cs
- StaticContext.cs
- PatternMatcher.cs
- Fx.cs
- BamlTreeUpdater.cs
- RpcAsyncResult.cs
- TransactionFilter.cs
- FlowDocumentPaginator.cs
- DocumentPage.cs
- DatePickerAutomationPeer.cs
- ChannelServices.cs
- HMACRIPEMD160.cs
- BitStream.cs
- TypefaceMetricsCache.cs
- BrushMappingModeValidation.cs
- ModelFunction.cs
- NamespaceInfo.cs
- TextEffect.cs
- RIPEMD160Managed.cs
- ContextTokenTypeConverter.cs
- GenericTypeParameterConverter.cs
- WebPartConnectVerb.cs
- SByteConverter.cs
- ListItemsCollectionEditor.cs
- GetResponse.cs
- AutoGeneratedField.cs
- ServiceObjectContainer.cs
- DrawingServices.cs
- WriterOutput.cs
- SerializationAttributes.cs
- TextFormatter.cs
- SQLRoleProvider.cs
- MgmtConfigurationRecord.cs
- WindowsStatusBar.cs
- PlatformCulture.cs
- TextClipboardData.cs
- WebPartExportVerb.cs
- WaitHandleCannotBeOpenedException.cs
- EnvelopedPkcs7.cs
- CriticalFinalizerObject.cs
- XmlSchemaFacet.cs
- PropertyValueUIItem.cs
- GenericRootAutomationPeer.cs
- GatewayDefinition.cs
- CompressStream.cs
- _IPv6Address.cs
- TreeNodeEventArgs.cs
- Transform.cs
- BitmapImage.cs
- InstanceDescriptor.cs
- SecurityStateEncoder.cs
- HttpPostedFileBase.cs
- ConfigurationValue.cs
- FixedSOMTable.cs
- SqlPersonalizationProvider.cs
- RewritingSimplifier.cs
- SoapAttributes.cs
- EntryPointNotFoundException.cs
- Operand.cs
- FixedBufferAttribute.cs
- CustomAttribute.cs
- EventHandlerList.cs
- SrgsRule.cs
- CheckBoxField.cs
- UserPreference.cs
- SoapTransportImporter.cs
- Floater.cs
- SessionStateContainer.cs
- PropertyItem.cs
- ConstraintEnumerator.cs
- PropertyItemInternal.cs
- SpecialNameAttribute.cs
- DataObjectCopyingEventArgs.cs
- ListView.cs
- UTF8Encoding.cs
- LiteralControl.cs