Code:
/ Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / Orcas / NetFXw7 / ndp / fx / src / DataEntity / System / Data / Common / Utils / ModifiableIteratorCollection.cs / 1 / ModifiableIteratorCollection.cs
//---------------------------------------------------------------------- //// Copyright (c) Microsoft Corporation. All rights reserved. // // // @owner [....] // @backupOwner [....] //--------------------------------------------------------------------- using System; using System.Collections; using System.Collections.Generic; using System.Text; using System.Diagnostics; namespace System.Data.Common.Utils { // A collection abstraction that allows elements to be removed during // iteration without resulting in missed or duplicate elements in the // iteration process. Also, allows the iterator to be restarted // midway. It is recommended that this abstractions be used for small // sets since Contains is an O(n) algorithm // Restriction: There can be at most ONE iterator on the object at any // given time. internal class ModifiableIteratorCollection: InternalBase { #region Constructors // effects: Generates a set based on values internal ModifiableIteratorCollection(IEnumerable elements) { m_elements = new List (elements); m_currentIteratorIndex = -1; } #endregion #region Fields // A constant to denote the fact that iterator is not running currently // The collection is simply a list private List m_elements; // The index where the iterator is currently at private int m_currentIteratorIndex; #endregion #region Properties // effects: Returns true if the collection has no elements internal bool IsEmpty { get { return m_elements.Count == 0; } } #endregion #region Available Methods // requires: IsEmpty is false // effects: Removes some element from this and returns it internal TElement RemoveOneElement() { Debug.Assert(false == IsEmpty, "Empty set - cannot remove any element"); // Remove the last element return Remove(m_elements.Count - 1); } // requires; An iterator is currently under progress // effects: Resets the current iterator so that it starts from the beginning internal void ResetIterator() { m_currentIteratorIndex = -1; // This will be incremented after the yield statement if the // iterator is on } // requires; An iterator is currently under progress // effects: Removes the current element being yielded while Ensuring // that no element is missed or repeated even after removal internal void RemoveCurrentOfIterator() { Debug.Assert(m_currentIteratorIndex >= 0, "Iterator not started yet"); Remove(m_currentIteratorIndex); // We removed an element at m_currentIteratorIndex by placing the // last element at m_currentIteratorIndex. We need to make // sure that this element is not missed. We reduce // m_currentIteratorIndex by 1 so that when it is incremented // in Elements. So this could even set it to -1 m_currentIteratorIndex--; } // requires; An iterator is not currently under progress // effects: Yields the elements in this internal IEnumerable Elements() { // We cannnot check that an iterator is under progress because // the last time around, the caller may have called a "break" in // their foreach // Yield the elements -- any removal method ensures that // m_currentIteratorIndex is set correctly so that the ++ does // the right thing m_currentIteratorIndex = 0; while (m_currentIteratorIndex < m_elements.Count) { yield return m_elements[m_currentIteratorIndex]; m_currentIteratorIndex++; } } internal override void ToCompactString(StringBuilder builder) { StringUtil.ToCommaSeparatedString(builder, m_elements); } #endregion #region Private Methods // requires: The array is at least of size index+1 // effects: Removes the element at index private TElement Remove(int index) { Debug.Assert(index < m_elements.Count, "Removing an entry with too high an index"); // Place the last element at "index" and remove the last element TElement element = m_elements[index]; int lastIndex = m_elements.Count - 1; m_elements[index] = m_elements[lastIndex]; m_elements.RemoveAt(lastIndex); return element; } #endregion } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. //---------------------------------------------------------------------- // // Copyright (c) Microsoft Corporation. All rights reserved. // // // @owner [....] // @backupOwner [....] //--------------------------------------------------------------------- using System; using System.Collections; using System.Collections.Generic; using System.Text; using System.Diagnostics; namespace System.Data.Common.Utils { // A collection abstraction that allows elements to be removed during // iteration without resulting in missed or duplicate elements in the // iteration process. Also, allows the iterator to be restarted // midway. It is recommended that this abstractions be used for small // sets since Contains is an O(n) algorithm // Restriction: There can be at most ONE iterator on the object at any // given time. internal class ModifiableIteratorCollection: InternalBase { #region Constructors // effects: Generates a set based on values internal ModifiableIteratorCollection(IEnumerable elements) { m_elements = new List (elements); m_currentIteratorIndex = -1; } #endregion #region Fields // A constant to denote the fact that iterator is not running currently // The collection is simply a list private List m_elements; // The index where the iterator is currently at private int m_currentIteratorIndex; #endregion #region Properties // effects: Returns true if the collection has no elements internal bool IsEmpty { get { return m_elements.Count == 0; } } #endregion #region Available Methods // requires: IsEmpty is false // effects: Removes some element from this and returns it internal TElement RemoveOneElement() { Debug.Assert(false == IsEmpty, "Empty set - cannot remove any element"); // Remove the last element return Remove(m_elements.Count - 1); } // requires; An iterator is currently under progress // effects: Resets the current iterator so that it starts from the beginning internal void ResetIterator() { m_currentIteratorIndex = -1; // This will be incremented after the yield statement if the // iterator is on } // requires; An iterator is currently under progress // effects: Removes the current element being yielded while Ensuring // that no element is missed or repeated even after removal internal void RemoveCurrentOfIterator() { Debug.Assert(m_currentIteratorIndex >= 0, "Iterator not started yet"); Remove(m_currentIteratorIndex); // We removed an element at m_currentIteratorIndex by placing the // last element at m_currentIteratorIndex. We need to make // sure that this element is not missed. We reduce // m_currentIteratorIndex by 1 so that when it is incremented // in Elements. So this could even set it to -1 m_currentIteratorIndex--; } // requires; An iterator is not currently under progress // effects: Yields the elements in this internal IEnumerable Elements() { // We cannnot check that an iterator is under progress because // the last time around, the caller may have called a "break" in // their foreach // Yield the elements -- any removal method ensures that // m_currentIteratorIndex is set correctly so that the ++ does // the right thing m_currentIteratorIndex = 0; while (m_currentIteratorIndex < m_elements.Count) { yield return m_elements[m_currentIteratorIndex]; m_currentIteratorIndex++; } } internal override void ToCompactString(StringBuilder builder) { StringUtil.ToCommaSeparatedString(builder, m_elements); } #endregion #region Private Methods // requires: The array is at least of size index+1 // effects: Removes the element at index private TElement Remove(int index) { Debug.Assert(index < m_elements.Count, "Removing an entry with too high an index"); // Place the last element at "index" and remove the last element TElement element = m_elements[index]; int lastIndex = m_elements.Count - 1; m_elements[index] = m_elements[lastIndex]; m_elements.RemoveAt(lastIndex); return element; } #endregion } } // 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
- SqlBuffer.cs
- NgenServicingAttributes.cs
- JpegBitmapEncoder.cs
- SystemEvents.cs
- RuntimeHandles.cs
- XmlStreamStore.cs
- Label.cs
- SystemNetworkInterface.cs
- XmlDocumentViewSchema.cs
- PenContext.cs
- figurelength.cs
- AuthenticationManager.cs
- NativeMethods.cs
- TypeConvertions.cs
- IdentityNotMappedException.cs
- AutomationPatternInfo.cs
- UpdateRecord.cs
- GridViewDeleteEventArgs.cs
- XPathParser.cs
- DisplayNameAttribute.cs
- ThumbAutomationPeer.cs
- StickyNoteContentControl.cs
- FixedSOMSemanticBox.cs
- DebugHandleTracker.cs
- ButtonPopupAdapter.cs
- FacetValues.cs
- AutoResizedEvent.cs
- ExpressionWriter.cs
- XmlTextWriter.cs
- BaseWebProxyFinder.cs
- XmlExtensionFunction.cs
- BinaryWriter.cs
- PriorityBinding.cs
- BinaryQueryOperator.cs
- ExpressionBinding.cs
- X509SecurityTokenProvider.cs
- NameValueCollection.cs
- TypedTableBaseExtensions.cs
- IISMapPath.cs
- ScriptReference.cs
- ObjectDataSourceEventArgs.cs
- MarshalByRefObject.cs
- IIS7ConfigurationLoader.cs
- ResourcePermissionBaseEntry.cs
- SignatureConfirmationElement.cs
- unsafenativemethodstextservices.cs
- SafeProcessHandle.cs
- MissingSatelliteAssemblyException.cs
- PngBitmapEncoder.cs
- Set.cs
- DataKey.cs
- CharacterMetricsDictionary.cs
- TextBox.cs
- ButtonStandardAdapter.cs
- StringValidator.cs
- Composition.cs
- XPathCompileException.cs
- SettingsSavedEventArgs.cs
- ObjectSet.cs
- ImageList.cs
- WebPartAddingEventArgs.cs
- ImageIndexEditor.cs
- ObjectStateEntryBaseUpdatableDataRecord.cs
- ProfessionalColors.cs
- ProvidersHelper.cs
- StateItem.cs
- DeviceContext2.cs
- RTLAwareMessageBox.cs
- CountAggregationOperator.cs
- ProxyRpc.cs
- UInt64Converter.cs
- RelOps.cs
- XmlSecureResolver.cs
- DomainUpDown.cs
- ProfilePropertySettings.cs
- SchemaImporterExtension.cs
- FileAuthorizationModule.cs
- HandleValueEditor.cs
- Registry.cs
- OrderByBuilder.cs
- NTAccount.cs
- HtmlPanelAdapter.cs
- DependencyPropertyKind.cs
- ImportCatalogPart.cs
- ExclusiveHandle.cs
- DPAPIProtectedConfigurationProvider.cs
- SyndicationSerializer.cs
- PerfProviderCollection.cs
- SamlAuthorizationDecisionClaimResource.cs
- ParallelRangeManager.cs
- COM2PropertyDescriptor.cs
- CompatibleComparer.cs
- InkCollectionBehavior.cs
- SecurityAttributeGenerationHelper.cs
- RoutedEventConverter.cs
- WindowsMenu.cs
- documentation.cs
- DrawingDrawingContext.cs
- Hashtable.cs
- SqlConnectionStringBuilder.cs