Code:
/ Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / Orcas / SP / 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
- RtfToken.cs
- ZoneMembershipCondition.cs
- IsolatedStorageFile.cs
- UnsafeNativeMethodsPenimc.cs
- FlowLayoutSettings.cs
- DetailsView.cs
- ExpressionBuilder.cs
- ValidationErrorCollection.cs
- HeaderUtility.cs
- CallbackBehaviorAttribute.cs
- UIPropertyMetadata.cs
- DbExpressionBuilder.cs
- HandlerElementCollection.cs
- TextFragmentEngine.cs
- LocatorGroup.cs
- DateTimeConverter2.cs
- FamilyMap.cs
- HotSpotCollectionEditor.cs
- Select.cs
- CookieParameter.cs
- GraphicsPath.cs
- StructuredProperty.cs
- SqlRetyper.cs
- MenuItemStyleCollectionEditor.cs
- GridView.cs
- BindingOperations.cs
- NotificationContext.cs
- Vector3DAnimationBase.cs
- PenLineJoinValidation.cs
- StorageMappingItemLoader.cs
- LinqDataSourceStatusEventArgs.cs
- HttpConfigurationSystem.cs
- BufferModesCollection.cs
- TableLayoutSettings.cs
- DataRow.cs
- ZoneIdentityPermission.cs
- Utils.cs
- Types.cs
- HttpListenerException.cs
- ExecutedRoutedEventArgs.cs
- MessageAction.cs
- UIElement.cs
- UidManager.cs
- MsmqTransportElement.cs
- MatrixValueSerializer.cs
- ListenerAdaptersInstallComponent.cs
- DesignerListAdapter.cs
- DataGridViewCellStyle.cs
- XPathNodeList.cs
- CallbackHandler.cs
- DataDocumentXPathNavigator.cs
- StreamGeometry.cs
- SelectionChangedEventArgs.cs
- DupHandleConnectionReader.cs
- ServerValidateEventArgs.cs
- TargetPerspective.cs
- UniqueSet.cs
- ObjectHandle.cs
- BevelBitmapEffect.cs
- SchemaContext.cs
- MailWebEventProvider.cs
- SByteStorage.cs
- ListBoxChrome.cs
- ConditionValidator.cs
- DetailsViewDeleteEventArgs.cs
- QueryOutputWriter.cs
- InvokePattern.cs
- BevelBitmapEffect.cs
- DrawingAttributesDefaultValueFactory.cs
- KeyEvent.cs
- ResourcePool.cs
- SafeEventHandle.cs
- ThemeDirectoryCompiler.cs
- DataBindEngine.cs
- SupportsEventValidationAttribute.cs
- ModelUtilities.cs
- SystemResourceHost.cs
- OleDbPermission.cs
- ColumnProvider.cs
- IntranetCredentialPolicy.cs
- AsymmetricSignatureDeformatter.cs
- SynchronousReceiveElement.cs
- NullableBoolConverter.cs
- DesignerExtenders.cs
- XmlElementAttributes.cs
- ModelVisual3D.cs
- DefaultValueTypeConverter.cs
- DataComponentGenerator.cs
- ContextStaticAttribute.cs
- XmlSchemaSimpleContentRestriction.cs
- ContainsRowNumberChecker.cs
- AssociationTypeEmitter.cs
- LogicalCallContext.cs
- DBBindings.cs
- SignedXml.cs
- BuildProviderCollection.cs
- ResourceKey.cs
- MessageQueueConverter.cs
- AuthStoreRoleProvider.cs
- BuildManagerHost.cs