Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / Merging / SynchronousChannelMergeEnumerator.cs / 1305376 / SynchronousChannelMergeEnumerator.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // SynchronousChannelMergeEnumerator.cs // //[....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Diagnostics.Contracts; namespace System.Linq.Parallel { ////// This enumerator merges multiple input channels into a single output stream. The merging process just /// goes from left-to-right, enumerating each channel in succession in its entirety. /// Assumptions: /// Before enumerating this object, all producers for all channels must have finished enqueueing new /// elements. /// ///internal sealed class SynchronousChannelMergeEnumerator : MergeEnumerator { private SynchronousChannel [] m_channels; // The channel array we will enumerate, from left-to-right. private int m_channelIndex; // The current channel index. This moves through the array as we enumerate. private T m_currentElement; // The last element remembered during enumeration. //------------------------------------------------------------------------------------ // Instantiates a new enumerator for a set of channels. // internal SynchronousChannelMergeEnumerator( QueryTaskGroupState taskGroupState, SynchronousChannel [] channels) : base(taskGroupState) { Contract.Assert(channels != null); #if DEBUG foreach (SynchronousChannel c in channels) Contract.Assert(c != null); #endif m_channels = channels; m_channelIndex = -1; } //----------------------------------------------------------------------------------- // Retrieves the current element. // // Notes: // This throws if we haven't begun enumerating or have gone past the end of the // data source. // public override T Current { get { // If we're at the beginning or the end of the array, it's invalid to be // retrieving the current element. We throw. if (m_channelIndex == -1 || m_channelIndex == m_channels.Length) { throw new InvalidOperationException(SR.GetString(SR.PLINQ_CommonEnumerator_Current_NotStarted)); } return m_currentElement; } } //----------------------------------------------------------------------------------- // Positions the enumerator over the next element. This includes merging as we // enumerate, by just incrementing indexes, etc. // // Return Value: // True if there's a current element, false if we've reached the end. // public override bool MoveNext() { Contract.Assert(m_channels != null); // If we're at the start, initialize the index. if (m_channelIndex == -1) { m_channelIndex = 0; } // If the index has reached the end, we bail. while (m_channelIndex != m_channels.Length) { SynchronousChannel current = m_channels[m_channelIndex]; Contract.Assert(current != null); if (current.Count == 0) { // We're done with this channel, move on to the next one. We don't // have to check that it's "done" since this is a synchronous consumer. m_channelIndex++; } else { // Remember the "current" element and return. m_currentElement = current.Dequeue(); return true; } } TraceHelpers.TraceInfo("[timing]: {0}: Completed the merge", DateTime.Now.Ticks); // If we got this far, it means we've exhausted our channels. Contract.Assert(m_channelIndex == m_channels.Length); return false; } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // SynchronousChannelMergeEnumerator.cs // // [....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Diagnostics.Contracts; namespace System.Linq.Parallel { ////// This enumerator merges multiple input channels into a single output stream. The merging process just /// goes from left-to-right, enumerating each channel in succession in its entirety. /// Assumptions: /// Before enumerating this object, all producers for all channels must have finished enqueueing new /// elements. /// ///internal sealed class SynchronousChannelMergeEnumerator : MergeEnumerator { private SynchronousChannel [] m_channels; // The channel array we will enumerate, from left-to-right. private int m_channelIndex; // The current channel index. This moves through the array as we enumerate. private T m_currentElement; // The last element remembered during enumeration. //------------------------------------------------------------------------------------ // Instantiates a new enumerator for a set of channels. // internal SynchronousChannelMergeEnumerator( QueryTaskGroupState taskGroupState, SynchronousChannel [] channels) : base(taskGroupState) { Contract.Assert(channels != null); #if DEBUG foreach (SynchronousChannel c in channels) Contract.Assert(c != null); #endif m_channels = channels; m_channelIndex = -1; } //----------------------------------------------------------------------------------- // Retrieves the current element. // // Notes: // This throws if we haven't begun enumerating or have gone past the end of the // data source. // public override T Current { get { // If we're at the beginning or the end of the array, it's invalid to be // retrieving the current element. We throw. if (m_channelIndex == -1 || m_channelIndex == m_channels.Length) { throw new InvalidOperationException(SR.GetString(SR.PLINQ_CommonEnumerator_Current_NotStarted)); } return m_currentElement; } } //----------------------------------------------------------------------------------- // Positions the enumerator over the next element. This includes merging as we // enumerate, by just incrementing indexes, etc. // // Return Value: // True if there's a current element, false if we've reached the end. // public override bool MoveNext() { Contract.Assert(m_channels != null); // If we're at the start, initialize the index. if (m_channelIndex == -1) { m_channelIndex = 0; } // If the index has reached the end, we bail. while (m_channelIndex != m_channels.Length) { SynchronousChannel current = m_channels[m_channelIndex]; Contract.Assert(current != null); if (current.Count == 0) { // We're done with this channel, move on to the next one. We don't // have to check that it's "done" since this is a synchronous consumer. m_channelIndex++; } else { // Remember the "current" element and return. m_currentElement = current.Dequeue(); return true; } } TraceHelpers.TraceInfo("[timing]: {0}: Completed the merge", DateTime.Now.Ticks); // If we got this far, it means we've exhausted our channels. Contract.Assert(m_channelIndex == m_channels.Length); return false; } } } // 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
- ExtenderProvidedPropertyAttribute.cs
- _PooledStream.cs
- MailWriter.cs
- DebugHandleTracker.cs
- SqlRecordBuffer.cs
- UpdatePanelTriggerCollection.cs
- SwitchCase.cs
- RemoteWebConfigurationHost.cs
- HybridDictionary.cs
- DataServiceClientException.cs
- followingsibling.cs
- NewExpression.cs
- HandlerFactoryWrapper.cs
- HideDisabledControlAdapter.cs
- ConfigurationElementCollection.cs
- TableLayoutCellPaintEventArgs.cs
- OleDbInfoMessageEvent.cs
- AxisAngleRotation3D.cs
- GetBrowserTokenRequest.cs
- TextFormatter.cs
- FlowLayout.cs
- WebResponse.cs
- SelectionRange.cs
- HtmlAnchor.cs
- SetStateDesigner.cs
- SByteStorage.cs
- ModuleBuilder.cs
- DataGridViewCellContextMenuStripNeededEventArgs.cs
- OutputCacheSettingsSection.cs
- Update.cs
- XmlnsCompatibleWithAttribute.cs
- XmlSerializer.cs
- SerializerWriterEventHandlers.cs
- SiblingIterators.cs
- TreeViewImageKeyConverter.cs
- MenuRendererStandards.cs
- XmlMapping.cs
- CommonBehaviorsSection.cs
- LayoutEvent.cs
- SQLByte.cs
- MediaScriptCommandRoutedEventArgs.cs
- WindowsHyperlink.cs
- VBIdentifierTrimConverter.cs
- ItemsControlAutomationPeer.cs
- HandlerBase.cs
- DataObject.cs
- Comparer.cs
- CapabilitiesRule.cs
- SHA1Managed.cs
- ResponseStream.cs
- GeneralTransform3D.cs
- UnsafeNativeMethodsPenimc.cs
- HashMembershipCondition.cs
- DesignTimeParseData.cs
- ParameterCollection.cs
- RequiredFieldValidator.cs
- UIElementParagraph.cs
- XmlName.cs
- TextPointer.cs
- WebZone.cs
- ToolStripArrowRenderEventArgs.cs
- ListCommandEventArgs.cs
- PerformanceCounterCategory.cs
- ToolZone.cs
- DrawingVisualDrawingContext.cs
- ObjectComplexPropertyMapping.cs
- OracleDataAdapter.cs
- ContextTokenTypeConverter.cs
- DataGridViewSelectedColumnCollection.cs
- cookieexception.cs
- ProcessHost.cs
- Label.cs
- CellTreeNodeVisitors.cs
- WsatConfiguration.cs
- SqlServices.cs
- X509CertificateValidator.cs
- ManagedWndProcTracker.cs
- TypeSystem.cs
- ClientRequest.cs
- DrawingAttributes.cs
- Vector3DAnimationUsingKeyFrames.cs
- BooleanKeyFrameCollection.cs
- RadioButtonRenderer.cs
- HorizontalAlignConverter.cs
- Quaternion.cs
- MessageEnumerator.cs
- TableAdapterManagerHelper.cs
- OneOf.cs
- HandlerWithFactory.cs
- CapabilitiesRule.cs
- MenuItemAutomationPeer.cs
- brushes.cs
- ClientSettingsProvider.cs
- PrintControllerWithStatusDialog.cs
- TextProviderWrapper.cs
- AsynchronousChannelMergeEnumerator.cs
- Property.cs
- DesignerActionItem.cs
- PageTrueTypeFont.cs
- SqlRetyper.cs