Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / QueryOperators / Inlined / IntMinMaxAggregationOperator.cs / 1305376 / IntMinMaxAggregationOperator.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // IntMinMaxAggregationOperator.cs // //[....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Collections.Generic; using System.Diagnostics.Contracts; using System.Threading; namespace System.Linq.Parallel { ////// An inlined min/max aggregation and its enumerator, for ints. /// internal sealed class IntMinMaxAggregationOperator : InlinedAggregationOperator{ private readonly int m_sign; // The sign (-1 for min, 1 for max). //---------------------------------------------------------------------------------------- // Constructs a new instance of a min/max associative operator. // internal IntMinMaxAggregationOperator(IEnumerable child, int sign) : base(child) { Contract.Assert(sign == -1 || sign == 1, "invalid sign"); m_sign = sign; } //--------------------------------------------------------------------------------------- // Executes the entire query tree, and aggregates the intermediate results into the // final result based on the binary operators and final reduction. // // Return Value: // The single result of aggregation. // protected override int InternalAggregate(ref Exception singularExceptionToThrow) { // Because the final reduction is typically much cheaper than the intermediate // reductions over the individual partitions, and because each parallel partition // will do a lot of work to produce a single output element, we prefer to turn off // pipelining, and process the final reductions serially. using (IEnumerator enumerator = GetEnumerator(ParallelMergeOptions.FullyBuffered, true)) { // Throw an error for empty results. if (!enumerator.MoveNext()) { singularExceptionToThrow = new InvalidOperationException(SR.GetString(SR.NoElements)); return default(int); } int best = enumerator.Current; // Based on the sign, do either a min or max reduction. if (m_sign == -1) { while (enumerator.MoveNext()) { int current = enumerator.Current; if (current < best) { best = current; } } } else { while (enumerator.MoveNext()) { int current = enumerator.Current; if (current > best) { best = current; } } } return best; } } //--------------------------------------------------------------------------------------- // Creates an enumerator that is used internally for the final aggregation step. // protected override QueryOperatorEnumerator CreateEnumerator ( int index, int count, QueryOperatorEnumerator source, object sharedData, CancellationToken cancellationToken) { return new IntMinMaxAggregationOperatorEnumerator (source, index, m_sign, cancellationToken); } //--------------------------------------------------------------------------------------- // This enumerator type encapsulates the intermediary aggregation over the underlying // (possibly partitioned) data source. // private class IntMinMaxAggregationOperatorEnumerator : InlinedAggregationOperatorEnumerator { private readonly QueryOperatorEnumerator m_source; // The source data. private readonly int m_sign; // The sign for comparisons (-1 means min, 1 means max). //---------------------------------------------------------------------------------------- // Instantiates a new aggregation operator. // internal IntMinMaxAggregationOperatorEnumerator(QueryOperatorEnumerator source, int partitionIndex, int sign, CancellationToken cancellationToken) : base(partitionIndex, cancellationToken) { Contract.Assert(source != null); m_source = source; m_sign = sign; } //--------------------------------------------------------------------------------------- // Tallies up the min/max of the underlying data source, walking the entire thing the first // time MoveNext is called on this object. // protected override bool MoveNextCore(ref int currentElement) { // Based on the sign, do either a min or max reduction. QueryOperatorEnumerator source = m_source; TKey keyUnused = default(TKey); if (source.MoveNext(ref currentElement, ref keyUnused)) { int i = 0; // We just scroll through the enumerator and find the min or max. if (m_sign == -1) { int elem = default(int); while (source.MoveNext(ref elem, ref keyUnused)) { if ((i++ & CancellationState.POLL_INTERVAL) == 0) CancellationState.ThrowIfCanceled(m_cancellationToken); if (elem < currentElement) { currentElement = elem; } } } else { int elem = default(int); while (source.MoveNext(ref elem, ref keyUnused)) { if ((i++ & CancellationState.POLL_INTERVAL) == 0) CancellationState.ThrowIfCanceled(m_cancellationToken); if (elem > currentElement) { currentElement = elem; } } } // The sum has been calculated. Now just return. return true; } return false; } //---------------------------------------------------------------------------------------- // Dispose of resources associated with the underlying enumerator. // protected override void Dispose(bool disposing) { Contract.Assert(m_source != null); m_source.Dispose(); } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // IntMinMaxAggregationOperator.cs // // [....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Collections.Generic; using System.Diagnostics.Contracts; using System.Threading; namespace System.Linq.Parallel { ////// An inlined min/max aggregation and its enumerator, for ints. /// internal sealed class IntMinMaxAggregationOperator : InlinedAggregationOperator{ private readonly int m_sign; // The sign (-1 for min, 1 for max). //---------------------------------------------------------------------------------------- // Constructs a new instance of a min/max associative operator. // internal IntMinMaxAggregationOperator(IEnumerable child, int sign) : base(child) { Contract.Assert(sign == -1 || sign == 1, "invalid sign"); m_sign = sign; } //--------------------------------------------------------------------------------------- // Executes the entire query tree, and aggregates the intermediate results into the // final result based on the binary operators and final reduction. // // Return Value: // The single result of aggregation. // protected override int InternalAggregate(ref Exception singularExceptionToThrow) { // Because the final reduction is typically much cheaper than the intermediate // reductions over the individual partitions, and because each parallel partition // will do a lot of work to produce a single output element, we prefer to turn off // pipelining, and process the final reductions serially. using (IEnumerator enumerator = GetEnumerator(ParallelMergeOptions.FullyBuffered, true)) { // Throw an error for empty results. if (!enumerator.MoveNext()) { singularExceptionToThrow = new InvalidOperationException(SR.GetString(SR.NoElements)); return default(int); } int best = enumerator.Current; // Based on the sign, do either a min or max reduction. if (m_sign == -1) { while (enumerator.MoveNext()) { int current = enumerator.Current; if (current < best) { best = current; } } } else { while (enumerator.MoveNext()) { int current = enumerator.Current; if (current > best) { best = current; } } } return best; } } //--------------------------------------------------------------------------------------- // Creates an enumerator that is used internally for the final aggregation step. // protected override QueryOperatorEnumerator CreateEnumerator ( int index, int count, QueryOperatorEnumerator source, object sharedData, CancellationToken cancellationToken) { return new IntMinMaxAggregationOperatorEnumerator (source, index, m_sign, cancellationToken); } //--------------------------------------------------------------------------------------- // This enumerator type encapsulates the intermediary aggregation over the underlying // (possibly partitioned) data source. // private class IntMinMaxAggregationOperatorEnumerator : InlinedAggregationOperatorEnumerator { private readonly QueryOperatorEnumerator m_source; // The source data. private readonly int m_sign; // The sign for comparisons (-1 means min, 1 means max). //---------------------------------------------------------------------------------------- // Instantiates a new aggregation operator. // internal IntMinMaxAggregationOperatorEnumerator(QueryOperatorEnumerator source, int partitionIndex, int sign, CancellationToken cancellationToken) : base(partitionIndex, cancellationToken) { Contract.Assert(source != null); m_source = source; m_sign = sign; } //--------------------------------------------------------------------------------------- // Tallies up the min/max of the underlying data source, walking the entire thing the first // time MoveNext is called on this object. // protected override bool MoveNextCore(ref int currentElement) { // Based on the sign, do either a min or max reduction. QueryOperatorEnumerator source = m_source; TKey keyUnused = default(TKey); if (source.MoveNext(ref currentElement, ref keyUnused)) { int i = 0; // We just scroll through the enumerator and find the min or max. if (m_sign == -1) { int elem = default(int); while (source.MoveNext(ref elem, ref keyUnused)) { if ((i++ & CancellationState.POLL_INTERVAL) == 0) CancellationState.ThrowIfCanceled(m_cancellationToken); if (elem < currentElement) { currentElement = elem; } } } else { int elem = default(int); while (source.MoveNext(ref elem, ref keyUnused)) { if ((i++ & CancellationState.POLL_INTERVAL) == 0) CancellationState.ThrowIfCanceled(m_cancellationToken); if (elem > currentElement) { currentElement = elem; } } } // The sum has been calculated. Now just return. return true; } return false; } //---------------------------------------------------------------------------------------- // Dispose of resources associated with the underlying enumerator. // protected override void Dispose(bool disposing) { Contract.Assert(m_source != null); m_source.Dispose(); } } } } // 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
- RoutedEventArgs.cs
- PropertyValue.cs
- TreeWalker.cs
- ColumnResult.cs
- EntityReference.cs
- LogArchiveSnapshot.cs
- Stylus.cs
- DateTimeConverter2.cs
- Pts.cs
- CurrencyWrapper.cs
- FontWeightConverter.cs
- xmlglyphRunInfo.cs
- Vector3dCollection.cs
- FullTextBreakpoint.cs
- TracingConnection.cs
- FixedFlowMap.cs
- RangeValidator.cs
- WebPartsPersonalization.cs
- HwndSourceKeyboardInputSite.cs
- xmlsaver.cs
- HtmlInputSubmit.cs
- XmlObjectSerializerWriteContextComplex.cs
- NullableIntMinMaxAggregationOperator.cs
- ConfigXmlComment.cs
- LogEntryUtils.cs
- EmbeddedMailObjectsCollection.cs
- ResourceType.cs
- DrawingBrush.cs
- BulletChrome.cs
- VirtualPathUtility.cs
- CommandConverter.cs
- WebErrorHandler.cs
- XmlDataSourceNodeDescriptor.cs
- FileDialogCustomPlace.cs
- MatrixAnimationBase.cs
- MessageAction.cs
- FieldValue.cs
- UTF7Encoding.cs
- EntitySet.cs
- UserPersonalizationStateInfo.cs
- PrintDialog.cs
- ToolBarTray.cs
- PropertyEntry.cs
- shaperfactory.cs
- NativeCppClassAttribute.cs
- DiscoveryExceptionDictionary.cs
- DomainUpDown.cs
- XamlSerializationHelper.cs
- FixedSOMTable.cs
- ProcessHost.cs
- SiteOfOriginPart.cs
- SchemaAttDef.cs
- SqlMethods.cs
- PolicyStatement.cs
- HtmlEncodedRawTextWriter.cs
- XmlQueryCardinality.cs
- SyntaxCheck.cs
- MenuItemBindingCollection.cs
- CollectionType.cs
- ChangeConflicts.cs
- COM2PictureConverter.cs
- AnnotationAdorner.cs
- ManifestSignedXml.cs
- PixelFormats.cs
- NumberSubstitution.cs
- FullTextLine.cs
- QilSortKey.cs
- DeviceFilterEditorDialog.cs
- _WebProxyDataBuilder.cs
- ThreadAbortException.cs
- SmtpClient.cs
- ScriptManagerProxy.cs
- ListViewCommandEventArgs.cs
- Axis.cs
- AutomationPeer.cs
- DockAndAnchorLayout.cs
- _ListenerResponseStream.cs
- ApplicationException.cs
- PolyBezierSegmentFigureLogic.cs
- OptimalBreakSession.cs
- SemanticAnalyzer.cs
- DataMemberFieldEditor.cs
- XmlILTrace.cs
- ResourceDescriptionAttribute.cs
- ModelUIElement3D.cs
- DivideByZeroException.cs
- _SslStream.cs
- SchemaImporterExtension.cs
- SerialPinChanges.cs
- ContextItem.cs
- MenuBase.cs
- HotSpot.cs
- HostSecurityManager.cs
- KeyValueConfigurationCollection.cs
- NotConverter.cs
- RepeaterDataBoundAdapter.cs
- ImageDesigner.cs
- InvocationExpression.cs
- LogFlushAsyncResult.cs
- WebResourceUtil.cs