Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / QueryOperators / Inlined / IntSumAggregationOperator.cs / 1305376 / IntSumAggregationOperator.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // IntSumAggregationOperator.cs // //[....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Collections.Generic; using System.Diagnostics.Contracts; using System.Threading; namespace System.Linq.Parallel { ////// Inlined aggregations for summing up primitives (int, long, float, double, decimal), as /// well as the nullable versions of each (int?, long?, float?, double?, decimal?). /// internal sealed class IntSumAggregationOperator : InlinedAggregationOperator{ //---------------------------------------------------------------------------------------- // Constructs a new instance of a sum associative operator. // internal IntSumAggregationOperator(IEnumerable child) : base(child) { } //--------------------------------------------------------------------------------------- // 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)) { // We just reduce the elements in each output partition. int sum = 0; while (enumerator.MoveNext()) { checked { sum += enumerator.Current; } } return sum; } } //--------------------------------------------------------------------------------------- // 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 IntSumAggregationOperatorEnumerator (source, index, cancellationToken); } //--------------------------------------------------------------------------------------- // This enumerator type encapsulates the intermediary aggregation over the underlying // (possibly partitioned) data source. // private class IntSumAggregationOperatorEnumerator : InlinedAggregationOperatorEnumerator { private readonly QueryOperatorEnumerator m_source; // The source data. //---------------------------------------------------------------------------------------- // Instantiates a new aggregation operator. // internal IntSumAggregationOperatorEnumerator(QueryOperatorEnumerator source, int partitionIndex, CancellationToken cancellationToken) : base(partitionIndex, cancellationToken) { Contract.Assert(source != null); m_source = source; } //--------------------------------------------------------------------------------------- // Tallies up the sum 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) { int element = default(int); TKey keyUnused = default(TKey); QueryOperatorEnumerator source = m_source; if (source.MoveNext(ref element, ref keyUnused)) { // We just scroll through the enumerator and accumulate the sum. int tempSum = 0; int i = 0; do { if ((i++ & CancellationState.POLL_INTERVAL) == 0) CancellationState.ThrowIfCanceled(m_cancellationToken); checked { tempSum += element; } } while (source.MoveNext(ref element, ref keyUnused)); // The sum has been calculated. Now just return. currentElement = tempSum; 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. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // IntSumAggregationOperator.cs // // [....] // // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- using System.Collections.Generic; using System.Diagnostics.Contracts; using System.Threading; namespace System.Linq.Parallel { ////// Inlined aggregations for summing up primitives (int, long, float, double, decimal), as /// well as the nullable versions of each (int?, long?, float?, double?, decimal?). /// internal sealed class IntSumAggregationOperator : InlinedAggregationOperator{ //---------------------------------------------------------------------------------------- // Constructs a new instance of a sum associative operator. // internal IntSumAggregationOperator(IEnumerable child) : base(child) { } //--------------------------------------------------------------------------------------- // 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)) { // We just reduce the elements in each output partition. int sum = 0; while (enumerator.MoveNext()) { checked { sum += enumerator.Current; } } return sum; } } //--------------------------------------------------------------------------------------- // 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 IntSumAggregationOperatorEnumerator (source, index, cancellationToken); } //--------------------------------------------------------------------------------------- // This enumerator type encapsulates the intermediary aggregation over the underlying // (possibly partitioned) data source. // private class IntSumAggregationOperatorEnumerator : InlinedAggregationOperatorEnumerator { private readonly QueryOperatorEnumerator m_source; // The source data. //---------------------------------------------------------------------------------------- // Instantiates a new aggregation operator. // internal IntSumAggregationOperatorEnumerator(QueryOperatorEnumerator source, int partitionIndex, CancellationToken cancellationToken) : base(partitionIndex, cancellationToken) { Contract.Assert(source != null); m_source = source; } //--------------------------------------------------------------------------------------- // Tallies up the sum 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) { int element = default(int); TKey keyUnused = default(TKey); QueryOperatorEnumerator source = m_source; if (source.MoveNext(ref element, ref keyUnused)) { // We just scroll through the enumerator and accumulate the sum. int tempSum = 0; int i = 0; do { if ((i++ & CancellationState.POLL_INTERVAL) == 0) CancellationState.ThrowIfCanceled(m_cancellationToken); checked { tempSum += element; } } while (source.MoveNext(ref element, ref keyUnused)); // The sum has been calculated. Now just return. currentElement = tempSum; 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
- ObjectDataSourceFilteringEventArgs.cs
- MultipartIdentifier.cs
- DbConnectionPoolCounters.cs
- DispatcherEventArgs.cs
- BufferModeSettings.cs
- Menu.cs
- SendActivityDesigner.cs
- AppearanceEditorPart.cs
- SchemaElementDecl.cs
- QilGenerator.cs
- SqlColumnizer.cs
- TypeSemantics.cs
- ToolBarButton.cs
- XslTransform.cs
- EntityClientCacheEntry.cs
- WindowsPrincipal.cs
- NetCodeGroup.cs
- InfoCardArgumentException.cs
- CompModHelpers.cs
- BitmapSizeOptions.cs
- DefaultExpression.cs
- StringUtil.cs
- RegexStringValidatorAttribute.cs
- TextRunCache.cs
- IncomingWebRequestContext.cs
- MatrixTransform3D.cs
- smtpconnection.cs
- SessionStateContainer.cs
- UpdateRecord.cs
- TextFormatterImp.cs
- PropertyGeneratedEventArgs.cs
- ExpressionPrefixAttribute.cs
- PeerName.cs
- DataGridViewSortCompareEventArgs.cs
- XmlDataSourceDesigner.cs
- ClaimSet.cs
- WinFormsUtils.cs
- RouteParametersHelper.cs
- FormsIdentity.cs
- Tile.cs
- DictionaryManager.cs
- SiteMapPath.cs
- ReverseQueryOperator.cs
- RegexTypeEditor.cs
- WhiteSpaceTrimStringConverter.cs
- MemberPath.cs
- TreeNodeCollection.cs
- Button.cs
- ThaiBuddhistCalendar.cs
- ArrangedElementCollection.cs
- DrawListViewSubItemEventArgs.cs
- RelationshipConstraintValidator.cs
- EncodedStreamFactory.cs
- MemoryFailPoint.cs
- SqlBooleanizer.cs
- TextServicesDisplayAttributePropertyRanges.cs
- RewritingProcessor.cs
- ProjectionCamera.cs
- RegistrySecurity.cs
- _HeaderInfoTable.cs
- CollectionMarkupSerializer.cs
- CultureInfo.cs
- AssociativeAggregationOperator.cs
- FlowLayoutSettings.cs
- BooleanKeyFrameCollection.cs
- ColorKeyFrameCollection.cs
- TrustManagerMoreInformation.cs
- UserPreferenceChangingEventArgs.cs
- X509ChainPolicy.cs
- LoginCancelEventArgs.cs
- NameSpaceExtractor.cs
- NumericUpDown.cs
- ContractSearchPattern.cs
- SystemInformation.cs
- XmlTextAttribute.cs
- IndexedSelectQueryOperator.cs
- SiteMapNode.cs
- PathSegmentCollection.cs
- Int64Converter.cs
- Pair.cs
- recordstate.cs
- GridViewAutomationPeer.cs
- StandardCommands.cs
- FixedTextView.cs
- DocumentApplication.cs
- EdmError.cs
- AspCompat.cs
- wgx_sdk_version.cs
- QueryTask.cs
- DefinitionProperties.cs
- RightsManagementEncryptionTransform.cs
- CachedFontFace.cs
- TemplatedMailWebEventProvider.cs
- SqlDelegatedTransaction.cs
- RewritingSimplifier.cs
- OutOfProcStateClientManager.cs
- ContainerParaClient.cs
- UriSectionData.cs
- ToolboxItemCollection.cs
- SequentialWorkflowHeaderFooter.cs