Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / QueryOperators / Inlined / LongMinMaxAggregationOperator.cs / 1305376 / LongMinMaxAggregationOperator.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // LongMinMaxAggregationOperator.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 longs. /// internal sealed class LongMinMaxAggregationOperator : 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 LongMinMaxAggregationOperator(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 long 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(long); } long best = enumerator.Current; // Based on the sign, do either a min or max reduction. if (m_sign == -1) { while (enumerator.MoveNext()) { long current = enumerator.Current; if (current < best) { best = current; } } } else { while (enumerator.MoveNext()) { long 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 LongMinMaxAggregationOperatorEnumerator (source, index, m_sign, cancellationToken); } //--------------------------------------------------------------------------------------- // This enumerator type encapsulates the intermediary aggregation over the underlying // (possibly partitioned) data source. // private class LongMinMaxAggregationOperatorEnumerator : InlinedAggregationOperatorEnumerator { private QueryOperatorEnumerator m_source; // The source data. private int m_sign; // The sign for comparisons (-1 means min, 1 means max). //---------------------------------------------------------------------------------------- // Instantiates a new aggregation operator. // internal LongMinMaxAggregationOperatorEnumerator(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 long 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) { long elem = default(long); while (source.MoveNext(ref elem, ref keyUnused)) { if ((i++ & CancellationState.POLL_INTERVAL) == 0) CancellationState.ThrowIfCanceled(m_cancellationToken); if (elem < currentElement) { currentElement = elem; } } } else { long elem = default(long); 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. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // LongMinMaxAggregationOperator.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 longs. /// internal sealed class LongMinMaxAggregationOperator : 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 LongMinMaxAggregationOperator(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 long 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(long); } long best = enumerator.Current; // Based on the sign, do either a min or max reduction. if (m_sign == -1) { while (enumerator.MoveNext()) { long current = enumerator.Current; if (current < best) { best = current; } } } else { while (enumerator.MoveNext()) { long 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 LongMinMaxAggregationOperatorEnumerator (source, index, m_sign, cancellationToken); } //--------------------------------------------------------------------------------------- // This enumerator type encapsulates the intermediary aggregation over the underlying // (possibly partitioned) data source. // private class LongMinMaxAggregationOperatorEnumerator : InlinedAggregationOperatorEnumerator { private QueryOperatorEnumerator m_source; // The source data. private int m_sign; // The sign for comparisons (-1 means min, 1 means max). //---------------------------------------------------------------------------------------- // Instantiates a new aggregation operator. // internal LongMinMaxAggregationOperatorEnumerator(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 long 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) { long elem = default(long); while (source.MoveNext(ref elem, ref keyUnused)) { if ((i++ & CancellationState.POLL_INTERVAL) == 0) CancellationState.ThrowIfCanceled(m_cancellationToken); if (elem < currentElement) { currentElement = elem; } } } else { long elem = default(long); 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
- AttachedAnnotation.cs
- XslNumber.cs
- CompositeKey.cs
- SystemIPGlobalStatistics.cs
- BlockCollection.cs
- HttpModuleCollection.cs
- XmlIlGenerator.cs
- QueryRewriter.cs
- Single.cs
- ObjectIDGenerator.cs
- InvalidWMPVersionException.cs
- XmlEnumAttribute.cs
- MarkupObject.cs
- WinFormsUtils.cs
- PerCallInstanceContextProvider.cs
- ProcessManager.cs
- ThreadExceptionEvent.cs
- SectionUpdates.cs
- ProfilePropertyNameValidator.cs
- ConditionalAttribute.cs
- StartUpEventArgs.cs
- IImplicitResourceProvider.cs
- PropertyMetadata.cs
- Range.cs
- ActivityDesignerHelper.cs
- MimeMapping.cs
- UpdateException.cs
- QilTargetType.cs
- PropertyEntry.cs
- DLinqTableProvider.cs
- JavaScriptString.cs
- WindowsEditBox.cs
- LazyTextWriterCreator.cs
- SizeAnimationUsingKeyFrames.cs
- RadioButtonFlatAdapter.cs
- TrimSurroundingWhitespaceAttribute.cs
- MarkupExtensionParser.cs
- ChameleonKey.cs
- UnsafePeerToPeerMethods.cs
- FlowDocumentView.cs
- XsltCompileContext.cs
- InvalidStoreProtectionKeyException.cs
- Flattener.cs
- TreeViewDesigner.cs
- ByteStack.cs
- DataGridViewRowConverter.cs
- ConnectionManagementElement.cs
- Attributes.cs
- XmlImplementation.cs
- DataServiceQueryProvider.cs
- RuleSettingsCollection.cs
- WebPartConnectionsCancelVerb.cs
- PrintControllerWithStatusDialog.cs
- MethodCallConverter.cs
- StatusStrip.cs
- Ref.cs
- ExpressionList.cs
- HwndHostAutomationPeer.cs
- EnumConverter.cs
- DataContract.cs
- CodeSnippetExpression.cs
- WindowsFormsEditorServiceHelper.cs
- EncodingNLS.cs
- SequentialUshortCollection.cs
- CodeSnippetTypeMember.cs
- WinFormsSpinner.cs
- Propagator.Evaluator.cs
- IfJoinedCondition.cs
- SaveLedgerEntryRequest.cs
- SafeFindHandle.cs
- MetadataItemEmitter.cs
- MatrixConverter.cs
- EqualityComparer.cs
- Polyline.cs
- StylusShape.cs
- XmlDataProvider.cs
- ResourceContainer.cs
- SqlCacheDependency.cs
- WorkflowWebHostingModule.cs
- ButtonField.cs
- MenuItemBinding.cs
- WebServiceClientProxyGenerator.cs
- filewebrequest.cs
- CacheMode.cs
- GlyphingCache.cs
- HtmlInputSubmit.cs
- NamedObject.cs
- PersonalizationStateInfo.cs
- InfoCardKeyedHashAlgorithm.cs
- ImageListImageEditor.cs
- HandleCollector.cs
- KeysConverter.cs
- UserControl.cs
- BitmapEffectState.cs
- BindingMAnagerBase.cs
- CopyNamespacesAction.cs
- DispatchChannelSink.cs
- KeyedHashAlgorithm.cs
- storepermission.cs
- TerminatorSinks.cs