Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / QueryOperators / Inlined / NullableIntMinMaxAggregationOperator.cs / 1305376 / NullableIntMinMaxAggregationOperator.cs
// ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // NullableIntMinMaxAggregationOperator.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 Nullable ints. /// internal sealed class NullableIntMinMaxAggregationOperator : 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 NullableIntMinMaxAggregationOperator(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)) { // Just return null right away for empty results. if (!enumerator.MoveNext()) { return null; } 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 (best == null || current < best) { best = current; } } } else { while (enumerator.MoveNext()) { int? current = enumerator.Current; if (best == null || 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 NullableIntMinMaxAggregationOperatorEnumerator (source, index, m_sign, cancellationToken); } //--------------------------------------------------------------------------------------- // This enumerator type encapsulates the intermediary aggregation over the underlying // (possibly partitioned) data source. // private class NullableIntMinMaxAggregationOperatorEnumerator : 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 NullableIntMinMaxAggregationOperatorEnumerator(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 (currentElement == null || 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 (currentElement == null || 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. // // ==--== // =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // // NullableIntMinMaxAggregationOperator.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 Nullable ints. /// internal sealed class NullableIntMinMaxAggregationOperator : 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 NullableIntMinMaxAggregationOperator(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)) { // Just return null right away for empty results. if (!enumerator.MoveNext()) { return null; } 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 (best == null || current < best) { best = current; } } } else { while (enumerator.MoveNext()) { int? current = enumerator.Current; if (best == null || 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 NullableIntMinMaxAggregationOperatorEnumerator (source, index, m_sign, cancellationToken); } //--------------------------------------------------------------------------------------- // This enumerator type encapsulates the intermediary aggregation over the underlying // (possibly partitioned) data source. // private class NullableIntMinMaxAggregationOperatorEnumerator : 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 NullableIntMinMaxAggregationOperatorEnumerator(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 (currentElement == null || 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 (currentElement == null || 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
- DeleteStoreRequest.cs
- sqlstateclientmanager.cs
- datacache.cs
- DecoderFallback.cs
- IndexOutOfRangeException.cs
- RichTextBoxConstants.cs
- BaseCodePageEncoding.cs
- unitconverter.cs
- KeyedCollection.cs
- BitmapCodecInfo.cs
- StringReader.cs
- ConfigurationValidatorAttribute.cs
- SimpleBitVector32.cs
- WebPartsPersonalizationAuthorization.cs
- LinkLabel.cs
- TraceUtility.cs
- EntityCommandExecutionException.cs
- TextElement.cs
- GlyphInfoList.cs
- DefaultAuthorizationContext.cs
- StreamAsIStream.cs
- JsonUriDataContract.cs
- NavigationWindowAutomationPeer.cs
- Message.cs
- LoginUtil.cs
- AstNode.cs
- ListViewTableRow.cs
- WindowsServiceElement.cs
- Operand.cs
- ConfigXmlSignificantWhitespace.cs
- BoundField.cs
- Panel.cs
- TagPrefixInfo.cs
- ColumnHeaderConverter.cs
- HttpListenerResponse.cs
- GroupItemAutomationPeer.cs
- GridViewColumnHeaderAutomationPeer.cs
- ResourceDescriptionAttribute.cs
- PackageRelationshipSelector.cs
- PromptStyle.cs
- XPathMessageFilterTable.cs
- InputScopeAttribute.cs
- RepeatEnumerable.cs
- CapabilitiesAssignment.cs
- DocumentAutomationPeer.cs
- UpDownBase.cs
- Pair.cs
- HttpProfileBase.cs
- _Semaphore.cs
- SoapExtensionReflector.cs
- TableProvider.cs
- SplashScreenNativeMethods.cs
- SafeSecurityHandles.cs
- SizeAnimationUsingKeyFrames.cs
- PathGradientBrush.cs
- HttpListenerException.cs
- ToolStripContentPanel.cs
- Serializer.cs
- CommunicationObjectAbortedException.cs
- DecimalConverter.cs
- ConnectionManagementElementCollection.cs
- MembershipValidatePasswordEventArgs.cs
- columnmapkeybuilder.cs
- BinaryOperationBinder.cs
- HostedElements.cs
- CommandBindingCollection.cs
- TdsParserSessionPool.cs
- XamlReaderConstants.cs
- ViewUtilities.cs
- HttpCookie.cs
- FlowPosition.cs
- DataContext.cs
- HelpInfo.cs
- EndpointIdentity.cs
- XamlVector3DCollectionSerializer.cs
- FormatConvertedBitmap.cs
- IPGlobalProperties.cs
- CapabilitiesPattern.cs
- connectionpool.cs
- XmlCharCheckingWriter.cs
- MouseWheelEventArgs.cs
- BulletedList.cs
- CultureData.cs
- SafeNativeMethods.cs
- XhtmlBasicTextViewAdapter.cs
- GridProviderWrapper.cs
- OracleNumber.cs
- WebPartAddingEventArgs.cs
- FatalException.cs
- httpserverutility.cs
- WindowsListViewItemCheckBox.cs
- Win32SafeHandles.cs
- RichTextBoxAutomationPeer.cs
- TaskFormBase.cs
- CorrelationKey.cs
- FlowPosition.cs
- RequestUriProcessor.cs
- listitem.cs
- DesignSurfaceEvent.cs
- SqlBooleanizer.cs