Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Core / System / Linq / Parallel / QueryOperators / Binary / UnionQueryOperator.cs / 1305376 / UnionQueryOperator.cs
// ==++==
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// ==--==
// =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
//
// UnionQueryOperator.cs
//
// [....]
//
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Threading;
namespace System.Linq.Parallel
{
///
/// Operator that yields the union of two data sources.
///
/// :
BinaryQueryOperator
{
private readonly IEqualityComparer m_comparer; // An equality comparer.
//----------------------------------------------------------------------------------------
// Constructs a new union operator.
//
internal UnionQueryOperator(ParallelQuery left, ParallelQuery right, IEqualityComparer comparer)
:base(left, right)
{
Contract.Assert(left != null && right != null, "child data sources cannot be null");
m_comparer = comparer;
m_outputOrdered = LeftChild.OutputOrdered || RightChild.OutputOrdered;
}
//---------------------------------------------------------------------------------------
// Just opens the current operator, including opening the child and wrapping it with
// partitions as needed.
//
internal override QueryResults Open(
QuerySettings settings, bool preferStriping)
{
// We just open our child operators, left and then right. Do not propagate the preferStriping value, but
// instead explicitly set it to false. Regardless of whether the parent prefers striping or range
// partitioning, the output will be hash-partititioned.
QueryResults leftChildResults = LeftChild.Open(settings, false);
QueryResults rightChildResults = RightChild.Open(settings, false);
return new BinaryQueryOperatorResults(leftChildResults, rightChildResults, this, settings, false);
}
public override void WrapPartitionedStream(
PartitionedStream leftStream, PartitionedStream rightStream,
IPartitionedStreamRecipient outputRecipient, bool preferStriping, QuerySettings settings)
{
Contract.Assert(leftStream.PartitionCount == rightStream.PartitionCount);
int partitionCount = leftStream.PartitionCount;
// Wrap both child streams with hash repartition
if (LeftChild.OutputOrdered)
{
PartitionedStream, TLeftKey> leftHashStream =
ExchangeUtilities.HashRepartitionOrdered(
leftStream, null, null, m_comparer, settings.CancellationState.MergedCancellationToken);
WrapPartitionedStreamFixedLeftType(
leftHashStream, rightStream, outputRecipient, partitionCount, settings.CancellationState.MergedCancellationToken);
}
else
{
PartitionedStream, int> leftHashStream =
ExchangeUtilities.HashRepartition(
leftStream, null, null, m_comparer, settings.CancellationState.MergedCancellationToken);
WrapPartitionedStreamFixedLeftType(
leftHashStream, rightStream, outputRecipient, partitionCount, settings.CancellationState.MergedCancellationToken);
}
}
//---------------------------------------------------------------------------------------
// A helper method that allows WrapPartitionedStream to fix the TLeftKey type parameter.
//
private void WrapPartitionedStreamFixedLeftType(
PartitionedStream, TLeftKey> leftHashStream, PartitionedStream rightStream,
IPartitionedStreamRecipient outputRecipient, int partitionCount, CancellationToken cancellationToken)
{
if (RightChild.OutputOrdered)
{
PartitionedStream, TRightKey> rightHashStream =
ExchangeUtilities.HashRepartitionOrdered(
rightStream, null, null, m_comparer, cancellationToken);
WrapPartitionedStreamFixedBothTypes(
leftHashStream, rightHashStream, outputRecipient, partitionCount, cancellationToken);
}
else
{
PartitionedStream, int> rightHashStream =
ExchangeUtilities.HashRepartition(
rightStream, null, null, m_comparer, cancellationToken);
WrapPartitionedStreamFixedBothTypes(
leftHashStream, rightHashStream, outputRecipient, partitionCount, cancellationToken);
}
}
//---------------------------------------------------------------------------------------
// A helper method that allows WrapPartitionedStreamHelper to fix the TRightKey type parameter.
//
private void WrapPartitionedStreamFixedBothTypes(
PartitionedStream, TLeftKey> leftHashStream,
PartitionedStream, TRightKey> rightHashStream,
IPartitionedStreamRecipient outputRecipient, int partitionCount,
CancellationToken cancellationToken)
{
if (LeftChild.OutputOrdered || RightChild.OutputOrdered)
{
IComparer> compoundKeyComparer =
ConcatKey.MakeComparer(leftHashStream.KeyComparer, rightHashStream.KeyComparer);
PartitionedStream> outputStream =
new PartitionedStream>(partitionCount, compoundKeyComparer, OrdinalIndexState.Shuffled);
for (int i = 0; i < partitionCount; i++)
{
outputStream[i] = new OrderedUnionQueryOperatorEnumerator(
leftHashStream[i], rightHashStream[i], LeftChild.OutputOrdered, RightChild.OutputOrdered,
m_comparer, compoundKeyComparer, cancellationToken);
}
outputRecipient.Receive(outputStream);
}
else
{
PartitionedStream outputStream =
new PartitionedStream(partitionCount, Util.GetDefaultComparer(), OrdinalIndexState.Shuffled);
for (int i = 0; i < partitionCount; i++)
{
outputStream[i] = new UnionQueryOperatorEnumerator(
leftHashStream[i], rightHashStream[i], i, m_comparer, cancellationToken);
}
outputRecipient.Receive(outputStream);
}
}
//----------------------------------------------------------------------------------------
// Returns an enumerable that represents the query executing sequentially.
//
internal override IEnumerable AsSequentialQuery(CancellationToken token)
{
IEnumerable wrappedLeftChild = CancellableEnumerable.Wrap(LeftChild.AsSequentialQuery(token), token);
IEnumerable wrappedRightChild = CancellableEnumerable.Wrap(RightChild.AsSequentialQuery(token), token);
return wrappedLeftChild.Union(wrappedRightChild, m_comparer);
}
//---------------------------------------------------------------------------------------
// Whether this operator performs a premature merge.
//
internal override bool LimitsParallelism
{
get { return false; }
}
//----------------------------------------------------------------------------------------
// This enumerator performs the union operation incrementally. It does this by maintaining
// a history -- in the form of a set -- of all data already seen. It is careful not to
// return any duplicates.
//
class UnionQueryOperatorEnumerator : QueryOperatorEnumerator
{
private QueryOperatorEnumerator, TLeftKey> m_leftSource; // Left data source.
private QueryOperatorEnumerator, TRightKey> m_rightSource; // Right data source.
private readonly int m_partitionIndex; // The current partition.
private Set m_hashLookup; // The hash lookup, used to produce the union.
private CancellationToken m_cancellationToken;
private Shared m_outputLoopCount;
private readonly IEqualityComparer m_comparer;
//----------------------------------------------------------------------------------------
// Instantiates a new union operator.
//
internal UnionQueryOperatorEnumerator(
QueryOperatorEnumerator, TLeftKey> leftSource,
QueryOperatorEnumerator, TRightKey> rightSource,
int partitionIndex, IEqualityComparer comparer,
CancellationToken cancellationToken)
{
Contract.Assert(leftSource != null);
Contract.Assert(rightSource != null);
m_leftSource = leftSource;
m_rightSource = rightSource;
m_partitionIndex = partitionIndex;
// @
m_comparer = comparer;
m_cancellationToken = cancellationToken;
}
//---------------------------------------------------------------------------------------
// Walks the two data sources, left and then right, to produce the union.
//
internal override bool MoveNext(ref TInputOutput currentElement, ref int currentKey)
{
if (m_hashLookup == null)
{
m_hashLookup = new Set(m_comparer);
m_outputLoopCount = new Shared(0);
}
Contract.Assert(m_hashLookup != null);
// Enumerate the left and then right data source. When each is done, we set the
// field to null so we will skip it upon subsequent calls to MoveNext.
if (m_leftSource != null)
{
// Iterate over this set's elements until we find a unique element.
TLeftKey keyUnused = default(TLeftKey);
Pair currentLeftElement = default(Pair);
int i = 0;
while (m_leftSource.MoveNext(ref currentLeftElement, ref keyUnused))
{
if ((i++ & CancellationState.POLL_INTERVAL) == 0)
CancellationState.ThrowIfCanceled(m_cancellationToken);
// We ensure we never return duplicates by tracking them in our set.
if (m_hashLookup.Add(currentLeftElement.First))
{
#if DEBUG
currentKey = unchecked((int)0xdeadbeef);
#endif
currentElement = currentLeftElement.First;
return true;
}
}
m_leftSource.Dispose();
m_leftSource = null;
}
if (m_rightSource != null)
{
// Iterate over this set's elements until we find a unique element.
TRightKey keyUnused = default(TRightKey);
Pair currentRightElement = default(Pair);
while (m_rightSource.MoveNext(ref currentRightElement, ref keyUnused))
{
if ((m_outputLoopCount.Value++ & CancellationState.POLL_INTERVAL) == 0)
CancellationState.ThrowIfCanceled(m_cancellationToken);
// We ensure we never return duplicates by tracking them in our set.
if (m_hashLookup.Add(currentRightElement.First))
{
#if DEBUG
currentKey = unchecked((int)0xdeadbeef);
#endif
currentElement = currentRightElement.First;
return true;
}
}
m_rightSource.Dispose();
m_rightSource = null;
}
return false;
}
protected override void Dispose(bool disposing)
{
if (m_leftSource != null)
{
m_leftSource.Dispose();
}
if (m_rightSource != null)
{
m_rightSource.Dispose();
}
}
}
class OrderedUnionQueryOperatorEnumerator : QueryOperatorEnumerator>
{
private QueryOperatorEnumerator, TLeftKey> m_leftSource; // Left data source.
private QueryOperatorEnumerator, TRightKey> m_rightSource; // Right data source.
private IComparer> m_keyComparer; // Comparer for compound order keys.
private IEnumerator, Pair>>> m_outputEnumerator; // Enumerator over the output of the union.
private bool m_leftOrdered; // Whether the left data source is ordered.
private bool m_rightOrdered; // Whether the right data source is ordered.
private IEqualityComparer m_comparer; // Comparer for the elements.
private CancellationToken m_cancellationToken;
//----------------------------------------------------------------------------------------
// Instantiates a new union operator.
//
internal OrderedUnionQueryOperatorEnumerator(
QueryOperatorEnumerator, TLeftKey> leftSource,
QueryOperatorEnumerator, TRightKey> rightSource,
bool leftOrdered, bool rightOrdered, IEqualityComparer comparer, IComparer> keyComparer,
CancellationToken cancellationToken)
{
Contract.Assert(leftSource != null);
Contract.Assert(rightSource != null);
m_leftSource = leftSource;
m_rightSource = rightSource;
m_keyComparer = keyComparer;
m_leftOrdered = leftOrdered;
m_rightOrdered = rightOrdered;
m_comparer = comparer;
if (m_comparer == null)
{
m_comparer = EqualityComparer.Default;
}
m_cancellationToken = cancellationToken;
}
//---------------------------------------------------------------------------------------
// Walks the two data sources, left and then right, to produce the union.
//
internal override bool MoveNext(ref TInputOutput currentElement, ref ConcatKey currentKey)
{
Contract.Assert(m_leftSource != null);
Contract.Assert(m_rightSource != null);
if (m_outputEnumerator == null)
{
IEqualityComparer> wrapperComparer = new WrapperEqualityComparer(m_comparer);
Dictionary, Pair>> union =
new Dictionary, Pair>>(wrapperComparer);
Pair elem = default(Pair);
TLeftKey leftKey = default(TLeftKey);
int i = 0;
while (m_leftSource.MoveNext(ref elem, ref leftKey))
{
if ((i++ & CancellationState.POLL_INTERVAL) == 0)
CancellationState.ThrowIfCanceled(m_cancellationToken);
ConcatKey key =
ConcatKey.MakeLeft(m_leftOrdered ? leftKey : default(TLeftKey));
Pair> oldEntry;
Wrapper wrappedElem = new Wrapper(elem.First);
if (!union.TryGetValue(wrappedElem, out oldEntry) || m_keyComparer.Compare(key, oldEntry.Second) < 0)
{
union[wrappedElem] = new Pair>(elem.First, key);
}
}
TRightKey rightKey = default(TRightKey);
while (m_rightSource.MoveNext(ref elem, ref rightKey))
{
if ((i++ & CancellationState.POLL_INTERVAL) == 0)
CancellationState.ThrowIfCanceled(m_cancellationToken);
ConcatKey key =
ConcatKey.MakeRight(m_rightOrdered ? rightKey : default(TRightKey));
Pair> oldEntry;
Wrapper wrappedElem = new Wrapper(elem.First);
if (!union.TryGetValue(wrappedElem, out oldEntry) || m_keyComparer.Compare(key, oldEntry.Second) < 0)
{
union[wrappedElem] = new Pair>(elem.First, key); ;
}
}
m_outputEnumerator = union.GetEnumerator();
}
if (m_outputEnumerator.MoveNext())
{
Pair> current = m_outputEnumerator.Current.Value;
currentElement = current.First;
currentKey = current.Second;
return true;
}
return false;
}
protected override void Dispose(bool disposing)
{
Contract.Assert(m_leftSource != null && m_rightSource != null);
m_leftSource.Dispose();
m_rightSource.Dispose();
}
}
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// ==++==
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// ==--==
// =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
//
// UnionQueryOperator.cs
//
// [....]
//
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Threading;
namespace System.Linq.Parallel
{
///
/// Operator that yields the union of two data sources.
///
/// :
BinaryQueryOperator
{
private readonly IEqualityComparer m_comparer; // An equality comparer.
//----------------------------------------------------------------------------------------
// Constructs a new union operator.
//
internal UnionQueryOperator(ParallelQuery left, ParallelQuery right, IEqualityComparer comparer)
:base(left, right)
{
Contract.Assert(left != null && right != null, "child data sources cannot be null");
m_comparer = comparer;
m_outputOrdered = LeftChild.OutputOrdered || RightChild.OutputOrdered;
}
//---------------------------------------------------------------------------------------
// Just opens the current operator, including opening the child and wrapping it with
// partitions as needed.
//
internal override QueryResults Open(
QuerySettings settings, bool preferStriping)
{
// We just open our child operators, left and then right. Do not propagate the preferStriping value, but
// instead explicitly set it to false. Regardless of whether the parent prefers striping or range
// partitioning, the output will be hash-partititioned.
QueryResults leftChildResults = LeftChild.Open(settings, false);
QueryResults rightChildResults = RightChild.Open(settings, false);
return new BinaryQueryOperatorResults(leftChildResults, rightChildResults, this, settings, false);
}
public override void WrapPartitionedStream(
PartitionedStream leftStream, PartitionedStream rightStream,
IPartitionedStreamRecipient outputRecipient, bool preferStriping, QuerySettings settings)
{
Contract.Assert(leftStream.PartitionCount == rightStream.PartitionCount);
int partitionCount = leftStream.PartitionCount;
// Wrap both child streams with hash repartition
if (LeftChild.OutputOrdered)
{
PartitionedStream, TLeftKey> leftHashStream =
ExchangeUtilities.HashRepartitionOrdered(
leftStream, null, null, m_comparer, settings.CancellationState.MergedCancellationToken);
WrapPartitionedStreamFixedLeftType(
leftHashStream, rightStream, outputRecipient, partitionCount, settings.CancellationState.MergedCancellationToken);
}
else
{
PartitionedStream, int> leftHashStream =
ExchangeUtilities.HashRepartition(
leftStream, null, null, m_comparer, settings.CancellationState.MergedCancellationToken);
WrapPartitionedStreamFixedLeftType(
leftHashStream, rightStream, outputRecipient, partitionCount, settings.CancellationState.MergedCancellationToken);
}
}
//---------------------------------------------------------------------------------------
// A helper method that allows WrapPartitionedStream to fix the TLeftKey type parameter.
//
private void WrapPartitionedStreamFixedLeftType(
PartitionedStream, TLeftKey> leftHashStream, PartitionedStream rightStream,
IPartitionedStreamRecipient outputRecipient, int partitionCount, CancellationToken cancellationToken)
{
if (RightChild.OutputOrdered)
{
PartitionedStream, TRightKey> rightHashStream =
ExchangeUtilities.HashRepartitionOrdered(
rightStream, null, null, m_comparer, cancellationToken);
WrapPartitionedStreamFixedBothTypes(
leftHashStream, rightHashStream, outputRecipient, partitionCount, cancellationToken);
}
else
{
PartitionedStream, int> rightHashStream =
ExchangeUtilities.HashRepartition(
rightStream, null, null, m_comparer, cancellationToken);
WrapPartitionedStreamFixedBothTypes(
leftHashStream, rightHashStream, outputRecipient, partitionCount, cancellationToken);
}
}
//---------------------------------------------------------------------------------------
// A helper method that allows WrapPartitionedStreamHelper to fix the TRightKey type parameter.
//
private void WrapPartitionedStreamFixedBothTypes(
PartitionedStream, TLeftKey> leftHashStream,
PartitionedStream, TRightKey> rightHashStream,
IPartitionedStreamRecipient outputRecipient, int partitionCount,
CancellationToken cancellationToken)
{
if (LeftChild.OutputOrdered || RightChild.OutputOrdered)
{
IComparer> compoundKeyComparer =
ConcatKey.MakeComparer(leftHashStream.KeyComparer, rightHashStream.KeyComparer);
PartitionedStream> outputStream =
new PartitionedStream>(partitionCount, compoundKeyComparer, OrdinalIndexState.Shuffled);
for (int i = 0; i < partitionCount; i++)
{
outputStream[i] = new OrderedUnionQueryOperatorEnumerator(
leftHashStream[i], rightHashStream[i], LeftChild.OutputOrdered, RightChild.OutputOrdered,
m_comparer, compoundKeyComparer, cancellationToken);
}
outputRecipient.Receive(outputStream);
}
else
{
PartitionedStream outputStream =
new PartitionedStream(partitionCount, Util.GetDefaultComparer(), OrdinalIndexState.Shuffled);
for (int i = 0; i < partitionCount; i++)
{
outputStream[i] = new UnionQueryOperatorEnumerator(
leftHashStream[i], rightHashStream[i], i, m_comparer, cancellationToken);
}
outputRecipient.Receive(outputStream);
}
}
//----------------------------------------------------------------------------------------
// Returns an enumerable that represents the query executing sequentially.
//
internal override IEnumerable AsSequentialQuery(CancellationToken token)
{
IEnumerable wrappedLeftChild = CancellableEnumerable.Wrap(LeftChild.AsSequentialQuery(token), token);
IEnumerable wrappedRightChild = CancellableEnumerable.Wrap(RightChild.AsSequentialQuery(token), token);
return wrappedLeftChild.Union(wrappedRightChild, m_comparer);
}
//---------------------------------------------------------------------------------------
// Whether this operator performs a premature merge.
//
internal override bool LimitsParallelism
{
get { return false; }
}
//----------------------------------------------------------------------------------------
// This enumerator performs the union operation incrementally. It does this by maintaining
// a history -- in the form of a set -- of all data already seen. It is careful not to
// return any duplicates.
//
class UnionQueryOperatorEnumerator : QueryOperatorEnumerator
{
private QueryOperatorEnumerator, TLeftKey> m_leftSource; // Left data source.
private QueryOperatorEnumerator, TRightKey> m_rightSource; // Right data source.
private readonly int m_partitionIndex; // The current partition.
private Set m_hashLookup; // The hash lookup, used to produce the union.
private CancellationToken m_cancellationToken;
private Shared m_outputLoopCount;
private readonly IEqualityComparer m_comparer;
//----------------------------------------------------------------------------------------
// Instantiates a new union operator.
//
internal UnionQueryOperatorEnumerator(
QueryOperatorEnumerator, TLeftKey> leftSource,
QueryOperatorEnumerator, TRightKey> rightSource,
int partitionIndex, IEqualityComparer comparer,
CancellationToken cancellationToken)
{
Contract.Assert(leftSource != null);
Contract.Assert(rightSource != null);
m_leftSource = leftSource;
m_rightSource = rightSource;
m_partitionIndex = partitionIndex;
// @
m_comparer = comparer;
m_cancellationToken = cancellationToken;
}
//---------------------------------------------------------------------------------------
// Walks the two data sources, left and then right, to produce the union.
//
internal override bool MoveNext(ref TInputOutput currentElement, ref int currentKey)
{
if (m_hashLookup == null)
{
m_hashLookup = new Set(m_comparer);
m_outputLoopCount = new Shared(0);
}
Contract.Assert(m_hashLookup != null);
// Enumerate the left and then right data source. When each is done, we set the
// field to null so we will skip it upon subsequent calls to MoveNext.
if (m_leftSource != null)
{
// Iterate over this set's elements until we find a unique element.
TLeftKey keyUnused = default(TLeftKey);
Pair currentLeftElement = default(Pair);
int i = 0;
while (m_leftSource.MoveNext(ref currentLeftElement, ref keyUnused))
{
if ((i++ & CancellationState.POLL_INTERVAL) == 0)
CancellationState.ThrowIfCanceled(m_cancellationToken);
// We ensure we never return duplicates by tracking them in our set.
if (m_hashLookup.Add(currentLeftElement.First))
{
#if DEBUG
currentKey = unchecked((int)0xdeadbeef);
#endif
currentElement = currentLeftElement.First;
return true;
}
}
m_leftSource.Dispose();
m_leftSource = null;
}
if (m_rightSource != null)
{
// Iterate over this set's elements until we find a unique element.
TRightKey keyUnused = default(TRightKey);
Pair currentRightElement = default(Pair);
while (m_rightSource.MoveNext(ref currentRightElement, ref keyUnused))
{
if ((m_outputLoopCount.Value++ & CancellationState.POLL_INTERVAL) == 0)
CancellationState.ThrowIfCanceled(m_cancellationToken);
// We ensure we never return duplicates by tracking them in our set.
if (m_hashLookup.Add(currentRightElement.First))
{
#if DEBUG
currentKey = unchecked((int)0xdeadbeef);
#endif
currentElement = currentRightElement.First;
return true;
}
}
m_rightSource.Dispose();
m_rightSource = null;
}
return false;
}
protected override void Dispose(bool disposing)
{
if (m_leftSource != null)
{
m_leftSource.Dispose();
}
if (m_rightSource != null)
{
m_rightSource.Dispose();
}
}
}
class OrderedUnionQueryOperatorEnumerator : QueryOperatorEnumerator>
{
private QueryOperatorEnumerator, TLeftKey> m_leftSource; // Left data source.
private QueryOperatorEnumerator, TRightKey> m_rightSource; // Right data source.
private IComparer> m_keyComparer; // Comparer for compound order keys.
private IEnumerator, Pair>>> m_outputEnumerator; // Enumerator over the output of the union.
private bool m_leftOrdered; // Whether the left data source is ordered.
private bool m_rightOrdered; // Whether the right data source is ordered.
private IEqualityComparer m_comparer; // Comparer for the elements.
private CancellationToken m_cancellationToken;
//----------------------------------------------------------------------------------------
// Instantiates a new union operator.
//
internal OrderedUnionQueryOperatorEnumerator(
QueryOperatorEnumerator, TLeftKey> leftSource,
QueryOperatorEnumerator, TRightKey> rightSource,
bool leftOrdered, bool rightOrdered, IEqualityComparer comparer, IComparer> keyComparer,
CancellationToken cancellationToken)
{
Contract.Assert(leftSource != null);
Contract.Assert(rightSource != null);
m_leftSource = leftSource;
m_rightSource = rightSource;
m_keyComparer = keyComparer;
m_leftOrdered = leftOrdered;
m_rightOrdered = rightOrdered;
m_comparer = comparer;
if (m_comparer == null)
{
m_comparer = EqualityComparer.Default;
}
m_cancellationToken = cancellationToken;
}
//---------------------------------------------------------------------------------------
// Walks the two data sources, left and then right, to produce the union.
//
internal override bool MoveNext(ref TInputOutput currentElement, ref ConcatKey currentKey)
{
Contract.Assert(m_leftSource != null);
Contract.Assert(m_rightSource != null);
if (m_outputEnumerator == null)
{
IEqualityComparer> wrapperComparer = new WrapperEqualityComparer(m_comparer);
Dictionary, Pair>> union =
new Dictionary, Pair>>(wrapperComparer);
Pair elem = default(Pair);
TLeftKey leftKey = default(TLeftKey);
int i = 0;
while (m_leftSource.MoveNext(ref elem, ref leftKey))
{
if ((i++ & CancellationState.POLL_INTERVAL) == 0)
CancellationState.ThrowIfCanceled(m_cancellationToken);
ConcatKey key =
ConcatKey.MakeLeft(m_leftOrdered ? leftKey : default(TLeftKey));
Pair> oldEntry;
Wrapper wrappedElem = new Wrapper(elem.First);
if (!union.TryGetValue(wrappedElem, out oldEntry) || m_keyComparer.Compare(key, oldEntry.Second) < 0)
{
union[wrappedElem] = new Pair>(elem.First, key);
}
}
TRightKey rightKey = default(TRightKey);
while (m_rightSource.MoveNext(ref elem, ref rightKey))
{
if ((i++ & CancellationState.POLL_INTERVAL) == 0)
CancellationState.ThrowIfCanceled(m_cancellationToken);
ConcatKey key =
ConcatKey.MakeRight(m_rightOrdered ? rightKey : default(TRightKey));
Pair> oldEntry;
Wrapper wrappedElem = new Wrapper(elem.First);
if (!union.TryGetValue(wrappedElem, out oldEntry) || m_keyComparer.Compare(key, oldEntry.Second) < 0)
{
union[wrappedElem] = new Pair>(elem.First, key); ;
}
}
m_outputEnumerator = union.GetEnumerator();
}
if (m_outputEnumerator.MoveNext())
{
Pair> current = m_outputEnumerator.Current.Value;
currentElement = current.First;
currentKey = current.Second;
return true;
}
return false;
}
protected override void Dispose(bool disposing)
{
Contract.Assert(m_leftSource != null && m_rightSource != null);
m_leftSource.Dispose();
m_rightSource.Dispose();
}
}
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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- TypeUtil.cs
- SqlNotificationRequest.cs
- ActivityLocationReferenceEnvironment.cs
- BaseCodeDomTreeGenerator.cs
- HtmlHistory.cs
- HwndSourceKeyboardInputSite.cs
- IntegerValidator.cs
- MarkupProperty.cs
- sqlstateclientmanager.cs
- SettingsSection.cs
- ProtocolsConfiguration.cs
- CmsInterop.cs
- ObjectHandle.cs
- SplineKeyFrames.cs
- StatusBar.cs
- ObjectFullSpanRewriter.cs
- DataControlCommands.cs
- SchemaImporterExtensionElement.cs
- SymDocumentType.cs
- WebRequestModuleElementCollection.cs
- DataControlLinkButton.cs
- BinaryMethodMessage.cs
- ModelFactory.cs
- SplitContainer.cs
- DeferredTextReference.cs
- ProfessionalColorTable.cs
- TraceLevelStore.cs
- GB18030Encoding.cs
- Model3DCollection.cs
- ButtonField.cs
- BitmapData.cs
- EntityDataSourceSelectedEventArgs.cs
- LocationReferenceEnvironment.cs
- webproxy.cs
- XomlCompilerParameters.cs
- ExpressionList.cs
- WebDisplayNameAttribute.cs
- CapacityStreamGeometryContext.cs
- WorkflowInstanceUnhandledExceptionRecord.cs
- VisualBasicReference.cs
- RelationshipEndMember.cs
- InvalidateEvent.cs
- SimpleApplicationHost.cs
- ProfileParameter.cs
- CodeTypeConstructor.cs
- PngBitmapDecoder.cs
- ObjectStateFormatter.cs
- Soap.cs
- ProxyBuilder.cs
- TagPrefixAttribute.cs
- PointHitTestResult.cs
- MatrixConverter.cs
- LoadWorkflowAsyncResult.cs
- HtmlHead.cs