internal static PartitionedStream <T, int> PartitionDataSource <T>(IEnumerable <T> source, int partitionCount, bool useStriping)
{
IParallelPartitionable <T> partitionable = source as IParallelPartitionable <T>;
if (partitionable != null)
{
QueryOperatorEnumerator <T, int>[] partitions = partitionable.GetPartitions(partitionCount);
if (partitions == null)
{
throw new InvalidOperationException(System.Linq.SR.GetString("ParallelPartitionable_NullReturn"));
}
if (partitions.Length != partitionCount)
{
throw new InvalidOperationException(System.Linq.SR.GetString("ParallelPartitionable_IncorretElementCount"));
}
PartitionedStream <T, int> stream2 = new PartitionedStream <T, int>(partitionCount, Util.GetDefaultComparer <int>(), OrdinalIndexState.Correct);
for (int i = 0; i < partitionCount; i++)
{
QueryOperatorEnumerator <T, int> enumerator = partitions[i];
if (enumerator == null)
{
throw new InvalidOperationException(System.Linq.SR.GetString("ParallelPartitionable_NullElement"));
}
stream2[i] = enumerator;
}
return(stream2);
}
return(new PartitionedDataSource <T>(source, partitionCount, useStriping));
}
//-----------------------------------------------------------------------------------
// A factory method to construct a partitioned stream over a data source.
//
// Arguments:
// source - the data source to be partitioned
// partitionCount - the number of partitions desired
// useOrdinalOrderPreservation - whether ordinal position must be tracked
// useStriping - whether striped partitioning should be used instead of range partitioning
//
internal static PartitionedStream <T, int> PartitionDataSource <T>(IEnumerable <T> source, int partitionCount, bool useStriping)
{
// The partitioned stream to return.
PartitionedStream <T, int> returnValue;
IParallelPartitionable <T> sourceAsPartitionable = source as IParallelPartitionable <T>;
if (sourceAsPartitionable != null)
{
// The type overrides the partitioning algorithm, so we will use it instead of the default.
// The returned enumerator must be the same size that we requested, otherwise we throw.
QueryOperatorEnumerator <T, int>[] enumerators = sourceAsPartitionable.GetPartitions(partitionCount);
if (enumerators == null)
{
throw new InvalidOperationException(SR.GetString(SR.ParallelPartitionable_NullReturn));
}
else if (enumerators.Length != partitionCount)
{
throw new InvalidOperationException(SR.GetString(SR.ParallelPartitionable_IncorretElementCount));
}
// Now just copy the enumerators into the stream, validating that the result is non-null.
PartitionedStream <T, int> stream =
new PartitionedStream <T, int>(partitionCount, Util.GetDefaultComparer <int>(), OrdinalIndexState.Correct);
for (int i = 0; i < partitionCount; i++)
{
QueryOperatorEnumerator <T, int> currentEnumerator = enumerators[i];
if (currentEnumerator == null)
{
throw new InvalidOperationException(SR.GetString(SR.ParallelPartitionable_NullElement));
}
stream[i] = currentEnumerator;
}
returnValue = stream;
}
else
{
returnValue = new PartitionedDataSource <T>(source, partitionCount, useStriping);
}
Contract.Assert(returnValue.PartitionCount == partitionCount);
return(returnValue);
}
