private GroupedItem <T>[] MergeBlocks(
IFileWriter fileWriter,
int blockSize,
GroupedItem <T>[] left,
GroupedItem <T>[] right
)
{
_Status = SortStatus.Merging;
if (left.Length == 0)
{
return(right);
}
if (right.Length == 0)
{
return(left);
}
if (
_comparer.Compare(left[0], left[left.Length - 1]) == 0 &&
_comparer.Compare(right[0], right[right.Length - 1]) == 0
)
{
if (_comparer.Compare(left[left.Length - 1], right[0]) <= 0)
{
Write(fileWriter, right);
_BlocksMerged += 2;
return(left);
}
Write(fileWriter, left);
_BlocksMerged += 2;
return(right);
}
left = _sortStrategy.Merge(left, right);
_BlocksMerged += 2;
Write(fileWriter, left.Skip(blockSize).ToArray());
return(left.Take(blockSize).ToArray());
}