/// <summary>
/// Generates a sequence of DiffItems representing differences in rawDiffStream.
/// </summary>
/// <param name="includeUnchangedBlocks">
/// Indicates whether to generate DiffItems for unchanged blocks.
/// </param>
/// <returns>A DiffItem generator.</returns>
public static IEnumerable<DiffItem> EnumerateDifferences(
StreamCombiner rawDiffStream, bool includeUnchangedBlocks)
{
DiffItem prevItem = null;
DiffItem item = null;
string line = null;
do
{
line = rawDiffStream == null ? null : rawDiffStream.ReadLine();
if (line != null && line.StartsWith("<"))
{
++item.BaseLineCount;
}
else if (line != null && line.StartsWith("-"))
{
continue;
}
else if (line != null && line.StartsWith(">"))
{
++item.DiffLineCount;
}
else if (line != null && line.Equals("\\ No newline at end of file"))
{ // This is a very annoying perforce thing. But we have to account for it.
continue;
}
else
{
if (item != null)
{
if (item.DiffLineCount == 0)
item.DiffType = DiffType.Deleted;
else if (item.BaseLineCount == 0)
item.DiffType = DiffType.Added;
else
item.DiffType = DiffType.Changed;
yield return item;
prevItem = item;
item = null;
}
if (line != null)
{
item = new DiffItem();
Match m = DiffDecoder.Match(line);
if (!m.Success)
yield break;
item.BaseStartLineNumber = Int32.Parse(m.Groups[1].Value);
// 'a' adds AFTER the line, but we do processing once we get to the line.
// So we need to really get to the next line.
if (m.Groups[3].Value.Equals("a"))
item.BaseStartLineNumber += 1;
}
if (includeUnchangedBlocks)
{
var unchangedItem = new DiffItem();
unchangedItem.DiffType = DiffType.Unchanged;
unchangedItem.BaseStartLineNumber =
prevItem == null ? 1 : prevItem.BaseStartLineNumber + prevItem.BaseLineCount;
unchangedItem.BaseLineCount = item == null ?
int.MaxValue : item.BaseStartLineNumber - unchangedItem.BaseStartLineNumber;
unchangedItem.DiffLineCount = unchangedItem.BaseLineCount;
if (unchangedItem.BaseLineCount != 0)
yield return unchangedItem;
}
}
} while (line != null);
}
