public IEnumerable<DiffMatchPatch.Patch> MakePatch(string contentOne, string contentTwo, CompareOptions options)
{
var diff = new my.utils.Diff();
var changes = diff.DiffText(contentOne, contentTwo);
var contentOneLines = contentOne.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
var contentTwoLines = contentTwo.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
var chunks = new HashSet<Chunk>();
Chunk currentChunk = null;
for (var i = 0; i < changes.Length; i++)
{
var change = changes[i];
Diff.Item? nextChange = null;
if (changes.Length > i + 1)
nextChange = changes.ElementAtOrDefault(i + 1);
var continuation = currentChunk != null;
if (!continuation)
{
currentChunk = CreateChunk(change, options);
chunks.Add(currentChunk);
}
if (change.StartA != 0 && !continuation)
{
// no start context needed
currentChunk.start1 = change.StartA - options.ContextSize;
currentChunk.start2 = change.StartB - options.ContextSize;
// stick some context in
var start = change.StartB - options.ContextSize;
for (var j = start; j < change.StartB; j++)
{
currentChunk.diffs.Add(new Line(Operation.EQUAL, contentTwoLines[j]));
}
}
if (change.deletedA > 0)
{
for (var j = 0; j < change.deletedA; j++)
{
var line = contentOneLines[j + change.StartA];
currentChunk.diffs.Add(new Line(Operation.DELETE, line));
}
}
if (change.insertedB > 0)
{
for (var j = 0; j < change.insertedB; j++)
{
var line = contentTwoLines[j + change.StartB];
currentChunk.diffs.Add(new Line(Operation.INSERT, line));
}
}
var start2 = change.StartB + change.insertedB;
int end;
if (nextChange.HasValue)
end = Min(start2 + options.ContextSize, contentTwoLines.Length, nextChange.Value.StartB);
else
end = Min(start2 + options.ContextSize, contentTwoLines.Length);
for (var j = start2; j < end; j++)
{
currentChunk.diffs.Add(new Line(Operation.EQUAL, contentTwoLines[j]));
}
if (nextChange.HasValue && nextChange.Value.StartB - end > 0)
{
// need to split the diff into multiple chunks
currentChunk = null;
}
}
foreach (var chunk in chunks)
{
chunk.length1 = chunk.diffs.Count(x => x.operation == Operation.EQUAL || x.operation == Operation.DELETE);
chunk.length2 = chunk.diffs.Count(x => x.operation == Operation.EQUAL || x.operation == Operation.INSERT);
}
return chunks;
}
public static Diff Compare(string fileOnePath, string fileOneContent, string fileTwoPath, string fileTwoContent, CompareOptions options)
{
if (fileOneContent == null && fileTwoContent == null)
throw new InvalidOperationException("Both files were null");
if (options.BomMode == BomMode.Ignore)
{
if (fileOneContent != null)
fileOneContent = RemoveBom(fileOneContent);
if (fileTwoContent != null)
fileTwoContent = RemoveBom(fileTwoContent);
}
if (fileTwoContent == null)
return DeletedFileDiff(fileOneContent, fileOnePath);
if (fileOneContent == null)
return NewFileDiff(fileTwoContent, fileTwoPath);
if (IsBinary(fileOneContent))
throw new BinaryFileException(fileOnePath);
if (IsBinary(fileTwoContent))
throw new BinaryFileException(fileTwoPath);
var patchMaker = new PatchMaker();
var patches = patchMaker.MakePatch(fileOneContent, fileTwoContent, options);
var chunks = new List<Chunk>();
foreach (var patch in patches)
{
var originalRange = new ChangeRange(patch.start1 + 1, patch.length1);
var newRange = new ChangeRange(patch.start2 + 1, patch.length2);
var range = new ChunkRange(originalRange, newRange);
var snippets = new List<ISnippet>();
var lines = new List<DiffMatchPatch.Diff>();
Operation? previousOperation = null;
var isModification = false;
foreach (var diff in patch.diffs)
{
if (previousOperation == null)
previousOperation = diff.operation;
if (previousOperation == Operation.DELETE && diff.operation == Operation.INSERT)
isModification = true;
else if (previousOperation != diff.operation)
{
// different operation
if (previousOperation == Operation.EQUAL)
snippets.Add(new ContextSnippet(lines.Select(x => new ContextLine(x.text)).Cast<ILine>()));
else if (isModification)
snippets.Add(new ModificationSnippet(
lines
.Where(x => x.operation == Operation.DELETE)
.Select(x => new SubtractionLine(x.text))
.Cast<ILine>(),
lines
.Where(x => x.operation == Operation.INSERT)
.Select(x => new AdditionLine(x.text))
.Cast<ILine>()
));
else if (previousOperation == Operation.INSERT)
snippets.Add(new AdditionSnippet(lines.Select(x => new AdditionLine(x.text)).Cast<ILine>()));
else if (previousOperation == Operation.DELETE)
snippets.Add(new SubtractionSnippet(lines.Select(x => new SubtractionLine(x.text)).Cast<ILine>()));
lines.Clear();
isModification = false;
}
lines.Add(diff);
previousOperation = diff.operation;
}
if (lines.Count > 0)
{
if (previousOperation == Operation.INSERT)
snippets.Add(new AdditionSnippet(lines.Select(x => new AdditionLine(x.text)).Cast<ILine>()));
else if (previousOperation == Operation.DELETE)
snippets.Add(new SubtractionSnippet(lines.Select(x => new SubtractionLine(x.text)).Cast<ILine>()));
else
snippets.Add(new ContextSnippet(lines.Select(x => new ContextLine(x.text)).Cast<ILine>()));
}
chunks.Add(new Chunk(range, snippets));
}
var header = new Header(new FormatType("generated"), new[]
{
new File('a', fileOnePath),
new File('b', fileTwoPath)
});
return new Diff(header, chunks);
}
private Chunk CreateChunk(Diff.Item change, CompareOptions options)
{
var chunk = new Chunk();
chunk.start1 = change.StartA;
chunk.start2 = change.StartB;
chunk.length1 = change.deletedA + options.ContextSize;
chunk.length2 = change.insertedB + options.ContextSize;
chunk.diffs = new List<Line>();
return chunk;
}