/// <summary>
/// Formats the results of a merge of <see cref="RawText"/> objects in a Git
/// conformant way. This method also assumes that the <see cref="RawText"/> objects
/// being merged are line oriented files which use LF as delimiter. This
/// method will also use LF to separate chunks and conflict metadata,
/// therefore it fits only to texts that are LF-separated lines.
/// </summary>
/// <param name="out">the outputstream where to write the textual presentation</param>
/// <param name="res">the merge result which should be presented</param>
/// <param name="seqName">
/// When a conflict is reported each conflicting range will get a
/// name. This name is following the "<<<<<<< " or ">>>>>>> "
/// conflict markers. The names for the sequences are given in
/// this list
/// </param>
/// <param name="charsetName">
/// the name of the characterSet used when writing conflict
/// metadata
/// </param>
public void formatMerge(BinaryWriter @out, MergeResult res,
List <String> seqName, string charsetName)
{
String lastConflictingName = null; // is set to non-null whenever we are
// in a conflict
bool threeWayMerge = (res.getSequences().Count == 3);
foreach (MergeChunk chunk in res)
{
RawText seq = (RawText)res.getSequences()[
chunk.getSequenceIndex()];
if (lastConflictingName != null &&
chunk.getConflictState() != MergeChunk.ConflictState.NEXT_CONFLICTING_RANGE)
{
// found the end of an conflict
@out.Write((">>>>>>> " + lastConflictingName + "\n").getBytes(charsetName));
lastConflictingName = null;
}
if (chunk.getConflictState() == MergeChunk.ConflictState.FIRST_CONFLICTING_RANGE)
{
// found the start of an conflict
@out.Write(("<<<<<<< " + seqName[chunk.getSequenceIndex()] +
"\n").getBytes(charsetName));
lastConflictingName = seqName[chunk.getSequenceIndex()];
}
else if (chunk.getConflictState() == MergeChunk.ConflictState.NEXT_CONFLICTING_RANGE)
{
// found another conflicting chunk
/*
* In case of a non-three-way merge I'll add the name of the
* conflicting chunk behind the equal signs. I also append the
* name of the last conflicting chunk after the ending
* greater-than signs. If somebody knows a better notation to
* present non-three-way merges - feel free to correct here.
*/
lastConflictingName = seqName[chunk.getSequenceIndex()];
@out.Write((threeWayMerge ? "=======\n" : "======= "
+ lastConflictingName + "\n").getBytes(charsetName));
}
// the lines with conflict-metadata are written. Now write the chunk
for (int i = chunk.getBegin(); i < chunk.getEnd(); i++)
{
if (i > 0)
{
@out.Write('\n');
}
seq.writeLine(@out.BaseStream, i);
}
}
// one possible leftover: if the merge result ended with a conflict we
// have to close the last conflict here
if (lastConflictingName != null)
{
@out.Write('\n');
@out.Write((">>>>>>> " + lastConflictingName + "\n").getBytes(charsetName));
}
}
/// <summary>
/// Formats the results of a merge of exactly two <see cref="RawText"/> objects in
/// a Git conformant way. This convenience method accepts the names for the
/// three sequences (base and the two merged sequences) as explicit
/// parameters and doesn't require the caller to specify a List
/// </summary>
/// <param name="out">
/// the <see cref="BinaryWriter"/> where to write the textual
/// presentation
/// </param>
/// <param name="res">the merge result which should be presented</param>
/// <param name="baseName">the name ranges from the base should get</param>
/// <param name="oursName">the name ranges from ours should get</param>
/// <param name="theirsName">the name ranges from theirs should get</param>
/// <param name="charsetName">
/// the name of the characterSet used when writing conflict
/// metadata
/// </param>
public void formatMerge(BinaryWriter @out, MergeResult res, String baseName,
String oursName, String theirsName, string charsetName)
{
var names = new List <String>(3);
names.Add(baseName);
names.Add(oursName);
names.Add(theirsName);
formatMerge(@out, res, names, charsetName);
}
public MergeChunkIterator(MergeResult mergeResult)
{
_mergeResult = mergeResult;
}
/// <summary>
/// Does the three way merge between a common base and two sequences.
/// </summary>
/// <param name="base">base the common base sequence</param>
/// <param name="ours">ours the first sequence to be merged</param>
/// <param name="theirs">theirs the second sequence to be merged</param>
/// <returns>the resulting content</returns>
public static MergeResult merge(Sequence @base, Sequence ours,
Sequence theirs)
{
List <Sequence> sequences = new List <Sequence>(3);
sequences.Add(@base);
sequences.Add(ours);
sequences.Add(theirs);
MergeResult result = new MergeResult(sequences);
EditList oursEdits = new MyersDiff(@base, ours).getEdits();
IteratorBase <Edit> baseToOurs = oursEdits.iterator();
EditList theirsEdits = new MyersDiff(@base, theirs).getEdits();
IteratorBase <Edit> baseToTheirs = theirsEdits.iterator();
int current = 0; // points to the next line (first line is 0) of base
// which was not handled yet
Edit oursEdit = nextEdit(baseToOurs);
Edit theirsEdit = nextEdit(baseToTheirs);
// iterate over all edits from base to ours and from base to theirs
// leave the loop when there are no edits more for ours or for theirs
// (or both)
while (theirsEdit != END_EDIT || oursEdit != END_EDIT)
{
if (oursEdit.EndA <= theirsEdit.BeginA)
{
// something was changed in ours not overlapping with any change
// from theirs. First add the common part in front of the edit
// then the edit.
if (current != oursEdit.BeginA)
{
result.add(0, current, oursEdit.BeginA,
MergeChunk.ConflictState.NO_CONFLICT);
}
result.add(1, oursEdit.BeginB, oursEdit.EndB,
MergeChunk.ConflictState.NO_CONFLICT);
current = oursEdit.EndA;
oursEdit = nextEdit(baseToOurs);
}
else if (theirsEdit.EndA <= oursEdit.BeginA)
{
// something was changed in theirs not overlapping with any
// from ours. First add the common part in front of the edit
// then the edit.
if (current != theirsEdit.BeginA)
{
result.add(0, current, theirsEdit.BeginA,
MergeChunk.ConflictState.NO_CONFLICT);
}
result.add(2, theirsEdit.BeginB, theirsEdit.EndB,
MergeChunk.ConflictState.NO_CONFLICT);
current = theirsEdit.EndA;
theirsEdit = nextEdit(baseToTheirs);
}
else
{
// here we found a real overlapping modification
// if there is a common part in front of the conflict add it
if (oursEdit.BeginA != current &&
theirsEdit.BeginA != current)
{
result.add(0, current, Math.Min(oursEdit.BeginA,
theirsEdit.BeginA), MergeChunk.ConflictState.NO_CONFLICT);
}
// set some initial values for the ranges in A and B which we
// want to handle
int oursBeginB = oursEdit.BeginB;
int theirsBeginB = theirsEdit.BeginB;
// harmonize the start of the ranges in A and B
if (oursEdit.BeginA < theirsEdit.BeginA)
{
theirsBeginB -= theirsEdit.BeginA
- oursEdit.BeginA;
}
else
{
oursBeginB -= oursEdit.BeginA - theirsEdit.BeginA;
}
// combine edits:
// Maybe an Edit on one side corresponds to multiple Edits on
// the other side. Then we have to combine the Edits of the
// other side - so in the end we can merge together two single
// edits.
//
// It is important to notice that this combining will extend the
// ranges of our conflict always downwards (towards the end of
// the content). The starts of the conflicting ranges in ours
// and theirs are not touched here.
//
// This combining is an iterative process: after we have
// combined some edits we have to do the check again. The
// combined edits could now correspond to multiple edits on the
// other side.
//
// Example: when this combining algorithm works on the following
// edits
// oursEdits=((0-5,0-5),(6-8,6-8),(10-11,10-11)) and
// theirsEdits=((0-1,0-1),(2-3,2-3),(5-7,5-7))
// it will merge them into
// oursEdits=((0-8,0-8),(10-11,10-11)) and
// theirsEdits=((0-7,0-7))
//
// Since the only interesting thing to us is how in ours and
// theirs the end of the conflicting range is changing we let
// oursEdit and theirsEdit point to the last conflicting edit
Edit nextOursEdit = nextEdit(baseToOurs);
Edit nextTheirsEdit = nextEdit(baseToTheirs);
for (; ;)
{
if (oursEdit.EndA > nextTheirsEdit.BeginA)
{
theirsEdit = nextTheirsEdit;
nextTheirsEdit = nextEdit(baseToTheirs);
}
else if (theirsEdit.EndA > nextOursEdit.BeginA)
{
oursEdit = nextOursEdit;
nextOursEdit = nextEdit(baseToOurs);
}
else
{
break;
}
}
// harmonize the end of the ranges in A and B
int oursEndB = oursEdit.EndB;
int theirsEndB = theirsEdit.EndB;
if (oursEdit.EndA < theirsEdit.EndA)
{
oursEndB += theirsEdit.EndA - oursEdit.EndA;
}
else
{
theirsEndB += oursEdit.EndA - theirsEdit.EndA;
}
// Add the conflict
result.add(1, oursBeginB, oursEndB,
MergeChunk.ConflictState.FIRST_CONFLICTING_RANGE);
result.add(2, theirsBeginB, theirsEndB,
MergeChunk.ConflictState.NEXT_CONFLICTING_RANGE);
current = Math.Max(oursEdit.EndA, theirsEdit.EndA);
oursEdit = nextOursEdit;
theirsEdit = nextTheirsEdit;
}
}
// maybe we have a common part behind the last edit: copy it to the
// result
if (current < @base.size())
{
result.add(0, current, @base.size(), MergeChunk.ConflictState.NO_CONFLICT);
}
return(result);
}
