/// <summary>
/// Returns the result of the difference computation
/// </summary>
/// <returns></returns>
public List <DiffResultSpan> DiffReport()
{
var retval = new List <DiffResultSpan>();
int dcount = _dest.Count();
int scount = _source.Count();
//Deal with the special case of empty files
if (dcount == 0)
{
if (scount > 0)
{
retval.Add(DiffResultSpan.CreateDeleteSource(0, scount));
}
return(retval);
}
else
{
if (scount == 0)
{
retval.Add(DiffResultSpan.CreateAddDestination(0, dcount));
return(retval);
}
}
_matchList.Sort();
int curDest = 0;
int curSource = 0;
DiffResultSpan last = null;
//Process each match record
foreach (DiffResultSpan drs in _matchList)
{
if ((!AddChanges(retval, curDest, drs.DestIndex, curSource, drs.SourceIndex)) &&
(last != null))
{
last.AddLength(drs.Length);
}
else
{
retval.Add(drs);
}
curDest = drs.DestIndex + drs.Length;
curSource = drs.SourceIndex + drs.Length;
last = drs;
}
//Process any tail end data
AddChanges(retval, curDest, dcount, curSource, scount);
return(retval);
}
private bool AddChanges(
List <DiffResultSpan> report,
int curDest,
int nextDest,
int curSource,
int nextSource)
{
bool retval = false;
int diffDest = nextDest - curDest;
int diffSource = nextSource - curSource;
int minDiff = 0;
if (diffDest > 0)
{
if (diffSource > 0)
{
minDiff = Math.Min(diffDest, diffSource);
report.Add(DiffResultSpan.CreateReplace(curDest, curSource, minDiff));
if (diffDest > diffSource)
{
curDest += minDiff;
report.Add(DiffResultSpan.CreateAddDestination(curDest, diffDest - diffSource));
}
else
{
if (diffSource > diffDest)
{
curSource += minDiff;
report.Add(DiffResultSpan.CreateDeleteSource(curSource, diffSource - diffDest));
}
}
}
else
{
report.Add(DiffResultSpan.CreateAddDestination(curDest, diffDest));
}
retval = true;
}
else
{
if (diffSource > 0)
{
report.Add(DiffResultSpan.CreateDeleteSource(curSource, diffSource));
retval = true;
}
}
return(retval);
}