// isRightSideContext is true when linenumber corresponds to the right side (sha2).
// linenumber is one-based
private DiffContext createDiffContext(int linenumber, bool isRightSideContext, FullContextDiff context,
ContextDepth depth)
{
int startLineNumber = Math.Max(1, linenumber - depth.Up);
int endLineNumber = linenumber + depth.Down;
SparsedListIterator <string> itLeft = context.Left.Begin();
SparsedListIterator <string> itRight = context.Right.Begin();
if (isRightSideContext)
{
itRight = SparsedListUtils.FindNth(itRight, startLineNumber - 1);
itLeft = SparsedListUtils.Advance(itLeft, itRight.Position);
}
else
{
itLeft = SparsedListUtils.FindNth(itLeft, startLineNumber - 1);
itRight = SparsedListUtils.Advance(itRight, itLeft.Position);
}
DiffContext diffContext = new DiffContext
{
Lines = new List <DiffContext.Line>()
};
int iContextLine = 0;
while (true)
{
int?leftLineNumber = itLeft.LineNumber != null ? itLeft.LineNumber + 1 : null;
int?rightLineNumber = itRight.LineNumber != null ? itRight.LineNumber + 1 : null;
DiffContext.Line line = getLineContext(leftLineNumber, rightLineNumber, itLeft.Current, itRight.Current);
diffContext.Lines.Add(line);
if ((leftLineNumber.HasValue && !isRightSideContext && leftLineNumber == linenumber) ||
(rightLineNumber.HasValue && isRightSideContext && rightLineNumber == linenumber))
{
// zero-based index of a selected line in DiffContext.Lines
diffContext.SelectedIndex = iContextLine;
}
if ((leftLineNumber.HasValue && !isRightSideContext && leftLineNumber >= endLineNumber) ||
(rightLineNumber.HasValue && isRightSideContext && rightLineNumber >= endLineNumber))
{
// we've just reached a line that should not be included in the context
break;
}
if (!itLeft.Next() || !itRight.Next())
{
// we've just reached the end
break;
}
++iContextLine;
}
return(diffContext);
}
/// <summary>
/// Advances passed iterator 'index' positions forward
/// </summary>
public static SparsedListIterator <T> Advance <T>(SparsedListIterator <T> iterator, int index) where T : class
{
int skipped = 0;
while (true)
{
if (skipped == index)
{
break;
}
skipped++;
if (!iterator.Next())
{
break;
}
}
return(iterator);
}
/// <summary>
/// Finds an N-th non-null item, where N is passed in 'index' argument
/// </summary>
public static SparsedListIterator <T> FindNth <T>(SparsedListIterator <T> iterator, int index) where T : class
{
int skipped = 0;
while (true)
{
if (iterator.GetLineNumber().HasValue)
{
if (skipped == index)
{
break;
}
skipped++;
}
if (!iterator.Next())
{
break;
}
}
return(iterator);
}