/// <summary>
/// Splits with the specified offset.
/// </summary>
/// <param name="offset">The offset.</param>
/// <returns>
/// The latter InsertSegment resulted from this split.
/// </returns>
public InsertSegment Split(int offset)
{
if (this.Offset >= offset || offset >= this.Offset + this.Length)
{
throw new ArgumentOutOfRangeException();
}
var result = new InsertSegment(
this.Event,
offset,
this.Offset + this.Length - offset,
this.Text.Substring(offset - this.Offset));
// Adjust my own length.
this.Length = offset - this.Offset;
this.Text = this.Text.Substring(0, offset - this.Offset);
return(result);
}
/// <summary>
/// Processes the insert change for Type I backtracking detection.
/// </summary>
/// <param name="anEvent">An event.</param>
/// <param name="offset">The offset.</param>
/// <param name="insertedText">The inserted text.</param>
private void ProcessInsertType1(Event anEvent, int offset, string insertedText)
{
// Iterate the segments list
List <InsertSegment> list = this.InsertSegments[this.CurrentFile];
InsertSegment segmentToBeAdded = new InsertSegment(anEvent, offset, insertedText.Length, insertedText);
bool added = false;
for (int i = 0; i < list.Count; ++i)
{
if (list[i].EndOffset <= offset)
{
continue;
}
else if (list[i].Offset < offset && offset < list[i].EndOffset)
{
list.Insert(i + 1, list[i].Split(offset));
list.Insert(i + 1, segmentToBeAdded);
added = true;
++i;
}
else if (offset <= list[i].Offset)
{
if (!added)
{
list.Insert(i, segmentToBeAdded);
added = true;
++i;
}
list[i].Offset += insertedText.Length;
}
else
{
Debug.Assert(false, "Invalid control flow");
}
}
if (!added)
{
list.Add(segmentToBeAdded);
added = true;
}
}
/// <summary>
/// Filters the given type1 backtracking instance with various heuristics.
/// </summary>
/// <param name="insertSegment">The insert segment.</param>
/// <param name="deletedText">The deleted text.</param>
/// <returns>
/// true if this instance should be detected, false otherwise.
/// </returns>
private bool FilterType1Backtracking(InsertSegment insertSegment, string deletedText)
{
if (deletedText == null)
{
return(false);
}
// Size heuristic.
if (deletedText.Trim().Length < Type1SizeThreshold)
{
return(false);
}
// Exclude "import" statements
if (deletedText.Trim().StartsWith("import"))
{
return(false);
}
return(true);
}
