// Constructor
internal DiffgramChangeNode(XmlDiffNode sourceNode, XmlDiffNode targetNode, XmlDiffOperation op, ulong operationID)
: base(operationID)
{
Debug.Assert(sourceNode != null);
Debug.Assert(targetNode != null);
Debug.Assert(XmlDiff.IsChangeOperation(op) || op == XmlDiffOperation.ChangeAttr);
_sourceNode = sourceNode;
_targetNode = targetNode;
_op = op;
}
// Constructor
internal EditScriptChange(int sourceIndex, int targetIndex, XmlDiffOperation changeOp, EditScript next)
: base(next)
{
Debug.Assert(sourceIndex > 0);
Debug.Assert(targetIndex > 0);
Debug.Assert(XmlDiff.IsChangeOperation(changeOp));
_sourceIndex = sourceIndex;
_targetIndex = targetIndex;
_changeOp = changeOp;
}
private void ComputeTreeDistance(int sourcePos, int targetPos)
{
int sourcePosLeft = _sourceNodes[sourcePos].Left;
int targetPosLeft = _targetNodes[targetPos].Left;
int i, j;
// init borders of _forestDist array
EditScriptAddOpened esAdd = new EditScriptAddOpened(targetPosLeft, EmptyEditScript);
EditScriptRemoveOpened esRemove = new EditScriptRemoveOpened(sourcePosLeft, EmptyEditScript);
_forestDist[sourcePosLeft - 1, targetPosLeft - 1]._cost = 0;
_forestDist[sourcePosLeft - 1, targetPosLeft - 1]._editScript = EmptyEditScript;
for (i = sourcePosLeft; i <= sourcePos; i++)
{
_forestDist[i, targetPosLeft - 1]._cost = (i - sourcePosLeft + 1) * OperationCost[(int)XmlDiffOperation.Remove];
_forestDist[i, targetPosLeft - 1]._editScript = esRemove;
}
for (j = targetPosLeft; j <= targetPos; j++)
{
_forestDist[sourcePosLeft - 1, j]._cost = (j - targetPosLeft + 1) * OperationCost[(int)XmlDiffOperation.Add];
_forestDist[sourcePosLeft - 1, j]._editScript = esAdd;
}
#if DEBUG
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, "\nForest distance (" + sourcePos + "," + targetPos + "):\n");
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, " 0 ");
for (j = targetPosLeft; j <= targetPos; j++)
{
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, j + " ");
}
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, "\n ");
for (j = targetPosLeft - 1; j <= targetPos; j++)
{
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, "*****");
}
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, "\n0 * 0 ");
for (j = targetPosLeft; j <= targetPos; j++)
{
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, "-" + _forestDist[sourcePosLeft - 1, j]._cost + " ");
}
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, "\n");
#endif
// compute the inside of _forestDist array
for (i = sourcePosLeft; i <= sourcePos; i++)
{
#if DEBUG
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, i + " * |" + _forestDist[i, targetPosLeft - 1]._cost + " ");
#endif
for (j = targetPosLeft; j <= targetPos; j++)
{
int sourceCurLeft = _sourceNodes[i].Left;
int targetCurLeft = _targetNodes[j].Left;
int removeCost = _forestDist[i - 1, j]._cost + OperationCost[(int)XmlDiffOperation.Remove];
int addCost = _forestDist[i, j - 1]._cost + OperationCost[(int)XmlDiffOperation.Add];
if (sourceCurLeft == sourcePosLeft && targetCurLeft == targetPosLeft)
{
XmlDiffOperation changeOp = _sourceNodes[i].GetDiffOperation(_targetNodes[j], _xmlDiff);
Debug.Assert(XmlDiff.IsChangeOperation(changeOp) ||
changeOp == XmlDiffOperation.Match ||
changeOp == XmlDiffOperation.Undefined);
if (changeOp == XmlDiffOperation.Match)
{
// identical nodes matched
OpNodesMatch(i, j);
}
else
{
int changeCost = _forestDist[i - 1, j - 1]._cost + OperationCost[(int)changeOp];
if (changeCost < addCost)
{
// operation 'change'
if (changeCost < removeCost)
{
OpChange(i, j, changeOp, changeCost);
}
// operation 'remove'
else
{
OpRemove(i, j, removeCost);
}
}
else
{
// operation 'add'
if (addCost < removeCost)
{
OpAdd(i, j, addCost);
}
// operation 'remove'
else
{
OpRemove(i, j, removeCost);
}
}
}
_treeDist[i, j]._cost = _forestDist[i, j]._cost;
_treeDist[i, j]._editScript = _forestDist[i, j]._editScript.GetClosedScript(i, j);;
}
else
{
int m = sourceCurLeft - 1;
int n = targetCurLeft - 1;
if (m < sourcePosLeft - 1)
{
m = sourcePosLeft - 1;
}
if (n < targetPosLeft - 1)
{
n = targetPosLeft - 1;
}
// cost of concatenating of the two edit scripts
int compoundEditCost = _forestDist[m, n]._cost + _treeDist[i, j]._cost;
if (compoundEditCost < addCost)
{
if (compoundEditCost < removeCost)
{
// copy script
if (_treeDist[i, j]._editScript == EmptyEditScript)
{
Debug.Assert(_treeDist[i, j]._cost == 0);
OpCopyScript(i, j, m, n);
}
// concatenate scripts
else
{
OpConcatScripts(i, j, m, n);
}
}
// operation 'remove'
else
{
OpRemove(i, j, removeCost);
}
}
else
{
// operation 'add'
if (addCost < removeCost)
{
OpAdd(i, j, addCost);
}
// operation 'remove'
else
{
OpRemove(i, j, removeCost);
}
}
}
#if DEBUG
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, _forestDist[i, j]._cost + " ");
#endif
}
#if DEBUG
Trace.WriteIf(XmlDiff.T_ForestDistance.Enabled, "\n");
#endif
}
}
