// Constructor
internal OperationDescrPrefixChange( DiffgramGenerator.PrefixChange prefixChange )
: base(prefixChange._opid)
{
_prefixChange = prefixChange;
}
Diffgram ZhangShashaAlgorithm()
{
// Preprocess the trees for the tree-to-tree comparison algorithm and diffgram generation.
// This includes post-order numbering of all nodes (the source and target nodes are stored
// in post-order in the _sourceNodes and _targetNodes arrays).
#if DEBUG
Trace.WriteLineIf( T_Phases.Enabled, "* Using Zhang-Shasha Algorithm" );
Trace.WriteLineIf( T_Phases.Enabled, "* Preprocessing trees..." );
#endif
#if MEASURE_PERF
int startTickCount = Environment.TickCount;
#endif
PreprocessTree( _sourceDoc, ref _sourceNodes );
PreprocessTree( _targetDoc, ref _targetNodes );
#if MEASURE_PERF
_xmlDiffPerf._preprocessTime = Environment.TickCount - startTickCount;
#endif
// Find minimal edit distance between the trees
#if DEBUG
Trace.WriteLineIf( T_Phases.Enabled, "* Computing minimal tree distance..." );
if ( T_Tree.Enabled )
{
Trace.WriteLine( "Source tree: " );
_sourceDoc.Dump( string.Empty );
Trace.WriteLine( "Target tree: " );
_targetDoc.Dump( string.Empty );
}
#endif
#if MEASURE_PERF
startTickCount = Environment.TickCount;
#endif
EditScript editScript = ( new MinimalTreeDistanceAlgo( this ) ).FindMinimalDistance();
Debug.Assert( editScript != null );
#if MEASURE_PERF
_xmlDiffPerf._treeDistanceTime = Environment.TickCount - startTickCount;
#endif
#if DEBUG
if ( T_EditScript.Enabled )
{
Trace.Write( "\nMinimal edit script: \n" );
editScript.Dump();
}
#endif
// Generate the diffgram
#if DEBUG
Trace.WriteLineIf( T_Phases.Enabled, "* Generating diffgram..." );
#endif
#if MEASURE_PERF
startTickCount = Environment.TickCount;
#endif
Diffgram diffgram = new DiffgramGenerator( this ).GenerateFromEditScript( editScript );
#if MEASURE_PERF
_xmlDiffPerf._diffgramGenerationTime = Environment.TickCount - startTickCount;
#endif
return diffgram;
}
// Constructor
internal OperationDescrNamespaceChange( DiffgramGenerator.NamespaceChange nsChange )
: base(nsChange._opid)
{
_nsChange = nsChange;
}
private bool Diff( XmlWriter diffgramWriter )
{
try
{
#if MEASURE_PERF
int startTickCount = Environment.TickCount;
#endif
// compare hash values of root nodes and return if same (the hash values were computed during load)
if ( IdenticalSubtrees( _sourceDoc, _targetDoc ) )
{
if ( diffgramWriter != null )
{
Diffgram emptyDiffgram = new DiffgramGenerator( this ).GenerateEmptyDiffgram();
emptyDiffgram.WriteTo( diffgramWriter );
diffgramWriter.Flush();
}
#if DEBUG
Trace.WriteLineIf( T_Phases.Enabled, "* Done." );
#endif
#if MEASURE_PERF
_xmlDiffPerf._identicalOrNoDiffWriterTime = Environment.TickCount - startTickCount;
#endif
return true;
}
else if ( diffgramWriter == null )
{
#if DEBUG
Trace.WriteLineIf( T_Phases.Enabled, "* Done." );
#endif
#if MEASURE_PERF
_xmlDiffPerf._identicalOrNoDiffWriterTime = Environment.TickCount - startTickCount;
#endif
return false;
}
#if MEASURE_PERF
_xmlDiffPerf._identicalOrNoDiffWriterTime = Environment.TickCount - startTickCount;
#endif
// Match & shrink identical subtrees
#if DEBUG
Trace.WriteLineIf( T_Phases.Enabled, "* Matching identical subtrees..." );
#endif
#if MEASURE_PERF
startTickCount = Environment.TickCount;
#endif
MatchIdenticalSubtrees();
#if MEASURE_PERF
_xmlDiffPerf._matchTime = Environment.TickCount - startTickCount;
#endif
#if DEBUG
Trace.WriteLineIf( T_Phases.Enabled, "* Source document shrinked: " + _sourceDoc.NodesCount + " nodes" );
Trace.WriteLineIf( T_Phases.Enabled, "* Target document shrinked: " + _targetDoc.NodesCount + " nodes" );
#endif
Diffgram diffgram = null;
// Choose algorithm
switch ( _algorithm ) {
case XmlDiffAlgorithm.Fast:
diffgram = WalkTreeAlgorithm();
break;
case XmlDiffAlgorithm.Precise:
diffgram = ZhangShashaAlgorithm();
break;
case XmlDiffAlgorithm.Auto:
if ( _sourceDoc.NodesCount + _targetDoc.NodesCount <= MaxTotalNodesCountForTreeDistance )
diffgram = ZhangShashaAlgorithm();
else
diffgram = WalkTreeAlgorithm();
break;
default:
Debug.Assert( false );
break;
}
// Output the diffgram
#if MEASURE_PERF
startTickCount = Environment.TickCount;
#endif
Debug.Assert( diffgramWriter != null );
diffgram.WriteTo( diffgramWriter );
diffgramWriter.Flush();
#if MEASURE_PERF
_xmlDiffPerf._diffgramSaveTime = Environment.TickCount - startTickCount;
#endif
#if DEBUG
Trace.WriteLineIf( T_Phases.Enabled, "* Done." );
#endif
}
finally
{
_sourceNodes = null;
_targetNodes = null;
}
return false;
}
