/// <summary>
/// Determines if a change will cause a structural change to the document and if not, applies it to the existing tree.
/// If a structural change would occur, automatically starts a reparse
/// </summary>
/// <remarks>
/// NOTE: The initial incremental parsing check and actual incremental parsing (if possible) occurs
/// on the callers thread. However, if a full reparse is needed, this occurs on a background thread.
/// </remarks>
/// <param name="change">The change to apply to the parse tree</param>
/// <returns>A PartialParseResult value indicating the result of the incremental parse</returns>
public virtual PartialParseResult CheckForStructureChanges(TextChange change)
{
// Validate the change
long?elapsedMs = null;
#if EDITOR_TRACING
Stopwatch sw = new Stopwatch();
sw.Start();
#endif
RazorEditorTrace.TraceLine(RazorResources.Trace_EditorReceivedChange, Path.GetFileName(FileName), change);
if (change.NewBuffer == null)
{
throw new ArgumentException(String.Format(CultureInfo.CurrentUICulture,
RazorResources.Structure_Member_CannotBeNull,
"Buffer",
"TextChange"), "change");
}
PartialParseResult result = PartialParseResult.Rejected;
// If there isn't already a parse underway, try partial-parsing
string changeString = String.Empty;
using (_parser.SynchronizeMainThreadState())
{
// Capture the string value of the change while we're synchronized
changeString = change.ToString();
// Check if we can partial-parse
if (CurrentParseTree != null && _parser.IsIdle)
{
result = TryPartialParse(change);
}
}
// If partial parsing failed or there were outstanding parser tasks, start a full reparse
if (result.HasFlag(PartialParseResult.Rejected))
{
_parser.QueueChange(change);
}
// Otherwise, remember if this was provisionally accepted for next partial parse
LastResultProvisional = result.HasFlag(PartialParseResult.Provisional);
VerifyFlagsAreValid(result);
#if EDITOR_TRACING
sw.Stop();
elapsedMs = sw.ElapsedMilliseconds;
sw.Reset();
#endif
RazorEditorTrace.TraceLine(RazorResources.Trace_EditorProcessedChange, Path.GetFileName(FileName), changeString, elapsedMs.HasValue ? elapsedMs.Value.ToString() : "?", result.ToString());
return(result);
}
public void QueueChange(TextChange change)
{
#if EDITOR_TRACING
RazorEditorTrace.TraceLine(RazorResources.Trace_QueuingParse, Path.GetFileName(_fileName), change);
#endif
EnsureOnThread();
lock (_stateLock)
{
// CurrentParcel token source is not null ==> There's a parse underway
if (_currentParcelCancelSource != null)
{
_currentParcelCancelSource.Cancel();
}
_changes.Add(change);
_hasParcel.Set();
}
}
// **** BACKGROUND THREAD ****
private void WorkerLoop()
{
long? elapsedMs = null;
string fileNameOnly = Path.GetFileName(_fileName);
#if EDITOR_TRACING
Stopwatch sw = new Stopwatch();
#endif
try
{
RazorEditorTrace.TraceLine(RazorResources.Trace_BackgroundThreadStart, fileNameOnly);
EnsureOnThread();
while (!_shutdownToken.IsCancellationRequested)
{
// Grab the parcel of work to do
WorkParcel parcel = _main.GetParcel();
if (parcel.Changes.Any())
{
RazorEditorTrace.TraceLine(RazorResources.Trace_ChangesArrived, fileNameOnly, parcel.Changes.Count);
try
{
DocumentParseCompleteEventArgs args = null;
using (var linkedCancel = CancellationTokenSource.CreateLinkedTokenSource(_shutdownToken, parcel.CancelToken))
{
if (parcel != null && !linkedCancel.IsCancellationRequested)
{
// Collect ALL changes
#if EDITOR_TRACING
if (_previouslyDiscarded != null && _previouslyDiscarded.Any())
{
RazorEditorTrace.TraceLine(RazorResources.Trace_CollectedDiscardedChanges, fileNameOnly, _previouslyDiscarded.Count);
}
#endif
var allChanges = Enumerable.Concat(
_previouslyDiscarded ?? Enumerable.Empty <TextChange>(), parcel.Changes).ToList();
var finalChange = allChanges.LastOrDefault();
if (finalChange != default(TextChange))
{
#if EDITOR_TRACING
sw.Start();
#endif
GeneratorResults results = ParseChange(finalChange.NewBuffer, linkedCancel.Token);
#if EDITOR_TRACING
sw.Stop();
elapsedMs = sw.ElapsedMilliseconds;
sw.Reset();
#endif
RazorEditorTrace.TraceLine(
RazorResources.Trace_ParseComplete,
fileNameOnly,
elapsedMs.HasValue ? elapsedMs.Value.ToString() : "?");
if (results != null && !linkedCancel.IsCancellationRequested)
{
// Clear discarded changes list
_previouslyDiscarded = null;
// Take the current tree and check for differences
#if EDITOR_TRACING
sw.Start();
#endif
bool treeStructureChanged = _currentParseTree == null || TreesAreDifferent(_currentParseTree, results.Document, allChanges, parcel.CancelToken);
#if EDITOR_TRACING
sw.Stop();
elapsedMs = sw.ElapsedMilliseconds;
sw.Reset();
#endif
_currentParseTree = results.Document;
RazorEditorTrace.TraceLine(RazorResources.Trace_TreesCompared,
fileNameOnly,
elapsedMs.HasValue ? elapsedMs.Value.ToString() : "?",
treeStructureChanged);
// Build Arguments
args = new DocumentParseCompleteEventArgs()
{
GeneratorResults = results,
SourceChange = finalChange,
TreeStructureChanged = treeStructureChanged
};
}
else
{
// Parse completed but we were cancelled in the mean time. Add these to the discarded changes set
RazorEditorTrace.TraceLine(RazorResources.Trace_ChangesDiscarded, fileNameOnly, allChanges.Count);
_previouslyDiscarded = allChanges;
}
#if CHECK_TREE
if (args != null)
{
// Rewind the buffer and sanity check the line mappings
finalChange.NewBuffer.Position = 0;
int lineCount = finalChange.NewBuffer.ReadToEnd().Split(new string[] { Environment.NewLine, "\r", "\n" }, StringSplitOptions.None).Count();
Debug.Assert(
!args.GeneratorResults.DesignTimeLineMappings.Any(pair => pair.Value.StartLine > lineCount),
"Found a design-time line mapping referring to a line outside the source file!");
Debug.Assert(
!args.GeneratorResults.Document.Flatten().Any(span => span.Start.LineIndex > lineCount),
"Found a span with a line number outside the source file");
Debug.Assert(
!args.GeneratorResults.Document.Flatten().Any(span => span.Start.AbsoluteIndex > parcel.NewBuffer.Length),
"Found a span with an absolute offset outside the source file");
}
#endif
}
}
}
if (args != null)
{
_main.ReturnParcel(args);
}
}
catch (OperationCanceledException)
{
}
}
else
{
RazorEditorTrace.TraceLine(RazorResources.Trace_NoChangesArrived, fileNameOnly, parcel.Changes.Count);
Thread.Yield();
}
}
}
catch (OperationCanceledException)
{
// Do nothing. Just shut down.
}
catch (Exception ex)
{
MonoDevelop.Core.LoggingService.LogInternalError("Internal error in Razor parser", ex);
}
finally
{
RazorEditorTrace.TraceLine(RazorResources.Trace_BackgroundThreadShutdown, fileNameOnly);
// Clean up main thread resources
_main.Dispose();
}
}