Indent correcting taking up too much time on large files

[Therzok]

Test scenario

Move on line 4856 and move lines up and down.

5.92%   OnKeyPressed  •  6,512 ms  •  5 calls  •  MonoDevelop.Components.Commands.CommandManager.OnKeyPressed(Object, KeyPressEventArgs)
  5.92%   ProcessKeyEvent  •  6,512 ms  •  5 calls  •  MonoDevelop.Components.Commands.CommandManager.ProcessKeyEvent(EventKey)
    5.92%   DispatchCommand  •  6,511 ms  •  4 calls  •  MonoDevelop.Components.Commands.CommandManager.DispatchCommand(Object, Object, Object, CommandSource, Nullable, CommandInfo)
      5.91%   <DispatchCommand>b__1  •  6,498 ms  •  4 calls  •  MonoDevelop.Components.Commands.CommandManager+<>c__DisplayClass107_3.<DispatchCommand>b__1
        5.91%   Run  •  6,498 ms  •  4 calls  •  MonoDevelop.Components.Commands.CommandHandlerInfo.Run(Object, Command)
          5.91%   Invoke  •  6,498 ms  •  4 calls  •  System.Reflection.MethodBase.Invoke(Object, Object[])
            3.01%   OnMoveBlockUp  •  3,309 ms  •  2 calls  •  MonoDevelop.Ide.Editor.Extension.DefaultCommandTextEditorExtension.OnMoveBlockUp
              3.01%   MoveBlockUp  •  3,309 ms  •  2 calls  •  MonoDevelop.Ide.Editor.EditActions.MoveBlockUp(TextEditor)
                3.01%   MoveBlockUp  •  3,309 ms  •  2 calls  •  MonoDevelop.SourceEditor.SourceEditorView.MoveBlockUp
                  2.74%   CorrectIndenting  •  3,020 ms  •  2 calls  •  MonoDevelop.SourceEditor.SourceEditorView.CorrectIndenting
                    2.74%   CorrectIndenting  •  3,020 ms  •  2 calls  •  MonoDevelop.Ide.CodeFormatting.CodeFormatter.CorrectIndenting(PolicyContainer, TextEditor, Int32)
                      2.74%   CorrectIndenting  •  3,020 ms  •  2 calls  •  MonoDevelop.Ide.CodeFormatting.AbstractCodeFormatter.CorrectIndenting(PolicyContainer, TextEditor, Int32)
                        2.74%   CorrectIndentingImplementation  •  3,020 ms  •  2 calls  •  MonoDevelop.CSharp.Formatting.CSharpFormatter.CorrectIndentingImplementation(PolicyContainer, TextEditor, Int32)
                          2.74%   Start  •  3,020 ms  •  2 calls  •  System.Runtime.CompilerServices.AsyncVoidMethodBuilder.Start(ref TStateMachine)
                            2.74%   MoveNext  •  3,020 ms  •  2 calls  •  MonoDevelop.CSharp.Formatting.CSharpFormatter+<CorrectIndentingImplementation>d__7.MoveNext
                              2.71%   Update  •  2,983 ms  •  2 calls  •  ICSharpCode.NRefactory6.CSharp.CSharpIndentEngine.Update(SourceText, Int32)
                                2.21%   Push  •  2,429 ms  •  339,867 calls  •  ICSharpCode.NRefactory6.CSharp.CSharpIndentEngine.Push(Char)
                                  1.00%   Push  •  1,100 ms  •  172,832 calls  •  ICSharpCode.NRefactory6.CSharp.BracesBodyState.Push(Char)
                                    ►0.62%   Push  •  685 ms  •  172,832 calls  •  ICSharpCode.NRefactory6.CSharp.BracketsBodyBaseState.Push(Char)
                                    ►0.12%   OnStatementExit  •  135 ms  •  2,988 calls  •  ICSharpCode.NRefactory6.CSharp.BracesBodyState.OnStatementExit
                                    ►0.10%   SetAlignment  •  108 ms  •  2,832 calls  •  ICSharpCode.NRefactory6.CSharp.Indent.SetAlignment(Int32, Boolean)
                                    ►0.04%   RemoveAlignment  •  49 ms  •  1,570 calls  •  ICSharpCode.NRefactory6.CSharp.Indent.RemoveAlignment
                                     0.04%   op_Equality  •  39 ms  •  172,832 calls  •  System.String.op_Equality(String, String)
                                     0.02%   ToString  •  27 ms  •  172,832 calls  •  System.Text.StringBuilder.ToString
                                     0.00%   2 functions hidden  •  5 ms total  •  11122 calls total
                                  ►0.42%   GetOption  •  459 ms  •  27,578 calls  •  Microsoft.CodeAnalysis.Options.OptionSet.GetOption(PerLanguageOption, String)
                                  ►0.31%   Push  •  345 ms  •  92,335 calls  •  ICSharpCode.NRefactory6.CSharp.ParenthesesBodyState.Push(Char)
                                  ►0.10%   CheckKeyword  •  106 ms  •  12,002 calls  •  ICSharpCode.NRefactory6.CSharp.BracesBodyState.CheckKeyword(String)
                                   0.05%   IsLetterOrDigit  •  50 ms  •  241,166 calls  •  System.Char.IsLetterOrDigit(Char)
                                  ►0.04%   Push  •  43 ms  •  33,686 calls  •  ICSharpCode.NRefactory6.CSharp.LineCommentState.Push(Char)
                                  ►0.04%   Push  •  43 ms  •  31,406 calls  •  ICSharpCode.NRefactory6.CSharp.DocCommentState.Push(Char)
                                   0.03%   IsNewLine  •  28 ms  •  339,867 calls  •  MonoDevelop.Core.Text.NewLine.IsNewLine(Char)
                                   0.02%   get_Length  •  25 ms  •  438,568 calls  •  System.Text.StringBuilder.get_Length
                                   0.02%   Append  •  22 ms  •  268,732 calls  •  System.Text.StringBuilder.Append(Char)
                                   0.01%   12 functions hidden  •  15 ms total  •  117847 calls total
                                   0.01%   ToString  •  15 ms  •  64,284 calls  •  System.Text.StringBuilder.ToString
                                  ►0.01%   Push  •  11 ms  •  746 calls  •  ICSharpCode.NRefactory6.CSharp.SquareBracketsBodyState.Push(Char)
                                   0.01%   IsLetter  •  6 ms  •  98,701 calls  •  System.Char.IsLetter(Char)
                                ►0.38%   get_Item  •  417 ms  •  339,867 calls  •  MonoDevelop.Ide.TypeSystem.MonoDevelopSourceText.get_Item(Int32)
                                 0.05%   get_Offset  •  60 ms  •  679,738 calls  •  ICSharpCode.NRefactory6.CSharp.CSharpIndentEngine.get_Offset
                              ►0.03%   ReplaceText  •  30 ms  •  1 call  •  MonoDevelop.Ide.Editor.TextEditor.ReplaceText(Int32, Int32, String)
                              ►0.01%   Push  •  6 ms  •  62 calls  •  ICSharpCode.NRefactory6.CSharp.CSharpIndentEngine.Push(Char)
                               0.00%   23 functions hidden  •  1 ms total  •  257 calls total
                             0.00%   2 functions hidden  •  0 ms total  •  4 calls total
                           0.00%   2 functions hidden  •  0 ms total  •  4 calls total
                        ►0.00%   get_LineCount  •  0 ms  •  2 calls  •  MonoDevelop.Ide.Editor.TextEditor.get_LineCount
                     0.00%   14 functions hidden  •  0 ms total  •  34 calls total
                  ►0.26%   RunAction  •  288 ms  •  2 calls  •  Mono.TextEditor.MonoTextEditor.RunAction(Action)
                   0.00%   4 functions hidden  •  1 ms total  •  10 calls total
                ►0.00%   get_EditorOperations  •  0 ms  •  2 calls  •  MonoDevelop.Ide.Editor.TextEditor.get_EditorOperations
               0.00%   get_Editor  •  0 ms  •  2 calls  •  MonoDevelop.Ide.Editor.Extension.TextEditorExtension.get_Editor
            ►2.90%   OnMoveBlockDown  •  3,189 ms  •  2 calls  •  MonoDevelop.Ide.Editor.Extension.DefaultCommandTextEditorExtension.OnMoveBlockDown
         0.00%   4 functions hidden  •  0 ms total  •  20 calls total
      ►0.01%   UpdateToolbars  •  12 ms  •  4 calls  •  MonoDevelop.Components.Commands.CommandManager.UpdateToolbars
       0.00%   32 functions hidden  •  1 ms total  •  676 calls total
     0.00%   21 functions hidden  •  1 ms total  •  104 calls total
   0.00%   2 functions hidden  •  0 ms total  •  10 calls total

VS bug #700292

[Therzok]

Shouldn't we be using one of these two?

https://github.com/dotnet/roslyn/blob/master/src/EditorFeatures/Core/Implementation/SmartIndent/IIndentationService.cs#L41-L49

[Therzok]

Looks like we can configure on host side what the behaviour of that service is via
http://source.roslyn.io/#Microsoft.CodeAnalysis.Workspaces/Formatting/Rules/IHostDependentFormattingRuleFactoryService.cs,0ad070ccc0ff9168,references

[mkrueger]

IndentationService is too unreliable for this operation and probably a performance issue as well - requesting an indentation for each line extra is basically a bad idea.

(That's why we're slow here in the first place - we query that for each line extra.)

[xamarin-release-manager]

Fixed in version 7.8.0.1104 (master)

Author: Mike Krüger
Commit: e253318 (mono/monodevelop)