Slow performance for --include with single file

[chriselion]

Hi,
I'm just experimenting with dotnet-format for the first time. I noticed that running it on a single file has more overhead than I would expect.

# Run on 223 files 
$ git ls-files | grep .cs$  > all_cs.txt
$ dotnet format --folder --include @all_cs.txt
  Formatting code files in workspace '/xyz/ml-agents'.
  ...
  Format complete in 2297ms.

# Run on 1 file
$ dotnet format --folder --include com.unity.ml-agents/Tests/Editor/MultinomialTest.cs
  Formatting code files in workspace '/xyz/ml-agents'.
  Format complete in 1325ms.

Is that expected? It's not horrible, but it would be mildly annoying to run incrementally on git commits.

Platform/version information:
MacOS 10.14.6

$ dotnet --version
3.1.401
$ dotnet-format --version
4.1.131201+82a5527cd93d66bffc885c0bb901499f5981db35

[RikkiGibson]

(sorry, I misunderstood the description in my original comment.) It does feel like there's an excessive amount of fixed-size overhead here.

[chriselion]

Thanks, sorry if I was being unclear - the fixed-size overhead was what I was complaining about.

Any profiling information that I can provide to help diagnose? I haven't tried diag verbosity yet; would there be anything useful in there?

[RikkiGibson]

A trace from a sampling profiler of some kind could be helpful. My guess though is that a lot of this overhead is in just spinning up the runtime, loading the compiler assemblies and jitting methods--assuming that we do not use any kind of multiproc or client/server model like we do when you run the compiler in order to build. Do you know @JoeRobich @jmarolf?

[jmarolf]

would be helpful to know if there is any better perf in the latest (unrelesed) version.

dotnet tool install -g dotnet-format --version 5.0.135301 --add-source https://dotnet.myget.org/F/format/api/v3/index.json

in general formatting whitespace should be very fast but semantic formatting (detecting if you are using var in your codebase and whether that is allowed) can take more time. @chriselion could you provide a sample of your editorconfig file?

[chriselion]

FWIW here's the results with -v diag on 4.1.131201.

 $ dotnet format --folder --include com.unity.ml-agents/Tests/Editor/MultinomialTest.cs -v diag
  The dotnet CLI version is '3.1.401'.
  Using MSBuild.exe located in '/usr/local/share/dotnet/sdk/3.1.401/'.
  Formatting code files in workspace '/Users/chris.elion/code/ml-agents'.
  Loading workspace.
  Complete in 966ms.
  Determining formattable files.
  Complete in 233ms.
  Running formatters.
  Complete in 194ms.
  Formatted 0 of 1 files.
  Format complete in 1396ms.

and with the new version

$ dotnet format --folder --include com.unity.ml-agents/Tests/Editor/MultinomialTest.cs -v diag
  The dotnet CLI version is '3.1.401'.
  Using MSBuild.exe located in '/usr/local/share/dotnet/sdk/3.1.401/'.
  Formatting code files in workspace '/Users/chris.elion/code/ml-agents'.
  Loading workspace.
  Complete in 1156ms.
  Determining formattable files.
  Complete in 223ms.
  Running formatters.
  Complete in 183ms.
  Formatted 0 of 1 files.
  Format complete in 1565ms.

The editor config can be found here and the file I'm formatting is here. I don't think there's anything special about that particular file; I just picked it at random.

[jmarolf]

Yep this should be fast. The second we spend discovering files is unnecessary. that at least gets us to 500ms

[chriselion]

Sounds good. Do you need any other info from me?

[jmarolf]

No, I'll likely use your project as the basis for some perf validation.

[chriselion]

Great, thanks.

Just for a little more context, I'm playing around with integrating with https://pre-commit.com/. That passes the list of files to check as command-line arguments (usually just the files being committed, unless you tell it to run on all files).

[jmarolf]

yeah. I'll need to look here but I think a reasonable place to start at is that we should be able to get single file formats under 500ms

[seriouz]

It is still slow as hell. 8 seconds for one file and this is without -s and -a.
go fmt runs in under a second for me.