Some performance improvements

[p-26]

I implemented some performance improvements because the analyzer takes ~35s on my machine in our solution:

[hermanussen]

I'll look into these changes as soon as I have some time. But looks pretty good so far. Thanks!

Do the tests pass? And do you have any data on the impact of the changes in terms of performance?

[p-26]

Thanks for your timely reply.
The tests pass, yes.
As of performance: I don't see any impacts unfortunately. 😕

[p-26]

I wanted to profile the Analyzer and wrote a test for it:

[Fact]
        public async Task TestPerformanceProfiling()
        {
            var source =
                File.ReadAllText(
                    @"ErpActionLink.Artifact.cs");
            var rules = File.ReadAllText(@".refrules");
            
            await ReferenceCopAnalyzerVerifier.VerifyReferenceCopAnalysis(source, rules,
                Array.Empty<DiagnosticResult>());
        }

It crashes with a StackOverflow:

The active test run was aborted. Reason: Test host process crashed : Stack overflow.

Here are the file contents:
TestFiles.zip

[p-26]

I fixed the test.

By removing RegexOptions.Compiled in the analyzer I was able to improve the performance by ~40%:

The profiling result of the original code looks like this:

Can you have a look at it? Thanks in advance!

[p-26]

Hi Robin, I replied to your questions in my PR. Can you have a look at it? Some performance improvements by p-26 · Pull Request #1 · hermanussen/ReferenceCopAnalyzer (github.com) <#1> Thanks, Nicolas Am Do., 7. Apr. 2022 um 11:23 Uhr schrieb Robin Hermanussen < ***@***.***>:

…

I'll look into these changes as soon as I have some time. But looks pretty good so far. Thanks! Do the tests pass? And do you have any data on the impact of the changes in terms of performance? — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AD36L6JFU2XENA3O2FI2T4TVD2SSVANCNFSM5SYRLGNQ> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[hermanussen]

Hi Nicolas,

Please be patient. I just haven't gotten to it yet. But I will eventually, I promise!

[p-26]

Hi Nicolas,

Please be patient. I just haven't gotten to it yet. But I will eventually, I promise!

Hi Robin,

Do you know, roughly, when you'll have the opportunity to review my pull request?

Thanks,
Nicolas

[hermanussen]

Well, I took a look this weekend. I changed the unit test you added to include timings and tested with the current as well as your new code. These are my results (run in Release configuration):

Current code:
Slowest 5139ms, Fastest 381ms, Average 718ms. Out of 25 runs.

After applying your improvements:
Slowest 5443ms, Fastest 366ms, Average 699ms. Out of 25 runs.

I wouldn't call that a significant performance increase. On the whole it seems rather slow anyway. Once I have some more time, I'll see if I can make some structural performance improvements.

By the way; if you look at the huge difference between the slowest and fastest runs, it seems like the test is not fully isolated and Roslyn does some optimizations/caching. I think that needs to be addressed as well for testing.