2.0.0 -> 3.1.1 performance degradation

[bugproof]

https://github.com/bugproof/TomlLibrariesBenchmark

[dezhidki]

Hi!

Thanks for bringing this up; this is quite a significant slowdown. After some basic profiling, it seems that the change to support TOML 1.0.0 caused a regression in date parsing performance:

The issue is likely the try-catch snippet which essentially causes unnecessary operations:

Tommy/Tommy/Tommy.cs

Lines 2011 to 2018 in 91e8fff

	try
	{
	dateTime = parser(s, format, CultureInfo.InvariantCulture, styles);
	}
	catch (Exception)
	{
	continue;
	}

Changing it back to original TryParse implementation indeed fixes the flamegraph:

Of course, supporting full TOML 1.0.0 spec causes a slight performance degradation that I cannot fully fix.
I pushed the fixed code right now (ecac69d, no release yet) if you feel like giving it a test. Here's the library if you don't want to compile it from the source:

Tommy.zip

I don't know about your testing setup, but on mine:

BenchmarkDotNet=v0.13.1, OS=Windows 10.0.19044.1415 (21H2)
AMD Ryzen 5 3600, 1 CPU, 12 logical and 6 physical cores
.NET SDK=6.0.100
  [Host]     : .NET 6.0.0 (6.0.21.52210), X64 RyuJIT
  DefaultJob : .NET 6.0.0 (6.0.21.52210), X64 RyuJIT

The fixed code now runs in 20.54 us, which is reasonable given the results with 2.0.0.

[bugproof]

Quite a big difference after replacing exceptions with TryParse. I will update the benchmark results when new version will be on NuGet.