This repo contains benchmarks for several popular managed PDB readers (for both Windows and Portable PDBs), with a specific interest in gauging which library is best for production diagnostic use cases, where the PDB reading will be performed in a production environment, and possibly from within the monitored application itself.

In most use cases, production diagnostics tools (such as debugger and profilers) only need to make a few (dozens or hundreds) reads from PDB at any given time. Even in the case of code coverage tools, which need to read sequence points for each and every executed method, the overall performance likely won't be hugely effected by PDB reading performance.

The motivation for creating these benchmarks is more around measuring the memory impact - as different libraries have wildly different characteristics both in terms of native and managed allocations. This is very significant, especially in memory constrained production environments (e.g. linux containers running in k8).

This repo utilizes Benchmark.NET and xUnit side by side, so that you can easily benchmark or run/debug each variation. In the unit tests, we employ snapshot testing with Verify in order to ensure the code fragments being benchmarked for the different libraries all return the exact same result.

See PDB Library enum.

• PPDB is a very nice native implementation of a Portable PDB reader, that seems to be very much based on System.Reflection.Metadata's design. This library was not included because it seems it has not been thoroughly tested in production use-cases.
• dbghelp is a Win32 API that can be easily used via PInvoke to read Windows PDBs with excellent performance. It was not included in this benchmark because, being a legacy API, it only has the notion of line numbers, and not column numbers, which makes it inadequate for handling modern C# code which may contain several lambda methods in the same line of code.

If you feel there is another library that is worth including in these benchmarks, please don't hesitate and create an issue/PR for it.

BenchmarkDotNet=v0.12.1, OS=Windows 10.0.22000
Intel Core i7-8750H CPU 2.20GHz (Coffee Lake), 1 CPU, 12 logical and 6 physical cores
  [Host]     : .NET Framework 4.8 (4.8.4470.0), X64 RyuJIT
  Job-OYCNNG : .NET Framework 4.8 (4.8.4470.0), X64 RyuJIT

IterationCount=100  LaunchCount=10  RunStrategy=Monitoring  
WarmupCount=0