Sync Method Generator

This .NET source generator produces a sync method from an async one.

Use cases

• A library which exposes both sync and async version of a method
• An application has to process two kinds of data in the same way:
  • Large data from I/O which cannot be stored in memory before processing: Original async method
  • Small sample of data in memory, usually a sample of the larger data: Generated sync method

How it works

Add CreateSyncVersionAttribute to your async method in your partial class

[Zomp.SyncMethodGenerator.CreateSyncVersion]
static async Task WriteAsync(ReadOnlyMemory<byte> buffer, Stream stream, 
CancellationToken ct)
    => await stream.WriteAsync(buffer, ct).ConfigureAwait(true);

And it will generate a sync version of the method:

static void Write(ReadOnlySpan<byte> buffer, Stream stream)
    => stream.Write(buffer);

A list of changes applied to the new synchronized method:

• Remove async modifier

• Remove await from methods as well as foreach statement

• Change types

  From	To
  Task or ValueTask	void
  Task<T> or ValueTask<T>	T
  IAsyncEnumerable<T>	IEnumerable<T>
  IAsyncEnumerator<T>	IEnumerator<T>
  Memory<T>	Span<T>
  ReadOnlyMemory<T>	ReadOnlySpan<T>

• Remove parameters

  • CancellationToken
  • IProgress<T>

• Invocation changes

  • Remove ConfigureAwait
  • Remove WithCancellation
  • Remove Async suffix from method calls (e.g. MoveNextAsync becomes MoveNext)
  • Remove CancellationToken parameter
  • Remove IProgress<T>.Report(T) call
  • Remove Memory<T>.Span property

• Remove CreateSyncVersionAttribute

• Update XML documentation

Installation

To add the library use:

dotnet add package Zomp.SyncMethodGenerator