TaskBatcher 3.0.0

TaskBatcher

This package collects incoming requests and processes them in batches. It is particularly useful in scenarios where multiple requests can be consolidated into a single database call, significantly reducing overhead and improving application scalability.

Usage/Examples

1) Define input that must be processed in batch:

public record Input(int V);

2) Define result:

public record Result(int V);

3) Define your bulk processing method:

public async Task<Dictionary<Guid, Result>> MyMethod(Dictionary<Guid, Input> reqs) {
	// Result guids must match request guids!!!  
	return reqs.toDictionary(el => el.Key, el => new Result(V: el.V));
}

4) Add taskBatcher under some unique key:

builder.Services.AddTaskBatcher<Input, Result>(
	"myUniqueKey",
	(sp) =>
	{
		return async (Dictionary<Guid, Input> reqs) =>
		{
			using var scope = sp.CreateScope(); // Create scope:
			var myService = scope.ServiceProvider.GetRequiredService<IMyService>(); // Get your services:
            return await myService.MyMethod(reqs); // Return results:  
		};
	}, 
	new TaskBatcherOptions
	{
		BatchSize = 50,
		WaitForBatchFill = TimeSpan.FromMilliseconds(10),
		WorkerCount = 1,
	}
);

4) Inject the TaskBatcher into your service and pass the request:

public class MyService(
	[FromKeyedServices("myUniqueKey")] TaskBatcher<Input, Result> myMethodBatched
) : IMyService {
    public async Task<Result> Example(Input req)
	{
		return await myMethodBatched.Run(new Input { V = 1 });
	}
}

TaskBatcher Options

new TaskBatcherOptions
{
    BatchSize = 50, // How many requests to process at once
    WaitForBatchFill = TimeSpan.FromMilliseconds(10), // How long to wait in case batch is not filled
    WorkerCount = 1 // How many batches to run in parallel
}

Auto Configuration

To make TaskBatcher automatically find bulk methods you have to:

1) Register auto configuration with:

builder.Services.ConfigureTaskBatchers(typeof(Program).Assembly);

Note that it must be done after the services configuration are made.

2) Mark your bulk methods with attribute:

[TaskBatchOperation("myUniqueKey")]

this will automatically invokes AddTaskBatcher on the target method.