Poolz.Finance.CSharp.Polly.Extensions 1.0.0

Poolz.Finance.CSharp.Polly.Extensions

Poolz.Finance.CSharp.Polly.Extensions is a lightweight helper library that adds ready-to-use retry primitives on top of Polly. It targets .NET Standard 2.1, so it can be consumed from modern .NET and .NET Core applications, background services, and libraries.

Features

• Sensible defaults for RetryStrategyOptions<T> via DefaultRetryStrategyOptions<T>.
• Built-in logging hook with optional custom formatter for retry attempts.
• Ignores OperationCanceledException by default so cooperative cancellation is preserved.
• IRetryExecutor/RetryExecutor wrapper to execute synchronous and asynchronous delegates without manually composing a ResiliencePipeline<T>.
• Works seamlessly with existing Polly pipelines and can be registered in dependency injection containers.

Default retry configuration

DefaultRetryStrategyOptions<T> ships with the following values out of the box:

A logging callback can be supplied, as well as a custom formatter that receives Polly's OnRetryArguments<T> and returns the message to emit. When no formatter is provided the library uses the built-in message: "[Retry] Attempt={n}, Delay={delay}, Exception={type}: {message}".

Installation

dotnet add package Poolz.Finance.CSharp.Polly.Extensions

The library depends on Polly (currently 8.6.x). If you build from source, run dotnet restore followed by dotnet build or dotnet test.

Getting started

Creating a retry pipeline with the defaults

using Polly;
using Poolz.Finance.CSharp.Polly.Extensions;

var options = new DefaultRetryStrategyOptions<HttpResponseMessage>(Console.WriteLine);
var pipeline = new ResiliencePipelineBuilder<HttpResponseMessage>()
    .AddRetry(options)
    .Build();

var response = await pipeline.ExecuteAsync(async token =>
{
    // Replace with your real operation.
    return await httpClient.SendAsync(request, token);
}, CancellationToken.None);

The log delegate (Console.WriteLine in the sample) will be invoked for every retry attempt. When no logger is provided the retries still occur silently.

Executing work via RetryExecutor

using Poolz.Finance.CSharp.Polly.Extensions;

IRetryExecutor retryExecutor = new RetryExecutor();

var user = await retryExecutor.ExecuteAsync(async token =>
{
    return await httpClient.GetFromJsonAsync<UserDto>("/users/42", cancellationToken: token);
});

var invoice = retryExecutor.Execute(_ =>
{
    // Synchronous operations are supported too.
    return invoiceService.GenerateInvoice();
});

RetryExecutor automatically constructs a ResiliencePipeline<T> using the provided options (or the defaults when none are passed) and forwards the CancellationToken that you supply.

Customising retry behaviour

using Poolz.Finance.CSharp.Polly.Extensions;

var options = new DefaultRetryStrategyOptions<int>(
    log: message => logger.LogWarning(message),
    format: args =>
        $"Attempt {args.AttemptNumber + 1} failed after {args.RetryDelay.TotalMilliseconds} ms"
)
{
    MaxRetryAttempts = 5,
    BackoffType = DelayBackoffType.Exponential,
    UseJitter = true
};

You can further tweak the retry strategy by updating the properties inherited from Polly's RetryStrategyOptions<T>. The supplied format delegate is optional�omit it to use the default message.

Dependency injection registration

services.AddSingleton<IRetryExecutor, RetryExecutor>();

Registering the executor in your DI container makes it trivial to consume resilient execution from any service that requires it.

Development

Clone the repository and execute the tests to validate your changes:

dotnet test

License

This project is licensed under the MIT License. See the LICENSE file for more information.