• Introduction
• Features
• Unit Test
• Projects
• Usage
  • ASP.NET Core
  • ASP.NET
  • Others
  • Todo List

Introduction

A rate limit library, support .NET Framework and .NET core.

Features

• Four algorithms: fixed window, sliding window, leaky bucket, token bucket.
• Two counting storages: memory and redis.
• Consistent rate-limit for distributed services.
• Locking for a period of time after triggering the limit.
• Flexible rate-limit target setting and rule matching.
• Supports updating rules at runtime.
• Any scenario that requires rate-limit.

Unit Test

Project: FireflySoft.RateLimit.Core.UnitTest

Code coverage:

Module	Line	Branch	Method
FireflySoft.RateLimit.Core	95.84%	85.77%	99.06%

Projects

Project	Descriptioin
FireflySoft.RateLmit.Core	algorithm, rules, persistence and other core codes.
FireflySoft.RateLmit.Core.Sample	FireflySoft.RateLmit.Core sample program.
FireflySoft.RateLimit.AspNet	ASP.NET rate-limit middleware based on .NET Framework.
FireflySoft.RateLimit.AspNet.Sample	FireflySoft.RateLimit.AspNet smample program.
FireflySoft.RateLimit.AspNetCore	ASP.NET Core rate-limit middleware.
FireflySoft.RateLimit.AspNetCore.Sample	FireflySoft.RateLimit.AspNetCore smample program.
FireflySoft.RateLimit.Core.UnitTest	Unit test for FireflySoft.RateLimit.Core.
FireflySoft.RateLimit.Core.BenchmarkTest	Benchmark test for FireflySoft.RateLimit.Core.

Usage

ASP.NET Core

1、Install Nuget Package

Package Manager:

Install-Package FireflySoft.RateLimit.AspNetCore

Or .NET CLI:

dotnet add package FireflySoft.RateLimit.AspNetCore

Or Project file：

<ItemGroup>
<PackageReference Include="FireflySoft.RateLimit.AspNetCore" Version="2.*" />
</ItemGroup>

2、Use Middleware

The following code calls the rate-limit middleware from Startup.Configure:

public void ConfigureServices(IServiceCollection services)
{
    ...

    app.AddRateLimit(new InProcessFixedWindowAlgorithm(
        new[] {
            new FixedWindowRule()
            {
                ExtractTarget = context =>
                {
                    return (context as HttpContext).Request.Path.Value;
                },
                CheckRuleMatching = context =>
                {
                    return true;
                },
                Name="default limit rule",
                LimitNumber=30,
                StatWindow=TimeSpan.FromSeconds(1)
            }
        })
    );

    ...
}

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    ...

    app.UseRateLimit();

    ...
}

ASP.NET

1、Install Nuget Package:

Package Manager:

Install-Package FireflySoft.RateLimit.AspNet

2、Register MessageHandler

Open Global.asax.cs, the following code adds the rate limit message handle:

protected void Application_Start()
{
    ...

    GlobalConfiguration.Configuration.MessageHandlers.Add(
        new RateLimitHandler(
            new Core.InProcessAlgorithm.InProcessFixedWindowAlgorithm(
                new[] {
                    new FixedWindowRule()
                    {
                        ExtractTarget = context =>
                        {
                            return (context as HttpRequestMessage).RequestUri.AbsolutePath;
                        },
                        CheckRuleMatching = context =>
                        {
                            return true;
                        },
                        Name="default limit rule",
                        LimitNumber=30,
                        StatWindow=TimeSpan.FromSeconds(1)
                    }
                })
        ));

    ...
}

Others

1、Install Nuget Package

Package Manager:

Install-Package FireflySoft.RateLimit.Core

Or .NET CLI:

dotnet add package FireflySoft.RateLimit.Core

2、Use IAlgorithm

Use IAlgorithm to filter every request, process the return value of Check method.

// Rule
var fixedWindowRules = new FixedWindowRule[]
    {
        new FixedWindowRule()
        {
            Id = "3",
            StatWindow=TimeSpan.FromSeconds(1),
            LimitNumber=30,
            ExtractTarget = (request) =>
            {
                return (request as SimulationRequest).RequestResource;
            },
            CheckRuleMatching = (request) =>
            {
                return true;
            },
        }
    };

// Algorithm
IAlgorithm algorithm = new InProcessFixedWindowAlgorithm(fixedWindowRules);

// Check
var result = algorithm.Check(new SimulationRequest()
    {
        RequestId = Guid.NewGuid().ToString(),
        RequestResource = "home",
        Parameters = new Dictionary<string, string>() {
                    { "from","sample" },
            }
    });

SimulationRequest is a custom request that you can modify to any type.

Todo List

• Add more convenient options for asp.net core.
• Use 'TIME' command in lua script when redis support 'scripts effects replication'.
• Add more unit tests.