Pre-compressed static files provider

This is a middleware for Asp.Net Core 3.1 that provides a static files provider capable of providing pre-compressed static files.

This solution is based on this repository.

Installation

You can install the latest stable version via NuGet.

> dotnet add package AspNetCore.PreCompressedStaticFiles

Documentation

Ensure that you are using the Kestrel server without the IIS Integration or that the "Dynamic Content Compression" is disabled in IIS.

Usage

Place app.UsePreCompressedStaticFiles(); instead of app.UseStaticFiles(); in Startup.Configure(). Also if using StaticFileOptions remember to replace it with PreCompressedStaticFileOptions. PreCompressedStaticFileOptions inherits from StaticFileOptions and supports all the options that come with StaticFileOptions.

This will ensure that your application will serve pre-compressed gzip (filename.ext.gz) or brotli (filename.ext.br) compressed files if the browser supports it. Without providing any options the default behavior is that, if the browser supports both gzip and brotli and if pre-compressed files for both types exist it will provide the gzipped files only.

Checkout the AspNetCore.PreCompressedStaticFiles.Example project for usage.

How to change preferred compression types

to change the order of the preferred compression types or to restrict it to only one type, create a PreCompressedStaticFileOptions object and then add the available types in the preferred order like below:

var options = new PreCompressedStaticFileOptions();
options.CompressionTypes.Add<Brotli>();
options.CompressionTypes.Add<Gzip>();
app.UsePreCompressedStaticFiles(options);

In the example above if the browser supports brotli and the pre-compressed brotli files exist it will provide brotli files otherwise it will provide gzipped files.

How to add more compression types

By default the middleware only supports gzip and brotli, to add more types you need to implement ICompressionType interface and then add it to the CompressionTypes list in PreCompressedStaticFileOptions.

Note: the compression type needs to be supported in the commonly used browsers otherwise the users will not benefit from it.

here is an example of how to create a custom compression type:

public class ExampleCompressionType: ICompressionType
{
    public string Encoding { get; } = "example";
    public string Extension { get; } = ".exm";
    public string ContentType { get; } = "application/example";
}

And here is how to set it up:

var options = new PreCompressedStaticFileOptions();
options.CompressionTypes.Add<ExampleCompressionType>();
app.UsePreCompressedStaticFiles(options);