Enabling GZip Compression in ASP.NET5

October 23, 2015 by Anuraj

aspnet5 dnx codeproject Compression

Compression is an easy and effective way to reduce the size and increase the speed of communication between a client and remote resource. Two common compression algorithms used on the web are GZip and Deflate. The Accept-Encoding header is used by a client to restrict the encoding types that are acceptable in the response.

Here is the Compression middleware implementation, which whether GZip compression supported by the “Accept-Encoding” header value. If it supports, middleware compress the body and send the compressed stream to the client. Since browser doesn’t know about the content encoding, you need to set the content encoding header value as well.

Here is the middleware implementation.

public class CompressionMiddleware
{
    private readonly RequestDelegate _next;

    public CompressionMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task Invoke(HttpContext httpContext)
    {
        var acceptEncoding = httpContext.Request.Headers["Accept-Encoding"];
        if (acceptEncoding != null)
        {
            if (acceptEncoding.ToString().IndexOf("gzip", StringComparison.CurrentCultureIgnoreCase) >= 0)
            {
                using (var memoryStream = new MemoryStream())
                {
                    var stream = httpContext.Response.Body;
                    httpContext.Response.Body = memoryStream;
                    await _next(httpContext);
                    using (var compressedStream = new GZipStream(stream, CompressionLevel.Optimal))
                    {
                        httpContext.Response.Headers.Add("Content-Encoding", new string[] { "gzip" });
                        memoryStream.Seek(0, SeekOrigin.Begin);
                        await memoryStream.CopyToAsync(compressedStream);
                    }
                }
            }
        }
    }
}

And here is the helper class, which helps to inject the middleware to the HTTP request pipeline.

public static class CompressionMiddlewareExtensions
{
    public static IApplicationBuilder UseCompression(this IApplicationBuilder builder)
    {
        return builder.UseMiddleware<CompressionMiddleware>();
    }
}

And you can use this middleware in the Configue method in Startup.cs file, like this

app.UseCompression();

Happy Programming

Copyright © 2024 Anuraj. Blog content licensed under the Creative Commons CC BY 2.5 | Unless otherwise stated or granted, code samples licensed under the MIT license. This is a personal blog. The opinions expressed here represent my own and not those of my employer. Powered by Jekyll. Hosted with ❤ by GitHub