using System;
using System.IO;
using System.IO.Compression;
using System.Web;

public class HttpCompressionModule : IHttpModule
{
    public void Init(HttpApplication context)
    {
        context.BeginRequest += new EventHandler(context_BeginRequest);
    }

    private void context_BeginRequest(object sender, EventArgs e)
    {
        HttpApplication app = (HttpApplication) sender;
        if (app.Request.Url.ToString().ToLower().IndexOf("aspx") < 0) return;
        string encodings = app.Request.Headers.Get("Accept-Encoding");
        if (encodings == null) return;

        Stream baseStream = app.Response.Filter;
        encodings = encodings.ToLower();

        if (encodings.Contains("gzip"))
        {
            app.Response.Filter = new GZipStream(baseStream,
                                                 CompressionMode.Compress);
            app.Response.AppendHeader("Content-Encoding", "gzip");
        }
        else if (encodings.Contains("deflate"))
        {
            app.Response.Filter = new DeflateStream(baseStream,
                                                    CompressionMode.Compress);
            app.Response.AppendHeader("Content-Encoding", "deflate");
        }
    }

    public void Dispose()
    {
    }
}