HttpCompress

An open compression engine for ASP.NET

News

Mar 12, 2012 – Moved to GitHub

I decided to move the source over to GitHub. Pull requests happily accepted.

Jan 14, 2008 – Version 7 available

A while ago I worked in a patch for the very commonly reported bug “HttpCompress doesn’t work for documents in the root of a site”, but never cut a release. So, here’s a release with that patch incorporated.

Oct 27, 2007 – Project Hosting now at Google Code

In an effort to allow others to easily contribute to this project, I’m now hosting it at http://code.google.com/p/httpcompress/. Head over there to track issues, contribute patches and keep up to date on what’s going on. I’ll still keep current downloads available here, but the build of the project will be taking place over on the new site.

Nov 15, 2005 – Version 6 for .NET 2.0 released!

This is a pretty simple recompile of the version 6 source, targeting the 2.0 version of the .NET Framework. It now uses the built-in deflate and gzip streams found in System.IO.Compression instead of #ziplib. I consider this a beta release; please test it thoroughly before releasing it onto any production systems. [Binary Only, Source Only]

Apr 21, 2004 – Version 6 released!

Another bugfix release:

• Changed how the Content-Encoding header is written. It is now written on the first call to the compressing stream’s Write method. This fixes the issue where the response would come back with a header indicating it was compressed when the filter was really skipped. This allows Server.Transfer and the default exception reporting mechanism in ASP.NET to work without modification, though their output will not be compressed.

Mar 19, 2004 – Version 5 released!

This is mainly a bugfix release over version 4. New Features:

• (v5) Plays nice with the OutputCache using the VaryByHeader property.
• (v5) No longer installs the filter if the CompressionLevel is set to “None”.
• (v5) No longer throws an exception if a q-value cannot be parsed.
• (v5) Properly install the INSTALLED_TAG, preventing double processing when
  a filter is not installed
• Path-based exclusions
• ContentType / MimeType based exclusions
• A newer SharpZipLib

Download

Current Version

• Version 7 for .NET 2.0, Binary Only

Older Versions

• Version 6 for .NET 2.0, Binary Only
• Version 6 for .NET 2.0, Source Only
• Version 6, Binary Only
• Version 6, Source
• Version 5, Binary Only
• Version 5, Source
• Version 4, Binary Only
• Version 4, Source
• Version 1.1
• Version 1.0

Known Bugs

Compression breaks when Server.Transfer is used

In ASP.NET 1.0 and 1.1, Server.Transfer and response filters do not play well together. Thankfully, a fix is available.

Images compressed with the filter are broken

This usually occurs with Internet Explorer 5.5 or 6.0. Both of these browsers can drop the first 2048 bytes of the response, breaking images that are compressed. The situation is documented by KnowledgeBase articles Q312496 for IE 6 and Q313712 for IE 5.5. The latest service pack fixes the issue for IE6, while you have to get a hotfix for IE 5.5.

Articles

OnDotNet -Filtering HTTP Requests with .NET

An article about filtering HTTP requests using ASP.NET. The article was based upon my experiences building the HttpCompressionModule.