Comments on: Reading gzip compressed data via Javascript

By: Stephen Lau

Stephen Lau — Wed, 07 May 2008 15:33:38 +0000

Yeah - the method I used gives me nice ASCII XML data which I can then parse more easily.

By: Neil

Neil — Wed, 07 May 2008 13:23:27 +0000

One possibility is to use a stream loader, although from JavaScript it gives you a rather useless array of byte values rather than the string you're looking for (which I hope is ASCII for your sake.)

Ideally what you could do with is some way of hooking up the stream listener for an XML document with the stream converter, though I don't see how to achieve that without hacking into the Gecko codebase.

By: Boris

Boris — Wed, 07 May 2008 03:01:06 +0000

Ah, this is a URI you don’t control. That’s unfortunate…

By: Stephen Lau

Stephen Lau — Wed, 07 May 2008 00:11:17 +0000

@Boris: The Magnatune store sends the gzip’d XML file with mime-type application/gzip instead of text/xml, so you can’t use XMLHttpRequest.

By: mozilla

mozilla — Tue, 06 May 2008 18:56:05 +0000

[...] The fetch was easy XMLHttpRequest, as was the parse DOMParser, but I had no idea how to do the expanhttp://whacked.net/2008/05/05/reading-gzip-compressed-data-via-javascript/Features and Case Studies ZDNet AustraliaThe mozilla Foundation is perhaps best known for its [...]

By: Stephen Lau

Stephen Lau — Tue, 06 May 2008 15:39:48 +0000

Thanks for the tip Dennis, I’ll try that.

By: Dennis

Dennis — Tue, 06 May 2008 09:26:43 +0000

Instead of doing: this._data += xx.

You should consider: this.data = []; this.data.push(xx) this._data.join("").

On large pieces of data thats alot faster.

By: ToTheBatCave

ToTheBatCave — Mon, 05 May 2008 21:44:55 +0000

If you turned this into an extension that ungzipped remote files on 3rd party servers that fail to serve the correct Content-encoding: gzip headers, you’ll find it very popular if combined with the functionality of “openinbrowser” at http://www.spasche.net/mozilla/ for when they also serve the wrong content-type. For instance, I’ve not found any free web hosting services (including archive.org) that serve .svgz files with that header, even though it would benefit them bandwidth-wise.

By: Jorge

Jorge — Mon, 05 May 2008 18:21:16 +0000

Interesting. When I needed to do something like this I opted to save the file locally and then open it with ZipReader. This sounds much more efficient and better encapsulated, though. Thank you for posting it.

By: Boris

Boris — Mon, 05 May 2008 18:12:50 +0000

Is the URI not an http: URI? You could just use HTTP content-encoding and have all of this handled for you behind the scenes…