Pipelined HTTP GET utility

While writing portsnap, I found myself in need of a utility for performing pipelined HTTP. This is different from "normal" HTTP in that it allows the HTTP client to have several HTTP requests "in flight" at once, and can dramatically increase performance when a large number of small files need to be downloaded. (This was the case with portsnap, where downloading 300 files of 200 bytes each is not unusual).

As a result, I've written a minimalist pipelined HTTP client and added it as an experimental feature to the latest version of portsnap; but I've also decided to package it separately here in case anyone else finds themselves in need of such code. Version 0.2 of phttpget is available here.

Note that phttpget is currently extremely minimalist. Of particular note:

Phttpget can only issue GET requests.
Phttpget cannot download files larger than 2GB (but this can be easily changed -- search for INT_MAX and replace it by something bigger).
Phttpget blithely ignores HTTP errors and redirects... in fact, if the HTTP status code is anything other than 200, phttpget will skip over that file and move on to the next file.
Phttpget ignores timestamps provided by the server. When it creates a file, the file's timestamp will be set to the current date, not the date provided by the server.
Phttpget creates downloaded files in the current directory, with names equal to final segment of the download path (i.e., if it downloads http://www.example.com/foo/bar/baz then it will create a file named baz in the current directory). Phttpget makes not attempt to check for symlinks or other nastiness. Do not use phttpget if any other user can write to your current directory!
If you already have a file where phttpget wants to create a file, it will silently remove the existing file.
I wrote phttpget in about 28 hours, and finished under 12 hours ago. It has had very little testing and probably still contains lots of bugs. (12 hours later: bugcount--. Version 0.1 had a deadlock when fetching a very large number of files due to a missing "break"; this is fixed in version 0.2.)

If you use this code, please contact me, both because I'm interested to know about these things and so that I can notify you in the unlikely event of a security issue being discovered.