Posted by Anil Madhavapeddy
Thu, 17 Apr 2008 10:58:00 GMT
I've been looking around at refreshing my current photo gallery to make it easier to update, since I'm around 1000 photos behind over the last year. Part of making it easier to use is to adopt an Aperture-based system of marking the metadata directly in the image itself, and figuring out how to render so many pictures more effectively in my gallery.
The best library I could find to do the job is Exiv2 and its associated Python bindings pyexiv2. They use the rather complex Boost.Python bindings, which are a total pain to compile on MacOS X Leopard.
In order to get it to work:
- Use the latest Fink to install:
python25boost1.34.python25libexiv2scons
- Download the latest pyexiv2 distribution, extract it, and drop in my exiv2 Leopard Makefile into the extracted directory.
- Type in:
- Test it out by running python2.5 and experimenting with importing pyexiv2 (see the pyexiv2 developer guide for more information.
I'll tidy this up into a fink package sometime, but for now I want to press on with finishing my Django experiments.
Posted in hacking | Tags macosx | no comments
Posted by Anil Madhavapeddy
Sat, 30 Dec 2006 01:11:00 GMT
Inspired by finishing my PhD corrections (!) today, I decided to hook up the DNS server from our Melange project up to the Internet. The authoritative server is called deens (since the co-author is one Tim Deegan, geddit?), and is written in pure OCaml.
This is all rather experimental, to put it mildly, but I stuck in the zone file below, hooked it up as a delegate to our main name-servers, checked it against the DNS Report, and it all seems to be working!
$ORIGIN deens.recoil.org. ;
$TTL 240
deens.recoil.org. 604800 IN SOA (
deens.recoil.org. anil.recoil.org.
2006122401 3600 1800 3024000 1800
)
IN NS ns1.deens.recoil.org.
IN NS deensns.recoil.org.
ns1 IN A 194.70.3.132
dynamic IN CNAME dynamic.recoil.org.
static IN CNAME static.recoil.org.
anil IN CNAME dynamic
stats IN CNAME dynamic
I also modified stats.recoil.org to be an alias to stats.deens.recoil.org, so all the requests for that domain will go via the deens setup. You actually need a user/pass to access the site, but that doesn't matter; if it gets that far, the DNS bit has worked.
There's still an awful lot of tedious work to get the server into a production-ready state, such as proper logging, more error handling and recovery, etc., but I really hope to find the time in 2007 to polish this up somewhat. Performance is excellent already; faster than BIND by quite a lot, and it can optionally use more memory to cache responses to shoot up to crazy levels.
Incidentally, the dig replacement utility also seems to be working fairly well, and David Scott has been messing around with a Bonjour implementation that will get finished sometime in 2007 as well (honest!).
Posted in research, hacking, net | no comments
Posted by Anil Madhavapeddy
Wed, 27 Dec 2006 20:59:00 GMT
Our lighttpd setup has been very unstable in recent months, probably brought on by the load of the large Mercurial repositories hosted on Recoil since the Google Summer of Code mentoring.
The source of the instability was really hard to track down, but it seems to be the automatic spawning of FastCGI processes by the web-server, and lighttpd failing to handle a SIGCHLD somewhere when a child process crashes. To sort this out, I just converted all the Ruby on Rails setups (this blog and Nick's) to use an external spawn.
This only leaves our Mercurial vhost hg.recoil.org to switch to using FastCGI, and I couldn't find a module for this anywhere and so lashed up some Python glue to do the job.
You can download the small distribution for Mercurial 0.9 (hg-fcgi-0.9.tar.gz). It has a FastCGI library written by someone else, the Python files to glue the Mercurial and FastCGI libraries together, and a simple rc script to launch the external web process.
Read more...
Posted in hacking, net | no comments
Posted by Anil Madhavapeddy
Mon, 28 Aug 2006 22:12:00 GMT
I noticed on the OCaml mailing list that Practical OCaml is due to be released in the US quite soon. Could this be the first real competition that Jon Harrop will face for his excellent but pricey Objective Caml for Scientists ?!
Things are heating up on the OCaml book front at last, and Jon has been getting some rave reviews of his book! We have a long-running joke about how much I hate the colour syntax highlighting he used in his book, and it amused me greatly to note that someone else in the comments for the rave review of his book also shared my heretical opinion, ha ha!
Incidentally, I just pushed the beginnings of an OCaml config file parsing library to the Melange source tree. The code in there is almost beginning to look useable...
Posted in hacking, books | 5 comments | no trackbacks
Posted by Anil Madhavapeddy
Sat, 15 Jul 2006 02:45:00 GMT
Ever since I got my first Powerbook back in 2000, I've been meaning to learn Cocoa and Carbon to hack on MacOS X GUIs. On the flight over to San Francisco, I finally found the uninterrupted time to knock up a simple GUI interface to my gallery meta-data files. Overall, the experience was pretty positive. It's definitely more satisfying than my experiences with Windows and UNIX GUI programming, mainly because the result is so pretty!
Objective-C has a really nice dynamic message dispatch mechanism, used to good effect by Cocoa. The autorelease mechanism plays well with C memory management to provide a reference-counted interface which is fairly well abstracted. My application still leaks memory like a sieve though; I miss OCaml! Cocoa provides a huge number of ways to do the same thing. Bindings are the fancy new thing, MVC is the older "paradigm", and of course Carbon predates all of this. The documentation is a bit of a mess for a beginner to the framework, as crucial facts on how to get simple stuff done are scattered across a myriad of documents. Thanks Google. Tiger has some funky new Cocoa controls. Check out the use of NSTokenField on the screenshot which lets the tag entry field auto-complete just like Mail does! The APIs can be unfortunately verbose at times, as the following code snippet which does a little bit of simple string manipulation shows.
NSArray *a = [tag componentsSeparatedByString:@" "];
iter2 = [a objectEnumerator];
while (s = [iter2 nextObject]) {
NSString *e = [s stringByTrimmingCharactersInSet:
[NSCharacterSet whitespaceCharacterSet]];
if (![e isEqual:@""])
[tags addObject:[e retain]];
}
I'm quite looking forward to doing more work on this simple application now that the basics are mastered. Hmm... preferences panes next, then a bit of Cocoa bindings, and perhaps I feel OCamlCocoa coming on...
Posted in hacking | 2 comments | no trackbacks
Posted by avsm
Fri, 23 Sep 2005 14:38:10 GMT
Well I've been back in Cambridge for a week now, catching up on stuff that's been languishing in the last month of travelling. So here are some blog quickies!
- Shouts out to the newest blogger, the least German-like German person I know! Whooooop yeah yeah...
- Released a new version of OpenFX, with some really cool new features from Dr. Stuart Ferguson!
- Sorry about the backlog of OpenBSD-related things; I think I've caught up on all my mails, and imported and updated lots of bits and bobs and ports. Please re-mail me if I've ignored anything you have sent me recently.
- Released a test version of review2atom, the result of my ocamlduce hackery (and many thanks to Alan Frisch for answering my incessant questions!).
- Submitted DarwinPorts for calendar (dports/devel/caml-calendar) and ocamlduce (dports/lang/ocamlduce).
- I'm going to buy a juicer; turnip smoothie is en route!
Posted in cambridge, hacking | no comments
Posted by avsm
Fri, 24 Jun 2005 13:14:37 GMT
I bought a Nokia 7610 some time ago, and have taken hundreds of pictures using it. When creating the gallery section of my site, I ran into an annoying limitation: the pictures contained on the phone did not embed the date the picture was taken as part of the image. Manually copying the date and time for 350 images was a bit much as well...
The problem with sending images via Bluetooth to my laptop is that the OBEX transfer stamps the date of the transfer instead of the date the picture was taken. There turned out to be a conveniently easy answer to this problem though, as Nokia released a version of Python for Symbian Series 60. This suddenly elevates the phone from being a complete pain to program (due to the Symbian C++ libraries being amazingly badly documented), to something that's actually quite usable.
It took about an hour to come up with the first cut of imgcollect.py, which assembles a list of mtimes for each image on my phone, performs Bluetooth Device Discovery, and transmits the mtimes and all the pictures to my laptop. After that, a little shell script on the laptop is enough to stamp the pictures with the correct mtime:
#!/bin/sh
while read FNAME MTIME; do
DATE=`date -r $MTIME "+%G%m%d%H%M.%S"`
touch -t $DATE $FNAME
done
I'm actually quite impressed with Nokia at last! Next step is to work out a two-way synchronization so that I don't keep re-transmitting images which I already have on the phone (unfortunately, iSync is pretty useless with the Nokia 7610, even in Tiger).
Posted in hacking | no comments
Posted by avsm
Tue, 21 Jun 2005 21:01:38 GMT
The Subethaedit syntax highlighting for OCaml is working nicely. I fixed up few minor bugs and packaged up version 1.1, available here. Have fun!
Posted in hacking | no comments
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