Month: April 2009

iPhoto – Removing redundant originals

/ TimBunce / 5 Comments

I recently came across this article on slimming down an iPhoto library by removing the ‘Original’ photo where a ‘Modified’ one existed.

(That’s one part of what the free iPhoto Diet app does, but it seems that’s not being maintained and doesn’t support recent versions of iPhoto.)

Inspired by the basic three-line shell script in the article I worked up this somewhat more advanced version:

#!/bin/sh -ex
cd ~/Pictures/
du -sh 'iPhoto Library'
dest=$HOME/Pictures/iPhoto-Redundant-Originals-`date "+%Y-%m-%d-%H%M"`
# for all files in iPhoto Library/Modified/...,
# move the corresponding iPhoto Library/Originals/...
# files into a zip archive file
find 'iPhoto Library/Modified' -type f -print \
    | perl -pe 's{iPhoto Library/Modified/}{iPhoto Library/Originals/}' \
    | zip -9 -T -m $dest -@ 2>&1 \
    | grep -v 'zip warning: name not matched'
du -sh 'iPhoto Library'

It has some advantages over the original: the photos are moved into a unique zip file, rather than the trash, and the file hierarchy is preserved, so files can be restored easily.

It could be modified to only operate on a subset of files, such as those older than a certain age.

Extra notes:

  1. After running this you’ll find that the photo will appear black in the ‘edit view’. That’s not a problem. The ‘edit view’ (which you enter by double clicking on a photo, for example) reconstructs the final image by taking the original and reapplying the edits-so-far. Since the original file has been removed you’ll just see a black image. Don’t worry. In all the other views, and for printing etc., your final modified picture will appear perfectly.
  2. iPhoto handles automatic rotation of images from cameras that record their orientation by performing a rotation ‘edit’ for you when you import the image. That rotation creates a modified copy, and that’s a common cause of bloat in your iPhoto library. It’s also why you may be surprised to see some originals being archived even though you haven’t editied them. It would be nice if iPhoto had an option to handle rotations destructively.

Usual caveats: this worked for me, your mileage may vary, cross your fingers, read the referenced article (and follow the links in contains), read the comments on them, quit iPhoto, take a backup, wear a tinfoil hat.

Examples of Modern Perl

/ TimBunce / 2 Comments

In the spirit of re-tweeting, this is a short post to highlight some great examples of “modern perl”. (I’m using the term modern perl very loosely, not referring specifically to any one book, website, or module or organization.)

Firstly I’d like to highlight a couple of recent posts by Jonathan Rockway:

* Unshortening URLs with Modern Perl (also available here). An interesting example application built with modern perl modules like MooseX::Declare, MooseX::Getopt, HTTP::Engine, AnyEvent::HTTP, TryCatch, and KiokuDB.

* Multimethods. Another great example from Jonathan highlighting the combined power of MooseX::Types, MooseX::Declare, and MooseX:: MultiMethods.

Then, from his work at the BBC, Curtis “Ovid” Poe has given us a great series of thoughtful posts on the benefits of replacing multiple inheritance with roles in a complex production code-base. The slides of his Inheritance vs Roles talk is a good place to start. Then dive in to the blog posts back here and work your way forward.

I ♥ modern perl!

Generate Treemaps for HTML from Perl, please.

/ TimBunce / 29 Comments

Seeing this video of treemap for perlcritic memory usage reminded me of something…

I’d really like to be able to use treemaps in NYTProf reports to visualize the time spent in different parts, and depths, of the package namespace hierarchy. Currently that information is reported in a series of tables.

A much better interface could be provided by treemaps. Ideally allowing the user to drill-down into deeper levels of the package namespace hierarchy. (It needn’t be this flashy, just 2D would be fine :-)

In case you’re not familiar with them, treemaps are a great way to visualise hierarchical data. Here’s an example treemap of the disk space used by the files in a directory tree (from schoschie) 82244D56-FA2C-4044-AE46-EE53B63861BE.jpg

Perl already has a Treemap module, which can generate treemap images via the Imager module. Treemap is designed to support more output formats by sub-classing.

I guess it wouldn’t be hard to write a sub-class to generate HTML client-side image map data along with the image, so clicks on the image could be used to drill-down into treemaps that have more detail of the specific area that was clicked on.

More interesting, and more flexible, would be a sub-class to generate the treemap as a Scalable Vector Graphics diagram using the SVG module (and others).

I’m not going to be able to work on either of those ideas anytime soon.

Any volunteers?

Perl DynaLoader hack using .bs files

/ TimBunce

I needed to install a perl extension from a third-party. It’s an interface to a shared library, a .so file, that they also supply.

Normally I’d add the directory containing the shared library to the LD_LIBRARY_PATH environment variable. Then when the extension is loaded the system dynamic loader can find it.

For various reasons I didn’t want to do that in this case.

An alternative approach is to pre-load the shared library with a flag to make it’s symbols globally available for later linking. (The flag is called RTLD_GLOBAL on Linux, Solaris and other systems that use dlopen(). This hack may not work on other systems.)

But how to pre-load the shared library, only when needed, and without changing any existing perl code? This is where the pesky little .bs files that get installed with perl extensions come in handy.

They’re known as ‘bootstrap’ files. If the .bs file for an extension not empty then DynaLoader (and XSLoader) will execute the contents just before loading the shared object for the extension.

So I put code like this into the .bs file for the extension:

    use DynaLoader;
    DynaLoader::dl_load_file("$ENV{...}/...so", 1)
	    or die DynaLoader::dl_error();

Not a recommended approach, but neat and handy for me in this case.