Posts tagged Python

Stephan Richter convinced me to try the ZCML optimization task. Zope 3 parses and interprets hundreds of little ZCML configuration files on startup. The idea was that if we can cache pre-parsed configuration on disk, we could speed up Zope 3 startup by 30–50%. I originally tried this approach back in 2004 but couldn't get it to work. Today, thanks to Stephan Richter, who took over the most boring and difficult parts (making view directives pickleable), we got to a point where Zope 3 works after loading the configuration pickle instead of parsing ZCMLs (and starts up in 2 seconds instead of 3).

One of the reasons I wanted to come to the Foliage sprint was to get acquainted with the brave new world of Zope 3 eggs. For this reason I chose to work on package dependency simplification. I spent a couple of hours reading setuptools documentation, easy_install and zc.buildout source code, trying to figure out the right way to extract dependency information from a set of eggs. Then philiKON mentioned tl.

I'm at the Zope 3 Foliage Sprint. The main point of this post is to fix the fact that the canonical sprint wiki page is not even on the first page of Google results. Update: apparently that's caused by <meta name="robots" content="noindex" /> in the HTML.

Previous entry. The numbers I posted earlier about zope.testing self-test coverage were incorrect. It turns out that when a test runner tries to trace a test that tests that a (different) test runner can use tracing to trace (different) tests, they both compete over a single sys.settrace() hook and only one of them wins. Basically you get to choose between a failing test or incomplete test coverage that ignores all subsequent tests.

Previous entry. During the second day I refactored the Zope 3 test runner to make nearly all of its output go through a single OutputFormatter class (in the output-refactoring branch), then created a subclass of it that uses ANSI color codes to highlight error messages (in the colorized-output branch). I've had this luxury before, and I can attest that it does increase productivity (being able to spot filenames and line numbers between several-hundred-line diffs produced by testbrowser tests is invaluable).