Hasan's project for the Hack Night was a log-file visualizer to be used with real-time-ish log parsing such that you could "waggle a mouse in this window and see the performance stats in this one" (he does video driver testing by day). We decided to step that down to parsing a sample data-file (in this case an apache log file) and rendering a time:downloaded-bytes plot.
We started off with a script that just parsed the whole test data-set into RAM and rendered it with OpenGLContext. After that we made it capable of doing data-window rendering, so that you just see the last 600 data-points rendered into a sliding window. I fixed a few bugs in that on the subway, and then added some scale labels after I got home.
I've uploaded the code to github, should anyone wish to play with it. The code was quite capable of rendering 47,000 data-points at >100fps, the current 600-at-a-time thing is just so that we could use a small data-set for testing iterative loading. Lots of code could be optimized, but honestly we just weren't hitting any limits to make it worthwhile doing so.