January 22nd, 2006

allegrocache screencast

I just finished watching an in-browser Flash demo of AllegroCache, performed by Jans Aasman. It is rough in a couple spots; he says things like "This isn't important to the demo" and "I'll go back and cut out this part". Overall, though, he does a good job of explaining what is happening on the screen, and he doesn't speak too quickly.

The demo quickly covers:

  • normal object persistence
  • using persistent objects with Allegro Prolog
  • persistent data structures (maps, sets)

It is not very technical, which disappointed me.

You can watch the screencast here.

The presentation is about 20 megabytes in size, so you need to wait quite a while before it starts playing (I downloaded the SWF file to disk and played from there). It lasts about 24 minutes.

lisp

sb-heapdump

David Lichteblau is working on a tool for SBCL called sb-heapdump. Here's an except from his recent message to sbcl-devel about it:

As an extension, sb-heapdump can write entire packages to disk, including all variables, functions, and classes in that package. Used this way, heapfiles provide a bit of a compromise between the modularity of fasl file loading and the speed of core files.

Load time example for clx, mcclim, and climacs (dumped into seperate files; times in seconds):

                |   sb-heapdump    | load-op (plus .asd loading time)
    ------------+------------------+----------------------------------
      clx       |   0.15           | 3.096   (0.433)
      mcclim    |   0.85           | 20.765  (1.509)
      climacs   |   1.30           | 28.2    (0.267)

SBCL's FASL loading is not very fast, and dumping a fully-loaded custom core sometimes seems like overkill, so this could be a very nice alternative to both.