Ivan Pavlov's Bookmarks

For a client we had to optimize the insane time ImageMagick spent on certain image processing tasks. After the first code review it became clear that imagemagick was coded for anything but speed.

We prototyped the needed code in C++, just for speed, and achieved processing times about 1/20 of what ImageMagick consumes.

In the library we will explore several new algorithms, e.g. for de-screening, de-skewing, data-dependant triangulation scaling, lossless JPEG transforms and others as we see need. You are very much welcome to contribute thrilling state-of-the-art algorithms.

is real-time query performance and diagnostics tool for the MySQL database server. Core features:







• Query, table and user performance


• Graphical visualisation


• Low overhead


• Easy to use

Another similar example would be to pack the whole directory of files into a compressed tarball:

$ tar -czf - . | pv > out.tgz
 117MB 0:00:55 [2.7MB/s] [>         ]

In this example pv shows just the output rate of “tar -czf” command. Not very interesting and it does not provide information about how much data is left. We need to provide the total size of data we are tarring to pv, it’s done this way:

$ tar -cf - . | pv -s $(du -sb . | awk '{print $1}') | gzip > out.tgz
 253MB 0:00:05 [46.7MB/s] [>     ]  1% ETA 0:04:49

What happens here is we tell tar to create “-c” an archive of all files in current dir “.” (recursively) and output the data to stdout “-f -”. Next we specify the size “-s” to pv of all files in current dir. The “du -sb . | awk ‘{print $1}’” returns number of bytes in current dir, and it gets fed as “-s” parameter to pv. Next we gzip the whole content and output the result to out.tgz file. This way “pv” knows how much data is still left to be processed and shows us that it will totally take 4 mins 49 secs to finish.

Joose is a self-hosting meta object system for JavaScript with support for classes, inheritance, mixins, traits, method modifiers and more.

Joose makes object-oriented programming with JavaScript easy, declarative and very productive. The Joose meta-object system is multi-paradigm. It supports class-based and prototype-based programming styles as well as class-based inheritance and role-based extention.

The Joose framework has been successfully used in multiple production systems for twelve months now and has been proven to be very stable. Joose is being tested using an automated unit-test suite that is being run in all major browsers (Firefox, IE, Safari, Opera and Chrome).

Ruby Enterprise Edition is a friendly branch of Ruby which includes
various enhancements:



• A copy-on-write friendly garbage collector. Phusion Passenger uses
  this, in combination with a technique called preforking, to reduce Ruby
  on Rails applications' memory usage by 33% on average.


• An improved memory allocator called tcmalloc,
  which improves performance quite a bit.


• The ability to tweak garbage collector settings for maximum server performance,
  and the ability to inspect the garbage collector's state.
  (RailsBench GC patch)


• The ability to dump stack traces for all running threads
  (caller_for_all_threads),
  making it easier for one to debug multithreaded Ruby web applications.