Derick Rethans has posted the next part of his series of posts about the latest version of XDebug (v2.3). In this new post he focuses on the profiler and the new ability of it to compress the resulting file.

When making profiling dumps with Xdebug, the file size can not really be ignored. Even with a simple Drupal page a profile file is easily close to 1Mb. For each function call, the file contains the location and name of the calling function, and then a list of functions that have been called.

He gives an example of the uncompressed output from an execution of Drupal, showing the duplicate content when the same method is called more than once. With this new feature, XDebug is smart enough to detect this and make use of name compression to essentially replace duplication with a reference to the previous call to the same bits of code.