Profiling support

[roxblnfk]

Helpers

Thoughts

• Add trap()->stackTrace(); maintenance #41 (required to be prepared for adding trap()::profile() methods)
• SPX
• XHProf (supported by Buggregator Server and UI)
• XDebug (local files, cachegrind format, 1)
• excimer (pecl, https://github.com/wikimedia/mediawiki-php-excimer)
  • XHGui (wikitech)

Parsing formats

• Parse XHProf content into XHProf events
• Parse XDebug content into XDebug events
• Parse SPX content into SPX events

Local profiling files

• Scan configured profiling directories from time to time #52

Rendering:

• xhProf console renderer #11