inotify and FSEvents...

[Jason Harris]

In the 2.3 Sprint we are talking about underlying notification. In OSX notification is through FSEvents:

Couple of points with FSEvent watching:
- Updates within a single directory are coalesced.  But all touched directories are
reported.  (Mads was correct here.)
- It looks like you can create FSEvents watchers which will report all changes to files as
well:  http://developer.apple.com/library/mac/#documentation/Darwin/Reference/FSEvents_Ref/FSEvents_h/index.html#//apple_ref/c/tag/FSEventStreamCreateFlags
This flag is unfortunately new to 10.7 and Mercurial should likely still support 10.6 (Snow Leopard
if not 10.5 Leopard....)

For info on FSEvents see:
 http://arstechnica.com/apple/2007/10/mac-os-x-10-5/7/
 http://developer.apple.com/library/mac/#documentation/Darwin/Reference/FSEvents_Ref/FSEvents_h/

- Spotlight works by having a fsevents daemon record to a compressed log file which
  directories are changed.  Then spotlight will examine this log at it's leisure to figure
  out what it needs to rescan...