Some improvments v2 ?

I had some problem witch you script eq 30 second freeze

• Why every 5 millisecond connect to mongodb and check for lock
  So i use wincache can be changed to APC to store lock $ID, and add expire
• Some fix witch names etc only for my script
  Too bad is not ->limit in mongodb when remove _gc
• Index only are create once when server start

ADD background an unique

$this->_mongo->ensureIndex(array('_id' => true),array('background' => true, 'unique' => true ));

• _write -> add "upsert" => true
• When read data -> get only filed 'D' witchout _id or other array('d' => 1,'_id' => 0 )

FULL code

https://gist.github.com/2670252