php mongo seq

Counter.php

<?php
//cakephpチックに書くとこんな感じ？
//cakephpでなければ適当にfunctions のところだけ抜き出して使ってください
App::uses('AppModel', 'Model');
 class Counter extends AppModel {
  public function connect() {
     $client = new MongoClient();
     $db = $client->selectDB('databaseName');
     return $db;
  }
  public function seq($collection) {
    $db = $this->connect();
    $seq = $db->command(
      array('findandmodify' => 'counters',
      'query' => array('_id' => $collection),//users とかシーケンス振りたいコレクション名とか
      'update' => array('$inc' => array('seq' => 1)),
      'new' => TRUE)
    );
    return $seq;
 }

 }