Call C2DM in parallel using PHP

class.C2DMParallel.php

<?php
/*
	class.C2DMParallel.php

	PHP Class to send single messages to multiple devices 
	using Google's C2DM service.  

*/

class C2DMParallel{
	private $client = ''; 	//Client ID
	private $secret = '';	// Client SECRET
	private $refresh = '';	// Refresh Key

	private $limit = 500;     // The number of calls to process at once

	private $access;


	public function __construct(){
		$this->access = $this->update_auth();
		if(is_null($this->access)){
			die('Cannot update auth');
		}
	}


	/*
		I'm putting this up top because it needs to be edited for your own purposes. 
		Google will return errors, you WILL need to handle them respectively 
	*/
	private function handle_responses($responses){
		foreach($responses as $registration_id => $response){

			// Split the response
			$exp = explode('=',$response);

			if($exp[0] == 'Error'){
				switch ($exp[1]) {
					case 'QuotaExceeded':
						// Don't send messages until next day
						break;
					case 'DeviceQuotaExceeded':
						// Give uer a break
						break;
					case 'InvalidRegistration':
						# Remove registration_id
						break;
					case 'NotRegistered':
						# Remove registration_id
						break;
					case 'MessageTooBig':
						# Stop process
						break;
					case 'MissingCollapseKey':
						# Stop process
						break;
					default:
						# code...
						break;
				}
			}
			print_r($exp);
		}
	}

	public function execute( $message, $users = array() , $collapse_key = 1){
		$groups = array_chunk($users, $this->limit);
		foreach($groups as $group){
			$tmp = $this->process_curl_parallel($group, $message,$collapse_key);
			$this->handle_responses($tmp);
			unset($tmp);	
		}
		
	}

	private function update_auth(){
		$url = "https://accounts.google.com/o/oauth2/token";
		$fields = array(
				'grant_type' => 'refresh_token',
				'client_id' => $this->client,
				'client_secret' => $this->secret,
				'refresh_token' => $this->refresh
			);

		$ch = curl_init();
		curl_setopt($ch,CURLOPT_URL,$url);
		curl_setopt($ch,CURLOPT_POSTFIELDS, $fields);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		$output = curl_exec($ch);
		$info = curl_getinfo($ch);
		curl_close($ch);
		$key = json_decode($output,TRUE);
		
		if(!isset($key['access_token'])){
			return null;
		} else {
			return $key['access_token'];
		}
	}


	/*
		Performs the curl_multi call
	*/

	private function process_curl_parallel($users,$data,$collapse_key){

		// Set Headers
		$headers = array('Authorization: Bearer ' . $this->access);

		// SET URL
		$url = 'https://android.apis.google.com/c2dm/send';
		//$url = 'https://android.apis.google.com/c2dm/send';


		// Prepare Message
		foreach($data as $key => $value){
			$message['data.' . $key] = $value;
		}

		// Init CURL MULTI 
		$mh = curl_multi_init();

		// Stage Individual Messages 
		$i = 0; 

		foreach($users as $key => $registration_id){
			// Complete staging for messages
			$message['registration_id'] = $registration_id;
			$message['collapse_key'] = $collapse_key;

			// Init Curl
			$ch[$registration_id] = curl_init();

			curl_setopt($ch[$registration_id], CURLOPT_URL, $url);
			curl_setopt($ch[$registration_id], CURLOPT_HEADER, 0);
			curl_setopt($ch[$registration_id], CURLOPT_POSTFIELDS, $message);
			curl_setopt($ch[$registration_id], CURLOPT_HTTPHEADER, $headers);
			curl_setopt($ch[$registration_id], CURLOPT_RETURNTRANSFER, TRUE);

			curl_multi_add_handle($mh,$ch[$registration_id]);

			$i++;
		}


		// Run the multi_curl

		$responses = array();
		
		do {
		  $code = curl_multi_exec($mh,$still_executing);
		  if ($code==CURLM_OK) { 
		    
		    while ($done=curl_multi_info_read($mh)) {
		      $c = $done['handle'];

		      // Grab the Key from the handle
		      $key = array_search($done['handle'], $ch);
		      
		      $responses[$key] = curl_multi_getcontent($c);

		      // Remove handles 
		      curl_multi_remove_handle($mh,$c);
		    }
		  } elseif ($code!=CURLM_CALL_MULTI_PERFORM) { 
		    throw new RuntimeException("multi_curl failure [$code]");
		  }
		} while ($still_executing);


		curl_multi_close($mh);

		return $responses;
	}
}





/*
	Usage
*/
$c2dm = new C2DMParallel();

/*
	$users = array('device_key','device_key','device_key');
*/
$users = array();

/*
	Messages are associative arrays.. Remember they are limited to 1024 bytes.
	$message = array(
					'field' => 'body',
					'field2' => 'body2'
				); 
*/
$message = array('type' => 2);
$c2dm->execute($message,$users,4);

?>