server/lib/updater.php

<?php
/**
 * ownCloud
 *
 * @author Frank Karlitschek
 * @copyright 2012 Frank Karlitschek frank@owncloud.org
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/**
 * Class that handels autoupdating of ownCloud
 */
class OC_Updater{

	/**
	 * Check if a new version is available
	 */
	public static function check() {

		// Look up the cache - it is invalidated all 30 minutes
		if((OC_Appconfig::getValue('core', 'lastupdatedat') + 1800) > time()) {
			return json_decode(OC_Appconfig::getValue('core', 'lastupdateResult'), true);
		}

		OC_Appconfig::setValue('core', 'lastupdatedat', time());

		if(OC_Appconfig::getValue('core', 'installedat', '')=='') {
			OC_Appconfig::setValue('core', 'installedat', microtime(true));
		}

		$updaterurl='http://apps.owncloud.com/updater.php';
		$version=OC_Util::getVersion();
		$version['installed']=OC_Appconfig::getValue('core', 'installedat');
		$version['updated']=OC_Appconfig::getValue('core', 'lastupdatedat');
		$version['updatechannel']='stable';
		$version['edition']=OC_Util::getEditionString();
		$versionstring=implode('x', $version);

		//fetch xml data from updater
		$url=$updaterurl.'?version='.$versionstring;

		// set a sensible timeout of 10 sec to stay responsive even if the update server is down.
		$ctx = stream_context_create(
			array(
				'http' => array(
					'timeout' => 10
				)
			)
		);
		$xml=@file_get_contents($url, 0, $ctx);
		if($xml==false) {
			return array();
		}
		$data=@simplexml_load_string($xml);

		$tmp=array();
		$tmp['version'] = $data->version;
		$tmp['versionstring'] = $data->versionstring;
		$tmp['url'] = $data->url;
		$tmp['web'] = $data->web;

		// Cache the result
		OC_Appconfig::setValue('core', 'lastupdateResult', json_encode($data));

		return $tmp;
	}
}