<?php
declare(strict_types=1);
namespace Sabre\DAV\Locks\Backend;
use Sabre\DAV\Locks\LockInfo;
/**
* This Locks backend stores all locking information in a single file.
*
* Note that this is not nearly as robust as a database. If you are considering
* using this backend, keep in mind that the PDO backend can work with SqLite,
* which is designed to be a good file-based database.
*
* It literally solves the problem this class solves as well, but much better.
*
* @copyright Copyright (C) fruux GmbH (https://fruux.com/)
* @author Evert Pot (http://evertpot.com/)
* @license http://sabre.io/license/ Modified BSD License
*/
class File extends AbstractBackend
{
/**
* The storage file.
*
* @var string
*/
private $locksFile;
/**
* Constructor.
*
* @param string $locksFile path to file
*/
public function __construct($locksFile)
{
$this->locksFile = $locksFile;
}
/**
* Returns a list of Sabre\DAV\Locks\LockInfo objects.
*
* This method should return all the locks for a particular uri, including
* locks that might be set on a parent uri.
*
* If returnChildLocks is set to true, this method should also look for
* any locks in the subtree of the uri for locks.
*
* @param string $uri
* @param bool $returnChildLocks
*
* @return array
*/
public function getLocks($uri, $returnChildLocks)
{
$newLocks = [];
$locks = $this->getData();
foreach ($locks as $lock) {
if ($lock->uri === $uri ||
//deep locks on parents
(0 != $lock->depth && 0 === strpos($uri, $lock->uri.'/')) ||
// locks on children
($returnChildLocks && (0 === strpos($lock->uri, $uri.'/')))) {
$newLocks[] = $lock;
}
}
// Checking if we can remove any of these locks
foreach ($newLocks as $k => $lock) {
if (time() > $lock->timeout + $lock->created) {
unset($newLocks[$k]);
}
}
return $newLocks;
}
/**
* Locks a uri.
*
* @param string $uri
*
* @return bool
*/
public function lock($uri, LockInfo $lockInfo)
{
// We're making the lock timeout 30 minutes
$lockInfo->timeout = 1800;
$lockInfo->created = time();
$lockInfo->uri = $uri;
$locks = $this->getData();
foreach ($locks as $k => $lock) {
if (
($lock->token == $lockInfo->token) ||
(time() > $lock->timeout + $lock->created)
) {
unset($locks[$k]);
}
}
$locks[] = $lockInfo;
$this->putData($locks);
return true;
}
/**
* Removes a lock from a uri.
*
* @param string $uri
*
* @return bool
*/
public function unlock($uri, LockInfo $lockInfo)
{
$locks = $this->getData();
foreach ($locks as $k => $lock) {
if ($lock->token == $lockInfo->token) {
unset($locks[$k]);
$this->putData($locks);
return true;
}
}
return false;
}
/**
* Loads the lockdata from the filesystem.
*
* @return array
*/
protected function getData()
{
if (!file_exists($this->locksFile)) {
return [];
}
// opening up the file, and creating a shared lock
$handle = fopen($this->locksFile, 'r');
flock($handle, LOCK_SH);
// Reading data until the eof
$data = stream_get_contents($handle);
// We're all good
flock($handle, LOCK_UN);
fclose($handle);
// Unserializing and checking if the resource file contains data for this file
$data = unserialize($data);
if (!$data) {
return [];
}
return $data;
}
/**
* Saves the lockdata.
*/
protected function putData(array $newData)
{
// opening up the file, and creating an exclusive lock
$handle = fopen($this->locksFile, 'a+');
flock($handle, LOCK_EX);
// We can only truncate and rewind once the lock is acquired.
ftruncate($handle, 0);
rewind($handle);
fwrite($handle, serialize($newData));
flock($handle, LOCK_UN);
fclose($handle);
}
}