<?php
/**
* PrivateBin
*
* a zero-knowledge paste bin
*
* @link https://github.com/PrivateBin/PrivateBin
* @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
* @license https://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
* @version 1.2.1
*/
namespace PrivateBin\Data;
use PrivateBin\Persistence\DataStore;
/**
* Filesystem
*
* Model for filesystem data access, implemented as a singleton.
*/
class Filesystem extends AbstractData
{
/**
* get instance of singleton
*
* @access public
* @static
* @param array $options
* @return Filesystem
*/
public static function getInstance(array $options)
{
// if needed initialize the singleton
if (!(self::$_instance instanceof self)) {
self::$_instance = new self;
}
// if given update the data directory
if (
is_array($options) &&
array_key_exists('dir', $options)
) {
DataStore::setPath($options['dir']);
}
return self::$_instance;
}
/**
* Create a paste.
*
* @access public
* @param string $pasteid
* @param array $paste
* @return bool
*/
public function create($pasteid, array $paste)
{
$storagedir = self::_dataid2path($pasteid);
$file = $storagedir . $pasteid . '.php';
if (is_file($file)) {
return false;
}
if (!is_dir($storagedir)) {
mkdir($storagedir, 0700, true);
}
return DataStore::store($file, $paste);
}
/**
* Read a paste.
*
* @access public
* @param string $pasteid
* @return array|false
*/
public function read($pasteid)
{
if (!$this->exists($pasteid)) {
return false;
}
return self::upgradePreV1Format(
DataStore::get(self::_dataid2path($pasteid) . $pasteid . '.php')
);
}
/**
* Delete a paste and its discussion.
*
* @access public
* @param string $pasteid
*/
public function delete($pasteid)
{
$pastedir = self::_dataid2path($pasteid);
if (is_dir($pastedir)) {
// Delete the paste itself.
if (is_file($pastedir . $pasteid . '.php')) {
unlink($pastedir . $pasteid . '.php');
}
// Delete discussion if it exists.
$discdir = self::_dataid2discussionpath($pasteid);
if (is_dir($discdir)) {
// Delete all files in discussion directory
$dir = dir($discdir);
while (false !== ($filename = $dir->read())) {
if (is_file($discdir . $filename)) {
unlink($discdir . $filename);
}
}
$dir->close();
rmdir($discdir);
}
}
}
/**
* Test if a paste exists.
*
* @access public
* @param string $pasteid
* @return bool
*/
public function exists($pasteid)
{
$basePath = self::_dataid2path($pasteid) . $pasteid;
$pastePath = $basePath . '.php';
// convert to PHP protected files if needed
if (is_readable($basePath)) {
DataStore::prependRename($basePath, $pastePath);
// convert comments, too
$discdir = self::_dataid2discussionpath($pasteid);
if (is_dir($discdir)) {
$dir = dir($discdir);
while (false !== ($filename = $dir->read())) {
if (substr($filename, -4) !== '.php' && strlen($filename) >= 16) {
$commentFilename = $discdir . $filename . '.php';
DataStore::prependRename($discdir . $filename, $commentFilename);
}
}
$dir->close();
}
}
return is_readable($pastePath);
}
/**
* Create a comment in a paste.
*
* @access public
* @param string $pasteid
* @param string $parentid
* @param string $commentid
* @param array $comment
* @return bool
*/
public function createComment($pasteid, $parentid, $commentid, array $comment)
{
$storagedir = self::_dataid2discussionpath($pasteid);
$file = $storagedir . $pasteid . '.' . $commentid . '.' . $parentid . '.php';
if (is_file($file)) {
return false;
}
if (!is_dir($storagedir)) {
mkdir($storagedir, 0700, true);
}
return DataStore::store($file, $comment);
}
/**
* Read all comments of paste.
*
* @access public
* @param string $pasteid
* @return array
*/
public function readComments($pasteid)
{
$comments = array();
$discdir = self::_dataid2discussionpath($pasteid);
if (is_dir($discdir)) {
$dir = dir($discdir);
while (false !== ($filename = $dir->read())) {
// Filename is in the form pasteid.commentid.parentid.php:
// - pasteid is the paste this reply belongs to.
// - commentid is the comment identifier itself.
// - parentid is the comment this comment replies to (It can be pasteid)
if (is_file($discdir . $filename)) {
$comment = DataStore::get($discdir . $filename);
$items = explode('.', $filename);
// Add some meta information not contained in file.
$comment['id'] = $items[1];
$comment['parentid'] = $items[2];
// Store in array
$key = $this->getOpenSlot($comments, (int) $comment['meta']['created']);
$comments[$key] = $comment;
}
}
$dir->close();
// Sort comments by date, oldest first.
ksort($comments);
}
return $comments;
}
/**
* Test if a comment exists.
*
* @access public
* @param string $pasteid
* @param string $parentid
* @param string $commentid
* @return bool
*/
public function existsComment($pasteid, $parentid, $commentid)
{
return is_file(
self::_dataid2discussionpath($pasteid) .
$pasteid . '.' . $commentid . '.' . $parentid . '.php'
);
}
/**
* Returns up to batch size number of paste ids that have expired
*
* @access private
* @param int $batchsize
* @return array
*/
protected function _getExpiredPastes($batchsize)
{
$pastes = array();
$mainpath = DataStore::getPath();
$firstLevel = array_filter(
scandir($mainpath),
'self::_isFirstLevelDir'
);
if (count($firstLevel) > 0) {
// try at most 10 times the $batchsize pastes before giving up
for ($i = 0, $max = $batchsize * 10; $i < $max; ++$i) {
$firstKey = array_rand($firstLevel);
$secondLevel = array_filter(
scandir($mainpath . DIRECTORY_SEPARATOR . $firstLevel[$firstKey]),
'self::_isSecondLevelDir'
);
// skip this folder in the next checks if it is empty
if (count($secondLevel) == 0) {
unset($firstLevel[$firstKey]);
continue;
}
$secondKey = array_rand($secondLevel);
$path = $mainpath . DIRECTORY_SEPARATOR .
$firstLevel[$firstKey] . DIRECTORY_SEPARATOR .
$secondLevel[$secondKey];
if (!is_dir($path)) {
continue;
}
$thirdLevel = array_filter(
array_map(
function ($filename) {
return strlen($filename) >= 20 ?
substr($filename, 0, -4) :
$filename;
},
scandir($path)
),
'PrivateBin\\Model\\Paste::isValidId'
);
if (count($thirdLevel) == 0) {
continue;
}
$thirdKey = array_rand($thirdLevel);
$pasteid = $thirdLevel[$thirdKey];
if (in_array($pasteid, $pastes)) {
continue;
}
if ($this->exists($pasteid)) {
$data = $this->read($pasteid);
if (
array_key_exists('expire_date', $data['meta']) &&
$data['meta']['expire_date'] < time()
) {
$pastes[] = $pasteid;
if (count($pastes) >= $batchsize) {
break;
}
}
}
}
}
return $pastes;
}
/**
* Convert paste id to storage path.
*
* The idea is to creates subdirectories in order to limit the number of files per directory.
* (A high number of files in a single directory can slow things down.)
* eg. "f468483c313401e8" will be stored in "data/f4/68/f468483c313401e8"
* High-trafic websites may want to deepen the directory structure (like Squid does).
*
* eg. input 'e3570978f9e4aa90' --> output 'data/e3/57/'
*
* @access private
* @static
* @param string $dataid
* @return string
*/
private static function _dataid2path($dataid)
{
return DataStore::getPath(
substr($dataid, 0, 2) . DIRECTORY_SEPARATOR .
substr($dataid, 2, 2) . DIRECTORY_SEPARATOR
);
}
/**
* Convert paste id to discussion storage path.
*
* eg. input 'e3570978f9e4aa90' --> output 'data/e3/57/e3570978f9e4aa90.discussion/'
*
* @access private
* @static
* @param string $dataid
* @return string
*/
private static function _dataid2discussionpath($dataid)
{
return self::_dataid2path($dataid) . $dataid .
'.discussion' . DIRECTORY_SEPARATOR;
}
/**
* Check that the given element is a valid first level directory.
*
* @access private
* @static
* @param string $element
* @return bool
*/
private static function _isFirstLevelDir($element)
{
return self::_isSecondLevelDir($element) &&
is_dir(DataStore::getPath($element));
}
/**
* Check that the given element is a valid second level directory.
*
* @access private
* @static
* @param string $element
* @return bool
*/
private static function _isSecondLevelDir($element)
{
return (bool) preg_match('/^[a-f0-9]{2}$/', $element);
}
}