gnu-social/lib/util/tempfile.php
Alexei Sorokin 7fa4d56f05 Implement a class for automatic temporary file handling
And adopt it all over the code.
2021-07-16 19:44:41 +01:00

156 lines
4.5 KiB
PHP

<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social 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 GNU social. If not, see <http://www.gnu.org/licenses/>.
/**
* @package GNUsocial
* @author Alexei Sorokin <sor.alexei@meowr.ru>
* @copyright 2020 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
defined('GNUSOCIAL') || die();
/**
* Exception wrapper for TemporaryFile errors
*
* @package GNUsocial
* @author Alexei Sorokin <sor.alexei@meowr.ru>
* @copyright 2020 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
class TemporaryFileException extends Exception
{
}
/**
* Class oriented at providing automatic temporary file handling.
*
* @package GNUsocial
* @author Alexei Sorokin <sor.alexei@meowr.ru>
* @copyright 2020 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
class TemporaryFile extends SplFileInfo
{
protected $resource = null;
/**
* @param string|null $prefix The file name will begin with that prefix
* ("php" by default)
* @param string|null $mode File open mode ("w+b" by default)
*/
public function __construct(
?string $prefix = null,
?string $mode = null
) {
$filename = tempnam(sys_get_temp_dir(), $prefix ?? 'gs-php');
if ($filename === false) {
throw new TemporaryFileException('Could not create file: ' . $filename);
}
parent::__construct($filename);
if (($this->resource = fopen($filename, $mode ?? 'w+b')) === false) {
$this->cleanup();
throw new TemporaryFileException('Could not open file: ' . $filename);
}
}
public function __destruct()
{
$this->close();
$this->cleanup();
}
/**
* Closes the file descriptor if opened.
*
* @return bool Whether successful
*/
protected function close(): bool
{
$ret = true;
if (!is_null($this->resource)) {
$ret = fclose($this->resource);
}
if ($ret) {
$this->resource = null;
}
return $ret;
}
/**
* Closes the file descriptor and removes the temporary file.
*
* @return void
*/
protected function cleanup(): void
{
$path = $this->getRealPath();
$this->close();
if (file_exists($path)) {
unlink($path);
}
}
/**
* Get the file resource.
*
* @return resource
*/
public function getResource()
{
return $this->resource;
}
/**
* Release the hold on the temporary file and move it to the desired
* location, setting file permissions in the process.
*
* @param string File destination
* @param int New file permissions (in octal mode)
* @return void
* @throws TemporaryFileException
*/
public function commit(string $destpath, int $umode = 0644): void
{
$temppath = $this->getRealPath();
// Might be attempted, and won't end well
if ($destpath === $temppath) {
throw new TemporaryFileException('Cannot use self as destination');
}
// Memorise if the file was there and see if there is access
$exists = file_exists($destpath);
if (!touch($destpath)) {
throw new TemporaryFileException(
'Insufficient permissions for destination: "' . $destpath . '"'
);
} elseif (!$exists) {
// If the file wasn't there, clean it up in case of a later failure
unlink($destpath);
}
if (!$this->close()) {
throw new TemporaryFileException('Could not close the resource');
}
rename($temppath, $destpath);
chmod($destpath, $umode);
}
}