<?php
namespace Doctrine\Common\Cache;
use FilesystemIterator;
use InvalidArgumentException;
use Iterator;
use RecursiveDirectoryIterator;
use RecursiveIteratorIterator;
use const DIRECTORY_SEPARATOR;
use const PATHINFO_DIRNAME;
use function bin2hex;
use function chmod;
use function defined;
use function disk_free_space;
use function file_exists;
use function file_put_contents;
use function gettype;
use function hash;
use function is_dir;
use function is_int;
use function is_writable;
use function mkdir;
use function pathinfo;
use function realpath;
use function rename;
use function rmdir;
use function sprintf;
use function strlen;
use function strrpos;
use function substr;
use function tempnam;
use function unlink;
/**
* Base file cache driver.
*/
abstract class FileCache extends CacheProvider
{
/**
* The cache directory.
*
* @var string
*/
protected $directory;
/**
* The cache file extension.
*
* @var string
*/
private $extension;
/** @var int */
private $umask;
/** @var int */
private $directoryStringLength;
/** @var int */
private $extensionStringLength;
/** @var bool */
private $isRunningOnWindows;
/**
* @param string $directory The cache directory.
* @param string $extension The cache file extension.
*
* @throws InvalidArgumentException
*/
public function __construct($directory, $extension = '', $umask = 0002)
{
// YES, this needs to be *before* createPathIfNeeded()
if (! is_int($umask)) {
throw new InvalidArgumentException(sprintf(
'The umask parameter is required to be integer, was: %s',
gettype($umask)
));
}
$this->umask = $umask;
if (! $this->createPathIfNeeded($directory)) {
throw new InvalidArgumentException(sprintf(
'The directory "%s" does not exist and could not be created.',
$directory
));
}
if (! is_writable($directory)) {
throw new InvalidArgumentException(sprintf(
'The directory "%s" is not writable.',
$directory
));
}
// YES, this needs to be *after* createPathIfNeeded()
$this->directory = realpath($directory);
$this->extension = (string) $extension;
$this->directoryStringLength = strlen($this->directory);
$this->extensionStringLength = strlen($this->extension);
$this->isRunningOnWindows = defined('PHP_WINDOWS_VERSION_BUILD');
}
/**
* Gets the cache directory.
*
* @return string
*/
public function getDirectory()
{
return $this->directory;
}
/**
* Gets the cache file extension.
*
* @return string
*/
public function getExtension()
{
return $this->extension;
}
/**
* @param string $id
*
* @return string
*/
protected function getFilename($id)
{
$hash = hash('sha256', $id);
// This ensures that the filename is unique and that there are no invalid chars in it.
if ($id === ''
|| ((strlen($id) * 2 + $this->extensionStringLength) > 255)
|| ($this->isRunningOnWindows && ($this->directoryStringLength + 4 + strlen($id) * 2 + $this->extensionStringLength) > 258)
) {
// Most filesystems have a limit of 255 chars for each path component. On Windows the the whole path is limited
// to 260 chars (including terminating null char). Using long UNC ("\\?\" prefix) does not work with the PHP API.
// And there is a bug in PHP (https://bugs.php.net/bug.php?id=70943) with path lengths of 259.
// So if the id in hex representation would surpass the limit, we use the hash instead. The prefix prevents
// collisions between the hash and bin2hex.
$filename = '_' . $hash;
} else {
$filename = bin2hex($id);
}
return $this->directory
. DIRECTORY_SEPARATOR
. substr($hash, 0, 2)
. DIRECTORY_SEPARATOR
. $filename
. $this->extension;
}
/**
* {@inheritdoc}
*/
protected function doDelete($id)
{
$filename = $this->getFilename($id);
return @unlink($filename) || ! file_exists($filename);
}
/**
* {@inheritdoc}
*/
protected function doFlush()
{
foreach ($this->getIterator() as $name => $file) {
if ($file->isDir()) {
// Remove the intermediate directories which have been created to balance the tree. It only takes effect
// if the directory is empty. If several caches share the same directory but with different file extensions,
// the other ones are not removed.
@rmdir($name);
} elseif ($this->isFilenameEndingWithExtension($name)) {
// If an extension is set, only remove files which end with the given extension.
// If no extension is set, we have no other choice than removing everything.
@unlink($name);
}
}
return true;
}
/**
* {@inheritdoc}
*/
protected function doGetStats()
{
$usage = 0;
foreach ($this->getIterator() as $name => $file) {
if ($file->isDir() || ! $this->isFilenameEndingWithExtension($name)) {
continue;
}
$usage += $file->getSize();
}
$free = disk_free_space($this->directory);
return [
Cache::STATS_HITS => null,
Cache::STATS_MISSES => null,
Cache::STATS_UPTIME => null,
Cache::STATS_MEMORY_USAGE => $usage,
Cache::STATS_MEMORY_AVAILABLE => $free,
];
}
/**
* Create path if needed.
*
* @return bool TRUE on success or if path already exists, FALSE if path cannot be created.
*/
private function createPathIfNeeded(string $path) : bool
{
if (! is_dir($path)) {
if (@mkdir($path, 0777 & (~$this->umask), true) === false && ! is_dir($path)) {
return false;
}
}
return true;
}
/**
* Writes a string content to file in an atomic way.
*
* @param string $filename Path to the file where to write the data.
* @param string $content The content to write
*
* @return bool TRUE on success, FALSE if path cannot be created, if path is not writable or an any other error.
*/
protected function writeFile(string $filename, string $content) : bool
{
$filepath = pathinfo($filename, PATHINFO_DIRNAME);
if (! $this->createPathIfNeeded($filepath)) {
return false;
}
if (! is_writable($filepath)) {
return false;
}
$tmpFile = tempnam($filepath, 'swap');
@chmod($tmpFile, 0666 & (~$this->umask));
if (file_put_contents($tmpFile, $content) !== false) {
@chmod($tmpFile, 0666 & (~$this->umask));
if (@rename($tmpFile, $filename)) {
return true;
}
@unlink($tmpFile);
}
return false;
}
private function getIterator() : Iterator
{
return new RecursiveIteratorIterator(
new RecursiveDirectoryIterator($this->directory, FilesystemIterator::SKIP_DOTS),
RecursiveIteratorIterator::CHILD_FIRST
);
}
/**
* @param string $name The filename
*/
private function isFilenameEndingWithExtension(string $name) : bool
{
return $this->extension === ''
|| strrpos($name, $this->extension) === (strlen($name) - $this->extensionStringLength);
}
}