<?php
/**
* SCSSPHP
*
* @copyright 2012-2020 Leaf Corcoran
*
* @license http://opensource.org/licenses/MIT MIT
*
* @link http://scssphp.github.io/scssphp
*/
namespace ScssPhp\ScssPhp;
use Exception;
use ScssPhp\ScssPhp\Version;
/**
* The scss cache manager.
*
* In short:
*
* allow to put in cache/get from cache a generic result from a known operation on a generic dataset,
* taking in account options that affects the result
*
* The cache manager is agnostic about data format and only the operation is expected to be described by string
*/
/**
* SCSS cache
*
* @author Cedric Morin <cedric@yterium.com>
*
* @internal
*/
class Cache
{
const CACHE_VERSION = 1;
/**
* directory used for storing data
*
* @var string|false
*/
public static $cacheDir = false;
/**
* prefix for the storing data
*
* @var string
*/
public static $prefix = 'scssphp_';
/**
* force a refresh : 'once' for refreshing the first hit on a cache only, true to never use the cache in this hit
*
* @var bool|string
*/
public static $forceRefresh = false;
/**
* specifies the number of seconds after which data cached will be seen as 'garbage' and potentially cleaned up
*
* @var int
*/
public static $gcLifetime = 604800;
/**
* array of already refreshed cache if $forceRefresh==='once'
*
* @var array<string, bool>
*/
protected static $refreshed = [];
/**
* Constructor
*
* @param array $options
*
* @phpstan-param array{cacheDir?: string, prefix?: string, forceRefresh?: string} $options
*/
public function __construct($options)
{
// check $cacheDir
if (isset($options['cacheDir'])) {
self::$cacheDir = $options['cacheDir'];
}
if (empty(self::$cacheDir)) {
throw new Exception('cacheDir not set');
}
if (isset($options['prefix'])) {
self::$prefix = $options['prefix'];
}
if (empty(self::$prefix)) {
throw new Exception('prefix not set');
}
if (isset($options['forceRefresh'])) {
self::$forceRefresh = $options['forceRefresh'];
}
self::checkCacheDir();
}
/**
* Get the cached result of $operation on $what,
* which is known as dependant from the content of $options
*
* @param string $operation parse, compile...
* @param mixed $what content key (e.g., filename to be treated)
* @param array $options any option that affect the operation result on the content
* @param int|null $lastModified last modified timestamp
*
* @return mixed
*
* @throws \Exception
*/
public function getCache($operation, $what, $options = [], $lastModified = null)
{
$fileCache = self::$cacheDir . self::cacheName($operation, $what, $options);
if (
((self::$forceRefresh === false) || (self::$forceRefresh === 'once' &&
isset(self::$refreshed[$fileCache]))) && file_exists($fileCache)
) {
$cacheTime = filemtime($fileCache);
if (
(\is_null($lastModified) || $cacheTime > $lastModified) &&
$cacheTime + self::$gcLifetime > time()
) {
$c = file_get_contents($fileCache);
$c = unserialize($c);
if (\is_array($c) && isset($c['value'])) {
return $c['value'];
}
}
}
return null;
}
/**
* Put in cache the result of $operation on $what,
* which is known as dependant from the content of $options
*
* @param string $operation
* @param mixed $what
* @param mixed $value
* @param array $options
*
* @return void
*/
public function setCache($operation, $what, $value, $options = [])
{
$fileCache = self::$cacheDir . self::cacheName($operation, $what, $options);
$c = ['value' => $value];
$c = serialize($c);
file_put_contents($fileCache, $c);
if (self::$forceRefresh === 'once') {
self::$refreshed[$fileCache] = true;
}
}
/**
* Get the cache name for the caching of $operation on $what,
* which is known as dependant from the content of $options
*
* @param string $operation
* @param mixed $what
* @param array $options
*
* @return string
*/
private static function cacheName($operation, $what, $options = [])
{
$t = [
'version' => self::CACHE_VERSION,
'scssphpVersion' => Version::VERSION,
'operation' => $operation,
'what' => $what,
'options' => $options
];
$t = self::$prefix
. sha1(json_encode($t))
. ".$operation"
. ".scsscache";
return $t;
}
/**
* Check that the cache dir exists and is writeable
*
* @return void
*
* @throws \Exception
*/
public static function checkCacheDir()
{
self::$cacheDir = str_replace('\\', '/', self::$cacheDir);
self::$cacheDir = rtrim(self::$cacheDir, '/') . '/';
if (! is_dir(self::$cacheDir)) {
throw new Exception('Cache directory doesn\'t exist: ' . self::$cacheDir);
}
if (! is_writable(self::$cacheDir)) {
throw new Exception('Cache directory isn\'t writable: ' . self::$cacheDir);
}
}
/**
* Delete unused cached files
*
* @return void
*/
public static function cleanCache()
{
static $clean = false;
if ($clean || empty(self::$cacheDir)) {
return;
}
$clean = true;
// only remove files with extensions created by SCSSPHP Cache
// css files removed based on the list files
$removeTypes = ['scsscache' => 1];
$files = scandir(self::$cacheDir);
if (! $files) {
return;
}
$checkTime = time() - self::$gcLifetime;
foreach ($files as $file) {
// don't delete if the file wasn't created with SCSSPHP Cache
if (strpos($file, self::$prefix) !== 0) {
continue;
}
$parts = explode('.', $file);
$type = array_pop($parts);
if (! isset($removeTypes[$type])) {
continue;
}
$fullPath = self::$cacheDir . $file;
$mtime = filemtime($fullPath);
// don't delete if it's a relatively new file
if ($mtime > $checkTime) {
continue;
}
unlink($fullPath);
}
}
}