<?php

/*
 * This file is part of Twig.
 *
 * (c) Fabien Potencier
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Implements a cache on the filesystem.
 *
 * @author Andrew Tch <andrew@noop.lv>
 */
class Twig_SupTwgDtgs_Cache_Filesystem implements Twig_SupTwgDtgs_CacheInterface
{
  const FORCE_BYTECODE_INVALIDATION = 1;

  private $directory;
  private $options;

  /**
   * @param $directory string The root cache directory
   * @param $options   int    A set of options
   */
  public function __construct($directory, $options = 0)
  {
    $this->directory = rtrim($directory, '\/') . '/';
    $this->options = $options;
  }

  public function generateKey($name, $className)
  {
    $hash = hash('sha256', $className);

    return $this->directory . $hash[0] . $hash[1] . '/' . $hash . '.php';
  }

  public function load($key)
  {
    if (file_exists($key)) {
      @include_once $key;
    }
  }

  public function write($key, $content)
  {
    $dir = dirname($key);
    if (!is_dir($dir)) {
      if (false === @mkdir($dir, 0777, true)) {
        if (PHP_VERSION_ID >= 50300) {
          clearstatcache(true, $dir);
        }
        if (!is_dir($dir)) {
          throw new RuntimeException(sprintf('Unable to create the cache directory (%s).', $dir));
        }
      }
    } elseif (!is_writable($dir)) {
      throw new RuntimeException(sprintf('Unable to write in the cache directory (%s).', $dir));
    }

    $tmpFile = tempnam($dir, basename($key));
    if (false !== @file_put_contents($tmpFile, $content) && @rename($tmpFile, $key)) {
      @chmod($key, 0666 & ~umask());

      if (self::FORCE_BYTECODE_INVALIDATION == ($this->options & self::FORCE_BYTECODE_INVALIDATION)) {
        // Compile cached file into bytecode cache
        if (function_exists('opcache_invalidate')) {
          opcache_invalidate($key, true);
        } elseif (function_exists('apc_compile_file')) {
          apc_compile_file($key);
        }
      }

      return;
    }

    throw new RuntimeException(sprintf('Failed to write cache file "%s".', $key));
  }

  public function getTimestamp($key)
  {
    if (!file_exists($key)) {
      return 0;
    }

    return (int) @filemtime($key);
  }
}
