<?php

/**
 * Реализует кэш в файловой системе.
 *
 * @author Andrew Tch <andrew@noop.lv>
 */
class Twig_Cache_Filesystem implements Twig_CacheInterface {

    const FORCE_BYTECODE_INVALIDATION = 1;

    private $directory;
    private $options;

    /**
     * @param $directory string Корневой каталог кэша
     * @param $options   int    Набор опций
     */
    public function __construct($directory, $options = 0) {
        $this->directory = rtrim($directory, '\/') . '/';
        $this->options = $options;
    }

    /**
     * {@inheritdoc}
     */
    public function generateKey($name, $className) {
        $hash = hash('sha256', $className);

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

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

    /**
     * {@inheritdoc}
     */
    public function write($key, $content) {
        $dir = dirname($key);
        if (!is_dir($dir)) {
            if (false === @mkdir($dir, 0777, true) && !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));
    }

    /**
     * {@inheritdoc}
     */
    public function getTimestamp($key) {
        if (!file_exists($key)) {
            return 0;
        }

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

}
