1 files changed, 293 insertions, 0 deletions
diff --git a/library/Icinga/Web/FileCache.php b/library/Icinga/Web/FileCache.php
new file mode 100644
index 0000000..03f0c19
--- /dev/null
+++ b/library/Icinga/Web/FileCache.php
@@ -0,0 +1,293 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Web;
+
+class FileCache
+{
+    /**
+     * FileCache singleton instances
+     *
+     * @var array
+     */
+    protected static $instances = array();
+
+    /**
+     * Cache instance base directory
+     *
+     * @var string
+     */
+    protected $basedir;
+
+    /**
+     * Instance name
+     *
+     * @var string
+     */
+    protected $name;
+
+    /**
+     * Whether the cache is enabled
+     *
+     * @var bool
+     */
+    protected $enabled = false;
+
+    /**
+     * The protected constructor creates a new instance with the given name
+     *
+     * @param string $name Cache instance name
+     */
+    protected function __construct($name)
+    {
+        $this->name = $name;
+        $tmpDir = sys_get_temp_dir();
+        $runtimePath = $tmpDir . '/FileCache_' . $name;
+        if (is_dir($runtimePath)) {
+            // Don't combine the following if with the above because else the elseif path will be evaluated if the
+            // runtime path exists and is not writeable
+            if (is_writeable($runtimePath)) {
+                $this->basedir = $runtimePath;
+                $this->enabled = true;
+            }
+        } elseif (is_dir($tmpDir) && is_writeable($tmpDir) && @mkdir($runtimePath, octdec('1750'), true)) {
+            // Suppress mkdir errors because it may error w/ no such file directory if the systemd private tmp directory
+            // for the web server has been removed
+            $this->basedir = $runtimePath;
+            $this->enabled = true;
+        }
+    }
+
+    /**
+     * Store the given content to the desired file name
+     *
+     * @param string $file    new (relative) filename
+     * @param string $content the content to be stored
+     *
+     * @return bool whether the file has been stored
+     */
+    public function store($file, $content)
+    {
+        if (! $this->enabled) {
+            return false;
+        }
+
+        return file_put_contents($this->filename($file), $content);
+    }
+
+    /**
+     * Find out whether a given file exists
+     *
+     * @param string $file      the (relative) filename
+     * @param int    $newerThan optional timestamp to compare against
+     *
+     * @return bool whether such file exists
+     */
+    public function has($file, $newerThan = null)
+    {
+        if (! $this->enabled) {
+            return false;
+        }
+
+        $filename = $this->filename($file);
+
+        if (! file_exists($filename) || ! is_readable($filename)) {
+            return false;
+        }
+
+        if ($newerThan === null) {
+            return true;
+        }
+
+        $info = stat($filename);
+
+        if ($info === false) {
+            return false;
+        }
+
+        return (int) $newerThan < $info['mtime'];
+    }
+
+    /**
+     * Get a specific file or false if no such file available
+     *
+     * @param string $file the disired file name
+     *
+     * @return string|bool Filename content or false
+     */
+    public function get($file)
+    {
+        if ($this->has($file)) {
+            return file_get_contents($this->filename($file));
+        }
+
+        return false;
+    }
+
+    /**
+     * Send a specific file to the browser (output)
+     *
+     * @param string $file the disired file name
+     *
+     * @return bool Whether the file has been sent
+     */
+    public function send($file)
+    {
+        if ($this->has($file)) {
+            readfile($this->filename($file));
+
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Get absolute filename for a given file
+     *
+     * @param string $file the disired file name
+     *
+     * @return string absolute filename
+     */
+    protected function filename($file)
+    {
+        return $this->basedir . '/' . $file;
+    }
+
+    /**
+     * Prepare a sub directory with the given name and return its path
+     *
+     * @param   string  $name
+     *
+     * @return  string|false    Returns FALSE in case the cache is not enabled or an error occurred
+     */
+    public function directory($name)
+    {
+        if (! $this->enabled) {
+            return false;
+        }
+
+        $path = $this->filename($name);
+        if (! is_dir($path) && ! @mkdir($path, octdec('1750'), true)) {
+            return false;
+        }
+
+        return $path;
+    }
+
+    /**
+     * Whether the given ETag matches a cached file
+     *
+     * If no ETag is given we'll try to fetch the one from the current
+     * HTTP request.
+     *
+     * @param string $file  The cached file you want to check
+     * @param string $match The ETag to match against
+     *
+     * @return string|bool ETag on match, otherwise false
+     */
+    public function etagMatchesCachedFile($file, $match = null)
+    {
+        return self::etagMatchesFiles($this->filename($file), $match);
+    }
+
+    /**
+     * Create an ETag for the given file
+     *
+     * @param string $file The desired cache file
+     *
+     * @return string your ETag
+     */
+    public function etagForCachedFile($file)
+    {
+        return self::etagForFiles($this->filename($file));
+    }
+
+    /**
+     * Whether the given ETag matchesspecific file(s) on disk
+     *
+     * @param string|array $files file(s) to check
+     * @param string       $match ETag to match against
+     *
+     * @return string|bool ETag on match, otherwise false
+     */
+    public static function etagMatchesFiles($files, $match = null)
+    {
+        if ($match === null) {
+            $match = isset($_SERVER['HTTP_IF_NONE_MATCH'])
+                ? trim($_SERVER['HTTP_IF_NONE_MATCH'], '"')
+                : false;
+        }
+        if (! $match) {
+            return false;
+        }
+
+        if (preg_match('/([0-9a-f]{8}-[0-9a-f]{8}-[0-9a-f]{8})-\w+/i', $match, $matches)) {
+            // Removes compression suffixes as our custom algorithm can't handle compressed cache files anyway
+            $match = $matches[1];
+        }
+
+        $etag = self::etagForFiles($files);
+        return $match === $etag ? $etag : false;
+    }
+
+    /**
+     * Create ETag for the given files
+     *
+     * Custom algorithm creating an ETag based on filenames, mtimes
+     * and file sizes. Supports single files or a list of files. This
+     * way we are able to create ETags for virtual files depending on
+     * multiple source files (e.g. compressed JS, CSS).
+     *
+     * @param string|array $files Single file or a list of such
+     *
+     * @return string The generated ETag
+     */
+    public static function etagForFiles($files)
+    {
+        if (is_string($files)) {
+            $files = array($files);
+        }
+
+        $sizes  = array();
+        $mtimes = array();
+
+        foreach ($files as $file) {
+            $file = realpath($file);
+            if ($file !== false && $info = stat($file)) {
+                $mtimes[] = $info['mtime'];
+                $sizes[]  = $info['size'];
+            } else {
+                $mtimes[] = time();
+                $sizes[]  = 0;
+            }
+        }
+
+        return sprintf(
+            '%s-%s-%s',
+            hash('crc32', implode('|', $files)),
+            hash('crc32', implode('|', $sizes)),
+            hash('crc32', implode('|', $mtimes))
+        );
+    }
+
+    /**
+     * Factory creating your cache instance
+     *
+     * @param string $name Instance name
+     *
+     * @return FileCache
+     */
+    public static function instance($name = 'icingaweb')
+    {
+        if ($name !== 'icingaweb') {
+            $name = 'icingaweb/modules/' . $name;
+        }
+
+        if (!array_key_exists($name, self::$instances)) {
+            self::$instances[$name] = new static($name);
+        }
+
+        return self::$instances[$name];
+    }
+}