--- /dev/null
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpFoundation\File\MimeType;
+
+use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
+use Symfony\Component\HttpFoundation\File\Exception\AccessDeniedException;
+
+/**
+ * A singleton mime type guesser.
+ *
+ * By default, all mime type guessers provided by the framework are installed
+ * (if available on the current OS/PHP setup).
+ *
+ * You can register custom guessers by calling the register() method on the
+ * singleton instance. Custom guessers are always called before any default ones.
+ *
+ * $guesser = MimeTypeGuesser::getInstance();
+ * $guesser->register(new MyCustomMimeTypeGuesser());
+ *
+ * If you want to change the order of the default guessers, just re-register your
+ * preferred one as a custom one. The last registered guesser is preferred over
+ * previously registered ones.
+ *
+ * Re-registering a built-in guesser also allows you to configure it:
+ *
+ * $guesser = MimeTypeGuesser::getInstance();
+ * $guesser->register(new FileinfoMimeTypeGuesser('/path/to/magic/file'));
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class MimeTypeGuesser implements MimeTypeGuesserInterface
+{
+ /**
+ * The singleton instance.
+ *
+ * @var MimeTypeGuesser
+ */
+ private static $instance = null;
+
+ /**
+ * All registered MimeTypeGuesserInterface instances.
+ *
+ * @var array
+ */
+ protected $guessers = array();
+
+ /**
+ * Returns the singleton instance.
+ *
+ * @return self
+ */
+ public static function getInstance()
+ {
+ if (null === self::$instance) {
+ self::$instance = new self();
+ }
+
+ return self::$instance;
+ }
+
+ /**
+ * Resets the singleton instance.
+ */
+ public static function reset()
+ {
+ self::$instance = null;
+ }
+
+ /**
+ * Registers all natively provided mime type guessers.
+ */
+ private function __construct()
+ {
+ if (FileBinaryMimeTypeGuesser::isSupported()) {
+ $this->register(new FileBinaryMimeTypeGuesser());
+ }
+
+ if (FileinfoMimeTypeGuesser::isSupported()) {
+ $this->register(new FileinfoMimeTypeGuesser());
+ }
+ }
+
+ /**
+ * Registers a new mime type guesser.
+ *
+ * When guessing, this guesser is preferred over previously registered ones.
+ *
+ * @param MimeTypeGuesserInterface $guesser
+ */
+ public function register(MimeTypeGuesserInterface $guesser)
+ {
+ array_unshift($this->guessers, $guesser);
+ }
+
+ /**
+ * Tries to guess the mime type of the given file.
+ *
+ * The file is passed to each registered mime type guesser in reverse order
+ * of their registration (last registered is queried first). Once a guesser
+ * returns a value that is not NULL, this method terminates and returns the
+ * value.
+ *
+ * @param string $path The path to the file
+ *
+ * @return string The mime type or NULL, if none could be guessed
+ *
+ * @throws \LogicException
+ * @throws FileNotFoundException
+ * @throws AccessDeniedException
+ */
+ public function guess($path)
+ {
+ if (!is_file($path)) {
+ throw new FileNotFoundException($path);
+ }
+
+ if (!is_readable($path)) {
+ throw new AccessDeniedException($path);
+ }
+
+ if (!$this->guessers) {
+ $msg = 'Unable to guess the mime type as no guessers are available';
+ if (!FileinfoMimeTypeGuesser::isSupported()) {
+ $msg .= ' (Did you enable the php_fileinfo extension?)';
+ }
+ throw new \LogicException($msg);
+ }
+
+ foreach ($this->guessers as $guesser) {
+ if (null !== $mimeType = $guesser->guess($path)) {
+ return $mimeType;
+ }
+ }
+ }
+}