From a42144c3f77bb55df186888aad009eec6c99fcee Mon Sep 17 00:00:00 2001
From: Matias Griese <matias@kunena.org>
Date: Mon, 18 Aug 2014 21:24:32 +0300
Subject: [PATCH] Implement stream wrappers

---
 system/config/streams.yaml                    |   6 +
 system/src/Grav/Common/Grav.php               |   7 +
 system/src/Grav/Common/Plugins.php            |  11 +-
 .../Common/Service/StreamsServiceProvider.php |  61 +++++
 .../Component/Filesystem/ResourceLocator.php  | 109 ++++++++
 .../StreamWrapper/ReadOnlyStream.php          |  71 +++++
 .../Filesystem/StreamWrapper/Stream.php       | 232 ++++++++++++++++
 .../StreamWrapper/StreamInterface.php         | 251 ++++++++++++++++++
 8 files changed, 742 insertions(+), 6 deletions(-)
 create mode 100644 system/config/streams.yaml
 create mode 100644 system/src/Grav/Common/Service/StreamsServiceProvider.php
 create mode 100644 system/src/Grav/Component/Filesystem/ResourceLocator.php
 create mode 100644 system/src/Grav/Component/Filesystem/StreamWrapper/ReadOnlyStream.php
 create mode 100644 system/src/Grav/Component/Filesystem/StreamWrapper/Stream.php
 create mode 100644 system/src/Grav/Component/Filesystem/StreamWrapper/StreamInterface.php

diff --git a/system/config/streams.yaml b/system/config/streams.yaml
new file mode 100644
index 000000000..8c4f239d3
--- /dev/null
+++ b/system/config/streams.yaml
@@ -0,0 +1,6 @@
+schemes:
+  plugin:
+    type: ReadOnlyStream
+    paths:
+      - user/plugins
+      - system/plugins
diff --git a/system/src/Grav/Common/Grav.php b/system/src/Grav/Common/Grav.php
index 2f9c30fe8..1de34b00e 100644
--- a/system/src/Grav/Common/Grav.php
+++ b/system/src/Grav/Common/Grav.php
@@ -1,7 +1,9 @@
 <?php
 namespace Grav\Common;
 
+use Grav\Common\Service\StreamsServiceProvider;
 use Grav\Component\DI\Container;
+use Grav\Component\Filesystem\ResourceLocator;
 
 /**
  * Grav
@@ -88,11 +90,16 @@ class Grav extends Container
             return new \phpUserAgent();
         };
 
+        $container->register(new StreamsServiceProvider);
+
         return $container;
     }
 
     public function process()
     {
+        // Initialize stream wrappers.
+        $this['locator'];
+
         $this['plugins']->init();
 
         $this->fireEvent('onAfterInitPlugins');
diff --git a/system/src/Grav/Common/Plugins.php b/system/src/Grav/Common/Plugins.php
index 92db56461..50278e10b 100644
--- a/system/src/Grav/Common/Plugins.php
+++ b/system/src/Grav/Common/Plugins.php
@@ -37,8 +37,7 @@ class Plugins extends Iterator
                 continue;
             }
 
-            $folder = PLUGINS_DIR . $plugin;
-            $filePath = $folder . DS . $plugin . PLUGIN_EXT;
+            $filePath = 'plugin://' . $plugin . DS . $plugin . PLUGIN_EXT;
             if (!is_file($filePath)) {
                 throw new \RuntimeException(sprintf("Plugin '%s' enabled but not found!", $filePath, $plugin));
             }
@@ -72,7 +71,7 @@ class Plugins extends Iterator
     static public function all()
     {
         $list = array();
-        $iterator = new \DirectoryIterator(PLUGINS_DIR);
+        $iterator = new \DirectoryIterator('plugin://');
 
         /** @var \DirectoryIterator $directory */
         foreach ($iterator as $directory) {
@@ -91,16 +90,16 @@ class Plugins extends Iterator
 
     static public function get($type)
     {
-        $blueprints = new Data\Blueprints(PLUGINS_DIR . $type);
+        $blueprints = new Data\Blueprints('plugin://' . $type);
         $blueprint = $blueprints->get('blueprints');
         $blueprint->name = $type;
 
         // Load default configuration.
-        $file = File\Yaml::instance(PLUGINS_DIR . "{$type}/{$type}" . YAML_EXT);
+        $file = File\Yaml::instance('plugin://' . "{$type}/{$type}" . YAML_EXT);
         $obj = new Data\Data($file->content(), $blueprint);
 
         // Override with user configuration.
-        $file = File\Yaml::instance(USER_DIR . "config/plugins/{$type}" . YAML_EXT);
+        $file = File\Yaml::instance('plugin://' . "config/plugins/{$type}" . YAML_EXT);
         $obj->merge($file->content());
 
         // Save configuration always to user/config.
diff --git a/system/src/Grav/Common/Service/StreamsServiceProvider.php b/system/src/Grav/Common/Service/StreamsServiceProvider.php
new file mode 100644
index 000000000..f29ba2a30
--- /dev/null
+++ b/system/src/Grav/Common/Service/StreamsServiceProvider.php
@@ -0,0 +1,61 @@
+<?php
+namespace Grav\Common\Service;
+
+use Grav\Component\DI\ServiceProviderInterface;
+use Grav\Component\Filesystem\ResourceLocator;
+use Grav\Component\Filesystem\StreamWrapper\ReadOnlyStream;
+use Grav\Component\Filesystem\StreamWrapper\Stream;
+use Pimple\Container;
+
+class StreamsServiceProvider implements ServiceProviderInterface
+{
+    public function register(Container $container)
+    {
+        $self = $this;
+
+        $container['locator'] = function($c) use ($self) {
+            $locator = new ResourceLocator;
+            $self->init($c, $locator);
+
+            return $locator;
+        };
+    }
+
+    protected function init(Container $container, ResourceLocator $locator)
+    {
+        $schemes = $container['config']->get('streams.schemes');
+
+        if (!$schemes) {
+            return;
+        }
+
+        // Set locator to both streams.
+        Stream::setLocator($locator);
+        ReadOnlyStream::setLocator($locator);
+
+        $registered = stream_get_wrappers();
+
+        foreach ($schemes as $scheme => $config) {
+            if (isset($config['paths'])) {
+                $locator->addPath($scheme, '', $config['paths']);
+            }
+            if (isset($config['prefixes'])) {
+                foreach ($config['prefixes'] as $prefix => $paths) {
+                    $locator->addPath($scheme, $prefix, $paths);
+                }
+            }
+
+            if (in_array($scheme, $registered)) {
+                stream_wrapper_unregister($scheme);
+            }
+            $type = !empty($config['type']) ? $config['type'] : 'ReadOnlyStream';
+            if ($type[0] != '\\') {
+                $type = '\\Grav\\Component\\Filesystem\\StreamWrapper\\' . $type;
+            }
+
+            if (!stream_wrapper_register($scheme, $type)) {
+                throw new \InvalidArgumentException("Stream '{$type}' could not be initialized.");
+            }
+        }
+    }
+}
diff --git a/system/src/Grav/Component/Filesystem/ResourceLocator.php b/system/src/Grav/Component/Filesystem/ResourceLocator.php
new file mode 100644
index 000000000..95c202cf3
--- /dev/null
+++ b/system/src/Grav/Component/Filesystem/ResourceLocator.php
@@ -0,0 +1,109 @@
+<?php
+
+namespace Grav\Component\Filesystem;
+
+/**
+ * Implements Uniform Resource Location
+ *
+ * @link http://webmozarts.com/2013/06/19/the-power-of-uniform-resource-location-in-php/
+ */
+class ResourceLocator
+{
+    /**
+     * @var array
+     */
+    protected $schemes = [];
+
+    /**
+     * @param string $scheme
+     * @param string $prefix
+     * @param string|array $paths
+     */
+    public function addPath($scheme, $prefix, $paths)
+    {
+        $list = [];
+        foreach((array) $paths as $path) {
+            $list[] = trim($path, '/');
+        }
+
+        if (isset($this->schemes[$scheme][$prefix])) {
+            $list = array_merge($list, $this->schemes[$scheme][$prefix]);
+        }
+
+        $this->schemes[$scheme][$prefix] = $list;
+
+        // Sort in reverse order to get longer prefixes to be matched first.
+        krsort($this->schemes[$scheme]);
+    }
+
+    /**
+     * @param $uri
+     * @return string|bool
+     */
+    public function __invoke($uri)
+    {
+        return $this->find($uri, false);
+    }
+
+    /**
+     * @param  string $uri
+     * @return string|bool
+     */
+    public function findResource($uri)
+    {
+        return $this->find($uri, false);
+    }
+
+    /**
+     * @param  string $uri
+     * @return array
+     */
+    public function findResources($uri)
+    {
+        return $this->find($uri, true);
+    }
+
+    /**
+     * @param  string $uri
+     * @param  bool $array
+     * @throws \InvalidArgumentException
+     * @return array|string|bool
+     */
+    protected function find($uri, $array)
+    {
+        $segments = explode('://', $uri, 2);
+        $file = array_pop($segments);
+        $scheme = array_pop($segments);
+
+        if (!$scheme) {
+            $scheme = 'file';
+        }
+
+        if (!$file || $uri[0] == ':') {
+            throw new \InvalidArgumentException('Invalid resource URI');
+        }
+        if (!isset($this->schemes[$scheme])) {
+            throw new \InvalidArgumentException("Invalid resource {$scheme}://");
+        }
+
+        $paths = $array ? [] : false;
+        foreach ($this->schemes[$scheme] as $prefix => $paths) {
+            if ($prefix && strpos($file, $prefix) !== 0) {
+                continue;
+            }
+
+            foreach ($paths as $path) {
+                $filename = ROOT_DIR . '/' . $path . '/' . ltrim(substr($file, strlen($prefix)), '\/');
+
+                if (file_exists($filename)) {
+                    if (!$array) {
+                        return $filename;
+                    }
+                    $paths[] = $filename;
+                }
+            }
+        }
+
+        return $paths;
+    }
+}
diff --git a/system/src/Grav/Component/Filesystem/StreamWrapper/ReadOnlyStream.php b/system/src/Grav/Component/Filesystem/StreamWrapper/ReadOnlyStream.php
new file mode 100644
index 000000000..dc1e88c65
--- /dev/null
+++ b/system/src/Grav/Component/Filesystem/StreamWrapper/ReadOnlyStream.php
@@ -0,0 +1,71 @@
+<?php
+namespace Grav\Component\Filesystem\StreamWrapper;
+
+use Grav\Component\Filesystem\ResourceLocator;
+
+class ReadOnlyStream extends Stream implements StreamInterface
+{
+    /**
+     * @var ResourceLocator
+     */
+    protected static $locator;
+
+    public function stream_open($uri, $mode, $options, &$opened_url)
+    {
+        if (!in_array($mode, ['r', 'rb', 'rt'])) {
+            if ($options & STREAM_REPORT_ERRORS) {
+                trigger_error('stream_open() write modes not supported for read-only stream wrappers', E_USER_WARNING);
+            }
+            return false;
+        }
+
+        $path = $this->getPath($uri);
+
+        if (!$path) {
+            return false;
+        }
+
+        $this->handle = ($options & STREAM_REPORT_ERRORS) ? fopen($path, $mode) : @fopen($path, $mode);
+
+        return (bool) $this->handle;
+    }
+
+    public function stream_lock($operation)
+    {
+        // Disallow exclusive lock or non-blocking lock requests
+        if (!in_array($operation, [LOCK_SH, LOCK_UN, LOCK_SH | LOCK_NB])) {
+            trigger_error(
+                'stream_lock() exclusive lock operations not supported for read-only stream wrappers',
+                E_USER_WARNING
+            );
+            return false;
+        }
+
+        return flock($this->handle, $operation);
+    }
+
+    public function stream_write($data)
+    {
+        throw new \BadMethodCallException('stream_write() not supported for read-only stream wrappers');
+    }
+
+    public function unlink($uri)
+    {
+        throw new \BadMethodCallException('unlink() not supported for read-only stream wrappers');
+    }
+
+    public function rename($from_uri, $to_uri)
+    {
+        throw new \BadMethodCallException('rename() not supported for read-only stream wrappers');
+    }
+
+    public function mkdir($uri, $mode, $options)
+    {
+        throw new \BadMethodCallException('mkdir() not supported for read-only stream wrappers');
+    }
+
+    public function rmdir($uri, $options)
+    {
+        throw new \BadMethodCallException('rmdir() not supported for read-only stream wrappers');
+    }
+}
diff --git a/system/src/Grav/Component/Filesystem/StreamWrapper/Stream.php b/system/src/Grav/Component/Filesystem/StreamWrapper/Stream.php
new file mode 100644
index 000000000..a1307bf4f
--- /dev/null
+++ b/system/src/Grav/Component/Filesystem/StreamWrapper/Stream.php
@@ -0,0 +1,232 @@
+<?php
+namespace Grav\Component\Filesystem\StreamWrapper;
+
+use Grav\Component\Filesystem\ResourceLocator;
+
+class Stream implements StreamInterface
+{
+    /**
+     * A generic resource handle.
+     *
+     * @var Resource
+     */
+    protected $handle = null;
+
+    /**
+     * @var ResourceLocator
+     */
+    protected static $locator;
+
+    /**
+     * @param ResourceLocator $locator
+     */
+    public static function setLocator(ResourceLocator $locator)
+    {
+        static::$locator = $locator;
+    }
+
+    public function stream_open($uri, $mode, $options, &$opened_url)
+    {
+        $path = $this->getPath($uri, $mode);
+
+        if (!$path) {
+            return false;
+        }
+
+        $this->handle = ($options & STREAM_REPORT_ERRORS) ? fopen($path, $mode) : @fopen($path, $mode);
+
+        return (bool) $this->handle;
+    }
+
+    public function stream_close()
+    {
+        return fclose($this->handle);
+    }
+
+    public function stream_lock($operation)
+    {
+        if (in_array($operation, [LOCK_SH, LOCK_EX, LOCK_UN, LOCK_NB])) {
+            return flock($this->handle, $operation);
+        }
+
+        return false;
+    }
+
+    public function stream_metadata($uri, $option, $value)
+    {
+        switch ($option) {
+            case STREAM_META_TOUCH:
+                list ($time, $atime) = $value;
+                return touch($uri, $time, $atime);
+
+            case STREAM_META_OWNER_NAME:
+            case STREAM_META_OWNER:
+                return chown($uri, $value);
+
+            case STREAM_META_GROUP_NAME:
+            case STREAM_META_GROUP:
+                return chgrp($uri, $value);
+
+            case STREAM_META_ACCESS:
+                return chmod($uri, $value);
+        }
+
+        return false;
+    }
+
+    public function stream_read($count)
+    {
+        return fread($this->handle, $count);
+    }
+
+    public function stream_write($data)
+    {
+        return fwrite($this->handle, $data);
+    }
+
+    public function stream_eof()
+    {
+        return feof($this->handle);
+    }
+
+    public function stream_seek($offset, $whence)
+    {
+        // fseek returns 0 on success and -1 on a failure.
+        return !fseek($this->handle, $offset, $whence);
+    }
+
+    public function stream_flush()
+    {
+        return fflush($this->handle);
+    }
+
+    public function stream_tell()
+    {
+        return ftell($this->handle);
+    }
+
+    public function stream_stat()
+    {
+        return fstat($this->handle);
+    }
+
+    public function unlink($uri)
+    {
+        $path = $this->getPath($uri);
+
+        if (!$path) {
+            return false;
+        }
+
+        return unlink($path);
+    }
+
+    public function rename($fromUri, $toUri)
+    {
+        $fromPath = $this->getPath($fromUri);
+        $toPath = $this->getPath($toUri);
+
+        if (!($fromPath && $toPath)) {
+            return false;
+        }
+
+        return rename($fromPath, $toPath);
+    }
+
+    public function mkdir($uri, $mode, $options)
+    {
+        $recursive = (bool) ($options & STREAM_MKDIR_RECURSIVE);
+        $path = $this->getPath($uri, $recursive ? $mode : null);
+
+        if (!$path) {
+            return false;
+        }
+
+        return ($options & STREAM_REPORT_ERRORS) ? mkdir($path, $mode, $recursive) : @mkdir($path, $mode, $recursive);
+    }
+
+    public function rmdir($uri, $options)
+    {
+        $path = $this->getPath($uri);
+
+        if (!$path) {
+            return false;
+        }
+
+        return ($options & STREAM_REPORT_ERRORS) ? rmdir($path) : @rmdir($path);
+    }
+
+    public function url_stat($uri, $flags)
+    {
+        $path = $this->getPath($uri);
+
+        if (!$path) {
+            return false;
+        }
+
+        // Suppress warnings if requested or if the file or directory does not
+        // exist. This is consistent with PHP's plain filesystem stream wrapper.
+        return ($flags & STREAM_URL_STAT_QUIET || !file_exists($path)) ? @stat($path) : stat($path);
+    }
+
+    public function dir_opendir($uri, $options)
+    {
+        $path = $this->getPath($uri);
+
+        if (!$path) {
+            return false;
+        }
+
+        $this->handle = opendir($path);
+
+        return (bool) $this->handle;
+    }
+
+    public function dir_readdir()
+    {
+        return readdir($this->handle);
+    }
+
+    public function dir_rewinddir()
+    {
+        rewinddir($this->handle);
+
+        return true;
+    }
+
+    public function dir_closedir()
+    {
+        closedir($this->handle);
+
+        return true;
+    }
+
+    protected function getPath($uri, $mode = null)
+    {
+        $path = $this->findPath($uri);
+
+        if ($mode == null || !$path || file_exists($path)) {
+            return $path;
+        }
+
+        if ($mode[0] == 'r') {
+            return false;
+        }
+
+        // We are either opening a file or creating directory.
+        list($scheme, $target) = explode('://', $uri, 2);
+
+        $path = $this->findPath($scheme . '://' . dirname($target));
+
+        if (!$path) {
+            return false;
+        }
+
+        return $path . '/' . basename($uri);
+    }
+
+    protected function findPath($uri)
+    {
+        return static::$locator ? static::$locator->findResource($uri) : false;
+    }
+}
diff --git a/system/src/Grav/Component/Filesystem/StreamWrapper/StreamInterface.php b/system/src/Grav/Component/Filesystem/StreamWrapper/StreamInterface.php
new file mode 100644
index 000000000..01b9bff29
--- /dev/null
+++ b/system/src/Grav/Component/Filesystem/StreamWrapper/StreamInterface.php
@@ -0,0 +1,251 @@
+<?php
+namespace Grav\Component\Filesystem\StreamWrapper;
+
+/**
+ * Generic PHP stream wrapper interface.
+ *
+ * @see http://www.php.net/manual/class.streamwrapper.php
+ */
+interface StreamInterface
+{
+    /**
+     * Support for fopen(), file_get_contents(), file_put_contents() etc.
+     *
+     * @param string $uri        A string containing the URI to the file to open.
+     * @param string $mode       The file mode ("r", "wb" etc.).
+     * @param int    $options    A bit mask of STREAM_USE_PATH and STREAM_REPORT_ERRORS.
+     * @param string $opened_url A string containing the path actually opened.
+     *
+     * @return bool Returns TRUE if file was opened successfully.
+     * @see http://php.net/manual/streamwrapper.stream-open.php
+     */
+    public function stream_open($uri, $mode, $options, &$opened_url);
+
+    /**
+     * Support for fclose().
+     *
+     * @return bool TRUE if stream was successfully closed.
+     * @see http://php.net/manual/streamwrapper.stream-close.php
+     */
+    public function stream_close();
+
+    /**
+     * Support for flock().
+     *
+     * @param $operation
+     *     One of the following:
+     *     - LOCK_SH to acquire a shared lock (reader).
+     *     - LOCK_EX to acquire an exclusive lock (writer).
+     *     - LOCK_UN to release a lock (shared or exclusive).
+     *     - LOCK_NB if you don't want flock() to block while locking (not
+     *     supported on Windows).
+     *
+     * @return bool Always returns TRUE at the present time.
+     * @see http://php.net/manual/streamwrapper.stream-lock.php
+     */
+    public function stream_lock($operation);
+
+    /**
+     * Support for touch(), chmod(), chown(), chgrp().
+     *
+     * @param $path
+     *     The file path or URL to set metadata. Note that in the case of a URL, it must be a :// delimited URL.
+     *     Other URL forms are not supported.
+     *
+     * @param $option
+     *     One of:
+     *     - STREAM_META_TOUCH      The method was called in response to touch()
+     *     - STREAM_META_OWNER_NAME The method was called in response to chown() with string parameter
+     *     - STREAM_META_OWNER      The method was called in response to chown()
+     *     - STREAM_META_GROUP_NAME The method was called in response to chgrp()
+     *     - STREAM_META_GROUP      The method was called in response to chgrp()
+     *     - STREAM_META_ACCESS     The method was called in response to chmod()
+     *
+     * @param $value
+     *     If option is
+     *     - STREAM_META_TOUCH:         Array consisting of two arguments of the touch() function.
+     *     - STREAM_META_OWNER_NAME or
+     *       STREAM_META_GROUP_NAME:    The name of the owner user/group as string.
+     *     - STREAM_META_OWNER or
+     *       STREAM_META_GROUP:         The value owner user/group argument as integer.
+     *     - STREAM_META_ACCESS:        The argument of the chmod() as integer.
+
+
+     *
+     * @return bool
+     * @see http://php.net/manual/en/streamwrapper.stream-metadata.php
+     */
+    public function stream_metadata($path, $option, $value);
+
+    /**
+     * Support for fread(), file_get_contents() etc.
+     *
+     * @param $count
+     *   Maximum number of bytes to be read.
+     *
+     * @return string|bool The string that was read, or FALSE in case of an error.
+     * @see http://php.net/manual/streamwrapper.stream-read.php
+     */
+    public function stream_read($count);
+
+    /**
+     * Support for fwrite(), file_put_contents() etc.
+     *
+     * @param $data
+     *   The string to be written.
+     *
+     * @return int The number of bytes written (integer).
+     * @see http://php.net/manual/streamwrapper.stream-write.php
+     */
+    public function stream_write($data);
+
+    /**
+     * Support for feof().
+     *
+     * @return bool TRUE if end-of-file has been reached.
+     * @see http://php.net/manual/streamwrapper.stream-eof.php
+     */
+    public function stream_eof();
+
+    /**
+     * Support for fseek().
+     *
+     * @param $offset
+     *   The byte offset to got to.
+     * @param $whence
+     *   SEEK_SET, SEEK_CUR, or SEEK_END.
+     *
+     * @return bool TRUE on success.
+     * @see http://php.net/manual/streamwrapper.stream-seek.php
+     */
+    public function stream_seek($offset, $whence);
+
+    /**
+     * Support for fflush().
+     *
+     * @return bool TRUE if data was successfully stored (or there was no data to store).
+     * @see http://php.net/manual/streamwrapper.stream-flush.php
+     */
+    public function stream_flush();
+
+    /**
+     * Support for ftell().
+     *
+     * @return int The current offset in bytes from the beginning of file.
+     * @see http://php.net/manual/streamwrapper.stream-tell.php
+     */
+    public function stream_tell();
+
+    /**
+     * Support for fstat().
+     *
+     * @return array An array with file status, or FALSE in case of an error - see fstat()
+     * @see http://php.net/manual/streamwrapper.stream-stat.php
+     */
+    public function stream_stat();
+
+    /**
+     * Support for unlink().
+     *
+     * @param $uri
+     *   A string containing the URI to the resource to delete.
+     *
+     * @return
+     *   TRUE if resource was successfully deleted.
+     * @see http://php.net/manual/streamwrapper.unlink.php
+     */
+    public function unlink($uri);
+
+    /**
+     * Support for rename().
+     *
+     * @param $from_uri ,
+     *                  The URI to the file to rename.
+     * @param $to_uri
+     *                  The new URI for file.
+     *
+     * @return bool TRUE if file was successfully renamed.
+     * @see http://php.net/manual/streamwrapper.rename.php
+     */
+    public function rename($from_uri, $to_uri);
+
+    /**
+     * Support for mkdir().
+     *
+     * @param $uri
+     *   A string containing the URI to the directory to create.
+     * @param $mode
+     *   Permission flags - see mkdir().
+     * @param $options
+     *   A bit mask of STREAM_REPORT_ERRORS and STREAM_MKDIR_RECURSIVE.
+     *
+     * @return bool TRUE if directory was successfully created.
+     * @see http://php.net/manual/streamwrapper.mkdir.php
+     */
+    public function mkdir($uri, $mode, $options);
+
+    /**
+     * Support for rmdir().
+     *
+     * @param $uri
+     *   A string containing the URI to the directory to delete.
+     * @param $options
+     *   A bit mask of STREAM_REPORT_ERRORS.
+     *
+     * @return
+     *   TRUE if directory was successfully removed.
+     *
+     * @see http://php.net/manual/streamwrapper.rmdir.php
+     */
+    public function rmdir($uri, $options);
+
+    /**
+     * Support for stat().
+     *
+     * @param $uri
+     *   A string containing the URI to get information about.
+     * @param $flags
+     *   A bit mask of STREAM_URL_STAT_LINK and STREAM_URL_STAT_QUIET.
+     *
+     * @return array An array with file status, or FALSE in case of an error - see fstat()
+     * @see http://php.net/manual/streamwrapper.url-stat.php
+     */
+    public function url_stat($uri, $flags);
+
+    /**
+     * Support for opendir().
+     *
+     * @param $uri
+     *   A string containing the URI to the directory to open.
+     * @param $options
+     *   Unknown (parameter is not documented in PHP Manual).
+     *
+     * @return bool TRUE on success.
+     * @see http://php.net/manual/streamwrapper.dir-opendir.php
+     */
+    public function dir_opendir($uri, $options);
+
+    /**
+     * Support for readdir().
+     *
+     * @return string The next filename, or FALSE if there are no more files in the directory.
+     * @see http://php.net/manual/streamwrapper.dir-readdir.php
+     */
+    public function dir_readdir();
+
+    /**
+     * Support for rewinddir().
+     *
+     * @return bool TRUE on success.
+     * @see http://php.net/manual/streamwrapper.dir-rewinddir.php
+     */
+    public function dir_rewinddir();
+
+    /**
+     * Support for closedir().
+     *
+     * @return bool TRUE on success.
+     * @see http://php.net/manual/streamwrapper.dir-closedir.php
+     */
+    public function dir_closedir();
+}