Refactor session away from Symfony's interface.

Session does not implement Symfony's SessionInterface any longer. That
caused us to have to implement a bunch of logic around "Bags" which we
never actually used in order to just support the interface. Instead
there is a new Illuminate\Contracts\Session\Session contract to define
our own interface for session handling, which allows us to slim the
session store down to what Laravel actually provides instead of having
to satisfy Symfony requirements.

Legacy method changes:

->set() should be changed to ->put()

->getToken() should be ->token()

Any type hints of Symfony session interface should be changed to new
Illuminate\Contracts\Session\Session contract.

src/Illuminate/Auth/SessionGuard.php

@@ -5,13 +5,13 @@
 use RuntimeException;
 use Illuminate\Support\Str;
 use Illuminate\Http\Response;
+use Illuminate\Contracts\Session\Session;
 use Illuminate\Contracts\Auth\UserProvider;
 use Illuminate\Contracts\Events\Dispatcher;
 use Illuminate\Contracts\Auth\StatefulGuard;
 use Symfony\Component\HttpFoundation\Request;
 use Illuminate\Contracts\Auth\SupportsBasicAuth;
 use Illuminate\Contracts\Cookie\QueueingFactory as CookieJar;
-use Symfony\Component\HttpFoundation\Session\SessionInterface;
 use Illuminate\Contracts\Auth\Authenticatable as AuthenticatableContract;
 
 class SessionGuard implements StatefulGuard, SupportsBasicAuth
@@ -44,7 +44,7 @@ class SessionGuard implements StatefulGuard, SupportsBasicAuth
     /**
      * The session used by the guard.
      *
-     * @var \Symfony\Component\HttpFoundation\Session\SessionInterface
+     * @var \Illuminate\Contracts\Session\Session
      */
     protected $session;
 
@@ -88,13 +88,13 @@ class SessionGuard implements StatefulGuard, SupportsBasicAuth
      *
      * @param  string  $name
      * @param  \Illuminate\Contracts\Auth\UserProvider  $provider
-     * @param  \Symfony\Component\HttpFoundation\Session\SessionInterface  $session
+     * @param  \Illuminate\Contracts\Session\Session  $session
      * @param  \Symfony\Component\HttpFoundation\Request  $request
      * @return void
      */
     public function __construct($name,
                                 UserProvider $provider,
-                                SessionInterface $session,
+                                Session $session,
                                 Request $request = null)
     {
         $this->name = $name;
@@ -430,7 +430,7 @@ public function login(AuthenticatableContract $user, $remember = false)
      */
     protected function updateSession($id)
     {
-        $this->session->set($this->getName(), $id);
+        $this->session->put($this->getName(), $id);
 
         $this->session->migrate(true);
     }

src/Illuminate/Contracts/Session/Session.php

@@ -0,0 +1,165 @@
+<?php
+
+namespace Illuminate\Contracts\Session;
+
+interface Session
+{
+    /**
+     * Get the name of the session.
+     *
+     * @return string
+     */
+    public function getName();
+
+    /**
+     * Get the current session ID.
+     *
+     * @return string
+     */
+    public function getId();
+
+    /**
+     * Set the session ID.
+     *
+     * @param  string  $id
+     * @return void
+     */
+    public function setId($id);
+
+    /**
+     * Start the session, reading the data from a handler.
+     *
+     * @return bool
+     */
+    public function start();
+
+    /**
+     * Save the session data to storage.
+     *
+     * @return bool
+     */
+    public function save();
+
+    /**
+     * Get all of the session data.
+     *
+     * @return array
+     */
+    public function all();
+
+    /**
+     * Checks if a key exists.
+     *
+     * @param  string|array  $key
+     * @return bool
+     */
+    public function exists($key);
+
+    /**
+     * Checks if an a key is present and not null.
+     *
+     * @param  string|array  $key
+     * @return bool
+     */
+    public function has($key);
+
+    /**
+     * Get an item from the session.
+     *
+     * @param  string  $key
+     * @param  mixed  $default
+     * @return void
+     */
+    public function get($key, $default = null);
+
+    /**
+     * Put a key / value pair or array of key / value pairs in the session.
+     *
+     * @param  string|array  $key
+     * @param  mixed       $value
+     * @return void
+     */
+    public function put($key, $value = null);
+
+    /**
+     * Get the CSRF token value.
+     *
+     * @return string
+     */
+    public function token();
+
+    /**
+     * Remove an item from the session, returning its value.
+     *
+     * @param  string  $key
+     * @return mixed
+     */
+    public function remove($key);
+
+    /**
+     * Remove one or many items from the session.
+     *
+     * @param  string|array  $keys
+     * @return void
+     */
+    public function forget($keys);
+
+    /**
+     * Remove all of the items from the session.
+     *
+     * @return void
+     */
+    public function flush();
+
+    /**
+     * Generate a new session ID for the session.
+     *
+     * @param  bool  $destroy
+     * @return bool
+     */
+    public function migrate($destroy = false);
+
+    /**
+     * Determine if the session has been started.
+     *
+     * @return bool
+     */
+    public function isStarted();
+
+    /**
+     * Get the previous URL from the session.
+     *
+     * @return string|null
+     */
+    public function previousUrl();
+
+    /**
+     * Set the "previous" URL in the session.
+     *
+     * @param  string  $url
+     * @return void
+     */
+    public function setPreviousUrl($url);
+
+    /**
+     * Get the session handler instance.
+     *
+     * @return \SessionHandlerInterface
+     */
+    public function getHandler();
+
+    /**
+     * Determine if the session handler needs a request.
+     *
+     * @return bool
+     */
+    public function handlerNeedsRequest();
+
+    /**
+     * Set the request on the handler instance.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @return void
+     */
+    public function setRequestOnHandler($request);
+}

src/Illuminate/Foundation/Application.php

@@ -1094,7 +1094,7 @@ public function registerCoreContainerAliases()
             'request'              => ['Illuminate\Http\Request', 'Symfony\Component\HttpFoundation\Request'],
             'router'               => ['Illuminate\Routing\Router', 'Illuminate\Contracts\Routing\Registrar', 'Illuminate\Contracts\Routing\BindingRegistrar'],
             'session'              => ['Illuminate\Session\SessionManager'],
-            'session.store'        => ['Illuminate\Session\Store', 'Symfony\Component\HttpFoundation\Session\SessionInterface'],
+            'session.store'        => ['Illuminate\Session\Store', 'Illuminate\Contracts\Session\Session'],
             'url'                  => ['Illuminate\Routing\UrlGenerator', 'Illuminate\Contracts\Routing\UrlGenerator'],
             'validator'            => ['Illuminate\Validation\Factory', 'Illuminate\Contracts\Validation\Factory'],
             'view'                 => ['Illuminate\View\Factory', 'Illuminate\Contracts\View\Factory'],

src/Illuminate/Foundation/helpers.php

@@ -328,7 +328,7 @@ function csrf_token()
         $session = app('session');
 
         if (isset($session)) {
-            return $session->getToken();
+            return $session->token();
         }
 
         throw new RuntimeException('Application session store not set.');

src/Illuminate/Http/Request.php

@@ -391,6 +391,17 @@ public function session()
         return $this->getSession();
     }
 
+    /**
+     * Set the session instance on the request.
+     *
+     * @param  \Illuminate\Contracts\Session\Session  $session
+     * @return void
+     */
+    public function setLaravelSession($session)
+    {
+        $this->session = $session;
+    }
+
     /**
      * Get the user making the request.
      *

src/Illuminate/Session/EncryptedStore.php

@@ -42,7 +42,7 @@ protected function prepareForUnserialize($data)
         try {
             return $this->encrypter->decrypt($data);
         } catch (DecryptException $e) {
-            return json_encode([]);
+            return serialize([]);
         }
     }
 

src/Illuminate/Session/Middleware/StartSession.php

@@ -7,7 +7,7 @@
 use Illuminate\Support\Arr;
 use Illuminate\Http\Request;
 use Illuminate\Session\SessionManager;
-use Illuminate\Session\SessionInterface;
+use Illuminate\Contracts\Session\Session;
 use Illuminate\Session\CookieSessionHandler;
 use Symfony\Component\HttpFoundation\Cookie;
 use Symfony\Component\HttpFoundation\Response;
@@ -56,7 +56,7 @@ public function handle($request, Closure $next)
         if ($this->sessionConfigured()) {
             $session = $this->startSession($request);
 
-            $request->setSession($session);
+            $request->setLaravelSession($session);
 
             $this->collectGarbage($session);
         }
@@ -93,7 +93,7 @@ public function terminate($request, $response)
      * Start the session for the given request.
      *
      * @param  \Illuminate\Http\Request  $request
-     * @return \Illuminate\Session\SessionInterface
+     * @return \Illuminate\Contracts\Session\Session
      */
     protected function startSession(Request $request)
     {
@@ -110,7 +110,7 @@ protected function startSession(Request $request)
      * Get the session implementation from the manager.
      *
      * @param  \Illuminate\Http\Request  $request
-     * @return \Illuminate\Session\SessionInterface
+     * @return \Illuminate\Contracts\Session\Session
      */
     public function getSession(Request $request)
     {
@@ -125,7 +125,7 @@ public function getSession(Request $request)
      * Store the current URL for the request if necessary.
      *
      * @param  \Illuminate\Http\Request  $request
-     * @param  \Illuminate\Session\SessionInterface  $session
+     * @param  \Illuminate\Contracts\Session\Session  $session
      * @return void
      */
     protected function storeCurrentUrl(Request $request, $session)
@@ -138,10 +138,10 @@ protected function storeCurrentUrl(Request $request, $session)
     /**
      * Remove the garbage from the session if necessary.
      *
-     * @param  \Illuminate\Session\SessionInterface  $session
+     * @param  \Illuminate\Contracts\Session\Session  $session
      * @return void
      */
-    protected function collectGarbage(SessionInterface $session)
+    protected function collectGarbage(Session $session)
     {
         $config = $this->manager->getSessionConfig();
 
@@ -168,10 +168,10 @@ protected function configHitsLottery(array $config)
      * Add the session cookie to the application response.
      *
      * @param  \Symfony\Component\HttpFoundation\Response  $response
-     * @param  \Illuminate\Session\SessionInterface  $session
+     * @param  \Illuminate\Contracts\Session\Session  $session
      * @return void
      */
-    protected function addCookieToResponse(Response $response, SessionInterface $session)
+    protected function addCookieToResponse(Response $response, Session $session)
     {
         if ($this->usingCookieSessions()) {
             $this->manager->driver()->save();