Laravel HTTP-路由加载源码分析

思考并回答以下问题：

前言

作为Laravel极其重要的一部分，route功能贯穿着整个网络请求，是request生命周期的主干。本文主要讲述route服务的注册与启动、路由的属性注册。本篇内容相对简单，更多的是框架添加路由的整体设计流程。

route服务的注册

Laravel在接受到请求后，先进行了服务容器与http核心的初始化，再进行了请求request的构造与分发。

route服务的注册-RoutingServiceProvider发生在服务容器container的初始化上；

route服务的启动与加载-RouteServiceProvider发生在request的分发上。

route服务的注册-RoutingServiceProvider

所有需要Laravel服务的请求都会加载入口文件index.php：

require __DIR__.'/../vendor/autoload.php';

$app = require_once __DIR__.'/../bootstrap/app.php';

第一句我们在之前的博客提过，是实现PSR0、PSR4标准自动加载的功能模块，第二句就是今天说的Container的初始化：

<?php

/*
|--------------------------------------------------------------------------
| Create The Application
|--------------------------------------------------------------------------
|
| The first thing we will do is create a new Laravel application instance
| which serves as the "glue" for all the components of Laravel, and is
| the IoC container for the system binding all of the various parts.
|
*/

$app = new Illuminate\Foundation\Application(
    $_ENV['APP_BASE_PATH'] ?? dirname(__DIR__)
);

/*
|--------------------------------------------------------------------------
| Bind Important Interfaces
|--------------------------------------------------------------------------
|
| Next, we need to bind some important interfaces into the container so
| we will be able to resolve them when needed. The kernels serve the
| incoming requests to this application from both the web and CLI.
|
*/

$app->singleton(
    Illuminate\Contracts\Http\Kernel::class,
    App\Http\Kernel::class
);

$app->singleton(
    Illuminate\Contracts\Console\Kernel::class,
    App\Console\Kernel::class
);

$app->singleton(
    Illuminate\Contracts\Debug\ExceptionHandler::class,
    App\Exceptions\Handler::class
);

/*
|--------------------------------------------------------------------------
| Return The Application
|--------------------------------------------------------------------------
|
| This script returns the application instance. The instance is given to
| the calling script so we can separate the building of the instances
| from the actual running of the application and sending responses.
|
*/

return $app;

Application：

namespace Illuminate\Foundation;

class Application extends Container implements ApplicationContract, CachesConfiguration, CachesRoutes, HttpKernelInterface
{
	/**
     * Create a new Illuminate application instance.
     *
     * @param  string|null  $basePath
     * @return void
     */
    public function __construct($basePath = null)
    {
        if ($basePath) {
            $this->setBasePath($basePath);
        }

        $this->registerBaseBindings();
        $this->registerBaseServiceProviders();
        $this->registerCoreContainerAliases();
    }
}

路由服务的注册就在registerBaseServiceProviders()这个函数中：

/**
 * Register all of the base service providers.
 *
 * @return void
 */
protected function registerBaseServiceProviders()
{
    $this->register(new EventServiceProvider($this));
    $this->register(new LogServiceProvider($this));
    $this->register(new RoutingServiceProvider($this));
}

RoutingServiceProvider：

namespace Illuminate\Routing;

class RoutingServiceProvider extends ServiceProvider
{
	public function register()
	{
		$this->registerRouter();
		...
	}

	/**
     * Register the router instance.
     *
     * @return void
     */
    protected function registerRouter()
    {
        $this->app->singleton('router', function ($app) {
            return new Router($app['events'], $app);
        });
    }

	...
}

可以看到，RoutingServiceProvider做的事情比较简单，就是向服务容易中注册router。

route服务的启动与加载-RouteServiceProvider

Laravel在初始化Application后，就要进行http/Kernel的构造：

$kernel = $app->make(Illuminate\Contracts\Http\Kernel::class);

$response = $kernel->handle(
    $request = Illuminate\Http\Request::capture()
);

初始化结束后，就会调用handle函数，这个函数用于Laravel各个功能服务的注册启动，还有request的分发：

public function handle($request)
{
	try {
		$request->enableHttpMethodParameterOverride();
		$response = $this->sendRequestThroughRouter($request);
	}
	return $response;
}

protected function sendRequestThroughRouter($request)
{
	$this->app->instance('request', $request);
	Facade::clearResolvedInstance('request');
	$this->bootstrap();//各种服务的注册与
	return (new Pipeline($this->app))//请求的分发
	->send($request)
	->through($this->app->shouldSkipMiddleware() ? [
	] : $this->middleware)
	->then($this->dispatchToRouter());
}

路由服务的启动与加载就在其中一个函数中bootstrap，这个函数用于各种服务的注册与启动，比较复杂，我们有机会在以后单独来说。

总之，这个函数会调用RouteServiceProvider这个类的两个函数：注册-register、启动-boot。

由于route的注册工作由之前RoutingServiceProvider完成，所以RouteServiceProvider的register是空的，这里它只负责路由的启动与加载工作，我们主要看boot：

namespace Illuminate\Foundation\Support\Providers;

class RouteServiceProvider extends ServiceProvider
{
	/**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        $this->setRootControllerNamespace();

        if ($this->routesAreCached()) {
            $this->loadCachedRoutes();
        } else {
            $this->loadRoutes();

            $this->app->booted(function () {
                $this->app['router']->getRoutes()->refreshNameLookups();
                $this->app['router']->getRoutes()->refreshActionLookups();
            });
        }
    }

	/**
     * Load the cached routes for the application.
     *
     * @return void
     */
    protected function loadCachedRoutes()
    {
        $this->app->booted(function () {
            require $this->app->getCachedRoutesPath();
        });
    }

	/**
     * Load the application routes.
     *
     * @return void
     */
    protected function loadRoutes()
    {
        if (method_exists($this, 'map')) {
            $this->app->call([$this, 'map']);
        }
    }
}

class Application extends Container implements ApplicationContract, CachesConfiguration, CachesRoutes, HttpKernelInterface
{
	/**
     * Determine if the application routes are cached.
     *
     * @return bool
     */
    public function routesAreCached()
    {
        return $this['files']->exists($this->getCachedRoutesPath());
    }

	/**
     * Get the path to the routes cache file.
     *
     * @return string
     */
    public function getCachedRoutesPath()
    {
        return $this->normalizeCachePath('APP_ROUTES_CACHE', 'cache/routes-v7.php');
    }
}

从boot中可以看出，Laravel首先去寻找路由的缓存文件，没有缓存文件再去进行加载路由。缓存文件一般在bootstrap/cache/routes.php文件中。

加载路由主要调用map函数，这个函数一般在App\Providers\RouteServiceProvider这个类中，这个类继承上面的Illuminate\Foundation\Support\Providers\RouteServiceProvider：

use Illuminate\Foundation\Support\Providers\RouteServiceProvider as ServiceProvider;

class RouteServiceProvider extends ServiceProvider
{
	public function map()
	{
		$this->mapApiRoutes();
		$this->mapWebRoutes();
		//
	}

	protected function mapWebRoutes()
	{
		Route::middleware('web')
			->namespace($this->namespace)
			->group(base_path('routes/web.php'));
	}

	protected function mapApiRoutes()
	{
		Route::prefix('api')
			->middleware('api')
			->namespace($this->namespace)
			->group(base_path('routes/api.php'));
	}
}

Laravel将路由分为两个大组：api、web。这两个部分的路由分别写在两个文件中：routes/web.php、routes/api.php。

路由的加载

所谓的路由加载，就是将定义路由时添加的属性，例如’name’、’domain’、’scheme’等等保存起来，以待后用。

• Laravel定义路由的属性的方法很灵活，可以定义在路由群组前，例如：

Route::domain('route.domain.name')->group(function() {
	Route::get('foo','controller@method');
})

• 可以定义在路由群组中，例如：

Route::group('domain' => 'group.domain.name',function() {
	Route::get('foo','controller@method');
})

• 可以定义在method的前面，例如：

Route::domain('route.domain.name')->get('foo','controller@method');

• 可以定义在method中，例如：

Route::get('foo', ['domain' => 'route.domain.name','use' => 'controller@method']);

• 还可以定义在method后，例如：

Route::get('{one}', 'use' => 'controller@method')->where('one', '(.+)');

事实上，路由的加载功能主要有三个类负责：

Illuminate\Routing\Router、Illuminate\Routing\Route、Illuminate\Routing\RouteRegistrar。

Router在整个路由功能中都是起着中枢的作用，RouteRegistrar主要负责位于group、method这些函数之前的属性注册，例如上面的第一种和第三种，route主要负责位于group、method这些函数之后的属性注册，例如第五种。

RouteRegistrar路由加载

属性注册

当我们想要在Route后面直接利用domain()、name()等函数来为路由注册属性的时候，我们实际调用的是router的魔术方法__call()：

namespace Illuminate\Routing;

class Router implements BindingRegistrar, RegistrarContract
{
	/**
     * Dynamically handle calls into the router instance.
     *
     * @param  string  $method
     * @param  array  $parameters
     * @return mixed
     */
    public function __call($method, $parameters)
    {
        if (static::hasMacro($method)) {
            return $this->macroCall($method, $parameters);
        }

        if ($method === 'middleware') {
            return (new RouteRegistrar($this))->attribute($method, is_array($parameters[0]) ? $parameters[0] : $parameters);
        }

        return (new RouteRegistrar($this))->attribute($method, $parameters[0]);
    }
}

在类RouteRegistrar中：

class RouteRegistrar
{
	/**
     * The attributes that can be set through this class.
     *
     * @var array
     */
    protected $allowedAttributes = [
        'as', 'domain', 'middleware', 'name', 'namespace', 'prefix', 'where',
    ];

    /**
     * Set the value for a given attribute.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return $this
     *
     * @throws \InvalidArgumentException
     */
    public function attribute($key, $value)
    {
        if (! in_array($key, $this->allowedAttributes)) {
            throw new InvalidArgumentException("Attribute [{$key}] does not exist.");
        }

        $this->attributes[Arr::get($this->aliases, $key, $key)] = $value;

        return $this;
    }
}

添加路由

注册属性之后，创建路由的时候，可以仅仅提供uri，可以提供uri与闭包，可以提供uri与控制器，可以提供uri与数组：

Route::as('Foo')->namespace('Namespace\\Example\\')->get('foo/bar'); // 仅仅uri

Route::as('Foo')->namespace('Namespace\\Example\\')->get('foo/bar', function () {

}); // uri与闭包

Route::as('Foo')->namespace('Namespace\\Example\\')->get('foo/bar', 'controller@method');// uri与控制器

Route::as('Foo')->namespace('Namespace\\Example\\')->get('foo/bar', ['as'=> 'foo','use' =>'controller@method']) ;// uri与数组

利用get、post等方法创建新的路由时，会调用类RouteRegistrar中的魔术方法__call()：

Illuminate\Routing\RouteRegistrar.php

class RouteRegistrar
{
	/**
     * The methods to dynamically pass through to the router.
     *
     * @var array
     */
    protected $passthru = [
        'get', 'post', 'put', 'patch', 'delete', 'options', 'any',
    ];


	/**
     * Dynamically handle calls into the route registrar.
     *
     * @param  string  $method
     * @param  array  $parameters
     * @return \Illuminate\Routing\Route|$this
     *
     * @throws \BadMethodCallException
     */
    public function __call($method, $parameters)
    {
        if (in_array($method, $this->passthru)) {
            return $this->registerRoute($method, ...$parameters);
        }

        if (in_array($method, $this->allowedAttributes)) {
            if ($method === 'middleware') {
                return $this->attribute($method, is_array($parameters[0]) ? $parameters[0] : $parameters);
            }

            return $this->attribute($method, $parameters[0]);
        }

        throw new BadMethodCallException(sprintf(
            'Method %s::%s does not exist.', static::class, $method
        ));
    }

	/**
     * Register a new route with the router.
     *
     * @param  string  $method
     * @param  string  $uri
     * @param  \Closure|array|string|null  $action
     * @return \Illuminate\Routing\Route
     */
    protected function registerRoute($method, $uri, $action = null)
    {
        if (! is_array($action)) {
            $action = array_merge($this->attributes, $action ? ['uses' => $action] : []);
        }

        return $this->router->{$method}($uri, $this->compileAction($action));
    }

	/**
     * Compile the action into an array including the attributes.
     *
     * @param  \Closure|array|string|null  $action
     * @return array
     */
    protected function compileAction($action)
    {
        if (is_null($action)) {
            return $this->attributes;
        }

        if (is_string($action) || $action instanceof Closure) {
            $action = ['uses' => $action];
        }

        return array_merge($this->attributes, $action);
    }
}

也就是说，RouteRegistrar在这里会为闭包或控制器等所有非数组的action添加use键，然后才会去router中创建路由。

添加路由群组

注册属性之后，还可以创建路由群组，但是这时路由群组不允许添加属性action：

class RouteRegistrar
{
	/**
     * Create a route group with shared attributes.
     *
     * @param  \Closure|string  $callback
     * @return void
     */
    public function group($callback)
    {
        $this->router->group($this->attributes, $callback);
    }
}

Router路由群组加载

路由群组的功能可以不断叠加递归，因此每次调用group，都要用新路由群组的属性与旧路由群组属性合并，以待新的路由去继承。group参数可以是闭包函数，也可以是包含定义路由的文件路径。

Illuminate\Routing\Router.php

<?php

namespace Illuminate\Routing;

/**
 * @mixin \Illuminate\Routing\RouteRegistrar
 */
class Router implements BindingRegistrar, RegistrarContract
{
	/**
     * Create a route group with shared attributes.
     *
     * @param  array  $attributes
     * @param  \Closure|string  $routes
     * @return void
     */
    public function group(array $attributes, $routes)
    {
        $this->updateGroupStack($attributes);

        // Once we have updated the group stack, we'll load the provided routes and
        // merge in the group's attributes when the routes are created. After we
        // have created the routes, we will pop the attributes off the stack.
        $this->loadRoutes($routes);

        array_pop($this->groupStack);
    }

	/**
     * Update the group stack with the given attributes.
     *
     * @param  array  $attributes
     * @return void
     */
    protected function updateGroupStack(array $attributes)
    {
        if ($this->hasGroupStack()) {
            $attributes = $this->mergeWithLastGroup($attributes);
        }

        $this->groupStack[] = $attributes;
    }

    /**
     * Determine if the router currently has a group stack.
     *
     * @return bool
     */
    public function hasGroupStack()
    {
        return ! empty($this->groupStack);
    }

    /**
     * Merge the given array with the last group stack.
     *
     * @param  array  $new
     * @param  bool  $prependExistingPrefix
     * @return array
     */
    public function mergeWithLastGroup($new, $prependExistingPrefix = true)
    {
        return RouteGroup::merge($new, end($this->groupStack), $prependExistingPrefix);
    }
}

关于路由群组属性的合并：

• prefix、as、namespace这几个属性会连接在一起，例如prefix1/prefix2/prefix3。
• where属性数组相同的会被替换，不同的会被合并。
• domain属性会被替换。
• 其他属性，例如middleware数组会直接被合并，即使存在相同的元素。

<?php

namespace Illuminate\Routing;

use Illuminate\Support\Arr;

class RouteGroup
{
    /**
     * Merge route groups into a new array.
     *
     * @param  array  $new
     * @param  array  $old
     * @param  bool  $prependExistingPrefix
     * @return array
     */
    public static function merge($new, $old, $prependExistingPrefix = true)
    {
        if (isset($new['domain'])) {
            unset($old['domain']);
        }

        $new = array_merge(static::formatAs($new, $old), [
            'namespace' => static::formatNamespace($new, $old),
            'prefix' => static::formatPrefix($new, $old, $prependExistingPrefix),
            'where' => static::formatWhere($new, $old),
        ]);

        return array_merge_recursive(Arr::except(
            $old, ['namespace', 'prefix', 'where', 'as']
        ), $new);
    }
}

Router路由加载

添加路由需要很多步骤，需要将路由本身的属性和路由群组的属性相结合。

class Router implements BindingRegistrar, RegistrarContract
{
	/**
     * Register a new GET route with the router.
     *
     * @param  string  $uri
     * @param  array|string|callable|null  $action
     * @return \Illuminate\Routing\Route
     */
    public function get($uri, $action = null)
    {
        return $this->addRoute(['GET', 'HEAD'], $uri, $action);
    }

	/**
     * Add a route to the underlying route collection.
     *
     * @param  array|string  $methods
     * @param  string  $uri
     * @param  array|string|callable|null  $action
     * @return \Illuminate\Routing\Route
     */
    public function addRoute($methods, $uri, $action)
    {
        return $this->routes->add($this->createRoute($methods, $uri, $action));
    }

	/**
     * Create a new route instance.
     *
     * @param  array|string  $methods
     * @param  string  $uri
     * @param  mixed  $action
     * @return \Illuminate\Routing\Route
     */
    protected function createRoute($methods, $uri, $action)
    {
        // If the route is routing to a controller we will parse the route action into
        // an acceptable array format before registering it and creating this route
        // instance itself. We need to build the Closure that will call this out.
        if ($this->actionReferencesController($action)) {
            $action = $this->convertToControllerAction($action);
        }

        $route = $this->newRoute(
            $methods, $this->prefix($uri), $action
        );

        // If we have groups that need to be merged, we will merge them now after this
        // route has already been created and is ready to go. After we're done with
        // the merge we will be ready to return the route back out to the caller.
        if ($this->hasGroupStack()) {
            $this->mergeGroupAttributesIntoRoute($route);
        }

        $this->addWhereClausesToRoute($route);

        return $route;
    }
}

从上面来看，添加一个新的路由需要：

• 给路由的控制器添加group的namespace
• 给路由的uri添加group的prefix前缀
• 创建新的路由
• 更新路由的属性信息
• 为路由添加router-pattern正则约束
• 路由添加到RouteCollection中

控制器namespace

路由控制器的命名空间一般不用特别指定，默认值是\App\Http\Controllers，每次创建新的路由，都要将默认的命名空间添加到控制器中去：

protected function actionReferencesController($action)
{
if (! $action instanceof Closure) {
return is_string($action) || (isset($action['uses']) &&
is_string($action['uses']));
}
return false;
}
protected function convertToControllerAction($action)
{
if (is_string($action)) {
$action = ['uses' => $action];
}
if (! empty($this->groupStack)) {
$action['uses'] = $this->prependGroupNamespace($action['
uses']);
}
$action['controller'] = $action['uses'];
return $action;
}
protected function prependGroupNamespace($class)
{
$group = end($this->groupStack);
return isset($group['namespace']) && strpos($class, '\\') !=
= 0
? $group['namespace'].'\\'.$class : $class;
}

uri前缀

在创建新的路由前，需要将路由群组的prefix添加到路由的uri中：

protected function prefix($uri)
{
return trim(trim($this->getLastGroupPrefix(), '/').'/'.trim(
$uri, '/'), '/') ?: '/';
}
public function getLastGroupPrefix()
{
if (! empty($this->groupStack)) {
$last = end($this->groupStack);
return isset($last['prefix']) ? $last['prefix'] : '';
}
return '';
}

创建新的路由

路由的创建需要Route类：

protected function newRoute($methods, $uri, $action)
{
return (new Route($methods, $uri, $action))
->setRouter($this)
->setContainer($this->container);
}

关于Router类添加新的路由我们在下一部分详细说。

更新路由属性信息

创建新的路由之后，需要将路由本身的属性action与路由群组的属性结合在一起：

public function hasGroupStack()
{
return ! empty($this->groupStack);
}
protected function mergeGroupAttributesIntoRoute($route)
{
$route->setAction($this->mergeWithLastGroup($route->getAction()));
}

添加全局正则约束到路由

上一篇文章我们说过，我们可以为路由通过pattern方法添加全局的参数正则约束，所有每次添加新的路由都要将这个全局正则约束添加到路由中：

public function pattern($key, $pattern)
{
$this->patterns[$key] = $pattern;
}
protected function addWhereClausesToRoute($route)
{
$route->where(array_merge(
$this->patterns, isset($route->getAction()['where']) ? $route->getAction()['where'] : []
));
return $route;
}

Route路由加载

前面说过，路由的创建是由Route这个类完成的：

public function __construct($methods, $uri, $action)
{
$this->uri = $uri;
$this->methods = (array) $methods;
$this->action = $this->parseAction($action);
if (in_array('GET', $this->methods) && ! in_array('HEAD', $t
his->methods)) {
$this->methods[] = 'HEAD';
}
if (isset($this->action['prefix'])) {
$this->prefix($this->action['prefix']);
}
}

由此可以看出，路由的创建主要是路由的各个属性的初始化，其中值得注意的有两个：action与prefix action解析

protected function parseAction($action)
{
return RouteAction::parse($this->uri, $action);
}

我们可以看出，添加新的路由时，action属性需要利用RouteAction类：

class RouteAction
{
public static function parse($uri, $action)
{
if (is_null($action)) {
return static::missingAction($uri);
}
if (is_callable($action)) {

return ['uses' => $action];
}
elseif (! isset($action['uses'])) {
$action['uses'] = static::findCallable($action);
}
if (is_string($action['uses']) && ! Str::contains($action['uses'], '@')) {
$action['uses'] = static::makeInvokable($action['uses']);
}
return $action;
}
protected static function findCallable(array $action)
{
return Arr::first($action, function ($value, $key) {
return is_callable($value) && is_numeric($key);
});
}
protected static function makeInvokable($action)
{
if (! method_exists($action, '__invoke')) {
throw new UnexpectedValueException("Invalid route ac
tion: [{$action}].");
}
return $action.'@__invoke';
}
}

前面的博客我们说过，创建路由的时候，除了为路由分配控制器之外，还可以为路由分配闭包函数，还有类函数，例如之前说的单动作控制器：

$router->get('foo/bar2', [‘domain’ => 'www.example.com', 'Illumi
nate\Tests\Routing\ActionStub']);
class ActionStub
{
public function __invoke()
{
return 'hello';
}
}

因此，解析action主要做两件事：

• 为闭包函数添加use键。对于此时没有use键的路由，由于之前在Router中已经为控制器添加use键，因此这时没有use键的，必然是闭包函数，在这里直接或者在action中寻找闭包函数后，为闭包函数添加use键。
• 单动作控制器添加__invoke 。对于单动作控制器来说，此时已经和控制器一样拥有’use’键，但是并没有@符号，此时就会调用makeInvokable函数来将__invoke添加到后面。

prefix前缀

路由自身也有prefix属性，而且这个属性要加在其他prefix的最前面，作为路由的uri：

public function prefix($prefix)
{
$uri = rtrim($prefix, '/').'/'.ltrim($this->uri, '/');
$this->uri = trim($uri, '/');
return $this;
}

Route路由属性加载

除了RouteRegistrar之外，Route也可以为路由添加属性：

prefix前缀

public function prefix($prefix)
{
$uri = rtrim($prefix, '/').'/'.ltrim($this->uri, '/');
$this->uri = trim($uri, '/');
return $this;
}

where正则约束

public function where($name, $expression = null)
{
foreach ($this->parseWhere($name, $expression) as $name => $
expression) {
$this->wheres[$name] = $expression;
}
return $this;
}
protected function parseWhere($name, $expression)
{
return is_array($name) ? $name : [$name => $expression];
}

middleware中间件

public function middleware($middleware = null)
{
if (is_null($middleware)) {
return (array) Arr::get($this->action, 'middleware', [])
;
}
if (is_string($middleware)) {
$middleware = func_get_args();
}
$this->action['middleware'] = array_merge(
(array) Arr::get($this->action, 'middleware', []), $middleware
);
return $this;
}

uses控制器

public function uses($action)
{
	$action = is_string($action) ? $this->addGroupNamespaceToStringUses($action) : $action;

	return $this->setAction(
		array_merge(
			$this->action, 
			$this->parseAction([
				'uses' => $action,
				'controller' => $action,
			])
		)
	);
}

name命名

public function name($name)
{
	$this->action['as'] = isset($this->action['as']) ? $this->action['as'].$name : $name;

	return $this;
}

RouteCollection添加路由

在上面的部分，我们看到添加路由的代码：

protected function addRoute($methods, $uri, $action)
{
	return $this->routes->add($this->createRoute($methods, $uri,$action));
}

新创建的路由会加入到RouteCollection中，会更新类中的routes、allRoutes、nameList、actionList。

<?php

namespace Illuminate\Routing;

use Illuminate\Container\Container;
use Illuminate\Http\Request;
use Illuminate\Support\Arr;

class RouteCollection extends AbstractRouteCollection
{
	/**
     * Add a Route instance to the collection.
     *
     * @param  \Illuminate\Routing\Route  $route
     * @return \Illuminate\Routing\Route
     */
    public function add(Route $route)
    {
        $this->addToCollections($route);

        $this->addLookups($route);

        return $route;
    }

	/**
     * Add the given route to the arrays of routes.
     *
     * @param  \Illuminate\Routing\Route  $route
     * @return void
     */
    protected function addToCollections($route)
    {
        $domainAndUri = $route->getDomain().$route->uri();

        foreach ($route->methods() as $method) {
            $this->routes[$method][$domainAndUri] = $route;
        }

        $this->allRoutes[$method.$domainAndUri] = $route;
    }

    /**
     * Add the route to any look-up tables if necessary.
     *
     * @param  \Illuminate\Routing\Route  $route
     * @return void
     */
    protected function addLookups($route)
    {
        // If the route has a name, we will add it to the name look-up table so that we
        // will quickly be able to find any route associate with a name and not have
        // to iterate through every route every time we need to perform a look-up.
        if ($name = $route->getName()) {
            $this->nameList[$name] = $route;
        }

        // When the route is routing to a controller we will also store the action that
        // is used by the route. This will let us reverse route to controllers while
        // processing a request and easily generate URLs to the given controllers.
        $action = $route->getAction();

        if (isset($action['controller'])) {
            $this->addToActionList($action, $route);
        }
    }

    /**
     * Add a route to the controller action dictionary.
     *
     * @param  array  $action
     * @param  \Illuminate\Routing\Route  $route
     * @return void
     */
    protected function addToActionList($action, $route)
    {
        $this->actionList[trim($action['controller'], '\\')] = $route;
    }
}

我们在上面路由的注册启动章节说道，路由的启动是namespace Illuminate\Foundation\Support\Providers\RouteServiceProvider完成的，调用的是boot函数：

public function boot()
{
$this->setRootControllerNamespace();
if ($this->app->routesAreCached()) {
$this->loadCachedRoutes();
} else {
$this->loadRoutes();
$this->app->booted(function () {
$this->app['router']->getRoutes()->refreshNameLookups();
});
}
}

在最后一句，程序将会在所有服务都启动后运行refreshNameLookups函数，把所有的name属性加载到RouteCollection中:

class RouteCollection extends AbstractRouteCollection
{
	/**
     * A flattened array of all of the routes.
     *
     * @var \Illuminate\Routing\Route[]
     */
    protected $allRoutes = [];

	/**
	 * Refresh the name look-up table.
	 *
	 * This is done in case any names are fluently defined or if routes are overwritten.
	 *
	 * @return void
	 */
	public function refreshNameLookups()
	{
	    $this->nameList = [];

	    foreach ($this->allRoutes as $route) 
	    {
	        if ($route->getName()) 
	        {
	            $this->nameList[$route->getName()] = $route;
	        }
	    }
	}
}

测试样例如下：

public function testRouteCollectionCanRefreshNameLookups()
{
	$routeIndex = new Route('GET', 'foo/index', ['uses' => 'FooController@index',]);

	$this->assertNull($routeIndex->getName());

	$this->routeCollection->add($routeIndex)->name('route_name');

	$this->assertNull($this->routeCollection->getByName('route_name'));

	$this->routeCollection->refreshNameLookups();

	$this->assertEquals($routeIndex, $this->routeCollection->getByName('route_name'));
}