Was ist Laravel-Routing?

Route::get('/user', 'UsersController@index');

app()->make('router')->get('user', 'UsersController@index');

//bootstrap/app.php
$app = new Illuminate\Foundation\Application(
    realpath(__DIR__.'/../')
);

//Application: 构造方法
public function __construct($basePath = null)
{
    if ($basePath) {
        $this->setBasePath($basePath);
    }

    $this->registerBaseBindings();

    $this->registerBaseServiceProviders();

    $this->registerCoreContainerAliases();
}

//Application: 注册基础的服务提供器
protected function registerBaseServiceProviders()
{
    $this->register(new EventServiceProvider($this));

    $this->register(new LogServiceProvider($this));

    $this->register(new RoutingServiceProvider($this));
}

//\Illuminate\Routing\RoutingServiceProvider: 绑定router到服务容器
protected function registerRouter()
{
    $this->app->singleton('router', function ($app) {
        return new Router($app['events'], $app);
    });
}

class RouteServiceProvider extends ServiceProvider
{
    public function boot()
    {
        parent::boot();
    }

    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'));
    }
}

namespace Illuminate\Foundation\Support\Providers;

class RouteServiceProvider extends ServiceProvider
{

    public function boot()
    {
        $this->setRootControllerNamespace();

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

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

    protected function loadCachedRoutes()
    {
        $this->app->booted(function () {
            require $this->app->getCachedRoutesPath();
        });
    }

    protected function loadRoutes()
    {
        if (method_exists($this, 'map')) {
            $this->app->call([$this, 'map']);
        }
    }
}

class Application extends Container implements ApplicationContract, HttpKernelInterface
{
    public function routesAreCached()
    {
        return $this['files']->exists($this->getCachedRoutesPath());
    }

    public function getCachedRoutesPath()
    {
        return $this->bootstrapPath().'/cache/routes.php';
    }
}

public function get($uri, $action = null)
{
    return $this->addRoute(['GET', 'HEAD'], $uri, $action);
}

public function post($uri, $action = null)
{
    return $this->addRoute('POST', $uri, $action);
}
....

//注册路由到RouteCollection
protected function addRoute($methods, $uri, $action)
{
    return $this->routes->add($this->createRoute($methods, $uri, $action));
}

//创建路由
protected function createRoute($methods, $uri, $action)
{
    if ($this->actionReferencesController($action)) {
        //controller@action类型的路由在这里要进行转换
        $action = $this->convertToControllerAction($action);
    }

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

    if ($this->hasGroupStack()) {
        $this->mergeGroupAttributesIntoRoute($route);
    }

    $this->addWhereClausesToRoute($route);

    return $route;
}

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;
}

[
    'uses' => 'App\Http\Controllers\SomeController@someAction',
    'controller' => 'App\Http\Controllers\SomeController@someAction'
]

class RouteCollection implements Countable, IteratorAggregate
{
    public function add(Route $route)
    {
        $this->addToCollections($route);

        $this->addLookups($route);

        return $route;
    }
    
    protected function addToCollections($route)
    {
        $domainAndUri = $route->getDomain().$route->uri();

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

        $this->allRoutes[$method.$domainAndUri] = $route;
    }
    
    protected function addLookups($route)
    {
        $action = $route->getAction();

        if (isset($action['as'])) {
            //如果时命名路由，将route对象映射到以路由名为key的数组值中方便查找
            $this->nameList[$action['as']] = $route;
        }

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

}

[
    'GET' => [
        $routeUri1 => $routeObj1
        ...
    ]
    ...
]