laravel源码分析

目录

laravel底层分析

一、生命周期

二、运行原理概述

三、详细源码分析


laravel底层分析

一、生命周期

laravel源码分析_第1张图片

二、运行原理概述

laravel的入口文件 public/index.php

1、引入自动加载 autoload.php

2、创建应用实例,并同时完成了:

  • 基本绑定($this、容器类Container等等)
  • 基本服务提供者的注册(Event、log、routing)
  • 核心类别名的注册(比如app、db、auth、config、router等)

3、开始Http请求的处理

  • make方法从容器中解析指定的值为实际的类,比如$app>make(Illuminate\\Contracts\\Http\\Kernel::class) 解析出
  • App\\Http\\Kernel::class-> handle方法对http请求进行处理
  • 实际上是handle中的sendRequestThroughRouter处理的http请求
  • 首先,将request绑定到共享实例 ,执行$this->bootstrap()方法,运行给定的引导类数组$bootstrappers,这里很关键,包括了加载配置文件、环境变量、服务提供者(config/app.php中的providers)、门面、异常处理、引导提供者
  • 进入Pipeline管道类,经过全局中间件的处理过滤后,再进行执行Router类的dispatchToRouter(用户请求的分发)
  • dispatchToRoute请求分发时,首先,findRoute查找与给定请求匹配的路由,路由匹配match然后执行runRoute方法,实际处理请求的是runRoute 方法中的runRouteWithinStack,并执行路由组中间件以及路由中间件
  • 经过runRouteWithinStack中的run方法,判断isControllerAction将请求分配到实际的控制器中runController或者执行runCallable,并得到响应结果

4、将处理结果返回

$this->prepareResponse方法返回了 Reqponse 实例,响应由Symfony\Component\HttpFoundation\Response实现

$response->send(); 将响应数据返回给客户端

send 中将设置好的那些 headers 设置到 HTTP 的头部字段中,然后将 Content 输出到 HTTP 的实体中,最后通过 PHP 将完整的 HTTP 响应发送给客户

5 、执行请求生命周期的所有最终操作

$kernel->terminate($request, $response);

最后是 terminate 逻辑的调用,Laravel 中间件会检查全局中间件和路由中间件中是否包含 trminate 方法,如果包含的话则认为改中间件为 终端中间件,并执行其中的 terminate 方法。

三、详细源码分析

1、注册自动加载器,实现文件的自动加载

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

2、创建应用容器实例Application(该实例继承自容器类Container),并绑定核心(web、命令行、异常),以便在需要时解析它们

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

app.php文件如下:

singleton(
    Illuminate\\Contracts\\Http\\Kernel::class,
    App\\Http\\Kernel::class
);
// 绑定命令行kernel
$app->singleton(
    Illuminate\\Contracts\\Console\\Kernel::class,
    App\\Console\\Kernel::class
);
// 绑定异常处理kernel
$app->singleton(
    Illuminate\\Contracts\\Debug\\ExceptionHandler::class,
    App\\Exceptions\\Handler::class
);
// 返回应用实例
return $app;

3、在创建应用实例(Application.php)的构造函数中,将基本绑定注册到容器中,并注册了所有的基本服务提供者,以及在容器中注册核心类别名

public function __construct($basePath = null)
{
    // 将基本绑定注册到容器中【3.1】
    $this->registerBaseBindings();
    // 注册所有基本服务提供者【3.2】
    $this->registerBaseServiceProviders();
    // 在容器中注册核心类别名【3.3】
    $this->registerCoreContainerAliases();
}

3.1、将基本绑定注册到容器中

 static::setInstance($this);
 $this->instance('app', $this);
 $this->instance(Container::class, $this);
 $this->singleton(Mix::class);
 $this->instance(PackageManifest::class, new PackageManifest(
     new Filesystem, $this->basePath(), $this->getCachedPackagesPath()
 ));
 # 注:instance方法为将...注册为共享实例,singleton方法为将...注册为共享绑定

3.2、注册所有基本服务提供者(事件、日志、路由)

protected function registerBaseServiceProviders()
{
    $this->register(new EventServiceProvider($this));
    $this->register(new LogServiceProvider($this));
    $this->register(new RoutingServiceProvider($this));
}

3.3、在容器中注册核心类别名

laravel源码分析_第2张图片

4、上面完成了类的自动加载、服务提供者注册、核心类的绑定、以及基本注册的绑定

5、开始解析http请求

index.php
// 5.1
$kernel = $app->make(Illuminate\\Contracts\\Http\\Kernel::class);
// 5.2
$response = $kernel->handle(
// 根据 Symfony 的 request 对象封装出 Illuminate\\Http\\Request
    $request = Illuminate\\Http\\Request::capture()
);

5.1 make方法是从容器解析给定值

$kernel = $app->make(Illuminate\\Contracts\\Http\\Kernel::class);中的Illuminate\\Contracts\\Http\\Kernel::class 是在index.php 中的

$app = require_once __DIR__.'/../bootstrap/app.php';这里面进行绑定的,

实际指向的就是App\\Http\\Kernel::class这个类 5.2 这里对http请求进行处理

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

进入$kernel所代表的类App\Http\Kernel.php中,我们可以看到其实里面只是定义了一些中间件相关的内容,并没有handle方法

我们再到它的父类use Illuminate\\Foundation\\Http\\Kernel as HttpKernel;

中找handle方法,可以看到handle方法是这样的

public function handle($request)
{
    try {
        $request->enableHttpMethodParameterOverride();
        // 最核心的处理http请求的地方【6】
        $response = $this->sendRequestThroughRouter($request);
    } catch (Exception $e) {
        $this->reportException($e);
        $response = $this->renderException($request, $e);
    } catch (Throwable $e) {
        $this->reportException($e = new FatalThrowableError($e));
        $response = $this->renderException($request, $e);
    }
    $this->app['events']->dispatch(
        new Events\\RequestHandled($request, $response)
    );
    return $response;
}

6、处理http请求(将request绑定到共享实例,并使用管道模式处理用户请求)

vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php的handle方法
// 最核心的处理http请求的地方
$response = $this->sendRequestThroughRouter($request);

进入sendRequestThroughRouter方法

protected function sendRequestThroughRouter($request)
{
    // 将请求$request绑定到共享实例
    $this->app->instance('request', $request);
    // 将请求request从已解析的门面实例中清除(因为已经绑定到共享实例中了,没必要再浪费资源了)
    Facade::clearResolvedInstance('request');
    // 引导应用程序进行HTTP请求
    $this->bootstrap();【7、8】
    // 进入管道模式,经过中间件,然后处理用户的请求【9、10】
    return (new Pipeline($this->app))//创建管道
                ->send($request)     //发送请求
                ->through($this->app->shouldSkipMiddleware() ? [] : $this->middleware)  //通过中间件
                ->then($this->dispatchToRouter());  //分发到路由
}

7、在bootstrap方法中,运行给定的引导类数组$bootstrappers,加载配置文件、环境变量、服务提供者、门面、异常处理、引导提供者,非常重要的一步

位置在vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php

/**
 * Bootstrap the application for HTTP requests.
 *
 * @return void
 */
public function bootstrap()
{
    if (! $this->app->hasBeenBootstrapped()) {
        $this->app->bootstrapWith($this->bootstrappers());
    }
}

/**
 * 运行给定的引导类数组
 *
 * @param  string[]  $bootstrappers
 * @return void
 */
public function bootstrapWith(array $bootstrappers)
{
    $this->hasBeenBootstrapped = true;
    foreach ($bootstrappers as $bootstrapper) {
        $this['events']->dispatch('bootstrapping: '.$bootstrapper, [$this]);
        $this->make($bootstrapper)->bootstrap($this);
        $this['events']->dispatch('bootstrapped: '.$bootstrapper, [$this]);
    }
}

/**
 * Get the bootstrap classes for the application.
 *
 * @return array
 */
protected function bootstrappers()
{
    return $this->bootstrappers;
}

/**
 * 应用程序的引导类
 *
 * @var array
 */
protected $bootstrappers = [
    // 加载环境变量
    \\Illuminate\\Foundation\\Bootstrap\\LoadEnvironmentVariables::class,
    // 加载config配置文件【重点】
    \\Illuminate\\Foundation\\Bootstrap\\LoadConfiguration::class,
    // 加载异常处理
    \\Illuminate\\Foundation\\Bootstrap\\HandleExceptions::class,
    // 加载门面注册
    \\Illuminate\\Foundation\\Bootstrap\\RegisterFacades::class,
    // 加载在config/app.php中的providers数组里所定义的服务【8 重点】
    \\Illuminate\\Foundation\\Bootstrap\\RegisterProviders::class,
    // 记载引导提供者
    \\Illuminate\\Foundation\\Bootstrap\\BootProviders::class,
];

8、加载config/app.php中的providers数组里所定义的服务

Illuminate\\Auth\\AuthServiceProvider::class,
Illuminate\\Broadcasting\\BroadcastServiceProvider::class,
Illuminate\\Bus\\BusServiceProvider::class,
Illuminate\\Cache\\CacheServiceProvider::class,
Illuminate\\Foundation\\Providers\\ConsoleSupportServiceProvider::class,
Illuminate\\Cookie\\CookieServiceProvider::class,
Illuminate\\Database\\DatabaseServiceProvider::class,
Illuminate\\Encryption\\EncryptionServiceProvider::class,
Illuminate\\Filesystem\\FilesystemServiceProvider::class,
Illuminate\\Foundation\\Providers\\FoundationServiceProvider::class,
Illuminate\\Hashing\\HashServiceProvider::class,
Illuminate\\Mail\\MailServiceProvider::class,
Illuminate\\Notifications\\NotificationServiceProvider::class,
Illuminate\\Pagination\\PaginationServiceProvider::class,
Illuminate\\Pipeline\\PipelineServiceProvider::class,
Illuminate\\Queue\\QueueServiceProvider::class,
Illuminate\\Redis\\RedisServiceProvider::class,
Illuminate\\Auth\\Passwords\\PasswordResetServiceProvider::class,
Illuminate\\Session\\SessionServiceProvider::class,
Illuminate\\Translation\\TranslationServiceProvider::class,
Illuminate\\Validation\\ValidationServiceProvider::class,
Illuminate\\View\\ViewServiceProvider::class,
App\\Providers\\AppServiceProvider::class,
App\\Providers\\AuthServiceProvider::class,
App\\Providers\\EventServiceProvider::class,
App\\Providers\\RouteServiceProvider::class,
/**
 * 自己添加的服务提供者
 */
\\App\\Providers\\HelperServiceProvider::class

可以看到,关于常用的 Redis、session、queue、auth、database、Route 等服务都是在这里进行加载的

9、使用管道模式处理用户请求,先经过中间件进行处理

return (new Pipeline($this->app))
    ->send($request)
    // 如果没有为程序禁用中间件,则加载中间件(位置在app/Http/Kernel.php的$middleware属性)
    ->through($this->app->shouldSkipMiddleware() ? [] : $this->middleware)
    ->then($this->dispatchToRouter());
}

app/Http/Kernel.php

/**
 * 应用程序的全局HTTP中间件
 *
 * These middleware are run during every request to your application.
 *
 * @var array
 */
protected $middleware = [
    \\App\\Http\\Middleware\\TrustHosts::class,
    \\App\\Http\\Middleware\\TrustProxies::class,
    \\Fruitcake\\Cors\\HandleCors::class,
    \\App\\Http\\Middleware\\CheckForMaintenanceMode::class,
    \\Illuminate\\Foundation\\Http\\Middleware\\ValidatePostSize::class,
    \\App\\Http\\Middleware\\TrimStrings::class,
    \\Illuminate\\Foundation\\Http\\Middleware\\ConvertEmptyStringsToNull::class
];

10、经过中间件处理后,再进行请求分发(包括查找匹配路由)

/**
 * 10.1 通过中间件/路由器发送给定的请求
 *
 * @param  \\Illuminate\\Http\\Request  $request
 * @return \\Illuminate\\Http\\Response
 */
 protected function sendRequestThroughRouter($request)
{
    ...
    return (new Pipeline($this->app))
        ...
        // 进行请求分发
        ->then($this->dispatchToRouter());
}

/**
 * 10.2 获取路由调度程序回调
 *
 * @return \\Closure
 */
protected function dispatchToRouter()
{
    return function ($request) {
        $this->app->instance('request', $request);
        // 将请求发送到应用程序
        return $this->router->dispatch($request);
    };
}

/**
 * 10.3 将请求发送到应用程序
 *
 * @param  \\Illuminate\\Http\\Request  $request
 * @return \\Illuminate\\Http\\Response|\\Illuminate\\Http\\JsonResponse
 */
 public function dispatch(Request $request)
{
    $this->currentRequest = $request;
    return $this->dispatchToRoute($request);
}

 /**
 * 10.4 将请求分派到路由并返回响应【重点在runRoute方法】
 *
 * @param  \\Illuminate\\Http\\Request  $request
 * @return \\Illuminate\\Http\\Response|\\Illuminate\\Http\\JsonResponse
 */
public function dispatchToRoute(Request $request)
{
    //查询路由并执行路由
    return $this->runRoute($request, $this->findRoute($request));
}

/**
 * 10.5 查找与给定请求匹配的路由
 *
 * @param  \\Illuminate\\Http\\Request  $request
 * @return \\Illuminate\\Routing\\Route
 */
protected function findRoute($request)
{
    // 匹配路由 
    $this->current = $route = $this->routes->match($request);
    $this->container->instance(Route::class, $route);
    return $route;
}

/**
 * 10.6 查找与给定请求匹配的第一条路由
 *
 * @param  \\Illuminate\\Http\\Request  $request
 * @return \\Illuminate\\Routing\\Route
 *
 * @throws \\Symfony\\Component\\HttpKernel\\Exception\\NotFoundHttpException
 */
public function match(Request $request)
{
    // 获取用户的请求类型(get、post、delete、put),然后根据请求类型选择对应的路由
    $routes = $this->get($request->getMethod());
    // 匹配路由
    $route = $this->matchAgainstRoutes($routes, $request);
    if (! is_null($route)) {
        return $route->bind($request);
    }
    $others = $this->checkForAlternateVerbs($request);
    if (count($others) > 0) {
        return $this->getRouteForMethods($request, $others);
    }
    throw new NotFoundHttpException;
}

到现在,已经找到与请求相匹配的路由了,之后将运行了,也就是10.4 中的runRoute 方法

/**
 * 10.4 将请求分派到路由并返回响应
 *
 * @param  \\Illuminate\\Http\\Request  $request
 * @return \\Illuminate\\Http\\Response|\\Illuminate\\Http\\JsonResponse
 */
public function dispatchToRoute(Request $request)
{
    return $this->runRoute($request, $this->findRoute($request));
}

/**
 * 10.7 返回给定路线的响应
 *
 * @param  \\Illuminate\\Http\\Request  $request
 * @param  \\Illuminate\\Routing\\Route  $route
 * @return \\Illuminate\\Http\\Response|\\Illuminate\\Http\\JsonResponse
 */
protected function runRoute(Request $request, Route $route)
{
    $request->setRouteResolver(function () use ($route) {
        return $route;
    });
    $this->events->dispatch(new Events\\RouteMatched($route, $request));
    return $this->prepareResponse($request,
        $this->runRouteWithinStack($route, $request)
    );
}

/**
 * Run the given route within a Stack "onion" instance.
 * 10.8 在栈中运行路由
 *
 * @param  \\Illuminate\\Routing\\Route  $route
 * @param  \\Illuminate\\Http\\Request  $request
 * @return mixed
 */
protected function runRouteWithinStack(Route $route, Request $request)
{
    $shouldSkipMiddleware = $this->container->bound('middleware.disable') &&
                            $this->container->make('middleware.disable') === true;
    $middleware = $shouldSkipMiddleware ? [] : $this->gatherRouteMiddleware($route);
    return (new Pipeline($this->container))
        ->send($request)
        ->through($middleware)
        ->then(function ($request) use ($route) {
            return $this->prepareResponse(
                $request, $route->run()
            );
        });
}

11、运行路由并返回响应[重点]

可以看到,10.7 中有一个方法是prepareResponse,该方法是从给定值创建响应实例,而 runRouteWithinStack 方法则是在栈中运行路由,也就是说,http的请求和响应都将在这里完成

prepareResponse调用toResponse,最后执行prepare

public function prepare(Request $request)
{
    $headers = $this->headers;

    if ($this->isInformational() || $this->isEmpty()) {
        $this->setContent(null);
        $headers->remove('Content-Type');
        $headers->remove('Content-Length');
        // prevent PHP from sending the Content-Type header based on default_mimetype
        ini_set('default_mimetype', '');
    } else {
        // Content-type based on the Request
        if (!$headers->has('Content-Type')) {
            $format = $request->getRequestFormat(null);
            if (null !== $format && $mimeType = $request->getMimeType($format)) {
                $headers->set('Content-Type', $mimeType);
            }
        }

        // Fix Content-Type
        $charset = $this->charset ?: 'UTF-8';
        if (!$headers->has('Content-Type')) {
            $headers->set('Content-Type', 'text/html; charset='.$charset);
        } elseif (0 === stripos($headers->get('Content-Type'), 'text/') && false === stripos($headers->get('Content-Type'), 'charset')) {
            // add the charset
            $headers->set('Content-Type', $headers->get('Content-Type').'; charset='.$charset);
        }

        // Fix Content-Length
        if ($headers->has('Transfer-Encoding')) {
            $headers->remove('Content-Length');
        }

        if ($request->isMethod('HEAD')) {
            // cf. RFC2616 14.13
            $length = $headers->get('Content-Length');
            $this->setContent(null);
            if ($length) {
                $headers->set('Content-Length', $length);
            }
        }
    }

    // Fix protocol
    if ('HTTP/1.0' != $request->server->get('SERVER_PROTOCOL')) {
        $this->setProtocolVersion('1.1');
    }

    // Check if we need to send extra expire info headers
    if ('1.0' == $this->getProtocolVersion() && str_contains($headers->get('Cache-Control', ''), 'no-cache')) {
        $headers->set('pragma', 'no-cache');
        $headers->set('expires', -1);
    }

    $this->ensureIEOverSSLCompatibility($request);

    if ($request->isSecure()) {
        foreach ($headers->getCookies() as $cookie) {
            $cookie->setSecureDefault(true);
        }
    }

    return $this;
}

12、返回response($response->send();)

public function send()
{
   // 发送headers头 12.1
    $this->sendHeaders();
		// 发送返回内容 12.2
    $this->sendContent();

    if (\\function_exists('fastcgi_finish_request')) {
        fastcgi_finish_request();
    } elseif (!\\in_array(\\PHP_SAPI, ['cli', 'phpdbg'], true)) {
        static::closeOutputBuffers(0, true);
    }

    return $this;
}

 12.1、发送HTTP报头

public function sendHeaders()
{
    // headers have already been sent by the developer
    if (headers_sent()) {
        return $this;
    }

    // headers
    foreach ($this->headers->allPreserveCaseWithoutCookies() as $name => $values) {
        $replace = 0 === strcasecmp($name, 'Content-Type');
        foreach ($values as $value) {
            header($name.': '.$value, $replace, $this->statusCode);
        }
    }

    // cookies
    foreach ($this->headers->getCookies() as $cookie) {
        header('Set-Cookie: '.$cookie, false, $this->statusCode);
    }

    // status
    header(sprintf('HTTP/%s %s %s', $this->version, $this->statusCode, $this->statusText), true, $this->statusCode);

    return $this;
}

12.2、为当前响应发送内容

public function sendContent()
{
    // 输出当前内容
    echo $this->content;

    return $this;
}

13、程序终止($kernel->terminate($request, $response);

public function terminate($request, $response)
{
		// 13.1 执行程序终止前的中间件回调
    $this->terminateMiddleware($request, $response);

    $this->app->terminate();
}

13.1、在任何可终止的中间件上调用terminate方法

protected function terminateMiddleware($request, $response)
{
   // 获取要执行的中间件,并合并路由中间件
    $middlewares = $this->app->shouldSkipMiddleware() ? [] : array_merge(
        $this->gatherRouteMiddleware($request),
        $this->middleware
    );
    foreach ($middlewares as $middleware) {
        if (! is_string($middleware)) {
            continue;
        }

        [$name] = $this->parseMiddleware($middleware);

        $instance = $this->app->make($name);
				// 判断是否存在terminate方法,存在则调用
        if (method_exists($instance, 'terminate')) {
            $instance->terminate($request, $response);
        }
    }
}

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