laravel响应的发送和程序终止

响应的发送是通过index.php中的$response->send();实现的

vendor\symfony\http-foundation\Response.php

     public function send()
     {
         $this->sendHeaders();
         $this->sendContent();

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

         return $this;
     }

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

         // headers
         foreach ($this->headers->allPreserveCase() as $name => $values) {
             foreach ($values as $value) {
                 header($name.': '.$value, false, $this->statusCode);
             }
         }

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

         return $this;
     }

    public function sendContent()
    {
        echo $this->content;

        return $this;
    }

　　

响应和发送分别是头信息发送和主题内容发送

头包括：状态行，首部字段和cookie的发送，状态行和首部字段是通过header()函数完成的，cookie发送是通过setcookie函数完成的

程序的终止

//程序的终止（index.php）
$kernel->terminate($request, $response);

    public function terminate($request, $response)
    {
        $this->terminateMiddleware($request, $response);

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

　　

    protected function terminateMiddleware($request, $response)
    {
        $middlewares = $this->app->shouldSkipMiddleware() ? [] : array_merge(
            $this->gatherRouteMiddleware($request),
            $this->middleware
        );

        foreach ($middlewares as $middleware) {
            if (! is_string($middleware)) {
                continue;
            }

            list($name) = $this->parseMiddleware($middleware);

            $instance = $this->app->make($name);

            if (method_exists($instance, 'terminate')) {
                $instance->terminate($request, $response);
            }
        }
    }

　　

\vendor\laravel\framework\src\Illuminate\Foundation\Application.php

    public function terminate()
    {
        foreach ($this->terminatingCallbacks as $terminating) {
            $this->call($terminating);
        }
    }