Laravel Kernel引導流程分析

Laravel Kernel引導流程分析

代碼展示

protected function sendRequestThroughRouter($request)
{# $this->app->instance('request', $request);# Facade::clearResolvedInstance('request');// 主要是這句代碼$this->bootstrap();# return (new Pipeline($this->app))#            ->send($request)#            ->through($this->app->shouldSkipMiddleware() ? [] : $this->middleware)#            ->then($this->dispatchToRouter());
}
public function bootstrap()
{if (! $this->app->hasBeenBootstrapped()) {$this->app->bootstrapWith($this->bootstrappers());}
}
protected function bootstrappers()
{######################################################################$bootstrappers = [#    \Illuminate\Foundation\Bootstrap\LoadEnvironmentVariables::class,#    \Illuminate\Foundation\Bootstrap\LoadConfiguration::class,#    \Illuminate\Foundation\Bootstrap\HandleExceptions::class,      #    \Illuminate\Foundation\Bootstrap\RegisterFacades::class,#    \Illuminate\Foundation\Bootstrap\RegisterProviders::class,      #    \Illuminate\Foundation\Bootstrap\BootProviders::class,#];#####################################################################return $this->bootstrappers;
}
public function bootstrapWith(array $bootstrappers)
{$this->hasBeenBootstrapped = true;foreach ($bootstrappers as $bootstrapper) {$this['events']->fire('bootstrapping: '.$bootstrapper, [$this]);$this->make($bootstrapper)->bootstrap($this);$this['events']->fire('bootstrapped: '.$bootstrapper, [$this]);}
}

$this->make($bootstrapper)->bootstrap($this)：會先創建$bootstrapper對象，在執行對象的引導方法，參數為應用對象

處理流程

  1. 加載并設置應用的系統環境變量(IlluminateFoundationBootstrapLoadEnvironmentVariables)

    public function bootstrap(Application $app)
{// /var/www/laravel/bootstrap/cache/config.php 存在則直接返回if ($app->configurationIsCached()) {return;}$this->checkForSpecificEnvironmentFile($app);try {// 委托Dotenv來臨時設置此次請求的系統環境變量，默認傳參依次為'/var/www/laravel'和'.env'(new Dotenv($app->environmentPath(), $app->environmentFile()))->load();} catch (InvalidPathException $e) {//}
}
protected function checkForSpecificEnvironmentFile($app)
{// cli模式下，并且存在--env參數（類似命令為： cammond --env=example）if (php_sapi_name() == 'cli' && with($input = new ArgvInput)->hasParameterOption('--env')) {// 將系統環境文件(類似：/var/www/laravel/.env.example)設置為$app應用的environmentFile屬性，供后面使用$this->setEnvironmentFilePath($app, $app->environmentFile().'.'.$input->getParameterOption('--env'));}if (! env('APP_ENV')) {return;}$this->setEnvironmentFilePath($app, $app->environmentFile().'.'.env('APP_ENV'));
}

    (new Dotenv($app->environmentPath(), $app->environmentFile()))->load()

    public function __construct($path, $file = '.env')
{// 類似/var/www/laravel/.env$this->filePath = $this->getFilePath($path, $file);// 創建加載器，委托Loader處理$this->loader = new Loader($this->filePath, true);
}
protected function getFilePath($path, $file)
{if (!is_string($file)) {$file = '.env';}$filePath = rtrim($path, DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR.$file;return $filePath;
}
public function load()
{return $this->loadData();
}
protected function loadData($overload = false)
{$this->loader = new Loader($this->filePath, !$overload);return $this->loader->load();
}

    new Loader($this->filePath, !$overload)

    public function __construct($filePath, $immutable = false)
{$this->filePath = $filePath;$this->immutable = $immutable;
}
public function load()
{$this->ensureFileIsReadable();$filePath = $this->filePath;$lines = $this->readLinesFromFile($filePath);foreach ($lines as $line) {// 如果行不是注釋行且含有=號，則進行if (!$this->isComment($line) && $this->looksLikeSetter($line)) {$this->setEnvironmentVariable($line);}}return $lines;
}
// 將文件按行的形式讀入到數組并返回
protected function readLinesFromFile($filePath)
{$autodetect = ini_get('auto_detect_line_endings');ini_set('auto_detect_line_endings', '1');$lines = file($filePath, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);ini_set('auto_detect_line_endings', $autodetect);return $lines;
}
public function setEnvironmentVariable($name, $value = null)
{// 檢測過濾校驗環境變量list($name, $value) = $this->normaliseEnvironmentVariable($name, $value);// 當immutable為真時，不覆蓋對應的環境變量if ($this->immutable && $this->getEnvironmentVariable($name) !== null) {return;}// apache運行環境下，嘗試臨時覆蓋系統環境變量if (function_exists('apache_getenv') && function_exists('apache_setenv') && apache_getenv($name)) {apache_setenv($name, $value);}// 嘗試臨時設置當前請求的系統環境變量if (function_exists('putenv')) {putenv("$name=$value");}// 賦值全局變量$_ENV[$name] = $value;$_SERVER[$name] = $value;
}

  2. 將應用配置文件目錄(/var/www/laravel/config)下所有php文件返回的數組載入到$config對象(IlluminateFoundationBootstrapLoadConfiguration)

    public function bootstrap(Application $app)
{$items = [];// /var/www/laravel/bootstrap/cache/config.php文件[配置文件的緩存合集，加快加載速度]存在則載入，并標記已加載if (file_exists($cached = $app->getCachedConfigPath())) {$items = require $cached;$loadedFromCache = true;}// 構建config對象，并注入到服務容器$app->instance('config', $config = new Repository($items));if (! isset($loadedFromCache)) {// 將系統的配置文件載入到$config對象$this->loadConfigurationFiles($app, $config);}// 設置$this['env']為系統環境變量app.env,沒有則默認為production$app->detectEnvironment(function () use ($config) {return $config->get('app.env', 'production');});date_default_timezone_set($config->get('app.timezone', 'UTC'));mb_internal_encoding('UTF-8');
}$config = new \Illuminate\Config\Repository($items)
public function __construct(array $items = [])
{$this->items = $items;
}protected function loadConfigurationFiles(Application $app, RepositoryContract $repository)
{foreach ($this->getConfigurationFiles($app) as $key => $path) {// 此操作將在$repository對象里面構造一個多維數組屬性$this->items，值為相應的系統配置文件返回的數組，后續可以直接通過get獲取$repository->set($key, require $path);}
}
/** $files數組形式如下['app' => '/var/www/laravel/config/app.php','auth' => '/var/www/laravel/config/auth.php','xx.file' => '/var/www/laravel/config/xx/file.php','xx.yy.file' => '/var/www/laravel/config/xx/yy/file.php',]
*/
protected function getConfigurationFiles(Application $app)
{$files = [];// 系統配置文件的路徑(/var/www/laravel/config)$configPath = realpath($app->configPath());// 文件相關的操作委托給Finder類(很強大)來處理，Finder實現了IteratorAggregate的getIterator方法foreach (Finder::create()->files()->name('*.php')->in($configPath) as $file) {// 迭代/var/www/laravel/config下面嵌套的層層子目錄構造成.形式的目錄$directory = $this->getNestedDirectory($file, $configPath);$files[$directory.basename($file->getRealPath(), '.php')] = $file->getRealPath();}return $files;
}$repository->set($key, require $path)
// 構造將.形式轉變為相應層級的數組$this->items。比如：$key='xx.yy.file',$value='/var/www/laravel/config/xx/yy/file.php'，將會構建為:$this->items['xx']['yy']['file'] = $value返回的數組。
public function set($key, $value = null)
{$keys = is_array($key) ? $key : [$key => $value];foreach ($keys as $key => $value) {Arr::set($this->items, $key, $value);}
}

    根據默認的系統配置文件目錄，以上操作的結果如下：
    $config對象（new Repository）里面的$this->items數組屬性，后期可以通過$config->get()來獲取

    $this->items['app'] = /var/www/laravel/config/app.php返回的數組;
$this->items['auth'] = /var/www/laravel/config/auth.php返回的數組;
$this->items['broadcasting'] = /var/www/laravel/config/broadcasting.php返回的數組;
$this->items['cache'] = /var/www/laravel/config/cache.php返回的數組;
$this->items['database'] = /var/www/laravel/config/database.php返回的數組;
$this->items['filesystems'] = /var/www/laravel/config/filesystems.php返回的數組;
$this->items['mail'] = /var/www/laravel/config/mail.php返回的數組;
$this->items['queue'] = /var/www/laravel/config/queue.php返回的數組;
$this->items['services'] = /var/www/laravel/config/services.php返回的數組;
$this->items['session'] = /var/www/laravel/config/session.php返回的數組;
$this->items['view'] = /var/www/laravel/config/view.php返回的數組;假如有這樣的文件（/var/www/laravel/config/xx/yy/zz/file.php），返回['a'=>'hello,world!']數組
將得到：$this->items['xx']['yy']['zz']['file'] = ['a'=>'hello,world!'];
獲取方式： $config->get('xx.yy.zz.file.a', $default)，直接返回'hello,world!';

  3. 設置應用的錯誤異常等處理事件(IlluminateFoundationBootstrapHandleExceptions)

    public function bootstrap(Application $app)
{$this->app = $app;error_reporting(-1);set_error_handler([$this, 'handleError']);set_exception_handler([$this, 'handleException']);register_shutdown_function([$this, 'handleShutdown']);if (! $app->environment('testing')) {ini_set('display_errors', 'Off');}
}
public function handleError($level, $message, $file = '', $line = 0, $context = [])
{if (error_reporting() & $level) {throw new ErrorException($message, 0, $level, $file, $line);}
}
public function handleException($e)
{if (! $e instanceof Exception) {$e = new FatalThrowableError($e);}$this->getExceptionHandler()->report($e);if ($this->app->runningInConsole()) {$this->renderForConsole($e);} else {$this->renderHttpResponse($e);}
}
// 核心代碼，獲取的\App\Exceptions\Handle對象
protected function getExceptionHandler()
{// make時將會直接調用$this->bindings['Illuminate\Contracts\Debug\ExceptionHandler']['concrete'](此代碼位于/var/www/laravel/bootstrap/app.php，應用對象化后，直接注入到服務容器的幾個單例)，返回\App\Exceptions\Handle對象，并將此對象注入到服務容器[參考]return $this->app->make(ExceptionHandler::class);
}
protected function renderHttpResponse(Exception $e)
{$this->getExceptionHandler()->render($this->app['request'], $e)->send();
}
// \App\Exceptions\Handle
public function render($request, Exception $e)
{$e = $this->prepareException($e);if ($e instanceof HttpResponseException) {return $e->getResponse();} elseif ($e instanceof AuthenticationException) {return $this->unauthenticated($request, $e);} elseif ($e instanceof ValidationException) {return $this->convertValidationExceptionToResponse($e, $request);}return $this->prepareResponse($request, $e);
}
protected function renderHttpException(HttpException $e)
{$status = $e->getStatusCode();view()->replaceNamespace('errors', [resource_path('views/errors'),__DIR__.'/views',]);if (view()->exists("errors::{$status}")) {return response()->view("errors::{$status}", ['exception' => $e], $status, $e->getHeaders());} else {return $this->convertExceptionToResponse($e);}
}
public function handleShutdown()
{if (! is_null($error = error_get_last()) && $this->isFatal($error['type'])) {$this->handleException($this->fatalExceptionFromError($error, 0));}
}

  4. 根據配置項設置應用的 Facades(IlluminateFoundationBootstrapRegisterFacades)

    public function bootstrap(Application $app)
{Facade::clearResolvedInstances();Facade::setFacadeApplication($app);// 將配置文件/var/www/laravel/config/app.php返回數組的鍵為aliases的值賦給\Illuminate\Foundation\AliasLoader的aliases屬性，并進行注冊AliasLoader::getInstance($app->make('config')->get('app.aliases', []))->register();
}
public static function clearResolvedInstances()
{static::$resolvedInstance = [];
}
public static function setFacadeApplication($app)
{static::$app = $app;
}\Illuminate\Foundation\AliasLoader
public static function getInstance(array $aliases = [])
{if (is_null(static::$instance)) {return static::$instance = new static($aliases);}$aliases = array_merge(static::$instance->getAliases(), $aliases);static::$instance->setAliases($aliases);return static::$instance;
}
private function __construct($aliases)
{$this->aliases = $aliases;
}
public function getAliases()
{return $this->aliases;
}
public function setAliases(array $aliases)
{$this->aliases = $aliases;
}
public function register()
{if (! $this->registered) {$this->prependToLoaderStack();$this->registered = true;}
}
protected function prependToLoaderStack()
{// 將$this->load注冊到自動加載器的最前面，失敗時拋異常spl_autoload_register([$this, 'load'], true, true);
}
public function load($alias)
{// $facadeNamespace = 'Facades\\'，估計是框架內部使用的，以后再看吧if (static::$facadeNamespace && strpos($alias, static::$facadeNamespace) === 0) {$this->loadFacade($alias);return true;}if (isset($this->aliases[$alias])) {return class_alias($this->aliases[$alias], $alias);}
}

    Facade的本質

    實際上是通過$app->make('config')->get('app.aliases', [])取出config/app.php文件里面的aliases數組并實例化AliasLoader，再將AliasLoader->load方法放到spl自動加載器最前面，最后通過class_alias($this->aliases[$alias], $alias)。當調用Cache::Method時，會觸發Facdes的__callStatic魔術方法，此方法會調用相應對象里面的方法。

  5. 注入配置項的服務提供者(IlluminateFoundationBootstrapRegisterProviders)

    public function bootstrap(Application $app)
{$app->registerConfiguredProviders();
}
public function registerConfiguredProviders()
{(new ProviderRepository($this, new Filesystem, $this->getCachedServicesPath()))->load($this->config['app.providers']);
}
public function getCachedServicesPath()
{return $this->bootstrapPath().'/cache/services.php';
}// 先取services緩存文件，再對\Illuminate\Foundation\ProviderRepository進行實例化，隨后加載系統配置文件(./config/app.php)里面的providers數組
(new ProviderRepository($this, new Filesystem, $this->getCachedServicesPath()))->load($this->config['app.providers'])
public function __construct(ApplicationContract $app, Filesystem $files, $manifestPath)
{$this->app = $app;$this->files = $files;$this->manifestPath = $manifestPath;
}
public function load(array $providers)
{$manifest = $this->loadManifest();if ($this->shouldRecompile($manifest, $providers)) {$manifest = $this->compileManifest($providers);}foreach ($manifest['when'] as $provider => $events) {$this->registerLoadEvents($provider, $events);}foreach ($manifest['eager'] as $provider) {// 直接注冊服務(將直接調用服務的register方法)$this->app->register($provider);}$this->app->addDeferredServices($manifest['deferred']);
}
public function loadManifest()
{if ($this->files->exists($this->manifestPath)) {$manifest = $this->files->getRequire($this->manifestPath);if ($manifest) {return array_merge(['when' => []], $manifest);}}
}
public function shouldRecompile($manifest, $providers)
{return is_null($manifest) || $manifest['providers'] != $providers;
}
protected function compileManifest($providers)
{$manifest = $this->freshManifest($providers);foreach ($providers as $provider) {$instance = $this->createProvider($provider);// 延遲加載的服務if ($instance->isDeferred()) {foreach ($instance->provides() as $service) {$manifest['deferred'][$service] = $provider;}// 注冊延遲的事件$manifest['when'][$provider] = $instance->when();}// 即時加載的服務else {$manifest['eager'][] = $provider;}}return $this->writeManifest($manifest);
}
protected function freshManifest(array $providers)
{return ['providers' => $providers, 'eager' => [], 'deferred' => []];
}
public function createProvider($provider)
{return new $provider($this->app);
}
public function isDeferred()
{return $this->defer;
}
public function writeManifest($manifest)
{if (! is_writable(dirname($this->manifestPath))) {throw new Exception('The bootstrap/cache directory must be present and writable.');}$this->files->put($this->manifestPath, '<?php return '.var_export($manifest, true).';');return array_merge(['when' => []], $manifest);
}
protected function registerLoadEvents($provider, array $events)
{if (count($events) < 1) {return;}$this->app->make('events')->listen($events, function () use ($provider) {$this->app->register($provider);});
}
public function addDeferredServices(array $services)
{$this->deferredServices = array_merge($this->deferredServices, $services);
}

    大致流程

    通過/var/www/laravel/bootstrap/cache/services.php等實例化IlluminateFoundationProviderRepository，并加載$this->config['app.providers']數組。實例化app.providers各服務提供者，根據其defer屬性將服務進行分類(延遲服務|即時服務)，從而得到一個$manifest數組(格式如services.php，延遲處理：deferred=>注冊延遲的服務，以后再進行調用；when=>注冊延遲的事件；即時處理：eager=>直接進行注冊調用等)，并重新寫入到services.php，然后根據此文件進行相應的處理。

  6. 啟動服務提供者的boot方法等操作(IlluminateFoundationBootstrapBootProviders)

    public function bootstrap(Application $app)
{$app->boot();
}
public function boot()
{if ($this->booted) {return;}// 可以通過應用的booting方法來注冊服務啟動前的事件監聽者$this->fireAppCallbacks($this->bootingCallbacks);// 嘗試調用所有的服務提供者的boot方法array_walk($this->serviceProviders, function ($p) {$this->bootProvider($p);});$this->booted = true;// 可以通過應用的booted方法來注冊服務啟動后的事件監聽者，若已經啟用了，則直接出發事件$this->fireAppCallbacks($this->bootedCallbacks);
}
protected function fireAppCallbacks(array $callbacks)
{foreach ($callbacks as $callback) {call_user_func($callback, $this);}
}
protected function bootProvider(ServiceProvider $provider)
{if (method_exists($provider, 'boot')) {return $this->call([$provider, 'boot']);}
}

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