Laravel Kernel引导流程分析

代码展示

protected function sendRequestThroughRouter($request)
{# $this->app->instance('request', $request);# Facade::clearResolvedInstance('request');// 主要是这句代码$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($this)：会先创建$bootstrapper对象，在执行对象的引导方法，参数为应用对象

处理流程

加载并设置应用的系统环境变量(IlluminateFoundationBootstrapLoadEnvironmentVariables)

public function bootstrap(Application $app)
{// /var/www/laravel/bootstrap/cache/config.php 存在则直接返回if ($app->configurationIsCached()) {return;}$this->checkForSpecificEnvironmentFile($app);try {// 委托Dotenv来临时设置此次请求的系统环境变量，默认传参依次为'/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参数（类似命令为： cammond --env=example）if (php_sapi_name() == 'cli' && with($input = new ArgvInput)->hasParameterOption('--env')) {// 将系统环境文件(类似：/var/www/laravel/.env.example)设置为$app应用的environmentFile属性，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, $file = '.env')
{// 类似/var/www/laravel/.env$this->filePath = $this->getFilePath($path, $file);// 创建加载器，委托Loader处理$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 $line) {// 如果行不是注释行且含有=号，则进行if (!$this->isComment($line) && $this->looksLikeSetter($line)) {$this->setEnvironmentVariable($line);}}return $lines;
}
// 将文件按行的形式读入到数组并返回
protected function readLinesFromFile($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, $value = null)
{// 检测过滤校验环境变量list($name, $value) = $this->normaliseEnvironmentVariable($name, $value);// 当immutable为真时，不覆盖对应的环境变量if ($this->immutable && $this->getEnvironmentVariable($name) !== null) {return;}// apache运行环境下，尝试临时覆盖系统环境变量if (function_exists('apache_getenv') && function_exists('apache_setenv') && apache_getenv($name)) {apache_setenv($name, $value);}// 尝试临时设置当前请求的系统环境变量if (function_exists('putenv')) {putenv("$name=$value");}// 赋值全局变量$_ENV[$name] = $value;$_SERVER[$name] = $value;
}

将应用配置文件目录(/var/www/laravel/config)下所有php文件返回的数组载入到$config对象(IlluminateFoundationBootstrapLoadConfiguration)

public function bootstrap(Application $app)
{$items = [];// /var/www/laravel/bootstrap/cache/config.php文件[配置文件的缓存合集，加快加载速度]存在则载入，并标记已加载if (file_exists($cached = $app->getCachedConfigPath())) {$items = require $cached;$loadedFromCache = true;}// 构建config对象，并注入到服务容器$app->instance('config', $config = new Repository($items));if (! isset($loadedFromCache)) {// 将系统的配置文件载入到$config对象$this->loadConfigurationFiles($app, $config);}// 设置$this['env']为系统环境变量app.env,没有则默认为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 => $path) {// 此操作将在$repository对象里面构造一个多维数组属性$this->items，值为相应的系统配置文件返回的数组，后续可以直接通过get获取$repository->set($key, require $path);}
}
/** $files数组形式如下['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 = [];// 系统配置文件的路径(/var/www/laravel/config)$configPath = realpath($app->configPath());// 文件相关的操作委托给Finder类(很强大)来处理，Finder实现了IteratorAggregate的getIterator方法foreach (Finder::create()->files()->name('*.php')->in($configPath) as $file) {// 迭代/var/www/laravel/config下面嵌套的层层子目录构造成.形式的目录$directory = $this->getNestedDirectory($file, $configPath);$files[$directory.basename($file->getRealPath(), '.php')] = $file->getRealPath();}return $files;
}$repository->set($key, require $path)
// 构造将.形式转变为相应层级的数组$this->items。比如：$key='xx.yy.file',$value='/var/www/laravel/config/xx/yy/file.php'，将会构建为:$this->items['xx']['yy']['file'] = $value返回的数组。
public function set($key, $value = null)
{$keys = is_array($key) ? $key : [$key => $value];foreach ($keys as $key => $value) {Arr::set($this->items, $key, $value);}
}

根据默认的系统配置文件目录，以上操作的结果如下：
$config对象（new Repository）里面的$this->items数组属性，后期可以通过$config->get()来获取

$this->items['app'] = /var/www/laravel/config/app.php返回的数组;
$this->items['auth'] = /var/www/laravel/config/auth.php返回的数组;
$this->items['broadcasting'] = /var/www/laravel/config/broadcasting.php返回的数组;
$this->items['cache'] = /var/www/laravel/config/cache.php返回的数组;
$this->items['database'] = /var/www/laravel/config/database.php返回的数组;
$this->items['filesystems'] = /var/www/laravel/config/filesystems.php返回的数组;
$this->items['mail'] = /var/www/laravel/config/mail.php返回的数组;
$this->items['queue'] = /var/www/laravel/config/queue.php返回的数组;
$this->items['services'] = /var/www/laravel/config/services.php返回的数组;
$this->items['session'] = /var/www/laravel/config/session.php返回的数组;
$this->items['view'] = /var/www/laravel/config/view.php返回的数组;假如有这样的文件（/var/www/laravel/config/xx/yy/zz/file.php），返回['a'=>'hello,world!']数组
将得到：$this->items['xx']['yy']['zz']['file'] = ['a'=>'hello,world!'];
获取方式： $config->get('xx.yy.zz.file.a', $default)，直接返回'hello,world!';

设置应用的错误异常等处理事件(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);}
}
// 核心代码，获取的\App\Exceptions\Handle对象
protected function getExceptionHandler()
{// make时将会直接调用$this->bindings['Illuminate\Contracts\Debug\ExceptionHandler']['concrete'](此代码位于/var/www/laravel/bootstrap/app.php，应用对象化后，直接注入到服务容器的几个单例)，返回\App\Exceptions\Handle对象，并将此对象注入到服务容器[参考]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));}
}

根据配置项设置应用的 Facades(IlluminateFoundationBootstrapRegisterFacades)

public function bootstrap(Application $app)
{Facade::clearResolvedInstances();Facade::setFacadeApplication($app);// 将配置文件/var/www/laravel/config/app.php返回数组的键为aliases的值赋给\Illuminate\Foundation\AliasLoader的aliases属性，并进行注册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();$this->registered = true;}
}
protected function prependToLoaderStack()
{// 将$this->load注册到自动加载器的最前面，失败时抛异常spl_autoload_register([$this, 'load'], true, true);
}
public function load($alias)
{// $facadeNamespace = 'Facades\\'，估计是框架内部使用的，以后再看吧if (static::$facadeNamespace && strpos($alias, static::$facadeNamespace) === 0) {$this->loadFacade($alias);return true;}if (isset($this->aliases[$alias])) {return class_alias($this->aliases[$alias], $alias);}
}

Facade的本质

实际上是通过$app->make('config')->get('app.aliases', [])取出config/app.php文件里面的aliases数组并实例化AliasLoader，再将AliasLoader->load方法放到spl自动加载器最前面，最后通过class_alias($this->aliases[$alias], $alias)。当调用Cache::Method时，会触发Facdes的__callStatic魔术方法，此方法会调用相应对象里面的方法。

注入配置项的服务提供者(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 $this->bootstrapPath().'/cache/services.php';
}// 先取services缓存文件，再对\Illuminate\Foundation\ProviderRepository进行实例化，随后加载系统配置文件(./config/app.php)里面的providers数组
(new ProviderRepository($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 $provider) {// 直接注册服务(将直接调用服务的register方法)$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);// 延迟加载的服务if ($instance->isDeferred()) {foreach ($instance->provides() as $service) {$manifest['deferred'][$service] = $provider;}// 注册延迟的事件$manifest['when'][$provider] = $instance->when();}// 即时加载的服务else {$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

通过/var/www/laravel/bootstrap/cache/services.php等实例化IlluminateFoundationProviderRepository，并加载$this->config['app.providers']数组。实例化app.providers各服务提供者，根据其defer属性将服务进行分类(延迟服务|即时服务)，从而得到一个$manifest数组(格式如services.php，延迟处理：deferred=>注册延迟的服务，以后再进行调用；when=>注册延迟的事件；即时处理：eager=>直接进行注册调用等)，并重新写入到services.php，然后根据此文件进行相应的处理。

启动服务提供者的boot方法等操作(IlluminateFoundationBootstrapBootProviders)

public function bootstrap(Application $app)
{$app->boot();
}
public function boot()
{if ($this->booted) {return;}// 可以通过应用的booting方法来注册服务启动前的事件监听者$this->fireAppCallbacks($this->bootingCallbacks);// 尝试调用所有的服务提供者的boot方法array_walk($this->serviceProviders, function ($p) {$this->bootProvider($p);});$this->booted = true;// 可以通过应用的booted方法来注册服务启动后的事件监听者，若已经启用了，则直接出发事件$this->fireAppCallbacks($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']);}
}