CI框架源码阅读笔记4 引导文件CodeIgniter.php

<?php  if ( ! defined(‘BASEPATH‘)) exit(‘No direct script access allowed‘);

/**
 * CodeIgniter Version
 */
    define(‘CI_VERSION‘, ‘2.1.4‘);

/**
 * CodeIgniter Branch (Core = TRUE, Reactor = FALSE)
 */
    define(‘CI_CORE‘, FALSE);

    require(BASEPATH.‘core/Common.php‘);

    /* 如有有相应的环境的配置文件，优先加载配置下的常量定义文件，否则加载config目录下的常量定义文件 */
    if (defined(‘ENVIRONMENT‘) AND file_exists(APPPATH.‘config/‘.ENVIRONMENT.‘/constants.php‘))
    {
        require(APPPATH.‘config/‘.ENVIRONMENT.‘/constants.php‘);
    }
    else
    {
        require(APPPATH.‘config/constants.php‘);
    }

    set_error_handler(‘_exception_handler‘);

    if ( ! is_php(‘5.3‘))
    {
        @set_magic_quotes_runtime(0); // Kill magic quotes
    }

/*
 *  Set the subclass_prefix
 */
    if (isset($assign_to_config[‘subclass_prefix‘]) AND $assign_to_config[‘subclass_prefix‘] != ‘‘)
    {
        get_config(array(‘subclass_prefix‘ => $assign_to_config[‘subclass_prefix‘]));
    }

/*
 *  Set a liberal script execution time limit
 */
    //if(function_exists("set_time_limit") && @!ini_get("safe_mode"))
    if (function_exists("set_time_limit") == TRUE AND @ini_get("safe_mode") == 0)
    {
        @set_time_limit(300);
    }

    $BM =& load_class(‘Benchmark‘, ‘core‘);
    $BM->mark(‘total_execution_time_start‘);
    $BM->mark(‘loading_time:_base_classes_start‘);

/*
 *  Instantiate the hooks class
 */
    $EXT =& load_class(‘Hooks‘, ‘core‘);

/*
 *  Is there a "pre_system" hook?
 */
    $EXT->_call_hook(‘pre_system‘);

/*
 *  Instantiate the config class
 */
    $CFG =& load_class(‘Config‘, ‘core‘);

    // Do we have any manually set config items in the index.php file?
    if (isset($assign_to_config))
    {
        $CFG->_assign_to_config($assign_to_config);
    }

/*
 *  Instantiate the UTF-8 class
 */
    $UNI =& load_class(‘Utf8‘, ‘core‘);

/*
 * ------------------------------------------------------
 *  Instantiate the URI class
 * ------------------------------------------------------
 */
    $URI =& load_class(‘URI‘, ‘core‘);

/*
 *  Instantiate the routing class and set the routing
 */
    $RTR =& load_class(‘Router‘, ‘core‘);
    $RTR->_set_routing();

    // Set any routing overrides that may exist in the main index file
    if (isset($routing))
    {
        $RTR->_set_overrides($routing);
    }

/*
 *  Instantiate the output class
 */
    $OUT =& load_class(‘Output‘, ‘core‘);

/*
 *    Is there a valid cache file?  If so, we‘re done...
 */
    if ($EXT->_call_hook(‘cache_override‘) === FALSE)
    {
        if ($OUT->_display_cache($CFG, $URI) == TRUE)
        {
            exit;
        }
    }

/*
 * Load the security class for xss and csrf support
 */
    $SEC =& load_class(‘Security‘, ‘core‘);

/*
 *  Load the Input class and sanitize globals
 */
    $IN    =& load_class(‘Input‘, ‘core‘);

/*
 *  Load the Language class
 */
    $LANG =& load_class(‘Lang‘, ‘core‘);

/*
 *  Load the app controller and local controller
 */
    // Load the base controller class
    require BASEPATH.‘core/Controller.php‘;

    function &get_instance()
    {
        return CI_Controller::get_instance();
    }

    if (file_exists(APPPATH.‘core/‘.$CFG->config[‘subclass_prefix‘].‘Controller.php‘))
    {
        require APPPATH.‘core/‘.$CFG->config[‘subclass_prefix‘].‘Controller.php‘;
    }

    if ( ! file_exists(APPPATH.‘controllers/‘.$RTR->fetch_directory().$RTR->fetch_class().‘.php‘))
    {
        show_error(‘Unable to load your default controller. Please make sure the controller specified in your Routes.php file is valid.‘);
    }

    include(APPPATH.‘controllers/‘.$RTR->fetch_directory().$RTR->fetch_class().‘.php‘);

    $BM->mark(‘loading_time:_base_classes_end‘);

/*
 *  Security check
 */
    $class  = $RTR->fetch_class();
    $method = $RTR->fetch_method();

    if ( ! class_exists($class)
        OR strncmp($method, ‘_‘, 1) == 0
        OR in_array(strtolower($method), array_map(‘strtolower‘, get_class_methods(‘CI_Controller‘)))
        )
    {
        if ( ! empty($RTR->routes[‘404_override‘]))
        {
            $x = explode(‘/‘, $RTR->routes[‘404_override‘]);
            $class = $x[0];
            $method = (isset($x[1]) ? $x[1] : ‘index‘);
            if ( ! class_exists($class))
            {
                if ( ! file_exists(APPPATH.‘controllers/‘.$class.‘.php‘))
                {
                    show_404("{$class}/{$method}");
                }

                include_once(APPPATH.‘controllers/‘.$class.‘.php‘);
            }
        }
        else
        {
            show_404("{$class}/{$method}");
        }
    }

/*
 *  Is there a "pre_controller" hook?
 */
    $EXT->_call_hook(‘pre_controller‘);

/*
 *  Instantiate the requested controller
 */
    // Mark a start point so we can benchmark the controller
    $BM->mark(‘controller_execution_time_( ‘.$class.‘ / ‘.$method.‘ )_start‘);

    $CI = new $class();

/*
 *  Is there a "post_controller_constructor" hook?
 */
    $EXT->_call_hook(‘post_controller_constructor‘);

/*
 *  Call the requested method
 */
    // Is there a "remap" function? If so, we call it instead
    if (method_exists($CI, ‘_remap‘))
    {
        $CI->_remap($method, array_slice($URI->rsegments, 2));
    }
    else
    {
        if ( ! in_array(strtolower($method), array_map(‘strtolower‘, get_class_methods($CI))))
        {
            if ( ! empty($RTR->routes[‘404_override‘]))
            {
                $x = explode(‘/‘, $RTR->routes[‘404_override‘]);
                $class = $x[0];
                $method = (isset($x[1]) ? $x[1] : ‘index‘);
                if ( ! class_exists($class))
                {
                    if ( ! file_exists(APPPATH.‘controllers/‘.$class.‘.php‘))
                    {
                        show_404("{$class}/{$method}");
                    }

                    include_once(APPPATH.‘controllers/‘.$class.‘.php‘);
                    unset($CI);
                    $CI = new $class();
                }
            }
            else
            {
                show_404("{$class}/{$method}");
            }
        }

        call_user_func_array(array(&$CI, $method), array_slice($URI->rsegments, 2));
    }

    // Mark a benchmark end point
    $BM->mark(‘controller_execution_time_( ‘.$class.‘ / ‘.$method.‘ )_end‘);

/*
 *  Is there a "post_controller" hook?
 */
    $EXT->_call_hook(‘post_controller‘);

/*
 *  Send the final rendered output to the browser
 */
    if ($EXT->_call_hook(‘display_override‘) === FALSE)
    {
        $OUT->_display();
    }

/*
 *  Is there a "post_system" hook?
 */
    $EXT->_call_hook(‘post_system‘);

/*
 *  Close the DB connection if one exists
 */
    if (class_exists(‘CI_DB‘) AND isset($CI->db))
    {
        $CI->db->close();
    }

/* End of file CodeIgniter.php */