一个非常完美的读写ini格式的PHP配置类分享

基本满足所有配置相关的需求。

    /**
     * 解析.ini格式的配置文件为一个树形结构的对象
     * 配置文件不同section通过冒号继承
     * 默认根据hostname确定使用的section，如果不能确定就优先使用production
     * 检测环境的时候总是优先检测production，其余section按定义顺序检测
     *
     * @author ares@phpdr.net
     *    
     */
    class Config {
     /**
     * 解析后的配置文件
     *
     * @var stdClass
     */
     private $config;
     /**
     * 一个二维数组，键是配置文件的section
     * 值是一个数组或回调函数
     * 如果是数组则计算hostname是否在数组中决定是否使用该section
     * 如果是回调函数通过返回值true或false来确定是否使用该section
     *
     * @var array
     */
     private $map = array ();

     /**
     * section会被解析，:表示继承
     * 配置项中的'.'用来区分层级关系
     * section中的'.'不会被解析，配置中的数组不受影响。
     *
     * @param string $conf     
     * @throws ErrorException
     * @return stdClass
     */
     function __construct($conf, $map) {
     $config = $this->parseIni ( ( object ) parse_ini_string ( $conf, true ) );
     if (array_key_exists ( 'production', $map )) {
      $production = $map ['production'];
      unset ( $map ['production'] );
      $map = array_merge ( array (
       'production' => $production ), $map );
     } else {
      throw new ErrorException ( 'production section not found in config' );
     }
     $section = 'production';
     $hostname = gethostname ();
     foreach ( $map as $k => $v ) {
      if (is_array ( $v )) {
      foreach ( $v as $v1 ) {
       if ($v1 == $hostname) {
       $section = $k;
       break 2;
       }
      }
      } elseif (is_callable ( $v )) {
      if (true == call_user_func ( $v )) {
       $section = $k;
       break;
      }
      } else {
      throw new ErrorException ( 'Wrong map value in ' . __CLASS__ );
      }
     }
     $this->config = $config->$section;
     }

     /**
     * 总是返回配置对象
     *
     * @return mixed
     */
     function __get($key) {
     if (isset ( $this->config->$key )) {
      return $this->config->$key;
     }
     }

     /**
     * 切分
     *
     * @param stdClass $v     
     * @param string $k1     
     * @param mixed $v1     
     */
     private function split($v, $k1, $v1) {
     $keys = explode ( '.', $k1 );
     $last = array_pop ( $keys );
     $node = $v;
     foreach ( $keys as $v2 ) {
      if (! isset ( $node->$v2 )) {
      $node->$v2 = new stdClass ();
      }
      $node = $node->$v2;
     }
     $node->$last = $v1;
     if (count ( $keys ) > 0) {
      unset ( $v->$k1 );
     }
     }

     /**
     * parseIni
     *
     * @param object $conf     
     * @return stdClass
     */
     private function parseIni($conf) {
     $confObj = new stdClass ();
     foreach ( $conf as $k => $v ) {
      // 是section
      if (is_array ( $v )) {
      $confObj->$k = ( object ) $v;
      foreach ( $v as $k1 => $v1 ) {
       call_user_func ( array (
        $this,
        'split' ), $confObj->$k, $k1, $v1 );
      }
      } else {
      call_user_func ( array (
       $this,
       'split' ), $confObj, $k, $v );
      }
     }
     unset ( $conf );
     // 处理继承
     foreach ( $confObj as $k => $v ) {
      if (false !== strpos ( $k, ':' )) {
      if (0 === strpos ( $k, ':' )) {
       throw new ErrorException ( 'config ' . $k . ' is invalid, ':' can't be the first char' );
      } elseif (1 < substr_count ( $k, ':' )) {
       throw new ErrorException ( 'config ' . $k . ' is invalid, ':' can appear only once' );
      } else {
       $keys = explode ( ':', $k );
       if (! isset ( $confObj->$keys [1] )) {
       throw new ErrorException ( 'parent section ' . $keys [1] . ' doesn't exist in config file' );
       } else {
       if (isset ( $confObj->$keys [0] )) {
        throw new ErrorException ( 'config is invalid, ' . $keys [0] . ' and ' . $k . ' conflicts' );
       } else {
        $confObj->$keys [0] = $this->deepCloneR ( $confObj->$keys [1] );
        $this->objectMergeR ( $confObj->$keys [0], $v );
        unset ( $confObj->$k );
       }
       }
      }
      }
     }
     return $confObj;
     }

     /**
     * php默认是浅克隆，函数实现深克隆
     *
     * @param object $obj     
     * @return object $obj
     */
     private function deepCloneR($obj) {
     $objClone = clone $obj;
     foreach ( $objClone as $k => $v ) {
      if (is_object ( $v )) {
      $objClone->$k = $this->deepCloneR ( $v );
      }
     }
     return $objClone;
     }

     /**
     * 递归的合并两个对象
     *
     * @param unknown $obj1     
     * @param unknown $obj2     
     */
     private function objectMergeR($obj1, $obj2) {
     foreach ( $obj2 as $k => $v ) {
      if (is_object ( $v ) && isset ( $obj1->$k ) && is_object ( $obj1->$k )) {
      $this->objectMergeR ( $obj1->$k, $v );
      } else {
      $obj1->$k = $v;
      }
     }
     }
    }

简单使用：

    $_ENV ['config'] = new Config ( file_get_contents ( __DIR__ . '/config.ini' ), array (
     'development' => array (
      'localhost.localdomain',
      'localhost'
     ),
     'production' => array ()
    ) );

配置文件示例：

    [product]
    db.default.dsn="mysql:host=127.0.0.1;dbname=default"
    db.default.username=root
    db.default.password=123456

    admin.username=admin
    admin.password=123456

    php.error_reporting=E_ALL
    php.display_errors=no
    php.log_errors=yes
    php.error_log=APP_PATH'/resource/log/phpError.log'
    php.session.save_path=APP_PATH'/resource/data/session'

    [development:product]
    db.test1.dsn="mysql:host=127.0.0.1;dbname=test1"
    db.test1.username=root
    db.test1.password=123456
    php.display_errors=yes