9. php流、公共文件、私有文件

在开始这个主题前我们做一个实验,在你的drupal8模块控制器中加一行代码:

file_put_contents("public://yunke.txt","Streams test");

然后访问这个控制器,看看发生了什么?没错页面上不会有什么改变,但也没有报告什么错误,那这行代码到底干了什么?

作为开发者你应该很熟悉 file_put_contents() 这个函数,代码意思是将"Streams test"这个字符串写入一个文件中,

可是文件名却是:"public://yunke.txt" ,它是什么意思?文件保存了吗?保存到哪里去了?

这就是本主题要讲的内容!

不知道 " public://yunke.txt ",很正常,但你可能知道php://input,没错,就是那个php读取原始post输入的东西

微信公众账号管理系统中就是用这个来读取收到的原始XML数据,其实public://yunke.txt和php://input差不多,它们源自同一个概念

就是php流及流包装器,由于在一般的开发中很少用到它,所以很多开发者并不熟悉,但它功能强大,是php这门语言的一个重点内容

Java中也有类似概念,如果你对C语言熟悉,那么会倍感熟悉,它或多或少基于ANSI C 标准IO函数簇。

由于php流这个知识点属于php学习的范畴,并不限于drupal源码分析,所以我单独写了篇博客来介绍它:

请看:http://blog.csdn.net/u011474028/article/details/52814049

那是本文的一部分,如果你对流不熟悉请务必暂停去阅读学习后再继续,否则你很难理解后面的内容,在文末附加一个流包装器的例子。

这里开始假定你已经学习完了流相关的知识,来看一看它在drupal8中的运用:

还是从 file_put_contents("public://yunke.txt","Streams test"); 说起

它是在公共文件目录里面建立一个叫做yunke.txt的文件,里面保存了字符串"Streams test",那么这个公共文件目录在哪里?

它可以在站点配置文件中指定,如果你没有指定,那么默认是 \sites\default\files ,如果你按上面的方法做了,看一看是不是有这个文件?

drupal使用流这个概念来储存公有及私有文件并提供操作上的方便,私有文件可以保存到一个web访客无法通过url访问到的地方,这样就比较安全了

如何在settings.php文件中配置公有及私有文件的主目录:

$settings['file_public_path'] = "./yunke"; //所有公共文件都将保存到站点根目录的yunke文件夹下,若无默认是 \sites\default\files
$settings['file_private_path'] = “/home/yunke”;  //设置后需要做权限设定,以防止web访客通过url访问到文件,配置中若有此项就会在容器中注册私有流包装器

关于流方面的源码储存在:\core\lib\Drupal\Core\StreamWrapper 里面

定义了一个php级别的流包装器接口:PhpStreamWrapperInterface

drupal用的包装器接口(继承自上面的接口):StreamWrapperInterface

LocalStream:抽象的本地流包装器

额外定义了公共流包装器、私有流包装器、临时流包装器、只读流

这些包装器用一个包装器管理器来管理:

StreamWrapperManager:实现了StreamWrapperManagerInterface接口,主要作用是注册流包装器

调用流包装器管理器的代码位于drupal核心:Drupal\Core\DrupalKernel preHandle 方法中,有以下代码:

// Register stream wrappers.
    $this->Container->get('stream_wrapper_manager')->register();

而 preHandle 方法的调用是在多层 HttpKernel 核心处理中的预处理层:
http_middleware.kernel_pre_handle(Drupal\Core\StackMiddleware\KernelPreHandle)
请看前面的《云客Drupal8源码分析之HttpKernel堆栈》一文

 

以上就是本主题的全部了,辅助内容区中提供了一个流包装器案例,是我从drupal8中抽取出来,做了修改,可以独立使用的一个类,可以研究下它的实现:

class yunkeWrapper  
{  
    public $context;  
    public $handle = null;  
    public $uri = null;  
    protected static $dir = "";  
    //public $dir = "dir";//可以是相对路径或绝对路径,空表示当前路径  
  
    public function dir_closedir()  
    {  
        closedir($this->handle);  
        // We do not really have a way to signal a failure as closedir() does not  
        // have a return value.  
        return true;  
    }  
  
    /** 
     * @return bool 
     */  
    public function dir_opendir($uri, $options)  
    {  
        $this->uri = $uri;  
        $this->handle = opendir($this->getLocalPath());  
        return (bool)$this->handle;  
    }  
  
    /** 
     * @return string 
     */  
    public function dir_readdir()  
    {  
        return readdir($this->handle);  
    }  
  
    /** 
     * @return bool 
     */  
    public function dir_rewinddir()  
    {  
        rewinddir($this->handle);  
        // We do not really have a way to signal a failure as rewinddir() does not  
        // have a return value and there is no way to read a directory handler  
        // without advancing to the next file.  
        return true;  
    }  
  
    /** 
     * @return bool 
     */  
    public function mkdir($uri, $mode, $options)  
    {  
        $this->uri = $uri;  
        $recursive = (bool)($options & STREAM_MKDIR_RECURSIVE);  
        if ($recursive) {  
            // $this->getLocalPath() fails if $uri has multiple levels of directories  
            // that do not yet exist.  
            $localpath = $this->getDirectoryPath() . '/' . $this->getTarget($uri);  
        } else {  
            $localpath = $this->getLocalPath($uri);  
        }  
        if ($options & STREAM_REPORT_ERRORS) {  
            return mkdir($localpath, $mode, $recursive);  
        } else {  
            return @mkdir($localpath, $mode, $recursive);  
        }  
    }  
  
    /** 
     * @return bool 
     */  
    public function rename($from_uri, $to_uri)  
    {  
        return rename($this->getLocalPath($from_uri), $this->getLocalPath($to_uri));  
    }  
  
    /** 
     * @return bool 
     */  
    public function rmdir($uri, $options)  
    {  
        $this->uri = $uri;  
        if ($options & STREAM_REPORT_ERRORS) {  
            return rmdir($this->getLocalPath());  
        } else {  
            return @rmdir($this->getLocalPath());  
        }  
    }  
  
    /** 
     * Retrieve the underlying stream resource. 
     * 
     * This method is called in response to stream_select(). 
     * 
     * @param int $cast_as 
     *   Can be STREAM_CAST_FOR_SELECT when stream_select() is calling 
     *   stream_cast() or STREAM_CAST_AS_STREAM when stream_cast() is called for 
     *   other uses. 
     * 
     * @return resource|false 
     *   The underlying stream resource or FALSE if stream_select() is not 
     *   supported. 
     * 
     * @see stream_select() 
     * @see http://php.net/manual/streamwrapper.stream-cast.php 
     */  
    public function stream_cast($cast_as)  
    {  
        return $this->handle ? $this->handle : false;  
    }  
  
    /** 
     * Closes stream. 
     */  
    public function stream_close()  
    {  
        return fclose($this->handle);  
    }  
  
    /** 
     * @return bool 
     */  
    public function stream_eof()  
    {  
        return feof($this->handle);  
    }  
  
    /** 
     * @return bool 
     */  
    public function stream_flush()  
    {  
        return fflush($this->handle);  
    }  
  
    /** 
     * @return bool 
     */  
    public function stream_lock($operation)  
    {  
        if (in_array($operation, array(  
            LOCK_SH,  
            LOCK_EX,  
            LOCK_UN,  
            LOCK_NB))) {  
            return flock($this->handle, $operation);  
        }  
  
        return true;  
    }  
  
    /** 
     * Sets metadata on the stream. 
     * 
     * @param string $path 
     *   A string containing the URI to the file to set metadata on. 
     * @param int $option 
     *   One of: 
     *   - STREAM_META_TOUCH: The method was called in response to touch(). 
     *   - STREAM_META_OWNER_NAME: The method was called in response to chown() 
     *     with string parameter. 
     *   - STREAM_META_OWNER: The method was called in response to chown(). 
     *   - STREAM_META_GROUP_NAME: The method was called in response to chgrp(). 
     *   - STREAM_META_GROUP: The method was called in response to chgrp(). 
     *   - STREAM_META_ACCESS: The method was called in response to chmod(). 
     * @param mixed $value 
     *   If option is: 
     *   - STREAM_META_TOUCH: Array consisting of two arguments of the touch() 
     *     function. 
     *   - STREAM_META_OWNER_NAME or STREAM_META_GROUP_NAME: The name of the owner 
     *     user/group as string. 
     *   - STREAM_META_OWNER or STREAM_META_GROUP: The value of the owner 
     *     user/group as integer. 
     *   - STREAM_META_ACCESS: The argument of the chmod() as integer. 
     * 
     * @return bool 
     *   Returns TRUE on success or FALSE on failure. If $option is not 
     *   implemented, FALSE should be returned. 
     * 
     * @see http://php.net/manual/streamwrapper.stream-metadata.php 
     */  
    public function stream_metadata($uri, $option, $value)  
    {  
        $target = $this->getLocalPath($uri);  
        $return = false;  
        switch ($option) {  
            case STREAM_META_TOUCH:  
                if (!empty($value)) {  
                    $return = touch($target, $value[0], $value[1]);  
                } else {  
                    $return = touch($target);  
                }  
                break;  
  
            case STREAM_META_OWNER_NAME:  
            case STREAM_META_OWNER:  
                $return = chown($target, $value);  
                break;  
  
            case STREAM_META_GROUP_NAME:  
            case STREAM_META_GROUP:  
                $return = chgrp($target, $value);  
                break;  
  
            case STREAM_META_ACCESS:  
                $return = chmod($target, $value);  
                break;  
        }  
        if ($return) {  
            // For convenience clear the file status cache of the underlying file,  
            // since metadata operations are often followed by file status checks.  
            clearstatcache(true, $target);  
        }  
        return $return;  
    }  
  
    /** 
     * @return bool 
     */  
    public function stream_open($uri, $mode, $options, &$opened_path)  
    {  
        $this->uri = $uri;  
        $path = $this->getLocalPath();  
        $this->handle = ($options & STREAM_REPORT_ERRORS) ? fopen($path, $mode) : @  
            fopen($path, $mode);  
  
        if ((bool)$this->handle && $options & STREAM_USE_PATH) {  
            $opened_path = $path;  
        }  
  
        return (bool)$this->handle;  
    }  
  
    /** 
     * @return string 
     */  
    public function stream_read($count)  
    {  
        return fread($this->handle, $count);  
    }  
  
    /** 
     * Seeks to specific location in a stream. 
     * 
     * This method is called in response to fseek(). 
     * 
     * The read/write position of the stream should be updated according to the 
     * offset and whence. 
     * 
     * @param int $offset 
     *   The byte offset to seek to. 
     * @param int $whence 
     *   Possible values: 
     *   - SEEK_SET: Set position equal to offset bytes. 
     *   - SEEK_CUR: Set position to current location plus offset. 
     *   - SEEK_END: Set position to end-of-file plus offset. 
     *   Defaults to SEEK_SET. 
     * 
     * @return bool 
     *   TRUE if the position was updated, FALSE otherwise. 
     * 
     * @see http://php.net/manual/streamwrapper.stream-seek.php 
     */  
    public function stream_seek($offset, $whence = SEEK_SET)  
    {  
        // fseek returns 0 on success and -1 on a failure.  
        // stream_seek   1 on success and  0 on a failure.  
        return !fseek($this->handle, $offset, $whence);  
    }  
  
    /** 
     * Change stream options. 
     * 
     * This method is called to set options on the stream. 
     * 
     * @param int $option 
     *   One of: 
     *   - STREAM_OPTION_BLOCKING: The method was called in response to 
     *     stream_set_blocking(). 
     *   - STREAM_OPTION_READ_TIMEOUT: The method was called in response to 
     *     stream_set_timeout(). 
     *   - STREAM_OPTION_WRITE_BUFFER: The method was called in response to 
     *     stream_set_write_buffer(). 
     * @param int $arg1 
     *   If option is: 
     *   - STREAM_OPTION_BLOCKING: The requested blocking mode: 
     *     - 1 means blocking. 
     *     - 0 means not blocking. 
     *   - STREAM_OPTION_READ_TIMEOUT: The timeout in seconds. 
     *   - STREAM_OPTION_WRITE_BUFFER: The buffer mode, STREAM_BUFFER_NONE or 
     *     STREAM_BUFFER_FULL. 
     * @param int $arg2 
     *   If option is: 
     *   - STREAM_OPTION_BLOCKING: This option is not set. 
     *   - STREAM_OPTION_READ_TIMEOUT: The timeout in microseconds. 
     *   - STREAM_OPTION_WRITE_BUFFER: The requested buffer size. 
     * 
     * @return bool 
     *   TRUE on success, FALSE otherwise. If $option is not implemented, FALSE 
     *   should be returned. 
     */  
    public function stream_set_option($option, $arg1, $arg2)  
    {  
        trigger_error('stream_set_option() not supported for local file based stream wrappers',  
            E_USER_WARNING);  
        return false;  
    }  
  
    /** 
     * @return array 
     */  
    public function stream_stat()  
    {  
        return fstat($this->handle);  
    }  
  
    /** 
     * @return int 
     */  
    public function stream_tell()  
    {  
        return ftell($this->handle);  
    }  
    /** 
     * Truncate stream. 
     * 
     * Will respond to truncation; e.g., through ftruncate(). 
     * 
     * @param int $new_size 
     *   The new size. 
     * 
     * @return bool 
     *   TRUE on success, FALSE otherwise. 
     */  
    public function stream_truncate($new_size)  
    {  
        return ftruncate($this->handle, $new_size);  
    }  
  
    /** 
     * @return int 
     */  
    public function stream_write($data)  
    {  
        return fwrite($this->handle, $data);  
    }  
  
    /** 
     * @return bool 
     */  
    public function unlink($uri)  
    {  
        $this->uri = $uri;  
        return unlink($this->getLocalPath());  
    }  
  
    /** 
     * @return array 
     */  
    public function url_stat($uri, $flags)  
    {  
        $this->uri = $uri;  
        $path = $this->getLocalPath();  
        // Suppress warnings if requested or if the file or directory does not  
        // exist. This is consistent with PHP's plain filesystem stream wrapper.  
        if ($flags & STREAM_URL_STAT_QUIET || !file_exists($path)) {  
            return @stat($path);  
        } else {  
            return stat($path);  
        }  
    }  
  
  
    /****************************************************以上为php流类原型定义的方法,以下为自定义方法*****************************************/  
    /** 
     * 设置流包装器需要操作的主目录 
     */  
    public static function setDirectoryPath($dir = '')  
    {  
        if (empty($dir)) {  
            self::$dir = "./";  
        }  
        if (!is_string($dir)) {  
            trigger_error('DirectoryPath must be string', E_USER_WARNING);  
        }  
        self::$dir = $dir;  
    }  
    /** 
     * 得到流包装器需要操作的主目录 
     */  
    public function getDirectoryPath()  
    {  
        self::$dir = empty(trim(self::$dir)) ? "./" : (self::$dir);  
        /* 
        if (!is_dir(self::$dir)) { 
        mkdir(self::$dir, 0777, true); 
        } 
        //为了方便在实用程序中可以这样做,为标准起见不这样,建立目录不应该是工具库的责任 
        */  
        return self::$dir;  
    }  
    /** 
     * 得到本地文件路径 
     */  
    protected function getLocalPath($uri = null)  
    {  
        if (!isset($uri)) {  
            $uri = $this->uri;  
        }  
        $path = $this->getDirectoryPath() . '/' . $this->getTarget($uri);  
  
        // In PHPUnit tests, the base path for local streams may be a virtual  
        // filesystem stream wrapper URI, in which case this local stream acts like  
        // a proxy. realpath() is not supported by vfsStream, because a virtual  
        // file system does not have a real filepath.  
        if (strpos($path, 'vfs://') === 0) {  
            return $path;  
        }  
        $realpath = realpath($path);  
        if (!$realpath) {  
            // This file does not yet exist.  
            $realpath = realpath(dirname($path)) . '/' . basename($path);  
        }  
        $directory = realpath($this->getDirectoryPath());  
        if (!$realpath || !$directory || strpos($realpath, $directory) !== 0) {  
            return false;  
        }  
  
        return $realpath;  
    }  
  
    /** 
     * 得到目标 
     */  
    protected function getTarget($uri = null)  
    {  
        if (!isset($uri)) {  
            $uri = $this->uri;  
        }  
  
        list(, $target) = explode('://', $uri, 2);  
  
        // Remove erroneous leading or trailing, forward-slashes and backsl ashes.  
        return trim($target, '\/');  
    }  
  
}  
  
stream_wrapper_register("yunke", "yunkeWrapper"); //注册yunke流包装器  
if (!is_dir("yunke://a/b")) {  
    mkdir("yunke://a/b", 0777, true); //创建目录是开发者用户的责任  
}  
if (file_put_contents("yunke://a/b/wrapperTest.txt", "it is a test by:yunke time20161014") !== false) {  
    echo "ok";  
} else {  
    echo "err";  
}  
  
$dir = "yunkenew/subdir"; //再次设定yunke流主目录  
yunkeWrapper::setDirectoryPath($dir);  
if (!is_dir($dir)) {  
    mkdir($dir, 0777, true); //创建yunke流的主目录是开发者用户的责任  
}  
if (file_put_contents("yunke://wrapperTest.txt", "it is a test by:yunke time20161015") !== false) {  
    echo "ok";  
} else {  
    echo "err";  
}  

 

本书共97小节:

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