abstract class MediaReadOnlyStreamWrapper in D7 Media 7.3
Same name and namespace in other branches
- 7.4 includes/MediaReadOnlyStreamWrapper.inc \MediaReadOnlyStreamWrapper
- 7 includes/MediaReadOnlyStreamWrapper.inc \MediaReadOnlyStreamWrapper
- 7.2 includes/MediaReadOnlyStreamWrapper.inc \MediaReadOnlyStreamWrapper
A base class for Resource Stream Wrappers.
This class provides a complete stream wrapper implementation. It passes incoming URL's through an interpolation method then recursively calls the invoking PHP filesystem function.
MediaReadOnlyStreamWrapper implementations need to override at least the interpolateUrl method to rewrite the URL before is it passed back into the calling function.
Hierarchy
- class \MediaReadOnlyStreamWrapper implements DrupalStreamWrapperInterface
Expanded class hierarchy of MediaReadOnlyStreamWrapper
File
- includes/
MediaReadOnlyStreamWrapper.inc, line 19 - Implements a base class for Resource Stream Wrappers.
View source
abstract class MediaReadOnlyStreamWrapper implements DrupalStreamWrapperInterface {
protected $parameters = array();
protected $base_url = NULL;
private $_DEBUG_MODE = NULL;
/**
* Utility function to return paramenters.
*/
public function get_parameters() {
return $this->parameters;
}
// As part of the inode protection mode returned by stat(), identifies the
// file as a regular file, as opposed to a directory, symbolic link, or other
// type of "file".
// @see http://linux.die.net/man/2/stat
const S_IFREG = 0100000;
/**
* Template for stat calls.
*
* All elements must be initialized.
*/
protected $_stat = array(
0 => 0,
// Device number
'dev' => 0,
1 => 0,
// Inode number
'ino' => 0,
// Inode protection mode. file_unmanaged_delete() requires is_file() to
// return TRUE.
2 => self::S_IFREG,
'mode' => self::S_IFREG,
3 => 0,
// Number of links.
'nlink' => 0,
4 => 0,
// Userid of owner.
'uid' => 0,
5 => 0,
// Groupid of owner.
'gid' => 0,
6 => -1,
// Device type, if inode device *
'rdev' => -1,
7 => 0,
// Size in bytes.
'size' => 0,
8 => 0,
// Time of last access (Unix timestamp).
'atime' => 0,
9 => 0,
// Time of last modification (Unix timestamp).
'mtime' => 0,
10 => 0,
// Time of last inode change (Unix timestamp).
'ctime' => 0,
11 => -1,
// Blocksize of filesystem IO.
'blksize' => -1,
12 => -1,
// Number of blocks allocated.
'blocks' => -1,
);
/**
* Handles parameters on the URL string.
*/
public function interpolateUrl() {
if ($parameters = $this
->get_parameters()) {
return $this->base_url . '?' . http_build_query($parameters);
}
}
/**
* Returns a web accessible URL for the resource.
*
* This function should return a URL that can be embedded in a web page
* and accessed from a browser. For example, the external URL of
* "youtube://xIpLd0WQKCY" might be
* "http://www.youtube.com/watch?v=xIpLd0WQKCY".
*
* @return string
* Returns a string containing a web accessible URL for the resource.
*/
public function getExternalUrl() {
return $this
->interpolateUrl();
}
/**
* Base implementation of getMimeType().
*/
public static function getMimeType($uri, $mapping = NULL) {
return 'application/octet-stream';
}
/**
* Base implementation of realpath().
*/
public function realpath() {
return $this
->getExternalUrl();
}
/**
* Stream context resource.
*
* @var Resource
*/
public $context;
/**
* A generic resource handle.
*
* @var Resource
*/
public $handle = NULL;
/**
* Instance URI (stream).
*
* A stream is referenced as "scheme://target".
*
* @var String
*/
protected $uri;
/**
* Base implementation of setUri().
*/
public function setUri($uri) {
$this->uri = $uri;
$this->parameters = $this
->_parse_url($uri);
}
/**
* Base implementation of getUri().
*/
public function getUri() {
return $this->uri;
}
/**
* Report an error.
*
* @param string $message
* The untranslated string to report.
* @param array $options
* An optional array of options to send to t().
* @param bool $display
* If TRUE, then we display the error to the user.
*
* @return bool
* We return FALSE, since we sometimes pass that back from the reporting
* function.
*/
private function _report_error($message, $options = array(), $display = FALSE) {
watchdog('resource', $message, $options, WATCHDOG_ERROR);
if ($display) {
drupal_set_message(t($message, $options), 'error');
}
return FALSE;
}
/**
* Sets the debug mode.
*/
private function _debug($message, $type = 'status') {
if ($this->_DEBUG_MODE) {
drupal_set_message($message, $type);
}
}
/**
* Returns an array of any parameters stored in the URL's path.
*
* @param string $url
* The URL to parse, such as youtube://v/[video-code]/t/[tags+more-tags].
*
* @return array
* An associative array of all the parameters in the path,
* or FALSE if the $url is ill-formed.
*/
protected function _parse_url($url) {
$path = explode('://', $url);
$parts = explode('/', $path[1]);
$params = array();
$count = 0;
$total = count($parts);
if (!$total || $total % 2) {
// If we have no parts, or an odd number of parts, it's malformed.
return FALSE;
}
while ($count < $total) {
// We iterate count for each step of the assignment to keep us honest.
$params[$parts[$count++]] = $parts[$count++];
}
return $params;
}
/**
* Support for fopen(), file_get_contents(), file_put_contents() etc.
*
* @param string $url
* A string containing the path to the file to open.
* @param string $mode
* The file mode ("r", "wb" etc.).
* @param bitmask $options
* A bit mask of STREAM_USE_PATH and STREAM_REPORT_ERRORS.
* @param string &$opened_url
* A string containing the path actually opened.
*
* @return bool
* TRUE if file was opened successfully.
*/
public function stream_open($url, $mode, $options, &$opened_url) {
$this
->_debug(t('Stream open: %url', array(
'%url' => $url,
)));
// We only handle Read-Only mode by default.
if ($mode != 'r' && $mode != 'rb') {
return $this
->_report_error('Attempted to open %url as mode: %mode.', array(
'%url' => $url,
'%mode' => $mode,
), $options & STREAM_REPORT_ERRORS);
}
// We parse a URL as youtube://v/dsyiufo34/t/cats+dogs to store
// the relevant code(s) in our private array of parameters.
$this->parameters = $this
->_parse_url($url);
if ($this->parameters === FALSE) {
return $this
->_report_error('Attempted to parse an ill-formed url: %url.', array(
'%url' => $url,
), $options & STREAM_REPORT_ERRORS);
}
if ((bool) $this->parameters && $options & STREAM_USE_PATH) {
$opened_url = $url;
}
$this
->_debug(t('Stream opened: %parameters', array(
'%parameters' => print_r($this->parameters, TRUE),
)));
return (bool) $this->parameters;
}
/**
* Undocumented PHP stream wrapper method.
*/
function stream_lock($operation) {
return FALSE;
}
/**
* Support for fread(), file_get_contents() etc.
*
* @param int $count
* Maximum number of bytes to be read.
*
* @return bool
* The string that was read, or FALSE in case of an error.
*/
public function stream_read($count) {
return FALSE;
}
/**
* Support for fwrite(), file_put_contents() etc.
*
* Since this is a read only stream wrapper this always returns false.
*
* @param string $data
* The string to be written.
*
* @return bool
* Returns FALSE.
*/
public function stream_write($data) {
return FALSE;
}
/**
* Support for feof().
*
* @return bool
* TRUE if end-of-file has been reached.
*/
public function stream_eof() {
return FALSE;
}
/**
* Support for fseek().
*
* @todo document why this returns false.
*
* @param int $offset
* The byte offset to got to.
* @param string $whence
* SEEK_SET, SEEK_CUR, or SEEK_END.
*
* @return bool
* TRUE on success
*/
public function stream_seek($offset, $whence) {
return FALSE;
}
/**
* Support for fflush().
*
* @todo document why this returns false.
*
* @return bool
* TRUE if data was successfully stored (or there was no data to store).
*/
public function stream_flush() {
return FALSE;
}
/**
* Support for ftell().
*
* @todo document why this returns false.
*
* @return bool
* The current offset in bytes from the beginning of file.
*/
public function stream_tell() {
return FALSE;
}
/**
* Support for fstat().
*
* @return array
* An array with file status, or FALSE in case of an error - see fstat()
* for a description of this array.
*/
public function stream_stat() {
return $this->_stat;
}
/**
* Support for fclose().
*
* @todo document why this returns TRUE.
*
* @return bool
* TRUE if stream was successfully closed.
*/
public function stream_close() {
return TRUE;
}
/**
* Support for stat().
*
* @param string $url
* A string containing the url to get information about.
* @param bitmask $flags
* A bit mask of STREAM_URL_STAT_LINK and STREAM_URL_STAT_QUIET.
*
* @return array
* An array with file status, or FALSE in case of an error - see fstat()
* for a description of this array.
*/
public function url_stat($url, $flags) {
return $this
->stream_stat();
}
/**
* Support for opendir().
*
* @param string $url
* A string containing the url to the directory to open.
* @param int $options
* Whether or not to enforce safe_mode (0x04).
*
* @return bool
* TRUE on success.
*/
public function dir_opendir($url, $options) {
return FALSE;
}
/**
* Support for readdir().
*
* @return bool
* The next filename, or FALSE if there are no more files in the directory.
*/
public function dir_readdir() {
return FALSE;
}
/**
* Support for rewinddir().
*
* @return bool
* TRUE on success.
*/
public function dir_rewinddir() {
return FALSE;
}
/**
* Support for closedir().
*
* @return bool
* TRUE on success.
*/
public function dir_closedir() {
return FALSE;
}
/**
* Undocumented.
*
* @todo document.
*/
public function getDirectoryPath() {
return '';
}
/**
* DrupalStreamWrapperInterface requires that these methods be implemented,
* but none of them apply to a read-only stream wrapper. On failure they
* are expected to return FALSE.
*/
/**
* Implements DrupalStreamWrapperInterface::unlink().
*/
public function unlink($uri) {
// Although the remote file itself can't be deleted, return TRUE so that
// file_delete() can remove the file record from the Drupal database.
return TRUE;
}
/**
* Implements DrupalStreamWrapperInterface::rename().
*/
public function rename($from_uri, $to_uri) {
return FALSE;
}
/**
* Implements DrupalStreamWrapperInterface::mkdir().
*/
public function mkdir($uri, $mode, $options) {
return FALSE;
}
/**
* Implements DrupalStreamWrapperInterface::rmdir().
*/
public function rmdir($uri, $options) {
return FALSE;
}
/**
* Implements DrupalStreamWrapperInterface::chmod().
*/
public function chmod($mode) {
return FALSE;
}
/**
* Implements DrupalStreamWrapperInterface::dirname().
*/
public function dirname($uri = NULL) {
return FALSE;
}
}