File Source for ChainedBlockStream.php

<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* Stream wrapper for reading data stored in an OLE file.
*
* PHP versions 4 and 5
*
* LICENSE: This source file is subject to version 3.0 of the PHP license
* that is available through the world-wide-web at the following URI:
* http://www.php.net/license/3_0.txt. If you did not receive a copy of
* the PHP License and are unable to obtain it through the web, please
* send a note to license@php.net so we can mail you a copy immediately.
*
* @category Structures
* @package OLE
* @author Christian Schmidt <schmidt@php.net>
* @license http://www.php.net/license/3_0.txt PHP License 3.0
* @version CVS: $Id: ChainedBlockStream.php,v 1.1 2007/02/13 21:00:42 schmidt Exp $
* @link http://pear.php.net/package/OLE
* @since File available since Release 0.6.0
*/
require_once 'PEAR.php';
require_once 'OLE.php';
/**
* Stream wrapper for reading data stored in an OLE file. Implements methods
* for PHP's stream_wrapper_register(). For creating streams using this
* wrapper, use OLE_PPS_File::getStream().
*
* @category Structures
* @package OLE
* @author Christian Schmidt <schmidt@php.net>
* @license http://www.php.net/license/3_0.txt PHP License 3.0
* @version Release: @package_version@
* @link http://pear.php.net/package/OLE
* @since Class available since Release 0.6.0
*/
class OLE_ChainedBlockStream extends PEAR
{
/**
* The OLE container of the file that is being read.
* @var OLE
*/
var $ole;
/**
* Parameters specified by fopen().
* @var array
*/
var $params;
/**
* The binary data of the file.
* @var string
*/
var $data;
/**
* The file pointer.
* @var int byte offset
*/
var $pos;
/**
* Implements support for fopen().
* For creating streams using this wrapper, use OLE_PPS_File::getStream().
* @param string resource name including scheme, e.g.
* ole-chainedblockstream://oleInstanceId=1
* @param string only "r" is supported
* @param int mask of STREAM_REPORT_ERRORS and STREAM_USE_PATH
* @param string absolute path of the opened stream (out parameter)
* @return bool true on success
*/
function stream_open($path, $mode, $options, &$openedPath)
{
if ($mode != 'r') {
if ($options & STREAM_REPORT_ERRORS) {
trigger_error('Only reading is supported', E_USER_WARNING);
}
return false;
}
// 25 is length of "ole-chainedblockstream://"
parse_str(substr($path, 25), $this->params);
if (!isset($this->params['oleInstanceId'],
$this->params['blockId'],
$GLOBALS['_OLE_INSTANCES'][$this->params['oleInstanceId']])) {
if ($options & STREAM_REPORT_ERRORS) {
trigger_error('OLE stream not found', E_USER_WARNING);
}
return false;
}
$this->ole = $GLOBALS['_OLE_INSTANCES'][$this->params['oleInstanceId']];
$blockId = $this->params['blockId'];
$this->data = '';
if (isset($this->params['size']) &&
$this->params['size'] < $this->ole->bigBlockThreshold &&
$blockId != $this->ole->root->_StartBlock) {
// Block id refers to small blocks
$rootPos = $this->ole->_getBlockOffset($this->ole->root->_StartBlock);
while ($blockId != -2) {
$pos = $rootPos + $blockId * $this->ole->bigBlockSize;
$blockId = $this->ole->sbat[$blockId];
fseek($this->ole->_file_handle, $pos);
$this->data .= fread($this->ole->_file_handle, $this->ole->bigBlockSize);
}
} else {
// Block id refers to big blocks
while ($blockId != -2) {
$pos = $this->ole->_getBlockOffset($blockId);
fseek($this->ole->_file_handle, $pos);
$this->data .= fread($this->ole->_file_handle, $this->ole->bigBlockSize);
$blockId = $this->ole->bbat[$blockId];
}
}
if (isset($this->params['size'])) {
$this->data = substr($this->data, 0, $this->params['size']);
}
if ($options & STREAM_USE_PATH) {
$openedPath = $path;
}
return true;
}
/**
* Implements support for fclose().
* @return string
*/
function stream_close()
{
$this->ole = null;
unset($GLOBALS['_OLE_INSTANCES']);
}
/**
* Implements support for fread(), fgets() etc.
* @param int maximum number of bytes to read
* @return string
*/
function stream_read($count)
{
if ($this->stream_eof()) {
return false;
}
$s = substr($this->data, $this->pos, $count);
$this->pos += $count;
return $s;
}
/**
* Implements support for feof().
* @return bool TRUE if the file pointer is at EOF; otherwise FALSE
*/
function stream_eof()
{
$eof = $this->pos >= strlen($this->data);
// Workaround for bug in PHP 5.0.x: http://bugs.php.net/27508
if (version_compare(PHP_VERSION, '5.0', '>=') &&
version_compare(PHP_VERSION, '5.1', '<')) {
$eof = !$eof;
}
return $eof;
}
/**
* Returns the position of the file pointer, i.e. its offset into the file
* stream. Implements support for ftell().
* @return int
*/
function stream_tell()
{
return $this->pos;
}
/**
* Implements support for fseek().
* @param int byte offset
* @param int SEEK_SET, SEEK_CUR or SEEK_END
* @return bool
*/
function stream_seek($offset, $whence)
{
if ($whence == SEEK_SET && $offset >= 0) {
$this->pos = $offset;
} elseif ($whence == SEEK_CUR && -$offset <= $this->pos) {
$this->pos += $offset;
} elseif ($whence == SEEK_END && -$offset <= sizeof($this->data)) {
$this->pos = strlen($this->data) + $offset;
} else {
return false;
}
return true;
}
/**
* Implements support for fstat(). Currently the only supported field is
* "size".
* @return array
*/
function stream_stat()
{
return array(
'size' => strlen($this->data),
);
}
// Methods used by stream_wrapper_register() that are not implemented:
// bool stream_flush ( void )
// int stream_write ( string data )
// bool rename ( string path_from, string path_to )
// bool mkdir ( string path, int mode, int options )
// bool rmdir ( string path, int options )
// bool dir_opendir ( string path, int options )
// array url_stat ( string path, int flags )
// string dir_readdir ( void )
// bool dir_rewinddir ( void )
// bool dir_closedir ( void )
}
?>

Source for file ChainedBlockStream.php