Viewing file:  OutputCompression.php (8.82 KB) -rw-rw-rw-
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<?php
// +----------------------------------------------------------------------+
// | PEAR :: Cache |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2003 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.0 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | license@php.net so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors: Ulf Wendel <ulf.wendel@phpdoc.de> |
// | Christian Stocker <chregu@phant.ch> |
// +----------------------------------------------------------------------+
require_once 'Cache/Output.php';
/**
* Cache using Output Buffering and contnet (gz) compression.
** Usage example:
*
* // place this somewhere in a central config file
* define(CACHE_STORAGE_CLASS, 'file');
* // file storage needs a dir to put the cache files
* define(CACHE_DIR, '/var/tmp/');
*
* // get a cache object
* $cache = new Cache_Output(CACHE_STORAGE_CLASS, array('cache_dir' => CACHE_DIR));
*
* if (!($content = $cache->start($cache->generateID($REQUEST_URI)))) {
* print "hello world";
* $cache->endPrint(+1000);
* }
* else {
* $cache->printContent();
* }
*
* OR
*
* if (($content = $cache->start($cache->generateID($REQUEST_URI)))) {
* $cache->printContent();
* die();
* }
* print "hello world";
* $cache->endPrint(+1000);
*
*
* Based upon a case study from Christian Stocker and inspired by jpcache.
*
* @version $Id: OutputCompression.php 178289 2005-01-26 09:47:28Z dufuz $
* @author Ulf Wendel <ulf.wendel@phpdoc.de>, Christian Stocker <chregu@phant.ch>
* @access public
* @package Cache
*/
class Cache_OutputCompression extends Cache_Output
{
/**
* Encoding, what the user (its browser) of your website accepts
*
* "auto" stands for test using $_SERVER['HTTP_ACCEPT_ENCODING']($HTTP_ACCEPT_ENCODING).
*
* @var string
* @see Cache_OutputCompression(), setEncoding()
*/
var $encoding = 'auto';
/**
* Method used for compression
*
* @var string
* @see isCompressed()
*/
var $compression = '';
/**
* Sets the storage details and the content encoding used (if not autodetection)
*
* @param string Name of container class
* @param array Array with container class options
* @param string content encoding mode - auto => test which encoding the user accepts
*/
function Cache_OutputCompression($container, $container_options = '', $encoding = 'auto')
{
$this->setEncoding($encoding);
$this->Cache($container, $container_options);
} // end constructor
/**
* Call parent deconstructor.
*/
function _Cache_OutputCompression()
{
$this->_Cache();
} // end deconstructor
function generateID($variable)
{
$this->compression = $this->getEncoding();
return md5(serialize($variable) . serialize($this->compression));
} // end generateID
function get($id, $group)
{
$this->content = '';
if (!$this->caching) {
return '';
}
if ($this->isCached($id, $group) && !$this->isExpired($id, $group)) {
$this->content = $this->load($id, $group);
}
return $this->content;
} // end func get
/**
* Stops the output buffering, saves it to the cache and returns the _compressed_ content.
*
* If you need the uncompressed content for further procession before
* it's saved in the cache use endGet(). endGet() does _not compress_.
*/
function end($expire = 0, $userdata = '')
{
$content = ob_get_contents();
ob_end_clean();
// store in the cache
if ($this->caching) {
$this->extSave($this->output_id, $content, $userdata, $expire, $this->output_group);
return $this->content;
}
return $content;
} // end func end()
function endPrint($expire = 0, $userdata = '')
{
$this->printContent($this->end($expire, $userdata));
} // end func endPrint
/**
* Saves the given data to the cache.
*
*/
function extSave($id, $cachedata, $userdata, $expires = 0, $group = 'default')
{
if (!$this->caching) {
return true;
}
if ($this->compression) {
$len = strlen($cachedata);
$crc = crc32($cachedata);
$cachedata = gzcompress($cachedata, 9);
$this->content = substr($cachedata, 0, strlen($cachedata) - 4) . pack('V', $crc) . pack('V', $len);
} else {
$this->content = $cachedata;
}
return $this->container->save($id, $this->content, $expires, $group, $userdata);
} // end func extSave
/**
* Sends the compressed data to the user.
*
* @param string
* @access public
*/
function printContent($content = '')
{
$server = &$this->_importGlobalVariable("server");
if ($content == '') {
$content = &$this->container->cachedata;
}
if ($this->compression && $this->caching) {
$etag = '"PEAR-Cache-' . md5(substr($content, -40)) .'"';
header("ETag: $etag");
if (isset($server['HTTP_IF_NONE_MATCH']) && strstr(stripslashes($server['HTTP_IF_NONE_MATCH']), $etag)) {
// not modified
header('HTTP/1.0 304');
return;
} else {
// client acceppts some encoding - send headers & data
header("Content-Encoding: {$this->compression}");
header('Vary: Accept-Encoding');
print "\x1f\x8b\x08\x00\x00\x00\x00\x00";
}
}
die($content);
} // end func printContent
/**
* Returns the encoding method of the current dataset.
*
* @access public
* @return string Empty string (which evaluates to false) means no compression
*/
function isCompressed()
{
return $this->compression;
} // end func isCompressed
/**
* Sets the encoding to be used.
*
* @param string "auto" means autodetect for every client
* @access public
* @see $encoding
*/
function setEncoding($encoding = 'auto')
{
$this->encoding = $encoding;
} // end func setEncoding
/**
* Returns the encoding to be used for the data transmission to the client.
*
* @see setEncoding()
*/
function getEncoding()
{
$server = &$this->_importGlobalVariable("server");
// encoding set by user
if ('auto' != $this->encoding) {
return $this->encoding;
}
// check what the client accepts
if (false !== strpos($server['HTTP_ACCEPT_ENCODING'], 'x-gzip')) {
return 'x-gzip';
}
if (false !== strpos($server['HTTP_ACCEPT_ENCODING'], 'gzip')) {
return 'gzip';
}
// no compression
return '';
} // end func getEncoding
// {{{ _importGlobalVariable()
/**
* Import variables from special namespaces.
*
* @access private
* @param string Type of variable (server, session, post)
* @return array
*/
function &_importGlobalVariable($variable)
{
$var = null;
switch (strtolower($variable)) {
case 'server':
if (isset($_SERVER)) {
$var = &$_SERVER;
} else {
$var = &$GLOBALS['HTTP_SERVER_VARS'];
}
break;
case 'session':
if (isset($_SESSION)) {
$var = &$_SESSION;
} else {
$var = &$GLOBALS['HTTP_SESSION_VARS'];
}
break;
case 'post':
if (isset($_POST)) {
$var = &$_POST;
} else {
$var = &$GLOBALS['HTTP_POST_VARS'];
}
break;
default:
break;
}
return $var;
}
// }}
} // end class OutputCompression
?>
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