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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: Fabien MARTY <fabien.marty@free.fr> |
// +----------------------------------------------------------------------+
//
// $Id: HTTP_Request.php 174777 2004-12-15 09:09:33Z dufuz $
require_once 'Cache.php';
require_once 'HTTP/Request.php';
define('CACHE_HTTP_REQUEST_GROUP_NAME', 'cache_http_request');
define('CACHE_HTTP_REQUEST_SUCCESS_RESPONSE_CODE', 200);
define('CACHE_HTTP_REQUEST_KEEP_LOCAL_COPY', 1);
define('CACHE_HTTP_REQUEST_RETURN_FALSE', 2);
define('CACHE_HTTP_REQUEST_RETURN_PEAR_ERROR', 3);
/**
* HTTP_Request Cache
*
* The classical example is :
*
* You want to get news from another site through RSS remote files. But you
* don't want to access to to the remote site at every time you display
* its news on your site. Because, if the remote site is down or slow...
* So you you need a class which makes a local cache copy of the remote file.
* Every x hours, the cache is updated. But if the remote site is down, the
* local cache copy is keeped (you can also get error messages if you want).
*
* So you need this class!
*
* Cache_HTTP_Request inherits from Cache and use HTTP_Request to access to
* the remote file.
*
* Usage example :
*
* <?php
* require_once('Cache/HTTP_Request.php');
*
* $cache = &new Cache_HTTP_Request('http://www.php.net', null, 'file', null, 3600);
* $cache->sendRequest();
* $remoteFileBody = $cache->getResponseBody();
*
* (...)
* ?>
*
* @author Fabien MARTY <fabien.marty@free.fr>
* @version $Id: HTTP_Request.php 174777 2004-12-15 09:09:33Z dufuz $
* @package Cache
*/
class Cache_HTTP_Request extends Cache
{
// --- Private properties ---
/**
* Lifetime in seconds (0 endless)
*
* @var int $_expires
*/
var $_expires;
/**
* HTTP Request
*
* @var object $_request
*/
var $_request;
/**
* Cache id for the classic cache file
*
* @see sendRequest()
* @var string $_id
*/
var $_id;
/**
* Cache id for the endless cache file
*
* @see sendRequest()
* @var string $_id
*/
var $_id2;
/**
* Data to use
*
* @see getReponseBody(), getReponseHeader(), getReponseCode()
* @var array $_data
*/
var $_data ;
// --- Public methods ---
/**
* Constructor
*
* @param $url The url to access
* @param $params Associative array of parameters which can be:
* method - Method to use, GET, POST etc
* http - HTTP Version to use, 1.0 or 1.1
* user - Basic Auth username
* pass - Basic Auth password
* proxy_host - Proxy server host
* proxy_port - Proxy server port
* proxy_user - Proxy auth username
* proxy_pass - Proxy auth password
* @param string $container Name of container class
* @param array $containerOptions Array with container class options
* @param int $mode What to do when the remote server is down :
* CACHE_HTTP_REQUEST_KEEP_LOCAL_COPY or
* CACHE_HTTP_REQUEST_RETURN_FALSE or
* CACHE_HTTP_REQUEST_RETURN_PEAR_ERROR
* @param int $expires lifetime of the cached data in seconds - 0 for endless
* @see Cache, HTTP_Request
* @access public
*/
function Cache_HTTP_Request($url, $params = null, $container = 'file',
$containerOptions = null, $expires = 3600,
$mode = CACHE_HTTP_REQUEST_KEEP_LOCAL_COPY)
{
if (!isset($params)) {
$params = array();
}
if (!isset($containerOptions)) {
$containerOptions = array (
'cache_dir' => '/tmp/',
'filename_prefix' => 'cache_'
);
}
$this->Cache($container, $containerOptions);
$this->_request = &new HTTP_Request($url, $params);
$this->_id = md5($url.serialize($params));
$this->_id2 = md5($this->_id); // we need two keys
$this->_mode = $mode;
$this->_expires = $expires;
}
/**
* Deconstructor
*
* @access public
*/
function _Cache_HTTP_Request()
{
$this->_Cache();
}
/**
* Get and return the response body (null if no data available)
*
* @see sendRequest()
* @return mixed response body
* @access public
*/
function getResponseBody()
{
return $this->_data['body'];
}
/**
* Get and return the response code (null if no data available)
*
* @see sendRequest()
* @return mixed response code
* @access public
*/
function getResponseCode()
{
return $this->_data['code'];
}
/**
* Get and return the response header (null if no data available)
*
* @see sendRequest()
* @return mixed response header
* @access public
*/
function getResponseHeader()
{
return $this->_data['header'];
}
/**
* Set a new mode when the server is down
*
* @param int $newMode What to do when the remote server is down :
* CACHE_HTTP_REQUEST_KEEP_LOCAL_COPY or
* CACHE_HTTP_REQUEST_RETURN_FALSE or
* CACHE_HTTP_REQUEST_RETURN_PEAR_ERROR
* @access public
*/
function setMode($newMode)
{
$this->_mode = $newMode;
}
/**
* Send the HTTP request or use the cache system
*
* If there is a cache file for this HTTP request, the request is not re-sent.
* Cached response is used. Yet, if the cache is expired, the HTTP request
* is re-sent. Then, if the remote server is down, this method will return :
* (depending on the selected mode)
* - false or
* - a PEAR_Error or (better)
* - true and the local copy of the latest valid response will be used.
*
* (technical)
* For the last choice, there is a technical tips.
* Indeed, there are two cache files. The first one (id key) is a classical one
* with the given lifetime. But it can be removed by automatic garbage collection
* for example. So to be able to use the latest valid response (when the remote
* server is dead), we make a second cache file with no lifetime (id2 key).
*
* @return mixed true or false or a PEAR_ERROR
* @access public
*/
function sendRequest()
{
if ($data = $this->get($this->_id, CACHE_HTTP_REQUEST_GROUP_NAME)) {
// --- Cache hit ---
$this->_data = $data;
return true;
} else {
// --- Cache miss ---
if ($this->_sendRequestAndGetResponse()) {
// So the remote server is ok...
$this->save($this->_id, $this->_data, $this->_expires, CACHE_HTTP_REQUEST_GROUP_NAME);
$this->save($this->_id2, $this->_data, 0, CACHE_HTTP_REQUEST_GROUP_NAME);
return true;
} else {
if ($data_sav = $this->get($this->_id2, CACHE_HTTP_REQUEST_GROUP_NAME)) {
// Ok, the "recover cache" is available...
switch ($this->_mode) {
case CACHE_HTTP_REQUEST_KEEP_LOCAL_COPY:
// We make a new local copy and keep it until it expires...
$this->save($this->_id, $data_sav, $this->_expires, CACHE_HTTP_REQUEST_GROUP_NAME);
$this->_data = $data_sav;
return true;
break;
case CACHE_HTTP_REQUEST_RETURN_FALSE:
// We return false
return false;
break;
case CACHE_HTTP_REQUEST_RETURN_PEAR_ERROR:
// We return a PEAR_Error!
return new Cache_Error('Remote file is not available!');
break;
}
} else {
// It's terrible! The remote server is down and definitively no cache available!
return new Cache_Error('Remote server down and no cache available!');
}
}
}
}
// --- Private Methods ---
/**
* Send HTTP request and get the response
*
* @return boolean success or not ?
* @see HTTP_Request
* @access private
*/
function _sendRequestAndGetResponse()
{
$this->_request->sendRequest();
$body = $this->_request->getResponseBody();
$code = $this->_request->getResponseCode();
$header = $this->_request->getResponseHeader();
$this->_data = array(
'body' => $body,
'code' => $code,
'header' => $header
);
return (($code==CACHE_HTTP_REQUEST_SUCCESS_RESPONSE_CODE) ? true : false);
}
}
?>
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