cvs: pear /Cache HTTP_Request.php

fab Tue May 28 12:27:59 2002 EDT Added files: /pear/Cache HTTP_Request.php Log: First commit !

Index: pear/Cache/HTTP_Request.php +++ pear/Cache/HTTP_Request.php <?php // +----------------------------------------------------------------------+ // | PHP Version 4 | // +----------------------------------------------------------------------+ // | Copyright (c) 1997, 1998, 1999, 2000, 2001 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,v 1.1 2002/05/28 16:27:59 fab Exp $ require_once("Cache/Cache.php"); require_once("Cache/Error.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,v 1.1 2002/05/28 16:27:59 fab Exp $ * @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 { echo("Nothing !!!"); // 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); } } ?>