source: inc/core/class.dc.store.reader.php @ 2319:abe2702e1585

<?php
# -- BEGIN LICENSE BLOCK ---------------------------------------
#
# This file is part of Dotclear 2.
#
# Copyright (c) 2003-2013 Olivier Meunier & Association Dotclear
# Licensed under the GPL version 2.0 license.
# See LICENSE file or
# http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
#
# -- END LICENSE BLOCK -----------------------------------------
if (!defined('DC_RC_PATH')) { return; }

/**
@ingroup DC_CORE
@brief Repository modules XML feed reader
@since 2.6

Provides an object to parse XML feed of modules from repository.
This class extends clearbricks netHttp class.
*/
class dcStoreReader extends netHttp
{
     /** @var  string    User agent used to query repository */
     protected $user_agent = 'DotClear.org RepoBrowser/0.1';
     /** @var  integer   User agent used to query repository */
     protected $timeout = 5;
     /** @var  array      HTTP Cache validators */
     protected $validators = null;
     /** @var  string    Cache temporary directory */
     protected $cache_dir = null;
     /** @var  string    Cache file prefix */
     protected $cache_file_prefix = 'dcrepo';
     /** @var  integer   Cache TTL */
     protected $cache_ttl = '-30 minutes';
     /** @var  boolean   'Cache' TTL on server failed */
     protected $cache_touch_on_fail = true;
     /** @var  boolean   Force query server */
     protected $force = false;

     /**
      * Constructor.
      *
      * Bypass first argument of clearbricks netHttp constructor.
      */
     public function __construct()
     {
          parent::__construct('');
          $this->setUserAgent(sprintf('Dotclear/%s)', DC_VERSION));
     }

     /**
      * Parse modules feed.
      *
      * @param string    $url      XML feed URL
      * @return     object    dcStore instance
      */
     public function parse($url)
     {
          $this->validators = array();

          if ($this->cache_dir) {
               return $this->withCache($url);
          }
          elseif (!$this->getModulesXML($url) || $this->getStatus() != '200') {
               return false;
          }

          return new dcStoreParser($this->getContent());
     }

     /**
      * Quick parse modules feed.
      *
      * @param string    $url      XML feed URL
      * @param string    $cache_dir     Cache directoy or null for no cache
      * @param boolean   $force         Force query repository
      * @return     object    Self instance
      */
     public static function quickParse($url, $cache_dir=null, $force=false)
     {
          $parser = new self();
          if ($cache_dir) {
               $parser->setCacheDir($cache_dir);
          }
          if ($force) {
               $parser->setForce($force);
          }

          return $parser->parse($url);
     }

     /**
      * Set cache directory.
      *
      * @param string    $dir      Cache directory
      * @return     boolean   True if cache dierctory is useable
      */
     public function setCacheDir($dir)
     {
          $this->cache_dir = null;

          if (!empty($dir) && is_dir($dir) && is_writeable($dir)) {
               $this->cache_dir = $dir;
               return true;
          }

          return false;
     }

     /**
      * Set cache TTL.
      *
      * @param string    $str      Cache TTL
      */
     public function setCacheTTL($str)
     {
          $str = trim($str);

          if (!empty($str)) {
               $this->cache_ttl = substr($str, 0, 1) == '-' ? $str : '-'.$str;
          }
     }

     /**
      * Set force query repository.
      *
      * @param boolean   $force    True to force query
      */
     public function setForce($force)
     {
          $this->force = $force;
     }

     /**
      * Get repository XML feed URL content.
      *
      * @param string    $url      XML feed URL
      * @return     string    Feed content
      */
     protected function getModulesXML($url)
     {
          if (!self::readURL($url, $ssl, $host, $port, $path, $user, $pass)) {
               return false;
          }
          $this->setHost($host, $port);
          $this->useSSL($ssl);
          $this->setAuthorization($user, $pass);

          try {
               return $this->get($path);
          }
          catch(Exception $e) {
               // @todo Log error when repository query fail
               return false;
          }
     }

     /**
      * Get repository modules list using cache.
      *
      * @param string    $url      XML feed URL
      * @return     array     Feed content or False on fail
      */
     protected function withCache($url)
     {
          $url_md5 = md5($url);
          $cached_file = sprintf('%s/%s/%s/%s/%s.ser',
               $this->cache_dir,
               $this->cache_file_prefix,
               substr($url_md5,0,2),
               substr($url_md5,2,2),
               $url_md5
          );

          $may_use_cached = false;

          # Use cache file ?
          if (@file_exists($cached_file) && !$this->force) {
               $may_use_cached = true;
               $ts = @filemtime($cached_file);
               if ($ts > strtotime($this->cache_ttl)) {
                    # Direct cache
                    return unserialize(file_get_contents($cached_file));
               }
               $this->setValidator('IfModifiedSince', $ts);
          }

          # Query repository
          if (!$this->getModulesXML($url)) {
               if ($may_use_cached) {
                    # Touch cache TTL even if query failed ?
                    if ($this->cache_touch_on_fail) {
                         @files::touch($cached_file);
                    }
                    # Connection failed - fetched from cache
                    return unserialize(file_get_contents($cached_file));
               }
               return false;
          }

          # Parse response
          switch ($this->getStatus())
          {
               # Not modified, use cache
               case '304':
                    @files::touch($cached_file);
                    return unserialize(file_get_contents($cached_file));
               # Ok, parse feed
               case '200':
                    if ($modules = new dcStoreParser($this->getContent())) {
                         try {
                              files::makeDir(dirname($cached_file), true);
                         }
                         catch (Exception $e) {
                              return $modules;
                         }

                         if (($fp = @fopen($cached_file, 'wb'))) {
                              fwrite($fp, serialize($modules));
                              fclose($fp);
                              files::inheritChmod($cached_file);
                         }
                         return $modules;
                    }
          }

          return false;
     }

     /**
      * Prepare query.
      *
      * @return     array     Query headers
      */
     protected function buildRequest()
     {
          $headers = parent::buildRequest();

          # Cache validators
          if (!empty($this->validators)) {
               if (isset($this->validators['IfModifiedSince'])) {
                    $headers[] = 'If-Modified-Since: '.$this->validators['IfModifiedSince'];
               }
               if (isset($this->validators['IfNoneMatch'])) {
                    if (is_array($this->validators['IfNoneMatch'])) {
                         $etags = implode(',', $this->validators['IfNoneMatch']);
                    }
                    else {
                         $etags = $this->validators['IfNoneMatch'];
                    }
                    $headers[] = '';
               }
          }

          return $headers;
     }

     /**
      * Tweak query cache validator.
      *
      * @param string    $key      Validator key
      * @param string    $value         Validator value
      */
     private function setValidator($key, $value)
     {
          if ($key == 'IfModifiedSince') {
               $value = gmdate('D, d M Y H:i:s', $value).' GMT';
          }

          $this->validators[$key] = $value;
     }
}