feedforall_scripts_cachingextension.php

RSS to SQL Caching Tools

<?php
//
// rss2html.php RSS feed to HTML webpage script XML Caching Extension
//
// Copyright 2005-2007 NotePage, Inc. all rights reserved
// http://www.feedforall.com
//
// NotePage, Inc. grants registerd users of our FeedForAll and/or
// FeedForAll Mac product(s) the right to install and use the
// FeedForAll_Scripts_CachingExtension.php script free of charge.  
// Please refer to the EULA included in the download for full license
// terms and conditions.
//
// $Id: FeedForAll_Scripts_CachingExtension.php,v 3.0 2007/04/16 14:23:03 housley Exp $
//
// $Log: FeedForAll_Scripts_CachingExtension.php,v $
// Revision 3.0  2007/04/16 14:23:03  housley
// Release version 3.0 of the scripts
//
// Revision 1.19  2007/04/10 17:16:44  housley
// Allow the input caching to be set during buildURL, only for one PHP include
// type
//
// Revision 1.18  2007/04/10 15:19:27  housley
// Allow for the caching for the HTML output of rss2html.php
//
// Revision 1.17  2007/04/04 20:55:46  housley
// Add the ability to set CURLOPT_CONNECTTIMEOUT
//
// Revision 1.16  2007/03/13 20:33:23  housley
// Update copyright year
//
// Revision 1.15  2007/03/05 01:19:45  housley
// Rename FeedForAll_rss2html_readFile() to FeedForAll_scripts_readFile()
//
// Revision 1.14  2007/02/24 12:42:03  housley
// Add checks for safe_mode and open_basedir to prevent warning about
// CURLOPT_FOLLOWLOCATION
//
// Revision 1.13  2007/02/21 13:39:06  housley
// * More small fixes for different directories
// * Add more debug statements
//
// Revision 1.12  2007/01/17 17:56:28  housley
// Fix the problem of no caching when called from a different directory.
// When the script is called from a different directory, the caching system
// will look for the cache folder in the current directory instead of the
// directory with the script.
//
// Revision 1.11  2006/09/29 19:07:15  housley
// Allow rss2html.php not to show an identity when used with any of the
// pay scripts.
//
// Revision 1.10  2006/09/07 01:24:15  housley
// Verify the length of the data read from the cache file is the same
// as the cache file.  A server was not returning the right data.
//
// Revision 1.9  2006/07/17 20:49:54  housley
// Add an option, FORCECACHEREFRESH, that will force cache updates
//
// Revision 1.8  2006/05/27 19:26:32  housley
// Ensure in all cases the cached file is readable.  If it is not readable,
// return so.
//
// Revision 1.7  2006/04/08 23:55:33  housley
// Rename the directory for cache storage
//
// Revision 1.6  2006/03/10 14:21:04  housley
// Update the licenses
//
// Revision 1.5  2006/02/19 14:36:45  housley
// Change so the read from cache is called twice.  The second time is on an error.
//
// Revision 1.4  2006/02/19 12:52:28  housley
// Allow the capability to return expired cache results when there is
// an error reaching the site for new contents
//
// Revision 1.3  2006/02/12 12:14:03  housley
// Allow the length of time each file is cached to be passed in
//
// Revision 1.2  2006/01/08 23:24:03  housley
// Update license statement
//
// Revision 1.1  2005/12/12 16:27:42  housley
// Create the ability to cache files
//
//
//

if (function_exists("FeedForAll_rss2html_AddIdentity") === FALSE) {
  Function FeedForAll_rss2html_AddIdentity($itemString) {
    return $itemString;
  }
}

if (function_exists("FeedForAll_scripts_readFile") === FALSE) {
  
  //
  // The variable $cacheTTL controls how many seconds a cached copy of an XML
  // file can be used before it must be refetched from the server.
  // $cacheTTL=60;      //cache files for 1 minute
  // $cacheTTL=3600;    //cache files for 1 hour
  $cacheTTL=86400;   //cache files for 1 day
  
  //
  // The variable $cacheFolder specifies the name of the directory, relative to
  // the location of rss2html.php, where the cached files are stored.  It not
  // recommened you change this with out a very good reason.
  $cacheFolder = "FeedForAllCacheFiles";
  
  //
  // The variable $useExpiredOnError when set to 1 causes the program to return
  // expired data from the cache when there is an error reaching the website
  // to get a new file.  Turn with on with caution because with this on there
  // is no indication of an error.
  $useExpiredOnError = 0;
  
  //
  // Used for trouble shooting with tech support
  // $debugLevel = 0;
  
  //
  // Output caching of resulting HTML.  CAUTION using both caching for the XML
  // and the HTML can cause hard to diagnose problem if not done right.
  //$outputCacheTTL = 3600;
  
  if (isset($GLOBALS["XMLCACHTTL"])) {
    $cacheTTL = $GLOBALS["XMLCACHETTL"];
  }
  if (isset($GLOBALS["ALLOWXMLCACHE"])) {
    $allowCachingXMLFiles = $GLOBALS["ALLOWXMLCACHE"];
  }
  if (isset($GLOBALS["OUTCACHTTL"])) {
    $outputCacheTTL = $GLOBALS["OUTCACHTTL"];
  }
  
  Function FeedForAll_scripts_contentOfCache($filename, $useCaching = 0, $actualCacheTTL = -1, $actualUseExpiredOnError = 0) {
    GLOBAL $cacheTTL, $cacheFolder;
    GLOBAL $debugLevel;
    
    if (isset($debugLevel) && ($debugLevel >= 1)) {
      echo "DIAG: FeedForAll_scripts_contentOfCache($filename, $useCaching, $actualCacheTTL, $actualUseExpiredOnError)<br>\n";
    }
    
    //
    // Add the path to $cacheFolder, incase it is called from a different directoy
    $localCacheFolder = dirname(__FILE__)."/$cacheFolder";
    
    if (!$useCaching) {
      if (isset($debugLevel) && ($debugLevel >= 1)) {
        echo "DIAG: FeedForAll_scripts_contentOfCache(): !useCaching<br>\n";
      }
      return FALSE;
    }
    
    if (isset($_REQUEST["FORCECACHEREFRESH"])) {
      if (isset($debugLevel) && ($debugLevel >= 1)) {
        echo "DIAG: FeedForAll_scripts_contentOfCache(): FORCECACHEREFRESH<br>\n";
      }
      return FALSE;
    }
    
    if ($actualCacheTTL == -1) {
      $actualCacheTTL = $cacheTTL;
    }
    
    //
    // Make the directory if it doesn't exist
    if (file_exists($localCacheFolder) === FALSE) {
      if (@mkdir($localCacheFolder, 0777) === FALSE) {
        if (isset($debugLevel) && ($debugLevel >= 1)) {
          echo "DIAG: FeedForAll_scripts_contentOfCache(): no cache folder<br>\n";
        }
        return FALSE;
      }
    }

    $encodedName = $localCacheFolder."/".md5($filename);
    
    if (file_exists($encodedName) === FALSE) {
      // File does not exist
      if (isset($debugLevel) && ($debugLevel >= 1)) {
        echo "DIAG: FeedForAll_scripts_contentOfCache(): file doesn't exist<br>\n";
      }
      return FALSE;
    }
    
    // File exists, so lets check the age
    if (((time() - filemtime($encodedName)) > $actualCacheTTL) && ($actualUseExpiredOnError == 0)) {
      if (isset($debugLevel) && ($debugLevel >= 3)) {
        echo "DIAG: FeedForAll_scripts_contentOfCache(): (time() - filemtime($encodedName)) > \$actualCacheTTL)<br>\n";
        echo "DIAG: FeedForAll_scripts_contentOfCache(): (".time()." - ".filemtime($encodedName).") > $actualCacheTTL)<br>\n";
      }
      if (isset($debugLevel) && ($debugLevel >= 1)) {
        echo "DIAG: FeedForAll_scripts_contentOfCache(): file too old<br>\n";
      }
      return FALSE;
    }
    
    // The file exists and has not expired
    if (($fd = @fopen($encodedName, "rb")) !== FALSE) {
      if (flock($fd, LOCK_SH)) {
        $result = fread($fd, filesize($encodedName));
        flock($fd, LOCK_UN);
        if (strlen($result) != filesize($encodedName)) {
          fclose($fd);
          if (isset($debugLevel) && ($debugLevel >= 1)) {
            echo "DIAG: FeedForAll_scripts_contentOfCache(): filesize mismatch<br>\n";
          }
          return FALSE;
        }
      } else {
        if (isset($debugLevel) && ($debugLevel >= 1)) {
          echo "DIAG: FeedForAll_scripts_contentOfCache(): flock() faild<br>\n";
        }
        return FALSE;
      }
      fclose($fd);
      if (isset($debugLevel) && ($debugLevel >= 1)) {
        echo "DIAG: FeedForAll_scripts_contentOfCache(): return SUCCESSFUL<br>\n";
      }
      return $result;
    }