PHP Decode

<?php 
// Copyright 2011 Toby Zerner, Simon Zerner 
// This file is part of esoTalk. Please see the included license file for usage information. 
 
// Sitemap: generates necessary sitemap files and outputs sitemap.xml. 
 
define("IN_ESOTALK", 1); 
 
// Include our config files. 
require "config.default.php"; 
@include "config/config.php"; 
if (!isset($config)) exit; 
// Combine config.default.php and config/config.php into $config (the latter will overwrite the former.) 
$config = array_merge($defaultConfig, $config); 
 
// Compare the hardcoded version of esoTalk (ESOTALK_VERSION) to the installed one ($versions["esoTalk"]). 
// If they're out-of-date, stop page execution. 
require "config/versions.php"; 
if ($versions["esoTalk"] != ESOTALK_VERSION) exit; 
 
require "lib/functions.php"; 
 
// If sitemap.xml is recent then we'll just use the cached version. 
// Otherwise, we'll regenerate all the sitemap files. 
if (!file_exists("sitemap.xml") or filemtime("sitemap.xml") < time() - $config["sitemapCacheTime"] - 200) { 
 
	// If there are lots of conversations, this might take a while... 
	set_time_limit(0); 
 
	// Connect to the database. 
	require "lib/database.php"; 
	$db = new Database(); 
	if (!$db->connect($config["mysqlHost"], $config["mysqlUser"], $config["mysqlPass"], $config["mysqlDB"])) exit; 
 
	// Does sitemap.general.xml exist? If not, create it. 
	if (!file_exists("sitemap.general.xml")) { 
		writeFile("sitemap.general.xml", "<?xml version='1.0' encoding='UTF-8'?><urlset xmlns='http://www.sitemaps.org/schemas/sitemap/0.9'><url><loc>{$config["baseURL"]}</loc><changefreq>hourly</changefreq><priority>1.0</priority></url></urlset>"); 
	} 
 
	// Initiate the counter and some settings. 
	$i = 1; 
	define("URLS_PER_SITEMAP", 40000); // 40,000 almost definitely will not exceed the 10MB sitemap limit. 
	define("ZLIB", extension_loaded("zlib") ? ".gz" : null); 
 
	// Generate conversation sitemap files until we run out of conversations. 
	while (true) { 
 
		// Set the filename with the counter. 
		$filename = "sitemap.conversations.$i.xml" . ZLIB; 
 
		// Get the next batch of public conversations from the database. 
		$r = mysql_query("SELECT conversationId, slug, posts / ((UNIX_TIMESTAMP() - startTime) / 86400) AS postsPerDay, IF(lastActionTime, lastActionTime, startTime) AS lastUpdated, posts FROM " . config("esoTalk.database.prefix") . "conversations WHERE !private LIMIT " . (($i - 1) * URLS_PER_SITEMAP) . "," . URLS_PER_SITEMAP); 
 
		// If there are no conversations left, break from the loop. 
		if (!mysql_num_rows($r)) break; 
 
		// Otherwise let's make the sitemap file. 
		else { 
			$urlset = "<?xml version='1.0' encoding='UTF-8'?><urlset xmlns='http://www.sitemaps.org/schemas/sitemap/0.9'>"; 
 
			// Create a <url> tag for each conversation in the result set. 
			while (list($conversationId, $slug, $postsPerDay, $lastUpdated, $posts) = mysql_fetch_row($r)) { 
 
				$urlset .= "<url><loc>{$config["baseURL"]}" . makeLink($conversationId, $slug) . "</loc><lastmod>" . gmdate("Y-m-d\TH:i:s+00:00", $lastUpdated) . "</lastmod><changefreq>"; 
 
				// How often should we tell them to check for updates? 
				if ($postsPerDay < 0.006) $urlset .= "yearly"; 
				elseif ($postsPerDay < 0.07) $urlset .= "monthly"; 
				elseif ($postsPerDay < 0.3) $urlset .= "weekly"; 
				elseif ($postsPerDay < 3) $urlset .= "daily"; 
				else $urlset .= "hourly"; 
				$urlset .= "</changefreq>"; 
 
				// Estimate the conversation's importance based upon the number of posts. 
				if ($posts < 50) ; // Default priority is 0.5, so specifying it is redundant. 
				elseif ($posts < 100) $urlset .= "<priority>0.6</priority>"; 
				elseif ($posts < 500) $urlset .= "<priority>0.7</priority>"; 
				elseif ($posts < 1000) $urlset .= "<priority>0.8</priority>"; 
				else $urlset .= "<priority>0.9</priority>"; 
				$urlset .= "</url>"; 
 
			} 
 
			// [Encode, and] write out the file. 
			$urlset .= "</urlset>"; 
			if (ZLIB) $urlset = gzencode($urlset, 9); 
			writeFile($filename, $urlset); 
 
			// And increment the counter for the next cycle. 
			$i++; 
		} 
	} 
 
	// Now we're gonna generate the sitemap index. 
	$sitemap = "<?xml version='1.0' encoding='UTF-8'?><sitemapindex xmlns='http://www.sitemaps.org/schemas/sitemap/0.9'><sitemap><loc>{$config["baseURL"]}sitemap.general.xml</loc></sitemap>"; 
	// For each conversation sitemap that we wrote, up until we break'd, add a <sitemap> entry to the index. 
	for ($j = 1; $j < $i; $j++) $sitemap .= "<sitemap><loc>{$config["baseURL"]}sitemap.conversations.$j.xml" . ZLIB . "</loc><lastmod>" . gmdate("Y-m-d\TH:i:s+00:00") . "</lastmod></sitemap>"; 
	$sitemap .= "</sitemapindex>"; 
 
	// And write out! 
	writeFile("sitemap.xml", $sitemap); 
} 
 
// Whether we generated new sitemaps or are using a cached version, let's include the sitemap index and serve it as xml. 
header("Content-type: text/xml"); 
$handle = fopen("sitemap.xml", "r"); 
echo fread($handle, filesize("sitemap.xml")); 
fclose($handle);