EXPERIMENTAL: Try not to build pages when we shouldn't have to.

inc/config.php

@@ -896,6 +896,9 @@
 	// Website favicon.
 	// $config['url_favicon'] = '/favicon.gif';
 	
+	// EXPERIMENTAL: Try not to build pages when we shouldn't have to.
+	$config['try_smarter'] = false;
+
 /*
  * ====================
  *  Mod settings

inc/functions.php

@@ -306,7 +306,7 @@ function sprintf3($str, $vars, $delim = '%') {
 		$replaces[$delim . $k . $delim] = $v;
 	}
 	return str_replace(array_keys($replaces),
-	                   array_values($replaces), $str);
+					   array_values($replaces), $str);
 }
 
 function mb_substr_replace($string, $replacement, $start, $length) {
@@ -344,6 +344,11 @@ function setupBoard($array) {
 }
 
 function openBoard($uri) {
+	global $config, $build_pages;
+
+	if ($config['try_smarter'])
+		$build_pages = array();
+
 	$board = getBoardInfo($uri);
 	if ($board) {
 		setupBoard($board);
@@ -996,6 +1001,16 @@ function clean() {
 	}
 }
 
+function thread_find_page($thread) {
+	global $config, $board;
+
+	$query = query(sprintf("SELECT `id` FROM ``posts_%s`` WHERE `thread` IS NULL ORDER BY `sticky` DESC, `bump` DESC", $board['uri'])) or error(db_error($query));
+	$threads = $query->fetchAll(PDO::FETCH_COLUMN);
+	if (($index = array_search($thread, $threads)) === false)
+		return false;
+	return floor(($config['threads_per_page'] + $index) / $config['threads_per_page']);
+}
+
 function index($page, $mod=false) {
 	global $board, $config, $debug;
 
@@ -1256,15 +1271,20 @@ function checkMute() {
 }
 
 function buildIndex() {
-	global $board, $config;
+	global $board, $config, $build_pages;
 
 	$pages = getPages();
 	$antibot = create_antibot($board['uri']);
 
-	$page = 1;
+	for ($page = 1; $page <= $config['max_pages']; $page++) {
-	while ($page <= $config['max_pages'] && $content = index($page)) {
 		$filename = $board['dir'] . ($page == 1 ? $config['file_index'] : sprintf($config['file_page'], $page));
 		
+		if ($config['try_smarter'] && isset($build_pages) && count($build_pages) && !in_array($page, $build_pages) && is_file($filename))
+			continue;
+		$content = index($page);
+		if (!$content)
+			break;
+
 		$antibot->reset();
 
 		$content['pages'] = $pages;
@@ -1273,8 +1293,6 @@ function buildIndex() {
 		$content['antibot'] = $antibot;
 
 		file_write($filename, Element('index.html', $content));
-		
-		$page++;
 	}
 	if ($page < $config['max_pages']) {
 		for (;$page<=$config['max_pages'];$page++) {
@@ -1671,7 +1689,7 @@ function strip_combining_chars($str) {
 }
 
 function buildThread($id, $return = false, $mod = false) {
-	global $board, $config;
+	global $board, $config, $build_pages;
 	$id = round($id);
 
 	if (event('build-thread', $id))
@@ -1719,6 +1737,9 @@ function buildThread($id, $return = false, $mod = false) {
 		'return' => ($mod ? '?' . $board['url'] . $config['file_index'] : $config['root'] . $board['dir'] . $config['file_index'])
 	));
 
+	if ($config['try_smarter'] && !$mod)
+		$build_pages[] = thread_find_page($id);
+
 	if ($return)
 		return $body;