APC CSS and JS check.

Author: davidstrauss

includes/common.inc

@@ -3448,7 +3448,7 @@ function drupal_build_css_cache($css) {
     $uri = $map[$key];
   }
 
-  if (empty($uri) || !file_exists($uri)) {
+  if (empty($uri) || !drupal_aggregated_file_exists($uri)) {
     // Build aggregate CSS file.
     foreach ($css as $stylesheet) {
       // Only 'file' stylesheets can be aggregated.
@@ -4776,6 +4776,15 @@ function drupal_add_tabledrag($table_id, $action, $relationship, $group, $subgro
   drupal_add_js($settings, 'setting');
 }
 
+function drupal_aggregated_file_exists($uri) {
+  $exists = apc_exists('file_exists_' . $uri);
+  if (!$exists && file_exists($uri)) {
+    $exists = TRUE;
+    apc_store('file_exists_' . $uri, TRUE, 86400);
+  }
+  return $exists;
+}
+
 /**
  * Aggregates JavaScript files into a cache file in the files directory.
  *
@@ -4809,7 +4818,7 @@ function drupal_build_js_cache($files) {
     $uri = $map[$key];
   }
 
-  if (empty($uri) || !file_exists($uri)) {
+  if (empty($uri) || !drupal_aggregated_file_exists($uri)) {
     // Build aggregate JS file.
     foreach ($files as $path => $info) {
       if ($info['preprocess']) {