Move files once, in shutdown

I wonder if this is a problem because file_move() calls file_save() itself.

Maybe it would be beneficial to have the file directory move be processed in using a queue or drupal_register_shutdown_function() that runs at the end of the request.

Hmm.. I applied the patch manually, but I get 500 error, when upload and image. The new diff against the last commit is:
I search, what the problem is, but I've never used drupal_register_shutdown.

diff --git a/fe_paths.module b/fe_paths.module
index 41d8a84..94d8480 100644
--- a/fe_paths.module
+++ b/fe_paths.module
@@ -105,9 +105,14 @@ function fe_paths_file_presave($file) {
   fe_paths_file_process($file);
 }
 
+/**
+ * Actually processes the files.
+ * @see fe_paths_file_presave().
+ * @see fe_paths_move_files().
+ */
 function fe_paths_file_process($file) {
-  // Set a drupal_static variable, to prevent multiple processing.
-  $processed = &drupal_static(__FUNCTION__, FALSE);
+  // Get a static of processed files to prevent infinite processing.
+  $processed = &drupal_static(__FUNCTION__, array());
 
   // Only work on local files, that have not been processed, and that already have a file_entity type.
   if (file_entity_file_is_local($file) && !array_key_exists($file->origname, $processed) && isset($file->type)) {
@@ -131,33 +136,37 @@ function fe_paths_file_process($file) {
 
     $paths = $path != '' ? explode('/', $path) : NULL;
 
-    $new_uri = $scheme . '://' . $path . '/' . $filename;
+    $new_uri = $scheme . '://' . $path . $filename;
     // Move the files, if necessary
     if ($file->uri != $new_uri) {
       $directory = $scheme . '://' . $path;
-      // Create directory, if necessary
-      file_prepare_directory($directory, FILE_CREATE_DIRECTORY);
-      // Set processed here true, to prevent another processing from file_move.
-      $processed = TRUE;
-
-      if (file_move($file, $new_uri)) {
-        // Because of file_move works with a cloned $file object, need to update
-        // this $file object.
-        $file->filename = $filename;
-        $file->uri = $new_uri;
-
-        // Check, if directory is empty, and delete it, if yes
-        $files = file_scan_directory($old_dir_uri, '/.*/');
-        if (empty($files)) {
-          drupal_rmdir($old_dir_uri);
-        }
-      };
+      drupal_register_shutdown_function('fe_paths_move_files', $directory, $file, $new_uri, $filename, $old_dir_uri);
     }
     $processed = TRUE;
   }
 }
 
 /**
+ * A function that can be called in the page shutdown to actually move files. Not safe against recursion.
+ */
+function fe_paths_move_files($directory, $file, $new_uri, $filename, $old_dir_uri) {
+  // Create directory, if necessary.
+  file_prepare_directory($directory, FILE_CREATE_DIRECTORY);
+  if (file_move($file, $new_uri)) {
+    // Because of file_move works with a cloned $file object, need to update
+    // this $file object.
+    $file->filename = $filename;
+    $file->uri = $new_uri;
+
+    // Check, if directory is empty, and delete it, if yes
+    $files = file_scan_directory($old_dir_uri, '/.*/');
+    if (file_exists($old_dir_uri) && empty($files)) {
+      drupal_rmdir($old_dir_uri);
+     }
+   }
+ }
+
+/**
  * Implements hook_token_info().
  */
 function fe_paths_token_info() {
(END)

My fail, wrong manual apply, it seems to work good. Commited.

It appears that the use of the drupal_register_shutdown_function() is preventing a bunch of the manual image cropping modules from working properly. While the use of the drupal_register_shutdown_function() makes sense, I'm trying to determine if there's a workaround for manual image cropping modules.

I've outlined the issues here: http://drupal.org/node/1647598

I don't think this is an issue with the FE Paths code, I'm just hoping to leverage some expertise to figure out how manual image cropping modules can play nicely with FE Paths.

Thanks in advance,
-mike