just some optimizations (especially for large dbs)

- replace some REGEXP with LIKE in sql
- optimized queries for the combination of large data sets with picture_url_style file

git-svn-id: http://piwigo.org/svn/branches/branch-1_7@2326 68402e56-0260-453c-a942-63ccdbb3a9ee

picture.php

@@ -38,9 +38,11 @@ if (isset($page['category']))
   check_restrictions($page['category']['id']);
 }
 
+$page['rank_of'] = array_flip($page['items']);
+
 // if this image_id doesn't correspond to this category, an error message is
 // displayed, and execution is stopped
-if (!in_array($page['image_id'], $page['items']))
+if ( !isset($page['rank_of'][$page['image_id']]) )
 {
   page_not_found(
     'The requested image does not belong to this image set',
@@ -103,8 +105,6 @@ function default_picture_content($content, $element_info)
 // |                            initialization                             |
 // +-----------------------------------------------------------------------+
 
-$page['rank_of'] = array_flip($page['items']);
-
 // caching first_rank, last_rank, current_rank in the displayed
 // section. This should also help in readability.
 $page['first_rank']   = 0;