Changeset 8319

Timestamp:

07/12/2008 03:40:57 PM (16 years ago)

Author:

ryan

Message:

Performance improvements for page_rows(). Props hailin. fixes #7286

File:

• trunk/wp-admin/includes/template.php (modified) (6 diffs)

trunk/wp-admin/includes/template.php

@@ -526 +526 @@
 
 /*
- * displays pages in hierarchical order
+ * displays pages in hierarchical order with paging support
  */
-
 function page_rows($pages, $pagenum = 1, $per_page = 20) {
     $level = 0;
@@ -539 +538 @@
     }
 
-    // splice pages into two parts: those without parent and those with parent
-    $top_level_pages = array();
-    $children_pages  = array();
-
-    // If searching, ignore hierarchy and treat everything as top level, otherwise split
-    // into top level and children
+    /* 
+     * arrange pages into two parts: top level pages and children_pages
+     * children_pages is two dimensional array, eg. 
+     * children_pages[10][] contains all sub-pages whose parent is 10. 
+     * It only takes O(N) to arrange this and it takes O(1) for subsequent lookup operations
+     * If searching, ignore hierarchy and treat everything as top level
+     */
     if ( empty($_GET['s']) )  {
+        
+        $top_level_pages = array();
+        $children_pages  = array();
+        
         foreach ( $pages as $page ) {
+            
             // catch and repair bad pages
             if ( $page->post_parent == $page->ID ) {
@@ -557 +562 @@
                 $top_level_pages[] = $page;
             else
-                $children_pages[] = $page;
+                $children_pages[ $page->post_parent ][] = $page;
         }
 
@@ -566 +571 @@
     $start = ($pagenum - 1) * $per_page;
     $end = $start + $per_page;
+    
     foreach ( $pages as $page ) {
         if ( $count >= $end )
             break;
 
-        $i++;
-
         if ( $count >= $start )
             echo "\t" . display_page_row( $page, $level );
@@ -580 +584 @@
             _page_rows( $children_pages, $count, $page->ID, $level + 1, $pagenum, $per_page );
     }
-}
-
-function _page_rows( $pages, &$count, $parent, $level, $pagenum, $per_page ) {
+    
+    // if it is the last pagenum and there are orphaned pages, display them with paging as well
+    if ( isset($children_pages) && $count < $end ){
+        foreach( $children_pages as $orphans ){
+            foreach ( $orphans as $op ) {
+                if ( $count >= $end )
+                    break;
+                if ( $count >= $start )
+                    echo "\t" . display_page_row( $op, 0 );
+                $count++;
+            }
+        }
+    }
+}
+
+/*
+ * Given a top level page ID, display the nested hierarchy of sub-pages
+ * together with paging support
+ */
+function _page_rows( &$children_pages, &$count, $parent, $level, $pagenum, $per_page ) {
+    
+    if ( ! isset( $children_pages[$parent] ) )
+        return; 
+        
     $start = ($pagenum - 1) * $per_page;
     $end = $start + $per_page;
-    $i = -1;
-    foreach ( $pages as $page ) {
+    
+    foreach ( $children_pages[$parent] as $page ) {
+        
         if ( $count >= $end )
             break;
-
-        $i++;
-
-        if ( $page->post_parent != $parent )
-            continue;
-
+            
         // If the page starts in a subtree, print the parents.
         if ( $count == $start && $page->post_parent > 0 ) {
@@ -615 +636 @@
         if ( $count >= $start )
             echo "\t" . display_page_row( $page, $level );
-
-        unset($pages[$i]); // Prune the working set     
+            
         $count++;
 
-        _page_rows( $pages, $count, $page->ID, $level + 1, $pagenum, $per_page );
-    }
+        _page_rows( $children_pages, $count, $page->ID, $level + 1, $pagenum, $per_page );
+    }
+    
+    unset( $children_pages[$parent] ); //required in order to keep track of orphans
 }