From d3487222d5cd01bde3800a54722691189eedea85 Mon Sep 17 00:00:00 2001
From: nacin <nacin@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Thu, 8 Mar 2012 07:46:39 +0000
Subject: [PATCH] In wp_get_themes() under multisite, filter out allowed themes
 before creating WP_Theme objects, rather than after.
 search_theme_directories() provides us the stylesheet of each theme which is
 all we need to do the proper intersection. This results in major performance
 gains on sites that have large numbers of themes unavailable to them. see
 #20103.

git-svn-id: http://svn.automattic.com/wordpress/trunk@20152 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/theme.php | 71 +++++++++++++++++++++++--------------------
 1 file changed, 38 insertions(+), 33 deletions(-)

diff --git a/wp-includes/theme.php b/wp-includes/theme.php
index 2c87e1b63..84d9405b4 100644
--- a/wp-includes/theme.php
+++ b/wp-includes/theme.php
@@ -25,45 +25,50 @@ function wp_get_themes( $args = array() ) {
 	$defaults = array( 'errors' => false, 'allowed' => null, 'blog_id' => 0 );
 	$args = wp_parse_args( $args, $defaults );
 
-	static $_themes;
-	if ( ! isset( $_themes ) ) {
-		$_themes = array();
-		$theme_data = search_theme_directories();
-		// Make sure the current theme wins out, in case search_theme_directories() picks the wrong
-		// one in the case of a conflict. (Normally, last registered theme root wins.)
-		$current_theme = get_stylesheet();
-		$current_theme_root = get_raw_theme_root( $current_theme );
-		if ( ! in_array( $current_theme_root, $wp_theme_directories ) )
-			$current_theme_root = WP_CONTENT_DIR . $current_theme_root;
-		foreach ( (array) $theme_data as $theme_slug => $data ) {
-			if ( $current_theme == $theme_slug && $current_theme_root != $data['theme_root'] )
-				$_themes[ $theme_slug ] = new WP_Theme( $theme_slug, $current_theme_root );
-			else
-				$_themes[ $theme_slug ] = new WP_Theme( $theme_slug, $data['theme_root'] );
+	static $_theme_directories, $_themes = array();
+	if ( ! isset( $_theme_directories ) ) {
+		$_theme_directories = search_theme_directories();
+		if ( count( $wp_theme_directories ) > 1 ) {
+			// Make sure the current theme wins out, in case search_theme_directories() picks the wrong
+			// one in the case of a conflict. (Normally, last registered theme root wins.)
+			$current_theme = get_stylesheet();
+			$root_of_current_theme = get_raw_theme_root( $current_theme );
+			if ( ! in_array( $root_of_current_theme, $wp_theme_directories ) )
+				$root_of_current_theme = WP_CONTENT_DIR . $current_theme_root;
+			$_theme_directories[ $current_theme ]['theme_root'] = $root_of_current_theme;
 		}
 	}
 
-	$themes = $_themes;
-	if ( empty( $themes ) )
-		return $themes;
+	if ( empty( $_theme_directories ) )
+		return array();
 
-	if ( null !== $args['errors'] ) {
-		foreach ( $themes as $theme_slug => $theme ) {
-			if ( $theme->errors() != $args['errors'] )
-				unset( $themes[ $theme_slug ] );
-		}
-	}
+	$theme_directories = $_theme_directories;
 
 	if ( is_multisite() && null !== $args['allowed'] ) {
-		if ( $allowed = $args['allowed'] ) {
-			if ( 'network' === $allowed )
-				$themes = array_intersect_key( $themes, WP_Theme::get_allowed_on_network( $args['blog_id'] ) );
-			elseif ( 'site' === $allowed )
-				$themes = array_intersect_key( $themes, WP_Theme::get_allowed_on_site( $args['blog_id'] ) );
-			else
-				$themes = array_intersect_key( $themes, WP_Theme::get_allowed( $args['blog_id'] ) );
-		} else {
-			$themes = array_diff_key( $themes, WP_Theme::get_allowed( $args['blog_id'] ) );
+		$allowed = $args['allowed'];
+		if ( 'network' === $allowed )
+			$theme_directories = array_intersect_key( $theme_directories, WP_Theme::get_allowed_on_network( $args['blog_id'] ) );
+		elseif ( 'site' === $allowed )
+			$theme_directories = array_intersect_key( $theme_directories, WP_Theme::get_allowed_on_site( $args['blog_id'] ) );
+		elseif ( $allowed )
+			$theme_directories = array_intersect_key( $theme_directories, WP_Theme::get_allowed( $args['blog_id'] ) );
+		else
+			$theme_directories = array_diff_key( $theme_directories, WP_Theme::get_allowed( $args['blog_id'] ) );
+	}
+
+	$themes = array();
+
+	foreach ( $theme_directories as $theme => $theme_root ) {
+		if ( isset( $_themes[ $theme ] ) )
+			$themes[ $theme ] = $_themes[ $theme ];
+		else
+			$themes[ $theme ] = $_themes[ $theme ] = new WP_Theme( $theme, $theme_root['theme_root'] );
+	}
+
+	if ( null !== $args['errors'] ) {
+		foreach ( $themes as $theme => $wp_theme ) {
+			if ( $wp_theme->errors() != $args['errors'] )
+				unset( $themes[ $theme ] );
 		}
 	}