Changeset 21403 for trunk/wp-includes/cache.php

Timestamp:

08/02/2012 06:31:14 PM (13 years ago)

Author:

ryan

Message:

Introduce wp_cache_switch_to_blog() and WP_Object_Cache::switch_to_blog() as a lighter/faster way to switch the cache to a new blog id.

Add the blog id to the cache keys for multisite installs.

Use wp_cache_switch_to_blog() instead of wp_cache_init() in switch_to_blog().

Use wp_cache_switch_to_blog() instead of wp_cache_reset() in wp_start_object_cache().

Deprecate wp_cache_reset().

This avoids the many queries needed to re-prime the cache after switch_to_blog() on multisite installs using the default cache backend.

fixes #21434

File:

• trunk/wp-includes/cache.php (modified) (15 diffs)

trunk/wp-includes/cache.php

@@ -181 +181 @@
 
 /**
+ * Switch the interal blog id.
+ *
+ * This changes the blog id used to create keys in blog specific groups.
+ *
+ * @param int $blog_id Blog ID
+ */
+function wp_cache_switch_to_blog( $blog_id ) {
+    global $wp_object_cache;
+
+    return $wp_object_cache->switch_to_blog( $blog_id );
+}
+
+/**
  * Adds a group or set of groups to the list of global groups.
  *
@@ -190 +203 @@
     global $wp_object_cache;
 
-    return $wp_object_cache->add_global_groups($groups);
+    return $wp_object_cache->add_global_groups( $groups );
 }
 
@@ -210 +223 @@
  *
  * @since 2.6.0
+ * @deprecated 3.5.0
  */
 function wp_cache_reset() {
+    _deprecated_function( __FUNCTION__, '3.5', 'wp_cache_switch_to_blog()' );
+
     global $wp_object_cache;
 
@@ -270 +286 @@
      */
     var $global_groups = array();
+
+    /**
+     * The blog prefix to prepend to keys in non-global groups.
+     *
+     * @var int
+     * @access private
+     * @since 3.5.0
+     */
+    var $blog_prefix;
 
     /**
@@ -293 +318 @@
             $group = 'default';
 
-        if ( $this->_exists($key, $group) )
+        $id = $key;
+        if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+            $id = $this->blog_prefix . $key;
+
+        if ( $this->_exists( $id, $group ) )
             return false;
 
@@ -309 +338 @@
         $groups = (array) $groups;
 
-        $this->global_groups = array_merge($this->global_groups, $groups);
-        $this->global_groups = array_unique($this->global_groups);
+        $groups = array_fill_keys( $groups, true );
+        $this->global_groups = array_merge( $this->global_groups, $groups );
     }
 
@@ -326 +355 @@
         if ( empty( $group ) )
             $group = 'default';
-        
+
+        if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+            $key = $this->blog_prefix . $key;
+
         if ( ! $this->_exists( $key, $group ) )
             return false;
@@ -362 +394 @@
             $group = 'default';
 
+        if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+            $key = $this->blog_prefix . $key;
+
         if ( ! $force && ! $this->_exists( $key, $group ) )
             return false;
@@ -402 +437 @@
         if ( empty( $group ) )
             $group = 'default';
+
+        if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+            $key = $this->blog_prefix . $key;
 
         if ( $this->_exists( $key, $group ) ) {
@@ -431 +469 @@
             $group = 'default';
 
+        if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+            $key = $this->blog_prefix . $key;
+
         if ( ! $this->_exists( $key, $group ) )
             return false;
@@ -459 +500 @@
      * @return bool False if not exists, true if contents were replaced
      */
-    function replace($key, $data, $group = 'default', $expire = '') {
+    function replace( $key, $data, $group = 'default', $expire = '' ) {
         if ( empty( $group ) )
             $group = 'default';
 
-        if ( ! $this->_exists( $key, $group ) )
+        $id = $key;
+        if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+            $id = $this->blog_prefix . $key;
+
+        if ( ! $this->_exists( $id, $group ) )
             return false;
 
-        return $this->set($key, $data, $group, $expire);
+        return $this->set( $key, $data, $group, $expire );
     }
 
@@ -473 +518 @@
      *
      * @since 3.0.0
+     * @deprecated 3.5.0
      */
     function reset() {
+        _deprecated_function( __FUNCTION__, '3.5', 'switch_to_blog()' );
+
         // Clear out non-global caches since the blog ID has changed.
-        foreach ( array_keys($this->cache) as $group ) {
-            if ( !in_array($group, $this->global_groups) )
-                unset($this->cache[$group]);
+        foreach ( array_keys( $this->cache ) as $group ) {
+            if ( ! isset( $this->global_groups[ $group ] ) )
+                unset( $this->cache[ $group ] );
         }
     }
@@ -506 +554 @@
             $group = 'default';
 
-        if ( is_object($data) )
+        if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+            $key = $this->blog_prefix . $key;
+
+        if ( is_object( $data ) )
             $data = clone $data;
 
@@ -534 +585 @@
 
     /**
+     * Switch the interal blog id.
+     *
+     * This changes the blog id used to create keys in blog specific groups.
+     *
+     * @param int $blog_id Blog ID
+     */
+    function switch_to_blog( $blog_id ) {
+        $blog_id = (int) $blog_id;
+        $this->blog_prefix = $this->multisite ? $blog_id . ':' : '';
+    }
+
+    /**
      * Utility function to determine whether a key exists in the cache.
      *
@@ -551 +614 @@
      */
     function __construct() {
+        global $blog_id;
+
+        $this->multisite = is_multisite();
+        $this->blog_prefix =  $this->multisite ? $blog_id . ':' : '';
+        
+
         /**
          * @todo This should be moved to the PHP4 style constructor, PHP5
          * already calls __destruct()
          */
-        register_shutdown_function(array(&$this, "__destruct"));
+        register_shutdown_function( array( &$this, '__destruct' ) );
     }