WPMU Domain Mapping - Add object caching

object-cache.patch

Index: domain_mapping.php
===================================================================
--- domain_mapping.php
+++ domain_mapping.php
@@ -30,6 +30,14 @@
 }
 add_action( 'init', 'dm_text_domain' );
 
+/**
+ * Registers our cache group globally with WordPress.
+ */
+function dm_cache_add_global_group() {
+	wp_cache_add_global_groups( 'wpmu-dm' );
+}
+add_action( 'plugins_loaded', 'dm_cache_add_global_group' );
+
 function domain_mapping_warning() {
 	echo "<div id='domain-mapping-warning' class='updated fade'><p><strong>".__( 'Domain Mapping Disabled.', 'wordpress-mu-domain-mapping' )."</strong> ".sprintf(__('You must <a href="%1$s">create a network</a> for it to work.', 'wordpress-mu-domain-mapping' ), "http://codex.wordpress.org/Create_A_Network")."</p></div>";
 }
@@ -155,9 +163,13 @@
 						$wpdb->query( $wpdb->prepare( "UPDATE {$wpdb->dmtable} SET blog_id = %d, domain = %s, active = %d WHERE domain = %s", $_POST[ 'blog_id' ], $domain, $_POST[ 'active' ], $_POST[ 'orig_domain' ] ) );
 						echo "<p><strong>" . __( 'Domain Updated', 'wordpress-mu-domain-mapping' ) . "</strong></p>";
 					}
+
+					wp_cache_delete( (int) $_POST['blog_id'], 'wpmu-dm' );
 				}
 			break;
 			case "del":
+				do_action( 'dm_handle_actions_del', $domain );
+
 				$wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->dmtable} WHERE domain = %s", $domain ) );
 				echo "<p><strong>" . __( 'Domain Deleted', 'wordpress-mu-domain-mapping' ) . "</strong></p>";
 			break;
@@ -504,45 +516,96 @@
 	echo "</div>";
 }
 
+/**
+ * Fetch the site URL for the current site.
+ *
+ * If the current site is a mapped domain, it will return the mapped site URL.
+ * If the current site is not mapped, it will return the subdomain site URL.
+ *
+ * @param mixed $setting Does nothing?
+ */
 function domain_mapping_siteurl( $setting ) {
-	global $wpdb, $current_blog;
-
-	// To reduce the number of database queries, save the results the first time we encounter each blog ID.
-	static $return_url = array();
+	global $wpdb;
 
 	$wpdb->dmtable = $wpdb->base_prefix . 'domain_mapping';
 
-	if ( !isset( $return_url[ $wpdb->blogid ] ) ) {
-		$s = $wpdb->suppress_errors();
+	// Fetch cached domain mapping data for the blog ID.
+	$dm = domain_mapping_get_data_by_id();
 
-		if ( get_site_option( 'dm_no_primary_domain' ) == 1 ) {
-			$domain = $wpdb->get_var( "SELECT domain FROM {$wpdb->dmtable} WHERE blog_id = '{$wpdb->blogid}' AND domain = '" . $wpdb->escape( $_SERVER[ 'HTTP_HOST' ] ) . "' LIMIT 1" );
-			if ( null == $domain ) {
-				$return_url[ $wpdb->blogid ] = untrailingslashit( get_original_url( "siteurl" ) );
-				return $return_url[ $wpdb->blogid ];
+	// Disable primary domain option is set.
+	if ( get_site_option( 'dm_no_primary_domain' ) == 1 ) {
+		//$domain = $wpdb->get_var( "SELECT domain FROM {$wpdb->dmtable} WHERE blog_id = '{$wpdb->blogid}' AND domain = '" . $wpdb->escape( $_SERVER[ 'HTTP_HOST' ] ) . "' LIMIT 1" );
+
+		$key = null;
+		if ( ! empty( $dm ) ) {
+			foreach ( $dm as $k => $d ) {
+				if ( $wpdb->escape( $_SERVER[ 'HTTP_HOST' ] ) === $d->domain ) {
+					$key = $k;
+				}
 			}
+		}
+
+		if ( null === $key ) {
+			return untrailingslashit( get_original_url( 'siteurl' ) );
 		} else {
-			// get primary domain, if we don't have one then return original url.
-			$domain = $wpdb->get_var( "SELECT domain FROM {$wpdb->dmtable} WHERE blog_id = '{$wpdb->blogid}' AND active = 1 LIMIT 1" );
-			if ( null == $domain ) {
-				$return_url[ $wpdb->blogid ] = untrailingslashit( get_original_url( "siteurl" ) );
-				return $return_url[ $wpdb->blogid ];
+			$domain = $dm[$key]->domain;
+		}
+
+	} else {
+		// get primary domain, if we don't have one then return original url.
+		//$domain = $wpdb->get_var( "SELECT domain FROM {$wpdb->dmtable} WHERE blog_id = '{$wpdb->blogid}' AND active = 1 LIMIT 1" );
+
+		$key = null;
+		if ( ! empty( $dm ) ) {
+			foreach( $dm as $k => $d ) {
+				if ( $d->active ) {
+					$key = $k;
+				}
 			}
 		}
 
-		$wpdb->suppress_errors( $s );
-		$protocol = is_ssl() ? 'https://' : 'http://';
-		if ( $domain ) {
-			$return_url[ $wpdb->blogid ] = untrailingslashit( $protocol . $domain  );
-			$setting = $return_url[ $wpdb->blogid ];
+		if ( null === $key ) {
+			return untrailingslashit( get_original_url( 'siteurl' ) );
 		} else {
-			$return_url[ $wpdb->blogid ] = false;
+			$domain = $dm[$key]->domain;
 		}
-	} elseif ( $return_url[ $wpdb->blogid ] !== FALSE) {
-		$setting = $return_url[ $wpdb->blogid ];
 	}
 
-	return $setting;
+	$protocol = is_ssl() ? 'https://' : 'http://';
+
+	return untrailingslashit( $protocol . $domain  );
+}
+
+/**
+ * Fetch domain mapping data by blog ID.
+ *
+ * @param  int $blog_id Blog ID to fetch domain mapping data for.
+ * @return object|null  Object on success, null on failure.
+ */
+function domain_mapping_get_data_by_id( $blog_id = 0 ) {
+	global $wpdb;
+
+	if ( empty( $blog_id ) ) {
+		$blog_id = $wpdb->blogid;
+	}
+	$blog_id = (int) $blog_id;
+
+	// Fetch cached domain mapping data for the site ID.
+	$dm = wp_cache_get( $blog_id, 'wpmu-dm' );
+
+	// Not in cache, so query for the data.
+	if ( false === $dm ) {
+		$s = $wpdb->suppress_errors();
+		$dm = $wpdb->get_results( "SELECT * FROM {$wpdb->dmtable} WHERE blog_id = '{$blog_id}'" );
+		$wpdb->suppress_errors( $s );
+
+		$dm = ! empty( $dm ) ? $dm : null;
+
+		// Cache it.
+		wp_cache_set( $blog_id, $dm, 'wpmu-dm' );
+	}
+
+	return $dm;
 }
 
 // url is siteurl or home
@@ -671,6 +734,20 @@
 if ( isset( $_GET[ 'dm' ] ) )
 	add_action( 'template_redirect', 'remote_login_js' );
 
+/**
+ * Clear cache when domain mapping is changed.
+ */
+add_action( 'dm_handle_actions_init', function( $domain ) {
+	$blog_id = (int) $_POST['blog_id'];
+	wp_cache_delete( $blog_id, 'wpmu-dm' );
+} );
+add_action( 'dm_handle_actions_del', function( $domain ) {
+	global $wpdb;
+
+	$blog_id = (int) $wpdb->get_var( "SELECT blog_id FROM {$wpdb->dmtable} WHERE domain = '{$domain}'" );
+	wp_cache_delete( $blog_id, 'wpmu-dm' );
+} );
+
 function remote_logout_loader() {
 	global $current_site, $current_blog, $wpdb;
 	$wpdb->dmtablelogins = $wpdb->base_prefix . 'domain_mapping_logins';