Suspend cache invalidation while importing posts with WP importer

git-svn-id: http://svn.automattic.com/wordpress/trunk@9106 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/import/wordpress.php

@@ -717,10 +717,12 @@ class WP_Import {
 
 		$this->import_start();
 		$this->get_authors_from_post();
+		wp_suspend_cache_invalidation(true);
 		$this->get_entries();
 		$this->process_categories();
 		$this->process_tags();
 		$result = $this->process_posts();
+		wp_suspend_cache_invalidation(false);
 		$this->backfill_parents();
 		$this->backfill_attachment_urls();
 		$this->import_end();

wp-includes/functions.php

@@ -2847,4 +2847,24 @@ function wp_guess_url() {
 	return $url;
 }
 
+/**
+ * Suspend cache invalidation.
+ *
+ * Turns cache invalidation on and off.  Useful during imports where you don't wont to do invalidations
+ * every time a post is inserted.  Callers must be sure that what they are doing won't lead to an inconsistent
+ * cache when invalidation is suspended.
+ *
+ * @since 2.7.0
+ *
+ * @param bool $suspend Whether to suspend or enable cache invalidation
+ * @return bool The current suspend setting
+ */
+function wp_suspend_cache_invalidation($suspend = true) {
+	global $_wp_suspend_cache_invalidation;
+
+	$current_suspend = $_wp_suspend_cache_invalidation;
+	$_wp_suspend_cache_invalidation = $suspend;
+	return $current_suspend;
+}
+
 ?>

wp-includes/post.php

@@ -2861,7 +2861,11 @@ function update_post_cache(&$posts) {
  * @param int $id The Post ID in the cache to clean
  */
 function clean_post_cache($id) {
-	global $wpdb;
+	global $_wp_suspend_cache_invalidation, $wpdb;
+
+	if ( !empty($_wp_suspend_cache_invalidation) )
+		return;
+
 	$id = (int) $id;
 
 	wp_cache_delete($id, 'posts');