Join decomposition on change_tag and change_tag_def when filtering

Since the service uses cache and MySQL also caches, this is faster

Bug: T194162
Change-Id: I57bbbf4f566d8140f9f80c16ecc454f857d363b2

diff --git a/includes/changetags/ChangeTags.php b/includes/changetags/ChangeTags.php
index 0bb8484..008a2f6 100644 (file)
--- a/includes/changetags/ChangeTags.php
+++ b/includes/changetags/ChangeTags.php
@@ -22,6 +22,7 @@
  */
 
 use MediaWiki\MediaWikiServices;
+use MediaWiki\Storage\NameTableAccessException;
 use Wikimedia\Rdbms\Database;
 
 class ChangeTags {
@@ -802,16 +803,18 @@ class ChangeTags {
                        throw new MWException( 'Unable to determine appropriate JOIN condition for tagging.' );
                }
 
+               $tagTables[] = 'change_tag';
                if ( $wgChangeTagsSchemaMigrationStage > MIGRATION_WRITE_BOTH ) {
-                       $tables[] = 'change_tag_def';
-                       $join_cond = [ $join_cond, 'ct_tag_id=ctd_id' ];
+                       $tagTables[] = 'change_tag_def';
+                       $join_cond_ts_tags = [ $join_cond, 'ct_tag_id=ctd_id' ];
                        $field = 'ctd_name';
                } else {
                        $field = 'ct_tag';
+                       $join_cond_ts_tags = $join_cond;
                }
 
                $fields['ts_tags'] = wfGetDB( DB_REPLICA )->buildGroupConcatField(
-                       ',', 'change_tag', $field, $join_cond
+                       ',', $tagTables, $field, $join_cond_ts_tags
                );
 
                if ( $wgUseTagFilter && $filter_tag ) {
@@ -821,9 +824,18 @@ class ChangeTags {
                        $tables[] = 'change_tag';
                        $join_conds['change_tag'] = [ 'INNER JOIN', $join_cond ];
                        if ( $wgChangeTagsSchemaMigrationStage > MIGRATION_WRITE_BOTH ) {
-                               $tables[] = 'change_tag_def';
-                               $join_conds['change_tag_def'] = [ 'INNER JOIN', 'ct_tag_id=ctd_id' ];
-                               $conds['ctd_name'] = $filter_tag;
+                               $filterTagIds = [];
+                               $changeTagDefStore = MediaWikiServices::getInstance()->getChangeTagDefStore();
+                               foreach ( (array)$filter_tag as $filterTagName ) {
+                                       try {
+                                               $filterTagIds[] = $changeTagDefStore->getId( $filterTagName );
+                                       } catch ( NameTableAccessException $exception ) {
+                                               // Return nothing.
+                                               $conds[] = '0';
+                                               break;
+                                       };
+                               }
+                               $conds['ct_tag_id'] = $filterTagIds;
                        } else {
                                $conds['ct_tag'] = $filter_tag;
                        }