From 9fed3f0fd3aeb66f06097a40a7cad9a34fb5020a Mon Sep 17 00:00:00 2001
From: Amir Sarabadani <ladsgroup@gmail.com>
Date: Wed, 11 Jul 2018 16:44:28 +0200
Subject: [PATCH] Add config to use change_tag_def table for Special:Tags

Bug: T199334
Change-Id: Ieb8709caf0d8ee16086296baa75f751c7723c101
---
 includes/DefaultSettings.php                  | 12 +++++
 includes/changetags/ChangeTags.php            | 30 +++++++++++
 .../includes/changetags/ChangeTagsTest.php    | 52 +++++++++++++++++++
 3 files changed, 94 insertions(+)

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 26428842f9..9f9d8ba08f 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -8944,6 +8944,18 @@ $wgExpiryWidgetNoDatePicker = false;
  */
 $wgChangeTagsSchemaMigrationStage = MIGRATION_OLD;
 
+/**
+ * Temporarily flag to use change_tag_def table as backend of change tag statistics.
+ * For example in case of Special:Tags. If set to false, it will use change_tag table.
+ * Before setting it to true set $wgChangeTagsSchemaMigrationStage to MIGRATION_WRITE_BOTH and run
+ * PopulateChangeTagDef maintaince script.
+ * It's redundant when $wgChangeTagsSchemaMigrationStage is set to MIGRATION_NEW
+ *
+ * @since 1.32
+ * @var bool
+ */
+$wgTagStatisticsNewTable = false;
+
 /**
  * For really cool vim folding this needs to be at the end:
  * vim: foldmarker=@{,@} foldmethod=marker
diff --git a/includes/changetags/ChangeTags.php b/includes/changetags/ChangeTags.php
index 7874640849..3bb777ec73 100644
--- a/includes/changetags/ChangeTags.php
+++ b/includes/changetags/ChangeTags.php
@@ -1507,6 +1507,13 @@ class ChangeTags {
 	 * @return array Array of string => int
 	 */
 	public static function tagUsageStatistics() {
+		global $wgChangeTagsSchemaMigrationStage, $wgTagStatisticsNewTable;
+		if ( $wgChangeTagsSchemaMigrationStage > MIGRATION_WRITE_BOTH ||
+			( $wgTagStatisticsNewTable && $wgChangeTagsSchemaMigrationStage > MIGRATION_OLD )
+		) {
+			return self::newTagUsageStatistics();
+		}
+
 		$fname = __METHOD__;
 		$cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
 		return $cache->getWithSetCallback(
@@ -1540,6 +1547,29 @@ class ChangeTags {
 		);
 	}
 
+	/**
+	 * Same self::tagUsageStatistics() but uses change_tag_def.
+	 *
+	 * @return array Array of string => int
+	 */
+	private static function newTagUsageStatistics() {
+		$dbr = wfGetDB( DB_REPLICA );
+		$res = $dbr->select(
+			'change_tag_def',
+			[ 'ctd_name', 'ctd_count' ],
+			[],
+			__METHOD__,
+			[ 'ORDER BY' => 'ctd_count DESC' ]
+		);
+
+		$out = [];
+		foreach ( $res as $row ) {
+			$out[$row->ctd_name] = $row->ctd_count;
+		}
+
+		return $out;
+	}
+
 	/**
 	 * Indicate whether change tag editing UI is relevant
 	 *
diff --git a/tests/phpunit/includes/changetags/ChangeTagsTest.php b/tests/phpunit/includes/changetags/ChangeTagsTest.php
index d7c8ec4520..03d0579a19 100644
--- a/tests/phpunit/includes/changetags/ChangeTagsTest.php
+++ b/tests/phpunit/includes/changetags/ChangeTagsTest.php
@@ -537,4 +537,56 @@ class ChangeTagsTest extends MediaWikiTestCase {
 		$this->assertEquals( $expected2, iterator_to_array( $res2, false ) );
 	}
 
+	public function testTagUsageStatisticsOldBackend() {
+		$this->setMwGlobals( 'wgChangeTagsSchemaMigrationStage', MIGRATION_OLD );
+		$this->setMwGlobals( 'wgTagStatisticsNewTable', false );
+
+		$dbw = wfGetDB( DB_MASTER );
+		$dbw->delete( 'change_tag', '*' );
+		$dbw->delete( 'change_tag_def', '*' );
+
+		$rcId = 123;
+		ChangeTags::updateTags( [ 'tag1', 'tag2' ], [], $rcId );
+
+		$rcId = 124;
+		ChangeTags::updateTags( [ 'tag1' ], [], $rcId );
+
+		$this->assertEquals( [ 'tag1' => 2, 'tag2' => 1 ], ChangeTags::tagUsageStatistics() );
+	}
+
+	public function testTagUsageStatisticsNewMigrationOldBackedn() {
+		$this->setMwGlobals( 'wgChangeTagsSchemaMigrationStage', MIGRATION_WRITE_BOTH );
+		$this->setMwGlobals( 'wgTagStatisticsNewTable', false );
+
+		$dbw = wfGetDB( DB_MASTER );
+		$dbw->delete( 'change_tag', '*' );
+		$dbw->delete( 'change_tag_def', '*' );
+		MediaWikiServices::getInstance()->resetServiceForTesting( 'ChangeTagDefStore' );
+
+		$rcId = 123;
+		ChangeTags::updateTags( [ 'tag1', 'tag2' ], [], $rcId );
+
+		$rcId = 124;
+		ChangeTags::updateTags( [ 'tag1' ], [], $rcId );
+
+		$this->assertEquals( [ 'tag1' => 2, 'tag2' => 1 ], ChangeTags::tagUsageStatistics() );
+	}
+
+	public function testTagUsageStatisticsNewBackend() {
+		$this->setMwGlobals( 'wgChangeTagsSchemaMigrationStage', MIGRATION_WRITE_BOTH );
+		$this->setMwGlobals( 'wgTagStatisticsNewTable', true );
+
+		$dbw = wfGetDB( DB_MASTER );
+		$dbw->delete( 'change_tag', '*' );
+		$dbw->delete( 'change_tag_def', '*' );
+		MediaWikiServices::getInstance()->resetServiceForTesting( 'ChangeTagDefStore' );
+
+		$rcId = 123;
+		ChangeTags::updateTags( [ 'tag1', 'tag2' ], [], $rcId );
+
+		$rcId = 124;
+		ChangeTags::updateTags( [ 'tag1' ], [], $rcId );
+
+		$this->assertEquals( [ 'tag1' => 2, 'tag2' => 1 ], ChangeTags::tagUsageStatistics() );
+	}
 }
-- 
2.20.1