I18N: Change how WP_Textdomain_Registry stores the default languages path.

`WP_Textdomain_Registry` was introduced in [53874] to store text domains and their language directory paths, addressing issues with just-in-time loading of textdomains when using locale switching and when using`load_*_textdomain()` functions.

Said change has inadvertently caused a performance regression exactly when using`load_*_textdomain()`, which still often is the case, where the cached information was not further used or even overridden.

This change addresses that issue by storing the default languages paths in a separate way, while at the same time making `WP_Textdomain_Registry` easier to maintain and adding new tests to catch future regressions.

Props flixos90, spacedmonkey, ocean90, SergeyBiryukov, costdev.
Merges [54669] to the 6.1 branch.
See #39210.

git-svn-id: https://develop.svn.wordpress.org/branches/6.1@54682 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-textdomain-registry.php

@@ -32,6 +32,18 @@ class WP_Textdomain_Registry {
 	 */
 	protected $current = array();
 
+	/**
+	 * List of domains and their custom language directory paths.
+	 *
+	 * @see load_plugin_textdomain()
+	 * @see load_theme_textdomain()
+	 *
+	 * @since 6.1.0
+	 *
+	 * @var array
+	 */
+	protected $custom_paths = array();
+
 	/**
 	 * Holds a cached list of available .mo files to improve performance.
 	 *
@@ -42,7 +54,7 @@ class WP_Textdomain_Registry {
 	protected $cached_mo_files;
 
 	/**
-	 * Returns the MO file path for a specific domain and locale.
+	 * Returns the languages directory path for a specific domain and locale.
 	 *
 	 * @since 6.1.0
 	 *
@@ -62,33 +74,21 @@ class WP_Textdomain_Registry {
 	/**
 	 * Determines whether any MO file paths are available for the domain.
 	 *
+	 * This is the case if a path has been set for the current locale,
+	 * or if there is no information stored yet, in which case
+	 * {@see _load_textdomain_just_in_time()} will fetch the information first.
+	 *
 	 * @since 6.1.0
 	 *
 	 * @param string $domain Text domain.
 	 * @return bool Whether any MO file paths are available for the domain.
 	 */
 	public function has( $domain ) {
-		return ! empty( $this->all[ $domain ] );
+		return ! empty( $this->current[ $domain ] ) || empty( $this->all[ $domain ] );
 	}
 
 	/**
-	 * Returns the current (most recent) MO file path for a specific domain.
-	 *
-	 * @since 6.1.0
-	 *
-	 * @param string $domain Text domain.
-	 * @return string|false Current MO file path or false if there is none available.
-	 */
-	public function get_current( $domain ) {
-		if ( isset( $this->current[ $domain ] ) ) {
-			return $this->current[ $domain ];
-		}
-
-		return false;
-	}
-
-	/**
-	 * Sets the MO file path for a specific domain and locale.
+	 * Sets the language directory path for a specific domain and locale.
 	 *
 	 * Also sets the 'current' property for direct access
 	 * to the path for the current (most recent) locale.
@@ -105,81 +105,84 @@ class WP_Textdomain_Registry {
 	}
 
 	/**
-	 * Resets the registry state.
+	 * Sets the custom path to the plugin's/theme's languages directory.
 	 *
-	 * @since 6.1.0
+	 * Used by {@see load_plugin_textdomain()} and {@see load_theme_textdomain()}.
+	 *
+	 * @param string $domain Text domain.
+	 * @param string $path   Language directory path.
 	 */
-	public function reset() {
-		$this->cached_mo_files = null;
-		$this->all             = array();
-		$this->current         = array();
+	public function set_custom_path( $domain, $path ) {
+		$this->custom_paths[ $domain ] = untrailingslashit( $path );
 	}
 
 	/**
-	 * Gets the path to a translation file in the languages directory for the current locale.
+	 * Gets the path to the language directory for the current locale.
+	 *
+	 * Checks the plugins and themes language directories as well as any
+	 * custom directory set via {@see load_plugin_textdomain()} or {@see load_theme_textdomain()}.
 	 *
 	 * @since 6.1.0
 	 *
+	 * @see _get_path_to_translation_from_lang_dir()
+	 *
 	 * @param string $domain Text domain.
 	 * @param string $locale Locale.
-	 * @return string|false MO file path or false if there is none available.
+	 * @return string|false Language directory path or false if there is none available.
 	 */
 	private function get_path_from_lang_dir( $domain, $locale ) {
-		if ( null === $this->cached_mo_files ) {
-			$this->set_cached_mo_files();
+		$locations = array(
+			WP_LANG_DIR . '/plugins',
+			WP_LANG_DIR . '/themes',
+		);
+
+		if ( isset( $this->custom_paths[ $domain ] ) ) {
+			$locations[] = $this->custom_paths[ $domain ];
 		}
 
-		$mofile = "{$domain}-{$locale}.mo";
+		$mofile = "$domain-$locale.mo";
 
-		$path = WP_LANG_DIR . '/plugins/' . $mofile;
+		foreach ( $locations as $location ) {
+			if ( ! isset( $this->cached_mo_files[ $location ] ) ) {
+				$this->set_cached_mo_files( $location );
+			}
 
-		if ( in_array( $path, $this->cached_mo_files, true ) ) {
-			$path = WP_LANG_DIR . '/plugins/';
+			$path = $location . '/' . $mofile;
+
+			if ( in_array( $path, $this->cached_mo_files[ $location ], true ) ) {
+				$this->set( $domain, $locale, $location );
+
+				return trailingslashit( $location );
+			}
+		}
+
+		// If no path is found for the given locale and a custom path has been set
+		// using load_plugin_textdomain/load_theme_textdomain, use that one.
+		if ( 'en_US' !== $locale && isset( $this->custom_paths[ $domain ] ) ) {
+			$path = trailingslashit( $this->custom_paths[ $domain ] );
 			$this->set( $domain, $locale, $path );
-
 			return $path;
 		}
 
-		$path = WP_LANG_DIR . '/themes/' . $mofile;
-		if ( in_array( $path, $this->cached_mo_files, true ) ) {
-			$path = WP_LANG_DIR . '/themes/';
-			$this->set( $domain, $locale, $path );
-
-			return $path;
-		}
-
-		// If no path is found for the given locale, check if an entry for the default
-		// en_US locale exists. This is the case when e.g. using load_plugin_textdomain
-		// with a custom path.
-		if ( 'en_US' !== $locale && isset( $this->all[ $domain ]['en_US'] ) ) {
-			$this->set( $domain, $locale, $this->all[ $domain ]['en_US'] );
-			return $this->all[ $domain ]['en_US'];
-		}
-
 		$this->set( $domain, $locale, false );
 
 		return false;
 	}
 
 	/**
-	 * Reads and caches all available MO files from the plugins and themes language directories.
+	 * Reads and caches all available MO files from a given directory.
 	 *
 	 * @since 6.1.0
+	 *
+	 * @param string $path Language directory path.
 	 */
-	protected function set_cached_mo_files() {
-		$this->cached_mo_files = array();
+	private function set_cached_mo_files( $path ) {
+		$this->cached_mo_files[ $path ] = array();
 
-		$locations = array(
-			WP_LANG_DIR . '/plugins',
-			WP_LANG_DIR . '/themes',
-		);
+		$mo_files = glob( $path . '/*.mo' );
 
-		foreach ( $locations as $location ) {
-			$mo_files = glob( $location . '/*.mo' );
-
-			if ( $mo_files ) {
-				$this->cached_mo_files = array_merge( $this->cached_mo_files, $mo_files );
-			}
+		if ( $mo_files ) {
+			$this->cached_mo_files[ $path ] = $mo_files;
 		}
 	}
 }

src/wp-includes/l10n.php

@@ -934,7 +934,7 @@ function load_plugin_textdomain( $domain, $deprecated = false, $plugin_rel_path
 		$path = WP_PLUGIN_DIR;
 	}
 
-	$wp_textdomain_registry->set( $domain, $locale, $path );
+	$wp_textdomain_registry->set_custom_path( $domain, $path );
 
 	return load_textdomain( $domain, $path . '/' . $mofile, $locale );
 }
@@ -968,7 +968,7 @@ function load_muplugin_textdomain( $domain, $mu_plugin_rel_path = '' ) {
 
 	$path = WPMU_PLUGIN_DIR . '/' . ltrim( $mu_plugin_rel_path, '/' );
 
-	$wp_textdomain_registry->set( $domain, $locale, $path );
+	$wp_textdomain_registry->set_custom_path( $domain, $path );
 
 	return load_textdomain( $domain, $path . '/' . $mofile, $locale );
 }
@@ -1016,7 +1016,7 @@ function load_theme_textdomain( $domain, $path = false ) {
 		$path = get_template_directory();
 	}
 
-	$wp_textdomain_registry->set( $domain, $locale, $path );
+	$wp_textdomain_registry->set_custom_path( $domain, $path );
 
 	return load_textdomain( $domain, $path . '/' . $locale . '.mo', $locale );
 }
@@ -1265,7 +1265,7 @@ function _load_textdomain_just_in_time( $domain ) {
 		return false;
 	}
 
-	if ( $wp_textdomain_registry->has( $domain ) && ! $wp_textdomain_registry->get_current( $domain ) ) {
+	if ( ! $wp_textdomain_registry->has( $domain ) ) {
 		return false;
 	}
 

tests/phpunit/tests/l10n/loadTextdomain.php

@@ -28,7 +28,7 @@ class Tests_L10n_LoadTextdomain extends WP_UnitTestCase {
 		/** @var WP_Textdomain_Registry $wp_textdomain_registry */
 		global $wp_textdomain_registry;
 
-		$wp_textdomain_registry->reset();
+		$wp_textdomain_registry = new WP_Textdomain_Registry();
 	}
 
 	public function tear_down() {
@@ -36,7 +36,7 @@ class Tests_L10n_LoadTextdomain extends WP_UnitTestCase {
 		/** @var WP_Textdomain_Registry $wp_textdomain_registry */
 		global $wp_textdomain_registry;
 
-		$wp_textdomain_registry->reset();
+		$wp_textdomain_registry = new WP_Textdomain_Registry();
 
 		parent::tear_down();
 	}

tests/phpunit/tests/l10n/loadTextdomainJustInTime.php

@@ -8,7 +8,6 @@ class Tests_L10n_LoadTextdomainJustInTime extends WP_UnitTestCase {
 	protected $orig_theme_dir;
 	protected $theme_root;
 	protected static $user_id;
-	private $locale_count;
 
 	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 		self::$user_id = $factory->user->create(
@@ -24,7 +23,6 @@ class Tests_L10n_LoadTextdomainJustInTime extends WP_UnitTestCase {
 
 		$this->theme_root     = DIR_TESTDATA . '/themedir1';
 		$this->orig_theme_dir = $GLOBALS['wp_theme_directories'];
-		$this->locale_count   = 0;
 
 		// /themes is necessary as theme.php functions assume /themes is the root if there is only one root.
 		$GLOBALS['wp_theme_directories'] = array( WP_CONTENT_DIR . '/themes', $this->theme_root );
@@ -37,7 +35,7 @@ class Tests_L10n_LoadTextdomainJustInTime extends WP_UnitTestCase {
 		/** @var WP_Textdomain_Registry $wp_textdomain_registry */
 		global $wp_textdomain_registry;
 
-		$wp_textdomain_registry->reset();
+		$wp_textdomain_registry = new WP_Textdomain_Registry();
 	}
 
 	public function tear_down() {
@@ -48,7 +46,7 @@ class Tests_L10n_LoadTextdomainJustInTime extends WP_UnitTestCase {
 		/** @var WP_Textdomain_Registry $wp_textdomain_registry */
 		global $wp_textdomain_registry;
 
-		$wp_textdomain_registry->reset();
+		$wp_textdomain_registry = new WP_Textdomain_Registry();
 
 		parent::tear_down();
 	}
@@ -262,7 +260,8 @@ class Tests_L10n_LoadTextdomainJustInTime extends WP_UnitTestCase {
 	public function test_get_locale_is_called_only_once_per_textdomain() {
 		$textdomain = 'foo-bar-baz';
 
-		add_filter( 'locale', array( $this, '_filter_locale_count' ) );
+		$filter = new MockAction();
+		add_filter( 'locale', array( $filter, 'filter' ) );
 
 		__( 'Foo', $textdomain );
 		__( 'Bar', $textdomain );
@@ -270,15 +269,31 @@ class Tests_L10n_LoadTextdomainJustInTime extends WP_UnitTestCase {
 		__( 'Foo Bar', $textdomain );
 		__( 'Foo Bar Baz', $textdomain );
 
-		remove_filter( 'locale', array( $this, '_filter_locale_count' ) );
+		$this->assertFalse( is_textdomain_loaded( $textdomain ) );
+		$this->assertSame( 1, $filter->get_call_count() );
+	}
+
+	/**
+	 * @ticket 37997
+	 * @ticket 39210
+	 *
+	 * @covers ::_load_textdomain_just_in_time
+	 */
+	public function test_get_locale_is_called_only_once_per_textdomain_with_custom_lang_dir() {
+		load_plugin_textdomain( 'custom-internationalized-plugin', false, dirname( plugin_basename( __FILE__ ) ) . '/languages' );
+
+		$textdomain = 'custom-internationalized-plugin';
+
+		$filter = new MockAction();
+		add_filter( 'locale', array( $filter, 'filter' ) );
+
+		__( 'Foo', $textdomain );
+		__( 'Bar', $textdomain );
+		__( 'Baz', $textdomain );
+		__( 'Foo Bar', $textdomain );
+		__( 'Foo Bar Baz', $textdomain );
 
 		$this->assertFalse( is_textdomain_loaded( $textdomain ) );
-		$this->assertSame( 1, $this->locale_count );
-	}
-
-	public function _filter_locale_count( $locale ) {
-		++$this->locale_count;
-
-		return $locale;
+		$this->assertSame( 1, $filter->get_call_count() );
 	}
 }

tests/phpunit/tests/l10n/wpLocaleSwitcher.php

@@ -27,7 +27,7 @@ class Tests_L10n_wpLocaleSwitcher extends WP_UnitTestCase {
 		/** @var WP_Textdomain_Registry $wp_textdomain_registry */
 		global $wp_textdomain_registry;
 
-		$wp_textdomain_registry->reset();
+		$wp_textdomain_registry = new WP_Textdomain_Registry();
 	}
 
 	public function tear_down() {
@@ -36,7 +36,7 @@ class Tests_L10n_wpLocaleSwitcher extends WP_UnitTestCase {
 		/** @var WP_Textdomain_Registry $wp_textdomain_registry */
 		global $wp_textdomain_registry;
 
-		$wp_textdomain_registry->reset();
+		$wp_textdomain_registry = new WP_Textdomain_Registry();
 
 		parent::tear_down();
 	}
@@ -478,11 +478,12 @@ class Tests_L10n_wpLocaleSwitcher extends WP_UnitTestCase {
 
 		require_once DIR_TESTDATA . '/plugins/custom-internationalized-plugin/custom-internationalized-plugin.php';
 
-		$registry_value = $wp_textdomain_registry->get( 'custom-internationalized-plugin', determine_locale() );
-
 		$actual = custom_i18n_plugin_test();
 
 		switch_to_locale( 'es_ES' );
+
+		$registry_value = $wp_textdomain_registry->get( 'custom-internationalized-plugin', determine_locale() );
+
 		switch_to_locale( 'de_DE' );
 
 		$actual_de_de = custom_i18n_plugin_test();
@@ -517,11 +518,12 @@ class Tests_L10n_wpLocaleSwitcher extends WP_UnitTestCase {
 
 		require_once get_stylesheet_directory() . '/functions.php';
 
-		$registry_value = $wp_textdomain_registry->get( 'custom-internationalized-theme', determine_locale() );
-
 		$actual = custom_i18n_theme_test();
 
 		switch_to_locale( 'es_ES' );
+
+		$registry_value = $wp_textdomain_registry->get( 'custom-internationalized-theme', determine_locale() );
+
 		switch_to_locale( 'de_DE' );
 
 		$actual_de_de = custom_i18n_theme_test();

tests/phpunit/tests/l10n/wpTextdomainRegistry.php

@@ -0,0 +1,150 @@
+<?php
+
+/**
+ * @group l10n
+ * @group i18n
+ *
+ * @coversDefaultClass WP_Textdomain_Registry
+ */
+class Tests_L10n_wpTextdomainRegistry extends WP_UnitTestCase {
+	/**
+	 * @var WP_Textdomain_Registry
+	 */
+	protected $instance;
+
+	public function set_up() {
+		parent::set_up();
+
+		$this->instance = new WP_Textdomain_Registry();
+	}
+
+	/**
+	 * @covers ::has
+	 * @covers ::get
+	 * @covers ::set_custom_path
+	 */
+	public function test_set_custom_path() {
+		$reflection          = new ReflectionClass( $this->instance );
+		$reflection_property = $reflection->getProperty( 'cached_mo_files' );
+		$reflection_property->setAccessible( true );
+
+		$this->assertNull(
+			$reflection_property->getValue( $this->instance ),
+			'Cache not empty by default'
+		);
+
+		$this->instance->set_custom_path( 'foo', WP_LANG_DIR . '/bar' );
+
+		$this->assertTrue(
+			$this->instance->has( 'foo' ),
+			'Incorrect availability status for textdomain with custom path'
+		);
+		$this->assertFalse(
+			$this->instance->get( 'foo', 'en_US' ),
+			'Should not return custom path for textdomain and en_US locale'
+		);
+		$this->assertSame(
+			WP_LANG_DIR . '/bar/',
+			$this->instance->get( 'foo', 'de_DE' ),
+			'Custom path for textdomain not returned'
+		);
+		$this->assertArrayHasKey(
+			WP_LANG_DIR . '/bar',
+			$reflection_property->getValue( $this->instance ),
+			'Custom path missing from cache'
+		);
+	}
+
+	/**
+	 * @covers ::get
+	 * @dataProvider data_domains_locales
+	 */
+	public function test_get( $domain, $locale, $expected ) {
+		$reflection          = new ReflectionClass( $this->instance );
+		$reflection_property = $reflection->getProperty( 'cached_mo_files' );
+		$reflection_property->setAccessible( true );
+
+		$actual = $this->instance->get( $domain, $locale );
+		$this->assertSame(
+			$expected,
+			$actual,
+			'Expected languages directory path not matching actual one'
+		);
+
+		$this->assertArrayHasKey(
+			WP_LANG_DIR . '/plugins',
+			$reflection_property->getValue( $this->instance ),
+			'Default plugins path missing from cache'
+		);
+	}
+
+	/**
+	 * @covers ::get_path_from_lang_dir
+	 */
+	public function test_get_does_not_check_themes_directory_for_plugin() {
+		$reflection          = new ReflectionClass( $this->instance );
+		$reflection_property = $reflection->getProperty( 'cached_mo_files' );
+		$reflection_property->setAccessible( true );
+
+		$this->instance->get( 'internationalized-plugin', 'de_DE' );
+
+		$this->assertArrayHasKey(
+			WP_LANG_DIR . '/plugins',
+			$reflection_property->getValue( $this->instance ),
+			'Default plugins path missing from cache'
+		);
+		$this->assertArrayNotHasKey(
+			WP_LANG_DIR . '/themes',
+			$reflection_property->getValue( $this->instance ),
+			'Default themes path should not be in cache'
+		);
+	}
+
+	/**
+	 * @covers ::set
+	 * @covers ::get
+	 */
+	public function test_set_populates_cache() {
+		$this->instance->set( 'foo-plugin', 'de_DE', '/foo/bar' );
+
+		$this->assertSame(
+			'/foo/bar/',
+			$this->instance->get( 'foo-plugin', 'de_DE' )
+		);
+	}
+
+	public function data_domains_locales() {
+		return array(
+			'Non-existent plugin'            => array(
+				'unknown-plugin',
+				'en_US',
+				false,
+			),
+			'Non-existent plugin with de_DE' => array(
+				'unknown-plugin',
+				'de_DE',
+				false,
+			),
+			'Available de_DE translations'   => array(
+				'internationalized-plugin',
+				'de_DE',
+				WP_LANG_DIR . '/plugins/',
+			),
+			'Available es_ES translations'   => array(
+				'internationalized-plugin',
+				'es_ES',
+				WP_LANG_DIR . '/plugins/',
+			),
+			'Unavailable fr_FR translations' => array(
+				'internationalized-plugin',
+				'fr_FR',
+				false,
+			),
+			'Unavailable en_US translations' => array(
+				'internationalized-plugin',
+				'en_US',
+				false,
+			),
+		);
+	}
+}