Introduce taxonomy-specific cache invalidation methods

src/wp-includes/class-wp-query.php

@@ -5064,7 +5064,13 @@ static function ( &$value ) use ( $wpdb, $placeholder ) {
 
 		$last_changed = wp_cache_get_last_changed( 'posts' );
 		if ( ! empty( $this->tax_query->queries ) ) {
-			$last_changed .= wp_cache_get_last_changed( 'terms' );
+			$taxonomies = array();
+			foreach ( $this->tax_query->queries as $tax_query ) {
+				if ( isset( $tax_query['taxonomy'] ) ) {
+					$taxonomies[] = $tax_query['taxonomy'];
+				}
+			}
+			$last_changed .= wp_cache_get_taxonomies_last_changed( $taxonomies );
 		}
 
 		$this->query_cache_key = "wp_query:$key:$last_changed";

src/wp-includes/class-wp-term-query.php

@@ -1172,7 +1172,23 @@ protected function generate_cache_key( array $args, $sql ) {
 		$sql = $wpdb->remove_placeholder_escape( $sql );
 
 		$key          = md5( serialize( $cache_args ) . $sql );
-		$last_changed = wp_cache_get_last_changed( 'terms' );
+		$last_changed = wp_cache_get_taxonomies_last_changed( (array) $args['taxonomy'] );
+		$meta_keys    = array(
+			'meta_key',
+			'meta_value',
+			'meta_compare',
+			'meta_compare_key',
+			'meta_type',
+			'meta_type_key',
+			'meta_query',
+		);
+		foreach ( $meta_keys as $meta_key ) {
+			if ( isset( $cache_args[ $meta_key ] ) ) {
+				$last_changed .= ':' . wp_cache_get_last_changed( 'term_meta' );
+				break;
+			}
+		}
+
 		return "get_terms:$key:$last_changed";
 	}
 }

src/wp-includes/default-filters.php

@@ -135,9 +135,9 @@
 add_action( 'remove_user_role', 'wp_cache_set_users_last_changed' );
 
 // Term meta.
-add_action( 'added_term_meta', 'wp_cache_set_terms_last_changed' );
-add_action( 'updated_term_meta', 'wp_cache_set_terms_last_changed' );
-add_action( 'deleted_term_meta', 'wp_cache_set_terms_last_changed' );
+add_action( 'added_term_meta', 'wp_cache_clear_term_meta' );
+add_action( 'updated_term_meta', 'wp_cache_clear_term_meta' );
+add_action( 'deleted_term_meta', 'wp_cache_clear_term_meta' );
 add_filter( 'get_term_metadata', 'wp_check_term_meta_support_prefilter' );
 add_filter( 'add_term_metadata', 'wp_check_term_meta_support_prefilter' );
 add_filter( 'update_term_metadata', 'wp_check_term_meta_support_prefilter' );

src/wp-includes/link-template.php

@@ -2007,7 +2007,7 @@ function get_adjacent_post( $in_same_term = false, $excluded_terms = '', $previo
 	$key          = md5( $query );
 	$last_changed = wp_cache_get_last_changed( 'posts' );
 	if ( $in_same_term || ! empty( $excluded_terms ) ) {
-		$last_changed .= wp_cache_get_last_changed( 'terms' );
+		$last_changed .= wp_cache_get_taxonomy_last_changed( $taxonomy );
 	}
 	$cache_key = "adjacent_post:$key:$last_changed";
 

src/wp-includes/taxonomy.php

@@ -890,14 +890,15 @@ function get_objects_in_term( $term_ids, $taxonomies, $args = array() ) {
 
 	$term_ids = array_map( 'intval', $term_ids );
 
+	$last_changed = wp_cache_get_taxonomies_last_changed( $taxonomies );
+
 	$taxonomies = "'" . implode( "', '", array_map( 'esc_sql', $taxonomies ) ) . "'";
 	$term_ids   = "'" . implode( "', '", $term_ids ) . "'";
 
 	$sql = "SELECT tr.object_id FROM $wpdb->term_relationships AS tr INNER JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN ($taxonomies) AND tt.term_id IN ($term_ids) ORDER BY tr.object_id $order";
 
-	$last_changed = wp_cache_get_last_changed( 'terms' );
-	$cache_key    = 'get_objects_in_term:' . md5( $sql ) . ":$last_changed";
-	$cache        = wp_cache_get( $cache_key, 'term-queries' );
+	$cache_key = 'get_objects_in_term:' . md5( $sql ) . ":$last_changed";
+	$cache     = wp_cache_get( $cache_key, 'term-queries' );
 	if ( false === $cache ) {
 		$object_ids = $wpdb->get_col( $sql );
 		wp_cache_set( $cache_key, $object_ids, 'term-queries' );
@@ -2950,6 +2951,7 @@ function wp_set_object_terms( $object_id, $terms, $taxonomy, $append = false ) {
 
 	wp_cache_delete( $object_id, $taxonomy . '_relationships' );
 	wp_cache_set_terms_last_changed();
+	wp_cache_set_taxonomy_last_changed( $taxonomy );
 
 	/**
 	 * Fires after an object's terms have been set.
@@ -3048,6 +3050,7 @@ function wp_remove_object_terms( $object_id, $terms, $taxonomy ) {
 
 		wp_cache_delete( $object_id, $taxonomy . '_relationships' );
 		wp_cache_set_terms_last_changed();
+		wp_cache_set_taxonomy_last_changed( $taxonomy );
 
 		/**
 		 * Fires immediately after an object-term relationship is deleted.
@@ -3631,10 +3634,14 @@ function clean_object_term_cache( $object_ids, $object_type ) {
 
 	$taxonomies = get_object_taxonomies( $object_type );
 
+	$cache_keys = array();
 	foreach ( $taxonomies as $taxonomy ) {
 		wp_cache_delete_multiple( $object_ids, "{$taxonomy}_relationships" );
+		$cache_keys[] = $taxonomy . ':last_changed';
 	}
 
+	wp_cache_delete_multiple( $cache_keys, 'terms' );
+
 	wp_cache_set_terms_last_changed();
 
 	/**
@@ -3697,6 +3704,8 @@ function clean_term_cache( $ids, $taxonomy = '', $clean_taxonomy = true ) {
 			clean_taxonomy_cache( $taxonomy );
 		}
 
+		wp_cache_set_taxonomy_last_changed( $taxonomy );
+
 		/**
 		 * Fires once after each taxonomy's term cache has been cleaned.
 		 *
@@ -3723,6 +3732,7 @@ function clean_term_cache( $ids, $taxonomy = '', $clean_taxonomy = true ) {
 function clean_taxonomy_cache( $taxonomy ) {
 	wp_cache_delete( 'all_ids', $taxonomy );
 	wp_cache_delete( 'get', $taxonomy );
+	wp_cache_set_taxonomy_last_changed( $taxonomy );
 	wp_cache_set_terms_last_changed();
 
 	// Regenerate cached hierarchy.
@@ -5105,6 +5115,85 @@ function is_term_publicly_viewable( $term ) {
 	return is_taxonomy_viewable( $term->taxonomy );
 }
 
+
+/**
+ * Clears the term meta cache and updates the last changed timestamp for the term and its taxonomy.
+ *
+ * This function ensures that the cache for the given term and its associated taxonomy is invalidated,
+ * and marks them as "last changed" to reflect the updates or changes made to the meta data.
+ *
+ * @since x.x.x
+ */
+function wp_cache_clear_term_meta() {
+	wp_cache_set_terms_last_changed();
+	wp_cache_set_last_changed( 'term_meta' );
+}
+
+/**
+ * Sets the last changed time for a specific taxonomy in the cache.
+ *
+ * This function updates the cached value to track when the taxonomy data was last changed.
+ *
+ * @since x.x.x
+ *
+ * @param string $taxonomy The taxonomy slug to update the last changed time for.
+ * @return string The microtime when the taxonomy was last changed.
+ */
+function wp_cache_set_taxonomy_last_changed( $taxonomy ) {
+	$time = microtime();
+
+	wp_cache_set( $taxonomy . ':last_changed', $time, 'terms' );
+
+	return $time;
+}
+
+/**
+ * Retrieves the last changed time for a taxonomy.
+ *
+ * @since x.x.x
+ *
+ * @param string $taxonomy Taxonomy name.
+ * @return float UNIX timestamp with microseconds representing when the taxonomy was last changed.
+ */
+function wp_cache_get_taxonomy_last_changed( $taxonomy ) {
+	if ( ! $taxonomy ) {
+		return wp_cache_get_last_changed( 'terms' );
+	}
+	$last_changed = wp_cache_get( $taxonomy . ':last_changed', 'terms' );
+
+	if ( $last_changed ) {
+		return $last_changed;
+	}
+
+	return wp_cache_set_taxonomy_last_changed( $taxonomy );
+}
+
+/**
+ * Retrieves the last changed time for the 'taxonomies' cache group.
+ *
+ * @since x.x.x
+ *
+ * @return string UNIX timestamp with microseconds representing when the group was last changed.
+ */
+function wp_cache_get_taxonomies_last_changed( array $taxonomies ) {
+	$taxonomies = array_unique( $taxonomies );
+	if ( empty( $taxonomies ) ) {
+		return wp_cache_get_last_changed( 'terms' );
+	}
+	sort( $taxonomies );
+	$cache_keys = array_map(
+		static function ( $taxonomy ) {
+			return $taxonomy . ':last_changed';
+		},
+		array_filter( $taxonomies )
+	);
+	wp_cache_get_multiple( $cache_keys, 'terms' );
+	$last_changes = array_map( 'wp_cache_get_taxonomy_last_changed', $taxonomies );
+	$last_changes = array_map( 'floatval', $last_changes );
+
+	return (string) array_sum( $last_changes );
+}
+
 /**
  * Sets the last changed time for the 'terms' cache group.
  *

tests/phpunit/tests/link/getAdjacentPost.php

@@ -426,6 +426,6 @@ public function test_get_adjacent_post_cache() {
 
 		$num_queries = get_num_queries();
 		$this->assertEquals( $post_four, get_adjacent_post( true, '', false ), 'Result of function call is wrong after after adding new term' );
-		$this->assertSame( get_num_queries() - $num_queries, 2, 'Number of queries run was not two after adding new term' );
+		$this->assertSame( get_num_queries() - $num_queries, 0, 'Number of queries run was not two after adding new term' );
 	}
 }

tests/phpunit/tests/query/cacheResults.php

@@ -26,6 +26,14 @@ class Test_Query_CacheResults extends WP_UnitTestCase {
 	 */
 	public static $t1;
 
+
+	/**
+	 * Term ID.
+	 *
+	 * @var int
+	 */
+	public static $t2;
+
 	/**
 	 * Author's user ID.
 	 *
@@ -62,7 +70,16 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 			)
 		);
 
+		self::$t2 = $factory->term->create(
+			array(
+				'taxonomy' => 'post_tag',
+				'slug'     => 'bar',
+				'name'     => 'Bar',
+			)
+		);
+
 		wp_set_post_terms( self::$posts[0], self::$t1, 'category' );
+		wp_set_post_terms( self::$posts[0], self::$t2, 'post_tag' );
 		add_post_meta( self::$posts[0], 'color', '#000000' );
 
 		// Make a user.
@@ -1986,6 +2003,70 @@ public function data_author_cache_warmed_by_the_loop() {
 		);
 	}
 
+	public function test_query_cache_empty_taxonomies() {
+		add_filter( 'split_the_query', '__return_false' );
+		$query1       = new WP_Query();
+		$query_args_1 = array(
+			'update_post_term_cache' => false,
+			'update_post_meta_cache' => false,
+			'no_found_rows'          => true,
+			'tax_query'              => array(
+				array(
+					'terms' => array( self::$t1 ),
+				),
+			),
+		);
+		$query1->query( $query_args_1 );
+
+		clean_term_cache( self::$t1, 'category' );
+		$num_queries = get_num_queries();
+
+		$query1->query( $query_args_1 );
+
+		$this->assertSame( $num_queries + 1, get_num_queries(), 'Query not should be cached.' );
+	}
+	public function test_query_cache_different_taxonomies() {
+		add_filter( 'split_the_query', '__return_false' );
+		$query1       = new WP_Query();
+		$query_args_1 = array(
+			'update_post_term_cache' => false,
+			'update_post_meta_cache' => false,
+			'no_found_rows'          => true,
+			'tax_query'              => array(
+				array(
+					'taxonomy' => 'category',
+					'terms'    => array( self::$t1 ),
+				),
+			),
+		);
+		$query1->query( $query_args_1 );
+		$query_args_2 = array(
+			'update_post_term_cache' => false,
+			'update_post_meta_cache' => false,
+			'no_found_rows'          => true,
+			'tax_query'              => array(
+				array(
+					'taxonomy' => 'post_tag',
+					'terms'    => array( self::$t2 ),
+				),
+			),
+		);
+		$query2       = new WP_Query();
+		$query2->query( $query_args_2 );
+
+		clean_term_cache( self::$t1, 'category' );
+		$num_queries = get_num_queries();
+
+		$query1->query( $query_args_1 );
+
+		$this->assertSame( $num_queries + 2, get_num_queries(), 'Query not should be cached.' );
+		$num_queries = get_num_queries();
+		$query2->query( $query_args_2 );
+		remove_filter( 'split_the_query', '__return_false' );
+
+		$this->assertSame( $num_queries, get_num_queries(), 'Query should be cached.' );
+	}
+
 	/**
 	 * Ensure lazy loading term meta queries all term meta in a single query.
 	 *
@@ -2025,8 +2106,9 @@ public function test_get_post_meta_lazy_loads_all_term_meta_data() {
 		 * 2: Post data
 		 * 3: Post meta data.
 		 * 4: Post term data.
+		 * 5. Term data
 		 */
-		$this->assertSame( 4, $num_queries, 'Unexpected number of queries while querying posts.' );
+		$this->assertSame( 5, $num_queries, 'Unexpected number of queries while querying posts.' );
 		$this->assertNotEmpty( $query_posts, 'Query posts is empty.' );
 
 		$num_queries_start = get_num_queries();

tests/phpunit/tests/taxonomy.php

@@ -452,6 +452,37 @@ public function test_post_deletion_should_invalidate_get_objects_in_term_cache()
 		$this->assertSame( array(), $after );
 	}
 
+	public function test_invalidate_different_taxonomy_get_objects_in_term_cache() {
+		register_taxonomy( 'wptests_tax_1', 'post' );
+		register_taxonomy( 'wptests_tax_2', 'post' );
+
+		$posts     = self::factory()->post->create_many( 2 );
+		$term_id_1 = self::factory()->term->create(
+			array(
+				'taxonomy' => 'wptests_tax_1',
+			)
+		);
+		$term_id_2 = self::factory()->term->create(
+			array(
+				'taxonomy' => 'wptests_tax_2',
+			)
+		);
+
+		wp_set_object_terms( $posts[1], $term_id_1, 'wptests_tax_1' );
+		wp_set_object_terms( $posts[1], $term_id_2, 'wptests_tax_2' );
+
+		// Prime cache.
+		$before = get_objects_in_term( $term_id_1, 'wptests_tax_1' );
+		$this->assertEqualSets( array( $posts[1] ), $before );
+
+		clean_term_cache( $term_id_2, 'wptests_tax_2' );
+
+		$num_queries = get_num_queries();
+		$after       = get_objects_in_term( $term_id_1, 'wptests_tax_1' );
+		$this->assertEqualSets( array( $posts[1] ), $after );
+		$this->assertSame( $num_queries, get_num_queries() );
+	}
+
 	/**
 	 * @ticket 25706
 	 */