Ticket #20875: 20875.4.diff

new file src/wp-includes/cache-compat.php

@@ +1 @@
+<?php
+
+/**
+ * Compatibility for cache drop-ins.
+ *
+ * @since 4.6.0
+ */
+
+if ( ! function_exists( 'wp_cache_get_multiple' ) ) :
+        function wp_cache_get_multiple( $groups ) {
+                $values = array();
+
+                foreach ( $groups as $group => $keys ) {
+                        foreach ( $keys as $keys ) {
+                                $values[ $group ][ $key ] = $this->get( $key, $group );
+                        }
+                }
+
+                return $values;
+        }
+endif;

src/wp-includes/cache.php

@@ -124 +124 @@
 }
 
 /**
+ * Gets multiple values from cache in one call.
+ *
+ * @since 4.6.0
+ * @uses $wp_object_cache Object Cache Class
+ *
+ * @param array $groups Multidimensional array, where the array keys are cache group names,
+ *                      and the values are arrays of keys to be fetched from that group.
+ * @return array|bool Array of values organized into groups.
+ */
+function wp_cache_get_multiple( $groups ) {
+        global $wp_object_cache;
+
+        return $wp_object_cache->get_multiple( $groups );
+}
+
+/**
  * Increment numeric cache item's value
  *
  * @since 3.3.0
@@ -560 +576 @@
         }
 
         /**
+         * Retrieves multiple values from the cache.
+         *
+         * @since 4.6.0
+         * @access public
+         *
+         * @param array $groups Multidimensional array, where the array keys are cache group names,
+         *                      and the values are arrays of keys to be fetched from that group.
+         * @return array Array of values organized into groups.
+         */
+        public function get_multiple( $groups ) {
+                $values = array();
+
+                foreach ( $groups as $group => $keys ) {
+                        foreach ( $keys as $key ) {
+                                $values[ $group ][ $key ] = $this->get( $key, $group );
+                        }
+                }
+
+                return $values;
+        }
+
+        /**
          * Increments numeric cache item's value.
          *
          * @since 3.3.0

src/wp-includes/load.php

@@ -462 +462 @@
                 wp_using_ext_object_cache( true );
         }
 
-        if ( ! wp_using_ext_object_cache() )
+        if ( wp_using_ext_object_cache() ) {
+                require_once ABSPATH . WPINC . '/cache-compat.php';
+        } else {
                 require_once ( ABSPATH . WPINC . '/cache.php' );
+        }
 
         /*
          * If cache supports reset, reset instead of init if already

tests/phpunit/tests/cache.php

@@ -313 +313 @@
                 // Make sure $fake_key is not stored
                 $this->assertFalse( wp_cache_get( $fake_key ) );
         }
+
+        /**
+         * @ticket 20875
+         */
+        public function test_get_multiple() {
+                wp_cache_set( 'foo1', 'bar', 'group1' );
+                wp_cache_set( 'foo2', 'bar', 'group1' );
+                wp_cache_set( 'foo1', 'bar', 'group2' );
+
+                $found = wp_cache_get_multiple( array(
+                        'group1' => array(
+                                'foo1',
+                                'foo2',
+                                'foo3',
+                        ),
+                        'group2' => array(
+                                'foo1',
+                        ),
+                ) );
+
+                $expected = array(
+                        'group1' => array(
+                                'foo1' => 'bar',
+                                'foo2' => 'bar',
+                                'foo3' => false,
+                        ),
+                        'group2' => array(
+                                'foo1' => 'bar',
+                        ),
+                );
+
+                $this->assertSame( $expected, $found );
+        }
 }