Changeset 39564

Timestamp:

12/11/2016 09:42:12 PM (8 years ago)

Author:

peterwilsoncc

Message:

Options: Prevent unnecessary SQL updates by update_option.

Previously an option containing an object would trigger an SQL UPDATE on all calls to update_option, even if the old and new values were identical. This was due to the old and new values having differing resource IDs.

This change compares the old and new values as serialized data to remove the resource ID from the comparison.

Props salcode, bradyvercher, peterwilsoncc.
Fixes #38903.

Location:

trunk

Files:

• src/wp-includes/option.php (modified) (1 diff)
• tests/phpunit/tests/option/updateOption.php (modified) (1 diff)

trunk/src/wp-includes/option.php

@@ -296 +296 @@
     $value = apply_filters( 'pre_update_option', $value, $option, $old_value );
 
-    // If the new and old values are the same, no need to update.
-    if ( $value === $old_value )
+    /*
+     * If the new and old values are the same, no need to update.
+     *
+     * Unserialized values will be adequate in most cases. If the unserialized
+     * data differs, the (maybe) serialized data is checked to avoid
+     * unnecessary database calls for otherwise identical object instances.
+     *
+     * See https://core.trac.wordpress.org/ticket/38903
+     */
+    if ( $value === $old_value || maybe_serialize( $value ) === maybe_serialize( $old_value ) ) {
         return false;
+    }
 
     /** This filter is documented in wp-includes/option.php */

trunk/tests/phpunit/tests/option/updateOption.php

@@ -167 +167 @@
 
     /**
+     * @ticket 38903
+     */
+    public function test_update_option_array_with_object() {
+        $array_w_object = array(
+            'url'       => 'http://src.wordpress-develop.dev/wp-content/uploads/2016/10/cropped-Blurry-Lights.jpg',
+            'meta_data' => (object) array(
+                'attachment_id' => 292,
+                'height'        => 708,
+                'width'         => 1260,
+            ),
+        );
+
+        // Add the option, it did not exist before this.
+        add_option( 'array_w_object', $array_w_object );
+
+        $num_queries_pre_update = get_num_queries();
+
+        // Update the option using the same array with an object for the value.
+        $this->assertFalse( update_option( 'array_w_object', $array_w_object ) );
+
+        // Check that no new database queries were performed.
+        $this->assertEquals( $num_queries_pre_update, get_num_queries() );
+    }
+
+    /**
      * `add_filter()` callback for test_should_respect_default_option_filter_when_option_does_not_yet_exist_in_database().
      */