alloptions.php

<?php

/**
 * @group option
 * @ticket 31245
 */
class Tests_Option_Alloptions extends WP_UnitTestCase {
	/**
	* Some cache implementations have a 1mb limit per-key. This shouldn't be an issue when get_multi() is in use, but this provides prior coverage.
	*/
	function test_alloptions_1mb() {
		$big_val = str_repeat( 'a', 1024*1024+1 ); // make sure we exceed 1mb

		wp_cache_flush();
		update_option( __FUNCTION__, $big_val, true ); // autoload = true
		wp_cache_flush();

		wp_load_alloptions();

		global $wpdb;
		$before = $wpdb->num_queries;
		$value = get_option( __FUNCTION__ );
		$after = $wpdb->num_queries;

		$this->assertEquals( $before, $after );
		$this->assertEquals( $value, $big_val ); // cached

		// clean up
		delete_option( __FUNCTION__ );

	}

	/**
	* Make sure wp_load_alloptions() correctly autoloads options such that get_option() does not hit the db.
	*/
	function test_load_alloptions() {

		global $wpdb;

		$autoload_keys = $wpdb->get_col( $wpdb->prepare( "SELECT option_name FROM $wpdb->options WHERE autoload = %s", 'yes' ) );

		wp_cache_flush();
		wp_load_alloptions();

		$before = $wpdb->num_queries;

		// Fetch all of the autoload options one by one
		foreach( $autoload_keys as $key ) {
			$value = get_option( $key );
			$this->assertNotSame( $value, false );
		}

		// Should have resulted in zero queries
		$after = $wpdb->num_queries;
		$this->assertEquals( $before, $after );

	}

	/**
	* Make sure wp_load_alloptions() only fetches autoload=yes.
	*/
	function test_load_not_alloptions() {

		global $wpdb;

		$not_autoload_keys = $wpdb->get_col( $wpdb->prepare( "SELECT option_name FROM $wpdb->options WHERE autoload = %s", 'no' ) );

		wp_cache_flush();
		wp_load_alloptions();

		$before = $wpdb->num_queries;

		// Fetch all of the autoload options one by one
		foreach( $not_autoload_keys as $key ) {
			$value = get_option( $key );
			$this->assertNotSame( $value, false );
		}

		// Should have resulted in zero queries
		$after = $wpdb->num_queries;
		$this->assertEquals( $before + count($not_autoload_keys), $after );

	}

	/**
	* Simulate a race condition like those described in #31245 and #25623
	* This test requires a memcached plugin/dropin; assuming one similar to Boren's plugin, hence:
	* @requires function WP_Object_Cache::get_mc
	*/
	function test_autoload_concurrency_failure() {
		// A separate object cache instance with a separate local cache array, to simulate a second process.
		$other_process_cache = new WP_Object_Cache();

		$value = 'Original value.';

		update_option( __FUNCTION__, $value , true ); // autoload = true
		wp_load_alloptions();

		// Simulate a second process changing the option in db and memcache.
		$value2 = 'Changed in second process.';
		global $wp_object_cache;
		$old_wp_object_cache = $wp_object_cache;
		$wp_object_cache = $other_process_cache;
		// In the second "process", change the option value, and make sure it stuck.
		wp_load_alloptions();
		update_option( __FUNCTION__, $value2, true);
		$this->assertEquals( $value2, get_option( __FUNCTION__) );
		$wp_object_cache = $old_wp_object_cache;

		// Now we change a different autoload option. This will clobber the first option in cache and db.
		update_option( __FUNCTION__ . '_2', 'An entirely separate option.', true);

		// If not for the clobbering bug, this would correctly refresh from memcache/db.
		global $wp_object_cache;
		$wp_object_cache->cache = array();

		$actual = get_option( __FUNCTION__ );
		$this->assertEquals( $value2, $actual );

		delete_option( __FUNCTION__ );
		delete_option( __FUNCTION__ . '_2' );
	}

	/**
	* Similar to test_autoload_concurrency_failure but without the clobbering update.
	* This is a negative test, just to make sure the previous test is successfully simulating the race condition.
	* @requires function WP_Object_Cache::get_mc
	*/
	function test_autoload_concurrency_pass() {
		// A separate object cache instance with a separate local cache array, to simulate a second process.
		$other_process_cache = new WP_Object_Cache();

		$value = 'Original value.';

		update_option( __FUNCTION__, $value , true ); // autoload = true
		wp_load_alloptions();

		// Simulate a second process changing the option in db and memcache.
		$value2 = 'Changed in second process.';
		global $wp_object_cache;
		$old_wp_object_cache = $wp_object_cache;
		$wp_object_cache = $other_process_cache;
		// In the second "process", change the option value, and make sure it stuck.
		wp_load_alloptions();
		update_option( __FUNCTION__, $value2, true);
		$this->assertEquals( $value2, get_option( __FUNCTION__) );
		$wp_object_cache = $old_wp_object_cache;

		// DON'T clobber the cache with an update_option() call this time.

		// If not for the clobbering bug, this would correctly refresh from memcache/db.
		global $wp_object_cache;
		$wp_object_cache->cache = array();

		$actual = get_option( __FUNCTION__ );
		$this->assertEquals( $value2, $actual );

		delete_option( __FUNCTION__ );
		delete_option( __FUNCTION__ . '_2' );
	}

}