[PHPBB3-15247] Add support for php v7 APCu cache API

Add new cache driver apcu.php (based closely on existing APC cache driver)
Add new unit test apcu_driver_test.php for the new driver
Update RUNNING_TESTS.md to clarify requirements for apc, apcu and apc_bc extensions
and add a couple of general hints to RUNNING_TESTS.md

PHPBB3-15247

tests/RUNNING_TESTS.md

@@ -30,7 +30,9 @@ Some of the functionality in phpBB and/or the test suite uses additional
 PHP extensions. If these extensions are not loaded, respective tests
 will be skipped:
 
-- apc (APC cache driver)
+- apc (APC cache driver, php5 only)
+- apcu (APCu cache driver - native API, php7+)
+- apcu_bc, apcu (APCu cache driver - APC API, php7+)
 - bz2 (compress tests)
 - mysql, pdo_mysql (MySQL database driver)
 - mysqli, pdo_mysql (MySQLi database driver)
@@ -117,6 +119,14 @@ directory (above phpBB):
 
     $ phpBB/vendor/bin/phpunit
 
+To generate an xml log file, run:
+
+    $ phpBB/vendor/bin/phpunit --log-junit tests/tmp/log/log.xml
+
+If you are getting a memory exhausted error after running a few tests, you can try running:
+
+    $ phpBB/vendor/bin/phpunit -d memory_limit=2048M
+
 Slow tests
 --------------
 

tests/cache/apcu_driver_test.php

@@ -0,0 +1,58 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+// Important: apc.enable_cli=1 must be in php.ini.
+// http://forums.devshed.com/php-development-5/apc-problem-561290.html
+// http://php.net/manual/en/apc.configuration.php
+
+require_once dirname(__FILE__) . '/common_test_case.php';
+
+class phpbb_cache_apcu_driver_test extends phpbb_cache_common_test_case
+{
+	protected static $config;
+	protected $driver;
+
+	public function getDataSet()
+	{
+		return $this->createXMLDataSet(dirname(__FILE__) . '/fixtures/config.xml');
+	}
+
+	static public function setUpBeforeClass()
+	{
+		if (!extension_loaded('apcu'))
+		{
+			self::markTestSkipped('APCu extension is not loaded');
+		}
+
+		$php_ini = new \bantu\IniGetWrapper\IniGetWrapper;
+
+		if (!$php_ini->getBool('apc.enabled'))
+		{
+			self::markTestSkipped('APCu is not enabled. Make sure apc.enabled=1 in php.ini');
+		}
+
+		if (PHP_SAPI == 'cli' && !$php_ini->getBool('apc.enable_cli'))
+		{
+			self::markTestSkipped('APCu is not enabled for CLI. Set apc.enable_cli=1 in php.ini');
+		}
+	}
+
+	protected function setUp()
+	{
+		parent::setUp();
+
+		$this->driver = new \phpbb\cache\driver\apcu;
+
+		$this->driver->purge();
+	}
+}