First Local Commit - After Clean up.

Signed-off-by: Rick Hays <rhays@haysgang.com>

system/Cache/CacheFactory.php

@@ -0,0 +1,117 @@
+<?php
+
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP
+ *
+ * This content is released under the MIT License (MIT)
+ *
+ * Copyright (c) 2014-2019 British Columbia Institute of Technology
+ * Copyright (c) 2019 CodeIgniter Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @package    CodeIgniter
+ * @author     CodeIgniter Dev Team
+ * @copyright  2019 CodeIgniter Foundation
+ * @license    https://opensource.org/licenses/MIT	MIT License
+ * @link       https://codeigniter.com
+ * @since      Version 4.0.0
+ * @filesource
+ */
+
+namespace CodeIgniter\Cache;
+
+use CodeIgniter\Cache\Exceptions\CacheException;
+use CodeIgniter\Exceptions\CriticalError;
+
+/**
+ * Class Cache
+ *
+ * A factory for loading the desired
+ *
+ * @package CodeIgniter\Cache
+ */
+class CacheFactory
+{
+	/**
+	 * Attempts to create the desired cache handler, based upon the
+	 *
+	 * @param $config
+	 * @param string $handler
+	 * @param string $backup
+	 *
+	 * @return \CodeIgniter\Cache\CacheInterface
+	 */
+	public static function getHandler($config, string $handler = null, string $backup = null)
+	{
+		if (! isset($config->validHandlers) || ! is_array($config->validHandlers))
+		{
+			throw CacheException::forInvalidHandlers();
+		}
+
+		if (! isset($config->handler) || ! isset($config->backupHandler))
+		{
+			throw CacheException::forNoBackup();
+		}
+
+		$handler = ! empty($handler) ? $handler : $config->handler;
+		$backup  = ! empty($backup) ? $backup : $config->backupHandler;
+
+		if (! array_key_exists($handler, $config->validHandlers) || ! array_key_exists($backup, $config->validHandlers))
+		{
+			throw CacheException::forHandlerNotFound();
+		}
+
+		// Get an instance of our handler.
+		$adapter = new $config->validHandlers[$handler]($config);
+
+		if (! $adapter->isSupported())
+		{
+			$adapter = new $config->validHandlers[$backup]($config);
+
+			if (! $adapter->isSupported())
+			{
+				// Log stuff here, don't throw exception. No need to raise a fuss.
+				// Fall back to the dummy adapter.
+				$adapter = new $config->validHandlers['dummy']();
+			}
+		}
+
+		// If $adapter->initialization throws a CriticalError exception, we will attempt to
+		// use the $backup handler, if that also fails, we resort to the dummy handler.
+		try
+		{
+			$adapter->initialize();
+		}
+		catch (CriticalError $e)
+		{
+			// log the fact that an exception occurred as well what handler we are resorting to
+			log_message('critical', $e->getMessage() . ' Resorting to using ' . $backup . ' handler.');
+
+			// get the next best cache handler (or dummy if the $backup also fails)
+			$adapter = self::getHandler($config, $backup, 'dummy');
+		}
+
+		return $adapter;
+	}
+
+	//--------------------------------------------------------------------
+}