Adding missing file

src/Database/Schema/CachedCollection.php

@@ -0,0 +1,99 @@
+<?php
+/**
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @link          http://cakephp.org CakePHP(tm) Project
+ * @since         3.0.0
+ * @license       http://www.opensource.org/licenses/mit-license.php MIT License
+ */
+namespace Cake\Database\Schema;
+
+use Cake\Cache\Cache;
+use Cake\Database\Connection;
+use Cake\Database\Schema\Collection;
+
+/**
+ * Extends the schema collection class to provide caching
+ *
+ */
+class CachedCollection extends Collection {
+
+/**
+ * The name of the cache config key to use for caching table metadata,
+ * of false if disabled.
+ *
+ * @var string|bool
+ */
+	protected $_cache = false;
+
+/**
+ * Constructor.
+ *
+ * @param \Cake\Database\Connection $connection The connection instance.
+ * @param string|boolean The cache key or boolean false to disable caching.
+ */
+	public function __construct(Connection $connection, $cacheKey = true) {
+		parent::__construct($connection);
+		$this->cacheMetadata($cacheKey);
+	}
+
+/**
+ * {@inheritDoc}
+ *
+ */
+	public function describe($name, array $options = []) {
+		$options += ['forceRefresh' => false];
+		$cacheConfig = $this->cacheMetadata();
+		$cacheKey = $this->cacheKey($name);
+
+		if (!empty($cacheConfig) && !$options['forceRefresh']) {
+			$cached = Cache::read($cacheKey, $cacheConfig);
+			if ($cached !== false) {
+				return $cached;
+			}
+		}
+
+		$table = parent::describe($name, $options);
+
+		if (!empty($cacheConfig)) {
+			Cache::write($cacheKey, $table, $cacheConfig);
+		}
+
+		return $table;
+	}
+
+/**
+ * Get the cache key for a given name.
+ *
+ * @param string $name The name to get a cache key for.
+ * @return string The cache key.
+ */
+	public function cacheKey($name) {
+		return $this->_connection->configName() . '_' . $name;
+	}
+
+/**
+ * Sets the cache config name to use for caching table metadata, or
+ * disabels it if false is passed.
+ * If called with no arguments it returns the current configuration name.
+ *
+ * @param bool $enable whether or not to enable caching
+ * @return string|bool
+ */
+	public function cacheMetadata($enable = null) {
+		if ($enable === null) {
+			return $this->_cache;
+		}
+		if ($enable === true) {
+			$enable = '_cake_model_';
+		}
+		return $this->_cache = $enable;
+	}
+
+}