--- /dev/null
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\Common\Cache;
+
+/**
+ * Cache provider that allows to easily chain multiple cache providers
+ *
+ * @author Michaƫl Gallego <mic.gallego@gmail.com>
+ */
+class ChainCache extends CacheProvider
+{
+ /**
+ * @var CacheProvider[]
+ */
+ private $cacheProviders = array();
+
+ /**
+ * Constructor
+ *
+ * @param CacheProvider[] $cacheProviders
+ */
+ public function __construct($cacheProviders = array())
+ {
+ $this->cacheProviders = $cacheProviders;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public function setNamespace($namespace)
+ {
+ parent::setNamespace($namespace);
+
+ foreach ($this->cacheProviders as $cacheProvider) {
+ $cacheProvider->setNamespace($namespace);
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ protected function doFetch($id)
+ {
+ foreach ($this->cacheProviders as $key => $cacheProvider) {
+ if ($cacheProvider->doContains($id)) {
+ $value = $cacheProvider->doFetch($id);
+
+ // We populate all the previous cache layers (that are assumed to be faster)
+ for ($subKey = $key - 1 ; $subKey >= 0 ; $subKey--) {
+ $this->cacheProviders[$subKey]->doSave($id, $value);
+ }
+
+ return $value;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ protected function doContains($id)
+ {
+ foreach ($this->cacheProviders as $cacheProvider) {
+ if ($cacheProvider->doContains($id)) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ protected function doSave($id, $data, $lifeTime = 0)
+ {
+ $stored = true;
+
+ foreach ($this->cacheProviders as $cacheProvider) {
+ $stored = $cacheProvider->doSave($id, $data, $lifeTime) && $stored;
+ }
+
+ return $stored;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ protected function doDelete($id)
+ {
+ $deleted = true;
+
+ foreach ($this->cacheProviders as $cacheProvider) {
+ $deleted = $cacheProvider->doDelete($id) && $deleted;
+ }
+
+ return $deleted;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ protected function doFlush()
+ {
+ $flushed = true;
+
+ foreach ($this->cacheProviders as $cacheProvider) {
+ $flushed = $cacheProvider->doFlush() && $flushed;
+ }
+
+ return $flushed;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ protected function doGetStats()
+ {
+ // We return all the stats from all adapters
+ $stats = array();
+
+ foreach ($this->cacheProviders as $cacheProvider) {
+ $stats[] = $cacheProvider->doGetStats();
+ }
+
+ return $stats;
+ }
+}