+ /**
+ * {@inheritdoc}
+ */
+ protected function doFetchMultiple(array $keys)
+ {
+ /* @var $traversedProviders CacheProvider[] */
+ $traversedProviders = [];
+ $keysCount = count($keys);
+ $fetchedValues = [];
+
+ foreach ($this->cacheProviders as $key => $cacheProvider) {
+ $fetchedValues = $cacheProvider->doFetchMultiple($keys);
+
+ // We populate all the previous cache layers (that are assumed to be faster)
+ if (count($fetchedValues) === $keysCount) {
+ foreach ($traversedProviders as $previousCacheProvider) {
+ $previousCacheProvider->doSaveMultiple($fetchedValues);
+ }
+
+ return $fetchedValues;
+ }
+
+ $traversedProviders[] = $cacheProvider;
+ }
+
+ return $fetchedValues;
+ }
+