Add a CacheChain prototype

src/Cache/CacheChain.php

@@ -0,0 +1,153 @@
+<?php
+/**
+ * Copyright 2024 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+ namespace Google\Auth\Cache;
+
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+
+ class CacheChain implements CacheItemPoolInterface
+ {
+    private array $pools = [];
+
+    /**
+     * @param CacheItemPoolInterface[] $pools 
+     */
+    public function __construct(array $pools)
+    {
+        foreach($pools as $pool) {
+            $this->addPool($pool);
+        }
+    }
+
+    public function getItem(string $key): CacheItemInterface
+    {
+        foreach($this->pools as $pool) {
+            $item = $pool->getItem($key);
+            if ($item->isHit()) {
+                return $item;
+            }
+        }
+
+        return new TypedItem($$key);
+    }
+
+    public function getItems(array $keys = []): iterable
+    {
+        $result = [];
+
+        foreach($keys as $key) {
+            $result[$key] = $this->getItem($key);
+        }
+
+        return $result;
+    }
+
+    public function hasItem(string $key): bool
+    {
+        foreach($this->pools as $pool) {
+            if($pool->hasItem($key)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    public function clear(): bool
+    {
+        $result = true;
+
+        foreach($this->pools as $pool) {
+            if(!$pool->clear()) {
+                $result = false;
+            }
+        }
+
+        return $result;
+    }
+
+    public function deleteItem(string $key): bool
+    {
+        $result = true;
+
+        foreach($this->pools as $pool) {
+            if(!$pool->deleteItem($key)) {
+                $result = false;
+            }
+        }
+
+        return $result;
+    }
+
+    public function deleteItems(array $keys): bool
+    {
+        $result = true;
+
+        foreach($keys as $key) {
+            if(!$this->deleteItem($key)) {
+                $result = false;
+            }
+        }
+
+        return $result;
+    }
+
+    public function save(CacheItemInterface $item): bool
+    {
+        $result = true;
+
+        foreach($this->pools as $pool) {
+            if(!$pool->save($item)) {
+                $result = false;
+            }
+        }
+
+        return $result;
+    }
+
+    public function saveDeferred(CacheItemInterface $item): bool
+    {
+        $result = true;
+
+        foreach($this->pools as $pool) {
+            if(!$pool->saveDeferred($item)) {
+                $result = false;
+            }
+        }
+
+        return $result;
+    }
+
+    public function commit(): bool
+    {
+        $result = true;
+
+        foreach($this->pools as $pool) {
+            if(!$pool->commit()) {
+                $result = false;
+            }
+        }
+
+        return $result;
+    }
+
+    private function addPool(CacheItemPoolInterface $pool)
+    {
+        array_push($this->pools, $pool);
+    }
+ }