made Stud.IP cache compatible with PSR-6, re #3701

Merge request studip/studip!2570

1 files changed, 98 insertions, 0 deletions

diff --git a/lib/classes/cache/MemoryCache.class.php b/lib/classes/cache/MemoryCache.class.php
new file mode 100644
index 0000000..93f6bbd
--- /dev/null
+++ b/lib/classes/cache/MemoryCache.class.php
@@ -0,0 +1,98 @@
+<?php
+
+namespace Studip\Cache;
+
+use DateTime;
+use Psr\Cache\CacheItemInterface;
+
+/**
+ * The php memory implementation of the StudipCache interface.
+ *
+ * @author  Jan-Hendrik Willms <tleilax+studip@gmail.com>
+ * @license GPL2 or any later version
+ * @since   Stud.IP 5.0
+ */
+class MemoryCache extends Cache
+{
+    protected array $memory_cache = [];
+
+    /**
+     * Expires just a single key.
+     *
+     * @param  string  the key
+     */
+    public function expire($key)
+    {
+        unset($this->memory_cache[$key]);
+    }
+
+    /**
+     * Expire all items from the cache.
+     */
+    public function flush()
+    {
+        $this->memory_cache = [];
+    }
+
+    public static function getDisplayName(): string
+    {
+        return 'Memory cache';
+    }
+
+    public function getStats(): array
+    {
+        return [];
+    }
+
+    public static function getConfig(): array
+    {
+        return [];
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getItem($key)
+    {
+        $item = new Item($key);
+        if (!isset($this->memory_cache[$key])) {
+            return $item;
+        }
+        if ($this->memory_cache[$key]['expires'] < time()) {
+            $this->expire($key);
+            return $item;
+        }
+        $item->setHit();
+        $item->set($this->memory_cache[$key]['data']);
+        if (!empty($this->memory_cache[$key]['expires'])) {
+            $expiration = new DateTime();
+            $expiration->setTimestamp($this->memory_cache[$key]['expires']);
+            $item->expiresAt($expiration);
+        }
+        return $item;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function hasItem($key)
+    {
+        return isset($this->memory_cache[$key])
+            && $this->memory_cache[$key]['expires'] < time();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function save(CacheItemInterface $item)
+    {
+        $expiration = $this->getExpiration($item);
+
+        $this->memory_cache[$item->getKey()] = [
+            'expires' => $expiration + time(),
+            'data'    => $item->get(),
+        ];
+
+        return true;
+    }
+}