update Piwik to version 2.16 (fixes #91)

www/analytics/vendor/piwik/cache/src/Lazy.php

@@ -0,0 +1,121 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/lgpl-3.0.html LGPL v3 or later
+ *
+ */
+namespace Piwik\Cache;
+
+use Piwik\Cache\Backend;
+
+class Lazy implements Cache
+{
+    private $backend;
+
+    /**
+     * Initializes the cache.
+     *
+     * @param Backend $backend Any backend that should be used to store / hold the cache entries.
+     */
+    public function __construct(Backend $backend)
+    {
+        $this->backend = $backend;
+    }
+
+    /**
+     * Fetches an entry from the cache.
+     *
+     * @param string $id The cache id.
+     * @return mixed The cached data or FALSE, if no cache entry exists for the given id.
+     */
+    public function fetch($id)
+    {
+        $id = $this->getCompletedCacheIdIfValid($id);
+
+        return $this->backend->doFetch($id);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function contains($id)
+    {
+        $id = $this->getCompletedCacheIdIfValid($id);
+
+        return $this->backend->doContains($id);
+    }
+
+    /**
+     * Puts data into the cache.
+     *
+     * @param string $id       The cache id.
+     * @param mixed  $data     The cache entry/data.
+     * @param int    $lifeTime The cache lifetime in seconds.
+     *                         If != 0, sets a specific lifetime for this cache entry (0 => infinite lifeTime).
+     *
+     * @return boolean TRUE if the entry was successfully stored in the cache, FALSE otherwise.
+     */
+    public function save($id, $data, $lifeTime = 0)
+    {
+        $id = $this->getCompletedCacheIdIfValid($id);
+
+        if (is_object($data)) {
+            throw new \InvalidArgumentException('You cannot use this cache to cache an object, only arrays, strings and numbers. Have a look at Transient cache.');
+            // for performance reasons we do currently not recursively search whether any array contains an object.
+        }
+
+        return $this->backend->doSave($id, $data, $lifeTime);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function delete($id)
+    {
+        $id = $this->getCompletedCacheIdIfValid($id);
+
+        return $this->backend->doDelete($id);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function flushAll()
+    {
+        return $this->backend->doFlush();
+    }
+
+    private function getCompletedCacheIdIfValid($id)
+    {
+        $this->checkId($id);
+        return 'piwikcache_' . $id;
+    }
+
+    private function checkId($id)
+    {
+        if (empty($id)) {
+            throw new \InvalidArgumentException('Empty cache id given');
+        }
+
+        if (!$this->isValidId($id)) {
+            throw new \InvalidArgumentException("Invalid cache id request $id");
+        }
+    }
+
+    /**
+     * Returns true if the string is a valid id.
+     *
+     * Id that start with a-Z or 0-9 and contain a-Z, 0-9, underscore(_), dash(-), and dot(.) will be accepted.
+     * Id beginning with anything but a-Z or 0-9 will be rejected (including .htaccess for example).
+     * Id containing anything other than above mentioned will also be rejected (file names with spaces won't be accepted).
+     *
+     * @param string $id
+     * @return bool
+     */
+    private function isValidId($id)
+    {
+        return (0 !== preg_match('/(^[a-zA-Z0-9]+([a-zA-Z_0-9.-]*))$/D', $id));
+    }
+}