added Google Cloud Storage support

lib/Data/GoogleCloudStorage.php

@@ -0,0 +1,251 @@
+<?php
+
+namespace PrivateBin\Data;
+
+use Exception;
+use Google\Cloud\Core\Exception\NotFoundException;
+use Google\Cloud\Storage\StorageClient;
+use PrivateBin\Json;
+
+class GoogleCloudStorage extends AbstractData
+{
+    /**
+     * returns a Google Cloud Storage data backend.
+     *
+     * @access public
+     * @static
+     * @param array $options
+     * @return GoogleCloudStorage
+     */
+    public static function getInstance(array $options)
+    {
+        $client = null;
+        $bucket = null;
+        $prefix = 'pastes';
+
+        if (getenv('PRIVATEBIN_GCS_BUCKET')) {
+            $bucket = getenv('PRIVATEBIN_GCS_BUCKET');
+        }
+        if (is_array($options) && array_key_exists('bucket', $options)) {
+            $bucket = $options['bucket'];
+        }
+        if (is_array($options) && array_key_exists('prefix', $options)) {
+            $prefix = $options['prefix'];
+        }
+        if (is_array($options) && array_key_exists('client', $options)) {
+            $client = $options['client'];
+        }
+
+        if (!(self::$_instance instanceof self)) {
+            self::$_instance = new self($bucket, $prefix, $client);
+        }
+        return self::$_instance;
+    }
+
+    protected $_client = null;
+    protected $_bucket = null;
+    protected $_prefix = 'pastes';
+
+    public function __construct($bucket, $prefix, $client = null)
+    {
+        parent::__construct();
+        if ($client == null) {
+            $this->_client = new StorageClient(array('suppressKeyFileNotice' => true));
+        } else {
+            // use given client for test purposes
+            $this->_client = $client;
+        }
+
+        $this->_bucket = $this->_client->bucket($bucket);
+        if ($prefix != null) {
+            $this->_prefix = $prefix;
+        }
+    }
+
+    /**
+     * returns the google storage object key for $pasteid in $this->_bucket.
+     * @param $pasteid string to get the key for
+     * @return string
+     */
+    private function _getKey($pasteid)
+    {
+        if ($this->_prefix != '') {
+            return $this->_prefix . '/' . $pasteid;
+        }
+        return $pasteid;
+    }
+
+    /**
+     * Uploads the payload in the $this->_bucket under the specified key.
+     * The entire payload is stored as a JSON document. The metadata is replicated
+     * as the GCS object's metadata except for the fields attachment, attachmentname
+     * and salt.
+     *
+     * @param $key string to store the payload under
+     * @param $payload array to store
+     * @return bool true if successful, otherwise false.
+     */
+    private function upload($key, $payload)
+    {
+        $metadata = array_key_exists('meta', $payload) ? $payload['meta'] : array();
+        unset($metadata['attachment'], $metadata['attachmentname'], $metadata['salt']);
+        foreach ($metadata as $k => $v) {
+            $metadata[$k] = strval($v);
+        }
+        try {
+            $this->_bucket->upload(Json::encode($payload), array(
+                'name'          => $key,
+                'chunkSize'     => 262144,
+                'predefinedAcl' => 'private',
+                'metadata'      => array(
+                    'content-type' => 'application/json',
+                    'metadata'     => $metadata,
+                ),
+            ));
+        } catch (Exception $e) {
+            error_log('failed to upload ' . $key . ' to ' . $this->_bucket->name() . ', ' .
+                trim(preg_replace('/\s\s+/', ' ', $e->getMessage())));
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function create($pasteid, array $paste)
+    {
+        if ($this->exists($pasteid)) {
+            return false;
+        }
+
+        return $this->upload($this->_getKey($pasteid), $paste);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function read($pasteid)
+    {
+        try {
+            $o    = $this->_bucket->object($this->_getKey($pasteid));
+            $data = $o->downloadAsString();
+            return Json::decode($data);
+        } catch (NotFoundException $e) {
+            return false;
+        } catch (Exception $e) {
+            error_log('failed to read ' . $pasteid . ' from ' . $this->_bucket->name() . ', ' .
+                trim(preg_replace('/\s\s+/', ' ', $e->getMessage())));
+            return false;
+        }
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function delete($pasteid)
+    {
+        $name = $this->_getKey($pasteid);
+
+        try {
+            foreach ($this->_bucket->objects(array('prefix' => $name . '/discussion/')) as $comment) {
+                try {
+                    $this->_bucket->object($comment->name())->delete();
+                } catch (NotFoundException $e) {
+                    // ignore if already deleted.
+                }
+            }
+        } catch (NotFoundException $e) {
+            // there are no discussions associated with the paste
+        }
+
+        try {
+            $this->_bucket->object($name)->delete();
+        } catch (NotFoundException $e) {
+            // ignore if already deleted
+        }
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function exists($pasteid)
+    {
+        $o = $this->_bucket->object($this->_getKey($pasteid));
+        return $o->exists();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function createComment($pasteid, $parentid, $commentid, array $comment)
+    {
+        if ($this->existsComment($pasteid, $parentid, $commentid)) {
+            return false;
+        }
+        $key = $this->_getKey($pasteid) . '/discussion/' . $parentid . '/' . $commentid;
+        return $this->upload($key, $comment);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function readComments($pasteid)
+    {
+        $comments = array();
+        $prefix   = $this->_getKey($pasteid) . '/discussion/';
+        try {
+            foreach ($this->_bucket->objects(array('prefix' => $prefix)) as $key) {
+                $comment         = JSON::decode($this->_bucket->object($key->name())->downloadAsString());
+                $comment['id']   = basename($key->name());
+                $slot            = $this->getOpenSlot($comments, (int) $comment['meta']['created']);
+                $comments[$slot] = $comment;
+            }
+        } catch (NotFoundException $e) {
+            // no comments found
+        }
+        return $comments;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function existsComment($pasteid, $parentid, $commentid)
+    {
+        $name = $this->_getKey($pasteid) . '/discussion/' . $parentid . '/' . $commentid;
+        $o    = $this->_bucket->object($name);
+        return $o->exists();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    protected function _getExpiredPastes($batchsize)
+    {
+        $expired = array();
+
+        $now    = time();
+        $prefix = $this->_prefix;
+        if ($prefix != '') {
+            $prefix = $prefix . '/';
+        }
+        try {
+            foreach ($this->_bucket->objects(array('prefix' => $prefix)) as $object) {
+                $metadata = $object->info()['metadata'];
+                if ($metadata != null && array_key_exists('expire_date', $metadata)) {
+                    $expire_at = intval($metadata['expire_date']);
+                    if ($expire_at != 0 && $expire_at < $now) {
+                        array_push($expired, basename($object->name()));
+                    }
+                }
+
+                if (count($expired) > $batchsize) {
+                    break;
+                }
+            }
+        } catch (NotFoundException $e) {
+            // no objects in the bucket yet
+        }
+        return $expired;
+    }
+}