New attachment driver with redundant storage for HA environments

git-svn-id: https://svn.roundcube.net/trunk@4745 208e9e7b-5314-0410-a742-e7e81cd9613c

1 files changed, 169 insertions, 0 deletions

diff --git a/plugins/redundant_attachments/redundant_attachments.php b/plugins/redundant_attachments/redundant_attachments.php
new file mode 100644
index 000000000..70976b43c
--- /dev/null
+++ b/plugins/redundant_attachments/redundant_attachments.php
@@ -0,0 +1,169 @@
+<?php
+/**
+ * Redundant attachments
+ * 
+ * This plugin provides a redundant storage for temporary uploaded
+ * attachment files. They are stored in both the database backed
+ * as well as on the local file system.
+ *
+ * This plugin relies on the core filesystem_attachments plugin
+ * and combines it with the functionality of the database_attachments plugin.
+ *
+ * @author Thomas Bruederli <roundcube@gmail.com>
+ * 
+ */
+require_once('plugins/filesystem_attachments/filesystem_attachments.php');
+
+class redundant_attachments extends filesystem_attachments
+{
+    // A prefix for the cache key used in the session and in the key field of the cache table
+    private $cache_prefix = "ATTACH.";
+    
+    /**
+     * Default constructor
+     */
+    function init()
+    {
+      parent::init();
+      
+      $this->db = rcmail::get_instance()->get_dbh();
+    }
+
+    /**
+     * Helper method to generate a unique key for the given attachment file
+     */
+    private function _key($args)
+    {
+        $uname = $args['path'] ? $args['path'] : $args['name'];
+        return  $this->cache_prefix . $args['group'] . md5(mktime() . $uname . $_SESSION['user_id']);
+    }
+
+    /**
+     * Save a newly uploaded attachment
+     */
+    function upload($args)
+    {
+        $args = parent::upload($args);
+        
+        $key = $this->_key($args);
+        $data = base64_encode(file_get_contents($args['path']));
+
+        $status = $this->db->query(
+            "INSERT INTO ".get_table_name('cache')."
+             (created, user_id, cache_key, data)
+             VALUES (".$this->db->now().", ?, ?, ?)",
+            $_SESSION['user_id'],
+            $key,
+            $data);
+            
+        if ($status) {
+            $args['id'] = $key;
+            $args['status'] = true;
+            unset($args['path']);
+        }
+        
+        return $args;
+    }
+
+    /**
+     * Save an attachment from a non-upload source (draft or forward)
+     */
+    function save($args)
+    {
+        $args = parent::save($args);
+
+        if ($args['path'])
+          $args['data'] = file_get_contents($args['path']);
+
+        $data = base64_encode($args['data']);
+        $key = $this->_key($args);
+
+        $status = $this->db->query(
+            "INSERT INTO ".get_table_name('cache')."
+             (created, user_id, cache_key, data)
+             VALUES (".$this->db->now().", ?, ?, ?)",
+            $_SESSION['user_id'],
+            $key,
+            $data);
+
+        if ($status) {
+            $args['id'] = $key;
+            $args['status'] = true;
+        }
+
+        return $args;
+    }
+
+    /**
+     * Remove an attachment from storage
+     * This is triggered by the remove attachment button on the compose screen
+     */
+    function remove($args)
+    {
+        $args['status'] = false;
+        $status = $this->db->query(
+            "DELETE FROM ".get_table_name('cache')."
+             WHERE  user_id=?
+             AND    cache_key=?",
+            $_SESSION['user_id'],
+            $args['id']);
+
+        if ($status)
+            $args['status'] = true;
+
+        return parent::remove($args);
+    }
+
+    /**
+     * When composing an html message, image attachments may be shown
+     * For this plugin, $this->get() will check the file and
+     * return it's contents
+     */
+    function display($args)
+    {
+        return $this->get($args);
+    }
+
+    /**
+     * When displaying or sending the attachment the file contents are fetched
+     * using this method. This is also called by the attachment_display hook.
+     */
+    function get($args)
+    {
+        // attempt to get file from local file system
+        $args = parent::get($args);
+        if ($args['path'] && ($args['status'] = file_exists($args['path'])))
+          return $args;
+        
+        // fetch from database if not found on FS
+        $sql_result = $this->db->query(
+            "SELECT cache_id, data
+             FROM ".get_table_name('cache')."
+             WHERE  user_id=?
+             AND    cache_key=?",
+            $_SESSION['user_id'],
+            $args['id']);
+
+        if ($sql_arr = $this->db->fetch_assoc($sql_result)) {
+            $args['data'] = base64_decode($sql_arr['data']);
+            $args['status'] = true;
+        }
+        
+        return $args;
+    }
+    
+    /**
+     * Delete all temp files associated with this user
+     */
+    function cleanup($args)
+    {
+        $prefix = $this->cache_prefix . $args['group'];
+        $this->db->query(
+            "DELETE FROM ".get_table_name('cache')."
+             WHERE  user_id=?
+             AND cache_key like '{$prefix}%'",
+            $_SESSION['user_id']);
+            
+        parent::cleanup($args);
+    }
+}