Framework files moved to lib/Roundcube

1 files changed, 0 insertions, 1160 deletions

diff --git a/program/include/rcube_imap_cache.php b/program/include/rcube_imap_cache.php
deleted file mode 100644
index 31214cfbf..000000000
--- a/program/include/rcube_imap_cache.php
+++ /dev/null
@@ -1,1160 +0,0 @@
-<?php
-
-/*
- +-----------------------------------------------------------------------+
- | program/include/rcube_imap_cache.php                                  |
- |                                                                       |
- | This file is part of the Roundcube Webmail client                     |
- | Copyright (C) 2005-2012, The Roundcube Dev Team                       |
- |                                                                       |
- | Licensed under the GNU General Public License version 3 or            |
- | any later version with exceptions for skins & plugins.                |
- | See the README file for a full license statement.                     |
- |                                                                       |
- | PURPOSE:                                                              |
- |   Caching of IMAP folder contents (messages and index)                |
- |                                                                       |
- +-----------------------------------------------------------------------+
- | Author: Thomas Bruederli <roundcube@gmail.com>                        |
- | Author: Aleksander Machniak <alec@alec.pl>                            |
- +-----------------------------------------------------------------------+
-*/
-
-
-/**
- * Interface class for accessing Roundcube messages cache
- *
- * @package    Framework
- * @subpackage Storage
- * @author     Thomas Bruederli <roundcube@gmail.com>
- * @author     Aleksander Machniak <alec@alec.pl>
- */
-class rcube_imap_cache
-{
-    /**
-     * Instance of rcube_imap
-     *
-     * @var rcube_imap
-     */
-    private $imap;
-
-    /**
-     * Instance of rcube_db
-     *
-     * @var rcube_db
-     */
-    private $db;
-
-    /**
-     * User ID
-     *
-     * @var int
-     */
-    private $userid;
-
-    /**
-     * Internal (in-memory) cache
-     *
-     * @var array
-     */
-    private $icache = array();
-
-    private $skip_deleted = false;
-
-    /**
-     * List of known flags. Thanks to this we can handle flag changes
-     * with good performance. Bad thing is we need to know used flags.
-     */
-    public $flags = array(
-        1       => 'SEEN',          // RFC3501
-        2       => 'DELETED',       // RFC3501
-        4       => 'ANSWERED',      // RFC3501
-        8       => 'FLAGGED',       // RFC3501
-        16      => 'DRAFT',         // RFC3501
-        32      => 'MDNSENT',       // RFC3503
-        64      => 'FORWARDED',     // RFC5550
-        128     => 'SUBMITPENDING', // RFC5550
-        256     => 'SUBMITTED',     // RFC5550
-        512     => 'JUNK',
-        1024    => 'NONJUNK',
-        2048    => 'LABEL1',
-        4096    => 'LABEL2',
-        8192    => 'LABEL3',
-        16384   => 'LABEL4',
-        32768   => 'LABEL5',
-    );
-
-
-    /**
-     * Object constructor.
-     */
-    function __construct($db, $imap, $userid, $skip_deleted)
-    {
-        $this->db           = $db;
-        $this->imap         = $imap;
-        $this->userid       = $userid;
-        $this->skip_deleted = $skip_deleted;
-    }
-
-
-    /**
-     * Cleanup actions (on shutdown).
-     */
-    public function close()
-    {
-        $this->save_icache();
-        $this->icache = null;
-    }
-
-
-    /**
-     * Return (sorted) messages index (UIDs).
-     * If index doesn't exist or is invalid, will be updated.
-     *
-     * @param string  $mailbox     Folder name
-     * @param string  $sort_field  Sorting column
-     * @param string  $sort_order  Sorting order (ASC|DESC)
-     * @param bool    $exiting     Skip index initialization if it doesn't exist in DB
-     *
-     * @return array Messages index
-     */
-    function get_index($mailbox, $sort_field = null, $sort_order = null, $existing = false)
-    {
-        if (empty($this->icache[$mailbox])) {
-            $this->icache[$mailbox] = array();
-        }
-
-        $sort_order = strtoupper($sort_order) == 'ASC' ? 'ASC' : 'DESC';
-
-        // Seek in internal cache
-        if (array_key_exists('index', $this->icache[$mailbox])) {
-            // The index was fetched from database already, but not validated yet
-            if (!array_key_exists('object', $this->icache[$mailbox]['index'])) {
-                $index = $this->icache[$mailbox]['index'];
-            }
-            // We've got a valid index
-            else if ($sort_field == 'ANY' || $this->icache[$mailbox]['index']['sort_field'] == $sort_field) {
-                $result = $this->icache[$mailbox]['index']['object'];
-                if ($result->get_parameters('ORDER') != $sort_order) {
-                    $result->revert();
-                }
-                return $result;
-            }
-        }
-
-        // Get index from DB (if DB wasn't already queried)
-        if (empty($index) && empty($this->icache[$mailbox]['index_queried'])) {
-            $index = $this->get_index_row($mailbox);
-
-            // set the flag that DB was already queried for index
-            // this way we'll be able to skip one SELECT, when
-            // get_index() is called more than once
-            $this->icache[$mailbox]['index_queried'] = true;
-        }
-
-        $data = null;
-
-        // @TODO: Think about skipping validation checks.
-        // If we could check only every 10 minutes, we would be able to skip
-        // expensive checks, mailbox selection or even IMAP connection, this would require
-        // additional logic to force cache invalidation in some cases
-        // and many rcube_imap changes to connect when needed
-
-        // Entry exists, check cache status
-        if (!empty($index)) {
-            $exists = true;
-
-            if ($sort_field == 'ANY') {
-                $sort_field = $index['sort_field'];
-            }
-
-            if ($sort_field != $index['sort_field']) {
-                $is_valid = false;
-            }
-            else {
-                $is_valid = $this->validate($mailbox, $index, $exists);
-            }
-
-            if ($is_valid) {
-                $data = $index['object'];
-                // revert the order if needed
-                if ($data->get_parameters('ORDER') != $sort_order) {
-                    $data->revert();
-                }
-            }
-        }
-        else {
-            if ($existing) {
-                return null;
-            }
-            else if ($sort_field == 'ANY') {
-                $sort_field = '';
-            }
-
-            // Got it in internal cache, so the row already exist
-            $exists = array_key_exists('index', $this->icache[$mailbox]);
-        }
-
-        // Index not found, not valid or sort field changed, get index from IMAP server
-        if ($data === null) {
-            // Get mailbox data (UIDVALIDITY, counters, etc.) for status check
-            $mbox_data = $this->imap->folder_data($mailbox);
-            $data      = $this->get_index_data($mailbox, $sort_field, $sort_order, $mbox_data);
-
-            // insert/update
-            $this->add_index_row($mailbox, $sort_field, $data, $mbox_data, $exists, $index['modseq']);
-        }
-
-        $this->icache[$mailbox]['index'] = array(
-            'object'     => $data,
-            'sort_field' => $sort_field,
-            'modseq'     => !empty($index['modseq']) ? $index['modseq'] : $mbox_data['HIGHESTMODSEQ']
-        );
-
-        return $data;
-    }
-
-
-    /**
-     * Return messages thread.
-     * If threaded index doesn't exist or is invalid, will be updated.
-     *
-     * @param string  $mailbox     Folder name
-     * @param string  $sort_field  Sorting column
-     * @param string  $sort_order  Sorting order (ASC|DESC)
-     *
-     * @return array Messages threaded index
-     */
-    function get_thread($mailbox)
-    {
-        if (empty($this->icache[$mailbox])) {
-            $this->icache[$mailbox] = array();
-        }
-
-        // Seek in internal cache
-        if (array_key_exists('thread', $this->icache[$mailbox])) {
-            return $this->icache[$mailbox]['thread']['object'];
-        }
-
-        // Get thread from DB (if DB wasn't already queried)
-        if (empty($this->icache[$mailbox]['thread_queried'])) {
-            $index = $this->get_thread_row($mailbox);
-
-            // set the flag that DB was already queried for thread
-            // this way we'll be able to skip one SELECT, when
-            // get_thread() is called more than once or after clear()
-            $this->icache[$mailbox]['thread_queried'] = true;
-        }
-
-        // Entry exist, check cache status
-        if (!empty($index)) {
-            $exists   = true;
-            $is_valid = $this->validate($mailbox, $index, $exists);
-
-            if (!$is_valid) {
-                $index = null;
-            }
-        }
-
-        // Index not found or not valid, get index from IMAP server
-        if ($index === null) {
-            // Get mailbox data (UIDVALIDITY, counters, etc.) for status check
-            $mbox_data = $this->imap->folder_data($mailbox);
-
-            if ($mbox_data['EXISTS']) {
-                // get all threads (default sort order)
-                $threads = $this->imap->fetch_threads($mailbox, true);
-            }
-            else {
-                $threads = new rcube_result_thread($mailbox, '* THREAD');
-            }
-
-            $index['object'] = $threads;
-
-            // insert/update
-            $this->add_thread_row($mailbox, $threads, $mbox_data, $exists);
-        }
-
-        $this->icache[$mailbox]['thread'] = $index;
-
-        return $index['object'];
-    }
-
-
-    /**
-     * Returns list of messages (headers). See rcube_imap::fetch_headers().
-     *
-     * @param string $mailbox  Folder name
-     * @param array  $msgs     Message UIDs
-     *
-     * @return array The list of messages (rcube_message_header) indexed by UID
-     */
-    function get_messages($mailbox, $msgs = array())
-    {
-        if (empty($msgs)) {
-            return array();
-        }
-
-        // Fetch messages from cache
-        $sql_result = $this->db->query(
-            "SELECT uid, data, flags"
-            ." FROM ".$this->db->table_name('cache_messages')
-            ." WHERE user_id = ?"
-                ." AND mailbox = ?"
-                ." AND uid IN (".$this->db->array2list($msgs, 'integer').")",
-            $this->userid, $mailbox);
-
-        $msgs   = array_flip($msgs);
-        $result = array();
-
-        while ($sql_arr = $this->db->fetch_assoc($sql_result)) {
-            $uid          = intval($sql_arr['uid']);
-            $result[$uid] = $this->build_message($sql_arr);
-
-            if (!empty($result[$uid])) {
-                // save memory, we don't need message body here (?)
-                $result[$uid]->body = null;
-
-                unset($msgs[$uid]);
-            }
-        }
-
-        // Fetch not found messages from IMAP server
-        if (!empty($msgs)) {
-            $messages = $this->imap->fetch_headers($mailbox, array_keys($msgs), false, true);
-
-            // Insert to DB and add to result list
-            if (!empty($messages)) {
-                foreach ($messages as $msg) {
-                    $this->add_message($mailbox, $msg, !array_key_exists($msg->uid, $result));
-                    $result[$msg->uid] = $msg;
-                }
-            }
-        }
-
-        return $result;
-    }
-
-
-    /**
-     * Returns message data.
-     *
-     * @param string $mailbox  Folder name
-     * @param int    $uid      Message UID
-     * @param bool   $update   If message doesn't exists in cache it will be fetched
-     *                         from IMAP server
-     * @param bool   $no_cache Enables internal cache usage
-     *
-     * @return rcube_message_header Message data
-     */
-    function get_message($mailbox, $uid, $update = true, $cache = true)
-    {
-        // Check internal cache
-        if ($this->icache['__message']
-            && $this->icache['__message']['mailbox'] == $mailbox
-            && $this->icache['__message']['object']->uid == $uid
-        ) {
-            return $this->icache['__message']['object'];
-        }
-
-        $sql_result = $this->db->query(
-            "SELECT flags, data"
-            ." FROM ".$this->db->table_name('cache_messages')
-            ." WHERE user_id = ?"
-                ." AND mailbox = ?"
-                ." AND uid = ?",
-                $this->userid, $mailbox, (int)$uid);
-
-        if ($sql_arr = $this->db->fetch_assoc($sql_result)) {
-            $message = $this->build_message($sql_arr);
-            $found   = true;
-        }
-
-        // Get the message from IMAP server
-        if (empty($message) && $update) {
-            $message = $this->imap->get_message_headers($uid, $mailbox, true);
-            // cache will be updated in close(), see below
-        }
-
-        // Save the message in internal cache, will be written to DB in close()
-        // Common scenario: user opens unseen message
-        // - get message (SELECT)
-        // - set message headers/structure (INSERT or UPDATE)
-        // - set \Seen flag (UPDATE)
-        // This way we can skip one UPDATE
-        if (!empty($message) && $cache) {
-            // Save current message from internal cache
-            $this->save_icache();
-
-            $this->icache['__message'] = array(
-                'object'  => $message,
-                'mailbox' => $mailbox,
-                'exists'  => $found,
-                'md5sum'  => md5(serialize($message)),
-            );
-        }
-
-        return $message;
-    }
-
-
-    /**
-     * Saves the message in cache.
-     *
-     * @param string               $mailbox  Folder name
-     * @param rcube_message_header $message  Message data
-     * @param bool                 $force    Skips message in-cache existance check
-     */
-    function add_message($mailbox, $message, $force = false)
-    {
-        if (!is_object($message) || empty($message->uid)) {
-            return;
-        }
-
-        $msg   = serialize($this->db->encode(clone $message));
-        $flags = 0;
-
-        if (!empty($message->flags)) {
-            foreach ($this->flags as $idx => $flag) {
-                if (!empty($message->flags[$flag])) {
-                    $flags += $idx;
-                }
-            }
-        }
-        unset($msg->flags);
-
-        // update cache record (even if it exists, the update
-        // here will work as select, assume row exist if affected_rows=0)
-        if (!$force) {
-            $res = $this->db->query(
-                "UPDATE ".$this->db->table_name('cache_messages')
-                ." SET flags = ?, data = ?, changed = ".$this->db->now()
-                ." WHERE user_id = ?"
-                    ." AND mailbox = ?"
-                    ." AND uid = ?",
-                $flags, $msg, $this->userid, $mailbox, (int) $message->uid);
-
-            if ($this->db->affected_rows()) {
-                return;
-            }
-        }
-
-        // insert new record
-        $this->db->query(
-            "INSERT INTO ".$this->db->table_name('cache_messages')
-            ." (user_id, mailbox, uid, flags, changed, data)"
-            ." VALUES (?, ?, ?, ?, ".$this->db->now().", ?)",
-            $this->userid, $mailbox, (int) $message->uid, $flags, $msg);
-    }
-
-
-    /**
-     * Sets the flag for specified message.
-     *
-     * @param string  $mailbox  Folder name
-     * @param array   $uids     Message UIDs or null to change flag
-     *                          of all messages in a folder
-     * @param string  $flag     The name of the flag
-     * @param bool    $enabled  Flag state
-     */
-    function change_flag($mailbox, $uids, $flag, $enabled = false)
-    {
-        if (empty($uids)) {
-            return;
-        }
-
-        $flag = strtoupper($flag);
-        $idx  = (int) array_search($flag, $this->flags);
-        $uids = (array) $uids;
-
-        if (!$idx) {
-            return;
-        }
-
-        // Internal cache update
-        if (($message = $this->icache['__message'])
-            && $message['mailbox'] === $mailbox
-            && in_array($message['object']->uid, $uids)
-        ) {
-            $message['object']->flags[$flag] = $enabled;
-
-            if (count($uids) == 1) {
-                return;
-            }
-        }
-
-        $this->db->query(
-            "UPDATE ".$this->db->table_name('cache_messages')
-            ." SET changed = ".$this->db->now()
-            .", flags = flags ".($enabled ? "+ $idx" : "- $idx")
-            ." WHERE user_id = ?"
-                ." AND mailbox = ?"
-                .($uids !== null ? " AND uid IN (".$this->db->array2list($uids, 'integer').")" : "")
-                ." AND (flags & $idx) ".($enabled ? "= 0" : "= $idx"),
-            $this->userid, $mailbox);
-    }
-
-
-    /**
-     * Removes message(s) from cache.
-     *
-     * @param string $mailbox  Folder name
-     * @param array  $uids     Message UIDs, NULL removes all messages
-     */
-    function remove_message($mailbox = null, $uids = null)
-    {
-        if (!strlen($mailbox)) {
-            $this->db->query(
-                "DELETE FROM ".$this->db->table_name('cache_messages')
-                ." WHERE user_id = ?",
-                $this->userid);
-        }
-        else {
-            // Remove the message from internal cache
-            if (!empty($uids) && ($message = $this->icache['__message'])
-                && $message['mailbox'] === $mailbox
-                && in_array($message['object']->uid, (array)$uids)
-            ) {
-                $this->icache['__message'] = null;
-            }
-
-            $this->db->query(
-                "DELETE FROM ".$this->db->table_name('cache_messages')
-                ." WHERE user_id = ?"
-                    ." AND mailbox = ?"
-                    .($uids !== null ? " AND uid IN (".$this->db->array2list((array)$uids, 'integer').")" : ""),
-                $this->userid, $mailbox);
-        }
-    }
-
-
-    /**
-     * Clears index cache.
-     *
-     * @param string  $mailbox     Folder name
-     * @param bool    $remove      Enable to remove the DB row
-     */
-    function remove_index($mailbox = null, $remove = false)
-    {
-        // The index should be only removed from database when
-        // UIDVALIDITY was detected or the mailbox is empty
-        // otherwise use 'valid' flag to not loose HIGHESTMODSEQ value
-        if ($remove) {
-            $this->db->query(
-                "DELETE FROM ".$this->db->table_name('cache_index')
-                ." WHERE user_id = ?"
-                    .(strlen($mailbox) ? " AND mailbox = ".$this->db->quote($mailbox) : ""),
-                $this->userid
-            );
-        }
-        else {
-            $this->db->query(
-                "UPDATE ".$this->db->table_name('cache_index')
-                ." SET valid = 0"
-                ." WHERE user_id = ?"
-                    .(strlen($mailbox) ? " AND mailbox = ".$this->db->quote($mailbox) : ""),
-                $this->userid
-            );
-        }
-
-        if (strlen($mailbox)) {
-            unset($this->icache[$mailbox]['index']);
-            // Index removed, set flag to skip SELECT query in get_index()
-            $this->icache[$mailbox]['index_queried'] = true;
-        }
-        else {
-            $this->icache = array();
-        }
-    }
-
-
-    /**
-     * Clears thread cache.
-     *
-     * @param string  $mailbox     Folder name
-     */
-    function remove_thread($mailbox = null)
-    {
-        $this->db->query(
-            "DELETE FROM ".$this->db->table_name('cache_thread')
-            ." WHERE user_id = ?"
-                .(strlen($mailbox) ? " AND mailbox = ".$this->db->quote($mailbox) : ""),
-            $this->userid
-        );
-
-        if (strlen($mailbox)) {
-            unset($this->icache[$mailbox]['thread']);
-            // Thread data removed, set flag to skip SELECT query in get_thread()
-            $this->icache[$mailbox]['thread_queried'] = true;
-        }
-        else {
-            $this->icache = array();
-        }
-    }
-
-
-    /**
-     * Clears the cache.
-     *
-     * @param string $mailbox  Folder name
-     * @param array  $uids     Message UIDs, NULL removes all messages in a folder
-     */
-    function clear($mailbox = null, $uids = null)
-    {
-        $this->remove_index($mailbox, true);
-        $this->remove_thread($mailbox);
-        $this->remove_message($mailbox, $uids);
-    }
-
-
-    /**
-     * Delete cache entries older than TTL
-     *
-     * @param string $ttl  Lifetime of message cache entries
-     */
-    function expunge($ttl)
-    {
-        // get expiration timestamp
-        $ts = get_offset_time($ttl, -1);
-
-        $this->db->query("DELETE FROM ".$this->db->table_name('cache_messages')
-              ." WHERE changed < " . $this->db->fromunixtime($ts));
-
-        $this->db->query("DELETE FROM ".$this->db->table_name('cache_index')
-              ." WHERE changed < " . $this->db->fromunixtime($ts));
-
-        $this->db->query("DELETE FROM ".$this->db->table_name('cache_thread')
-              ." WHERE changed < " . $this->db->fromunixtime($ts));
-    }
-
-
-    /**
-     * Fetches index data from database
-     */
-    private function get_index_row($mailbox)
-    {
-        // Get index from DB
-        $sql_result = $this->db->query(
-            "SELECT data, valid"
-            ." FROM ".$this->db->table_name('cache_index')
-            ." WHERE user_id = ?"
-                ." AND mailbox = ?",
-            $this->userid, $mailbox);
-
-        if ($sql_arr = $this->db->fetch_assoc($sql_result)) {
-            $data  = explode('@', $sql_arr['data']);
-            $index = @unserialize($data[0]);
-            unset($data[0]);
-
-            if (empty($index)) {
-                $index = new rcube_result_index($mailbox);
-            }
-
-            return array(
-                'valid'      => $sql_arr['valid'],
-                'object'     => $index,
-                'sort_field' => $data[1],
-                'deleted'    => $data[2],
-                'validity'   => $data[3],
-                'uidnext'    => $data[4],
-                'modseq'     => $data[5],
-            );
-        }
-
-        return null;
-    }
-
-
-    /**
-     * Fetches thread data from database
-     */
-    private function get_thread_row($mailbox)
-    {
-        // Get thread from DB
-        $sql_result = $this->db->query(
-            "SELECT data"
-            ." FROM ".$this->db->table_name('cache_thread')
-            ." WHERE user_id = ?"
-                ." AND mailbox = ?",
-            $this->userid, $mailbox);
-
-        if ($sql_arr = $this->db->fetch_assoc($sql_result)) {
-            $data   = explode('@', $sql_arr['data']);
-            $thread = @unserialize($data[0]);
-            unset($data[0]);
-
-            if (empty($thread)) {
-                $thread = new rcube_result_thread($mailbox);
-            }
-
-            return array(
-                'object'   => $thread,
-                'deleted'  => $data[1],
-                'validity' => $data[2],
-                'uidnext'  => $data[3],
-            );
-        }
-
-        return null;
-    }
-
-
-    /**
-     * Saves index data into database
-     */
-    private function add_index_row($mailbox, $sort_field,
-        $data, $mbox_data = array(), $exists = false, $modseq = null)
-    {
-        $data = array(
-            serialize($data),
-            $sort_field,
-            (int) $this->skip_deleted,
-            (int) $mbox_data['UIDVALIDITY'],
-            (int) $mbox_data['UIDNEXT'],
-            $modseq ? $modseq : $mbox_data['HIGHESTMODSEQ'],
-        );
-        $data = implode('@', $data);
-
-        if ($exists) {
-            $sql_result = $this->db->query(
-                "UPDATE ".$this->db->table_name('cache_index')
-                ." SET data = ?, valid = 1, changed = ".$this->db->now()
-                ." WHERE user_id = ?"
-                    ." AND mailbox = ?",
-                $data, $this->userid, $mailbox);
-        }
-        else {
-            $sql_result = $this->db->query(
-                "INSERT INTO ".$this->db->table_name('cache_index')
-                ." (user_id, mailbox, data, valid, changed)"
-                ." VALUES (?, ?, ?, 1, ".$this->db->now().")",
-                $this->userid, $mailbox, $data);
-        }
-    }
-
-
-    /**
-     * Saves thread data into database
-     */
-    private function add_thread_row($mailbox, $data, $mbox_data = array(), $exists = false)
-    {
-        $data = array(
-            serialize($data),
-            (int) $this->skip_deleted,
-            (int) $mbox_data['UIDVALIDITY'],
-            (int) $mbox_data['UIDNEXT'],
-        );
-        $data = implode('@', $data);
-
-        if ($exists) {
-            $sql_result = $this->db->query(
-                "UPDATE ".$this->db->table_name('cache_thread')
-                ." SET data = ?, changed = ".$this->db->now()
-                ." WHERE user_id = ?"
-                    ." AND mailbox = ?",
-                $data, $this->userid, $mailbox);
-        }
-        else {
-            $sql_result = $this->db->query(
-                "INSERT INTO ".$this->db->table_name('cache_thread')
-                ." (user_id, mailbox, data, changed)"
-                ." VALUES (?, ?, ?, ".$this->db->now().")",
-                $this->userid, $mailbox, $data);
-        }
-    }
-
-
-    /**
-     * Checks index/thread validity
-     */
-    private function validate($mailbox, $index, &$exists = true)
-    {
-        $object    = $index['object'];
-        $is_thread = is_a($object, 'rcube_result_thread');
-
-        // sanity check
-        if (empty($object)) {
-            return false;
-        }
-
-        // Get mailbox data (UIDVALIDITY, counters, etc.) for status check
-        $mbox_data = $this->imap->folder_data($mailbox);
-
-        // @TODO: Think about skipping validation checks.
-        // If we could check only every 10 minutes, we would be able to skip
-        // expensive checks, mailbox selection or even IMAP connection, this would require
-        // additional logic to force cache invalidation in some cases
-        // and many rcube_imap changes to connect when needed
-
-        // Check UIDVALIDITY
-        if ($index['validity'] != $mbox_data['UIDVALIDITY']) {
-            $this->clear($mailbox);
-            $exists = false;
-            return false;
-        }
-
-        // Folder is empty but cache isn't
-        if (empty($mbox_data['EXISTS'])) {
-            if (!$object->is_empty()) {
-                $this->clear($mailbox);
-                $exists = false;
-                return false;
-            }
-        }
-        // Folder is not empty but cache is
-        else if ($object->is_empty()) {
-            unset($this->icache[$mailbox][$is_thread ? 'thread' : 'index']);
-            return false;
-        }
-
-        // Validation flag
-        if (!$is_thread && empty($index['valid'])) {
-            unset($this->icache[$mailbox]['index']);
-            return false;
-        }
-
-        // Index was created with different skip_deleted setting
-        if ($this->skip_deleted != $index['deleted']) {
-            return false;
-        }
-
-        // Check HIGHESTMODSEQ
-        if (!empty($index['modseq']) && !empty($mbox_data['HIGHESTMODSEQ'])
-            && $index['modseq'] == $mbox_data['HIGHESTMODSEQ']
-        ) {
-            return true;
-        }
-
-        // Check UIDNEXT
-        if ($index['uidnext'] != $mbox_data['UIDNEXT']) {
-            unset($this->icache[$mailbox][$is_thread ? 'thread' : 'index']);
-            return false;
-        }
-
-        // @TODO: find better validity check for threaded index
-        if ($is_thread) {
-            // check messages number...
-            if (!$this->skip_deleted && $mbox_data['EXISTS'] != $object->count_messages()) {
-                return false;
-            }
-            return true;
-        }
-
-        // The rest of checks, more expensive
-        if (!empty($this->skip_deleted)) {
-            // compare counts if available
-            if (!empty($mbox_data['UNDELETED'])
-                && $mbox_data['UNDELETED']->count() != $object->count()
-            ) {
-                return false;
-            }
-            // compare UID sets
-            if (!empty($mbox_data['UNDELETED'])) {
-                $uids_new = $mbox_data['UNDELETED']->get();
-                $uids_old = $object->get();
-
-                if (count($uids_new) != count($uids_old)) {
-                    return false;
-                }
-
-                sort($uids_new, SORT_NUMERIC);
-                sort($uids_old, SORT_NUMERIC);
-
-                if ($uids_old != $uids_new)
-                    return false;
-            }
-            else {
-                // get all undeleted messages excluding cached UIDs
-                $ids = $this->imap->search_once($mailbox, 'ALL UNDELETED NOT UID '.
-                    rcube_imap_generic::compressMessageSet($object->get()));
-
-                if (!$ids->is_empty()) {
-                    return false;
-                }
-            }
-        }
-        else {
-            // check messages number...
-            if ($mbox_data['EXISTS'] != $object->count()) {
-                return false;
-            }
-            // ... and max UID
-            if ($object->max() != $this->imap->id2uid($mbox_data['EXISTS'], $mailbox, true)) {
-                return false;
-            }
-        }
-
-        return true;
-    }
-
-
-    /**
-     * Synchronizes the mailbox.
-     *
-     * @param string $mailbox Folder name
-     */
-    function synchronize($mailbox)
-    {
-        // RFC4549: Synchronization Operations for Disconnected IMAP4 Clients
-        // RFC4551: IMAP Extension for Conditional STORE Operation
-        //          or Quick Flag Changes Resynchronization
-        // RFC5162: IMAP Extensions for Quick Mailbox Resynchronization
-
-        // @TODO: synchronize with other methods?
-        $qresync   = $this->imap->get_capability('QRESYNC');
-        $condstore = $qresync ? true : $this->imap->get_capability('CONDSTORE');
-
-        if (!$qresync && !$condstore) {
-            return;
-        }
-
-        // Get stored index
-        $index = $this->get_index_row($mailbox);
-
-        // database is empty
-        if (empty($index)) {
-            // set the flag that DB was already queried for index
-            // this way we'll be able to skip one SELECT in get_index()
-            $this->icache[$mailbox]['index_queried'] = true;
-            return;
-        }
-
-        $this->icache[$mailbox]['index'] = $index;
-
-        // no last HIGHESTMODSEQ value
-        if (empty($index['modseq'])) {
-            return;
-        }
-
-        if (!$this->imap->check_connection()) {
-            return;
-        }
-
-        // Enable QRESYNC
-        $res = $this->imap->conn->enable($qresync ? 'QRESYNC' : 'CONDSTORE');
-        if ($res === false) {
-            return;
-        }
-
-        // Close mailbox if already selected to get most recent data
-        if ($this->imap->conn->selected == $mailbox) {
-            $this->imap->conn->close();
-        }
-
-        // Get mailbox data (UIDVALIDITY, HIGHESTMODSEQ, counters, etc.)
-        $mbox_data = $this->imap->folder_data($mailbox);
-
-        if (empty($mbox_data)) {
-             return;
-        }
-
-        // Check UIDVALIDITY
-        if ($index['validity'] != $mbox_data['UIDVALIDITY']) {
-            $this->clear($mailbox);
-            return;
-        }
-
-        // QRESYNC not supported on specified mailbox
-        if (!empty($mbox_data['NOMODSEQ']) || empty($mbox_data['HIGHESTMODSEQ'])) {
-            return;
-        }
-
-        // Nothing new
-        if ($mbox_data['HIGHESTMODSEQ'] == $index['modseq']) {
-            return;
-        }
-
-        $uids    = array();
-        $removed = array();
-
-        // Get known UIDs
-        $sql_result = $this->db->query(
-            "SELECT uid"
-            ." FROM ".$this->db->table_name('cache_messages')
-            ." WHERE user_id = ?"
-                ." AND mailbox = ?",
-            $this->userid, $mailbox);
-
-        while ($sql_arr = $this->db->fetch_assoc($sql_result)) {
-            $uids[] = $sql_arr['uid'];
-        }
-
-        // Synchronize messages data
-        if (!empty($uids)) {
-            // Get modified flags and vanished messages
-            // UID FETCH 1:* (FLAGS) (CHANGEDSINCE 0123456789 VANISHED)
-            $result = $this->imap->conn->fetch($mailbox,
-                $uids, true, array('FLAGS'), $index['modseq'], $qresync);
-
-            if (!empty($result)) {
-                foreach ($result as $id => $msg) {
-                    $uid = $msg->uid;
-                    // Remove deleted message
-                    if ($this->skip_deleted && !empty($msg->flags['DELETED'])) {
-                        $removed[] = $uid;
-                        // Invalidate index
-                        $index['valid'] = false;
-                        continue;
-                    }
-
-                    $flags = 0;
-                    if (!empty($msg->flags)) {
-                        foreach ($this->flags as $idx => $flag) {
-                            if (!empty($msg->flags[$flag])) {
-                                $flags += $idx;
-                            }
-                        }
-                    }
-
-                    $this->db->query(
-                        "UPDATE ".$this->db->table_name('cache_messages')
-                        ." SET flags = ?, changed = ".$this->db->now()
-                        ." WHERE user_id = ?"
-                            ." AND mailbox = ?"
-                            ." AND uid = ?"
-                            ." AND flags <> ?",
-                        $flags, $this->userid, $mailbox, $uid, $flags);
-                }
-            }
-
-            // VANISHED found?
-            if ($qresync) {
-                $mbox_data = $this->imap->folder_data($mailbox);
-
-                // Removed messages found
-                $uids = rcube_imap_generic::uncompressMessageSet($mbox_data['VANISHED']);
-                if (!empty($uids)) {
-                    $removed = array_merge($removed, $uids);
-                    // Invalidate index
-                    $index['valid'] = false;
-                }
-            }
-
-            // remove messages from database
-            if (!empty($removed)) {
-                $this->remove_message($mailbox, $removed);
-            }
-        }
-
-        // Invalidate thread index (?)
-        if (!$index['valid']) {
-            $this->remove_thread($mailbox);
-        }
-
-        $sort_field = $index['sort_field'];
-        $sort_order = $index['object']->get_parameters('ORDER');
-        $exists     = true;
-
-        // Validate index
-        if (!$this->validate($mailbox, $index, $exists)) {
-            // Update index
-            $data = $this->get_index_data($mailbox, $sort_field, $sort_order, $mbox_data);
-        }
-        else {
-            $data = $index['object'];
-        }
-
-        // update index and/or HIGHESTMODSEQ value
-        $this->add_index_row($mailbox, $sort_field, $data, $mbox_data, $exists);
-
-        // update internal cache for get_index()
-        $this->icache[$mailbox]['index']['object'] = $data;
-    }
-
-
-    /**
-     * Converts cache row into message object.
-     *
-     * @param array $sql_arr Message row data
-     *
-     * @return rcube_message_header Message object
-     */
-    private function build_message($sql_arr)
-    {
-        $message = $this->db->decode(unserialize($sql_arr['data']));
-
-        if ($message) {
-            $message->flags = array();
-            foreach ($this->flags as $idx => $flag) {
-                if (($sql_arr['flags'] & $idx) == $idx) {
-                    $message->flags[$flag] = true;
-                }
-           }
-        }
-
-        return $message;
-    }
-
-
-    /**
-     * Saves message stored in internal cache
-     */
-    private function save_icache()
-    {
-        // Save current message from internal cache
-        if ($message = $this->icache['__message']) {
-            // clean up some object's data
-            $object = $this->message_object_prepare($message['object']);
-
-            // calculate current md5 sum
-            $md5sum = md5(serialize($object));
-
-            if ($message['md5sum'] != $md5sum) {
-                $this->add_message($message['mailbox'], $object, !$message['exists']);
-            }
-
-            $this->icache['__message']['md5sum'] = $md5sum;
-        }
-    }
-
-
-    /**
-     * Prepares message object to be stored in database.
-     */
-    private function message_object_prepare($msg)
-    {
-        // Remove body too big (>25kB)
-        if ($msg->body && strlen($msg->body) > 25 * 1024) {
-            unset($msg->body);
-        }
-
-        // Fix mimetype which might be broken by some code when message is displayed
-        // Another solution would be to use object's copy in rcube_message class
-        // to prevent related issues, however I'm not sure which is better
-        if ($msg->mimetype) {
-            list($msg->ctype_primary, $msg->ctype_secondary) = explode('/', $msg->mimetype);
-        }
-
-        if (is_array($msg->structure->parts)) {
-            foreach ($msg->structure->parts as $idx => $part) {
-                $msg->structure->parts[$idx] = $this->message_object_prepare($part);
-            }
-        }
-
-        return $msg;
-    }
-
-
-    /**
-     * Fetches index data from IMAP server
-     */
-    private function get_index_data($mailbox, $sort_field, $sort_order, $mbox_data = array())
-    {
-        if (empty($mbox_data)) {
-            $mbox_data = $this->imap->folder_data($mailbox);
-        }
-
-        if ($mbox_data['EXISTS']) {
-            // fetch sorted sequence numbers
-            $index = $this->imap->index_direct($mailbox, $sort_field, $sort_order);
-        }
-        else {
-            $index = new rcube_result_index($mailbox, '* SORT');
-        }
-
-        return $index;
-    }
-}
-
-// for backward compat.
-class rcube_mail_header extends rcube_message_header { }