--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/program/lib/Roundcube/rcube_cache_shared.php	Thu Jan 04 15:52:31 2018 -0500
@@ -0,0 +1,657 @@
+<?php
+
+/**
+ +-----------------------------------------------------------------------+
+ | This file is part of the Roundcube Webmail client                     |
+ | Copyright (C) 2011-2013, The Roundcube Dev Team                       |
+ | Copyright (C) 2011-2013, Kolab Systems AG                             |
+ |                                                                       |
+ | 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:                                                              |
+ |   Shared (cross-user) caching engine                                  |
+ +-----------------------------------------------------------------------+
+ | Author: Thomas Bruederli <roundcube@gmail.com>                        |
+ | Author: Aleksander Machniak <alec@alec.pl>                            |
+ +-----------------------------------------------------------------------+
+*/
+
+/**
+ * Interface class for accessing Roundcube shared cache
+ *
+ * @package    Framework
+ * @subpackage Cache
+ * @author     Thomas Bruederli <roundcube@gmail.com>
+ * @author     Aleksander Machniak <alec@alec.pl>
+ */
+class rcube_cache_shared
+{
+    /**
+     * Instance of database handler
+     *
+     * @var rcube_db|Memcache|bool
+     */
+    private $db;
+    private $type;
+    private $prefix;
+    private $ttl;
+    private $packed;
+    private $index;
+    private $table;
+    private $debug;
+    private $index_changed = false;
+    private $cache         = array();
+    private $cache_changes = array();
+    private $cache_sums    = array();
+    private $max_packet    = -1;
+
+
+    /**
+     * Object constructor.
+     *
+     * @param string $type   Engine type ('db' or 'memcache' or 'apc')
+     * @param string $prefix Key name prefix
+     * @param string $ttl    Expiration time of memcache/apc items
+     * @param bool   $packed Enables/disabled data serialization.
+     *                       It's possible to disable data serialization if you're sure
+     *                       stored data will be always a safe string
+     */
+    function __construct($type, $prefix='', $ttl=0, $packed=true)
+    {
+        $rcube = rcube::get_instance();
+        $type  = strtolower($type);
+
+        if ($type == 'memcache') {
+            $this->type  = 'memcache';
+            $this->db    = $rcube->get_memcache();
+            $this->debug = $rcube->config->get('memcache_debug');
+        }
+        else if ($type == 'apc') {
+            $this->type  = 'apc';
+            $this->db    = function_exists('apc_exists'); // APC 3.1.4 required
+            $this->debug = $rcube->config->get('apc_debug');
+        }
+        else {
+            $this->type  = 'db';
+            $this->db    = $rcube->get_dbh();
+            $this->table = $this->db->table_name('cache_shared', true);
+        }
+
+        // convert ttl string to seconds
+        $ttl = get_offset_sec($ttl);
+        if ($ttl > 2592000) $ttl = 2592000;
+
+        $this->ttl       = $ttl;
+        $this->packed    = $packed;
+        $this->prefix    = $prefix;
+    }
+
+    /**
+     * Returns cached value.
+     *
+     * @param string $key Cache key name
+     *
+     * @return mixed Cached value
+     */
+    function get($key)
+    {
+        if (!array_key_exists($key, $this->cache)) {
+            return $this->read_record($key);
+        }
+
+        return $this->cache[$key];
+    }
+
+    /**
+     * Sets (add/update) value in cache.
+     *
+     * @param string $key  Cache key name
+     * @param mixed  $data Cache data
+     */
+    function set($key, $data)
+    {
+        $this->cache[$key]         = $data;
+        $this->cache_changes[$key] = true;
+    }
+
+    /**
+     * Returns cached value without storing it in internal memory.
+     *
+     * @param string $key Cache key name
+     *
+     * @return mixed Cached value
+     */
+    function read($key)
+    {
+        if (array_key_exists($key, $this->cache)) {
+            return $this->cache[$key];
+        }
+
+        return $this->read_record($key, true);
+    }
+
+    /**
+     * Sets (add/update) value in cache and immediately saves
+     * it in the backend, no internal memory will be used.
+     *
+     * @param string $key  Cache key name
+     * @param mixed  $data Cache data
+     *
+     * @param boolean True on success, False on failure
+     */
+    function write($key, $data)
+    {
+        return $this->write_record($key, $this->serialize($data));
+    }
+
+    /**
+     * Clears the cache.
+     *
+     * @param string  $key         Cache key name or pattern
+     * @param boolean $prefix_mode Enable it to clear all keys starting
+     *                             with prefix specified in $key
+     */
+    function remove($key=null, $prefix_mode=false)
+    {
+        // Remove all keys
+        if ($key === null) {
+            $this->cache         = array();
+            $this->cache_changes = array();
+            $this->cache_sums    = array();
+        }
+        // Remove keys by name prefix
+        else if ($prefix_mode) {
+            foreach (array_keys($this->cache) as $k) {
+                if (strpos($k, $key) === 0) {
+                    $this->cache[$k] = null;
+                    $this->cache_changes[$k] = false;
+                    unset($this->cache_sums[$k]);
+                }
+            }
+        }
+        // Remove one key by name
+        else {
+            $this->cache[$key] = null;
+            $this->cache_changes[$key] = false;
+            unset($this->cache_sums[$key]);
+        }
+
+        // Remove record(s) from the backend
+        $this->remove_record($key, $prefix_mode);
+    }
+
+    /**
+     * Remove cache records older than ttl
+     */
+    function expunge()
+    {
+        if ($this->type == 'db' && $this->db && $this->ttl) {
+            $this->db->query(
+                "DELETE FROM {$this->table}"
+                . " WHERE `cache_key` LIKE ?"
+                . " AND `expires` < " . $this->db->now(),
+                $this->prefix . '.%');
+        }
+    }
+
+    /**
+     * Remove expired records of all caches
+     */
+    static function gc()
+    {
+        $rcube = rcube::get_instance();
+        $db    = $rcube->get_dbh();
+
+        $db->query("DELETE FROM " . $db->table_name('cache_shared', true) . " WHERE `expires` < " . $db->now());
+    }
+
+    /**
+     * Writes the cache back to the DB.
+     */
+    function close()
+    {
+        foreach ($this->cache as $key => $data) {
+            // The key has been used
+            if ($this->cache_changes[$key]) {
+                // Make sure we're not going to write unchanged data
+                // by comparing current md5 sum with the sum calculated on DB read
+                $data = $this->serialize($data);
+
+                if (!$this->cache_sums[$key] || $this->cache_sums[$key] != md5($data)) {
+                    $this->write_record($key, $data);
+                }
+            }
+        }
+
+        if ($this->index_changed) {
+            $this->write_index();
+        }
+
+        // reset internal cache index, thanks to this we can force index reload
+        $this->index         = null;
+        $this->index_changed = false;
+        $this->cache         = array();
+        $this->cache_sums    = array();
+        $this->cache_changes = array();
+    }
+
+    /**
+     * Reads cache entry.
+     *
+     * @param string  $key     Cache key name
+     * @param boolean $nostore Enable to skip in-memory store
+     *
+     * @return mixed Cached value
+     */
+    private function read_record($key, $nostore=false)
+    {
+        if (!$this->db) {
+            return null;
+        }
+
+        if ($this->type != 'db') {
+            $this->load_index();
+
+            // Consistency check (#1490390)
+            if (!in_array($key, $this->index)) {
+                // we always check if the key exist in the index
+                // to have data in consistent state. Keeping the index consistent
+                // is needed for keys delete operation when we delete all keys or by prefix.
+            }
+            else {
+                $ckey = $this->ckey($key);
+
+                if ($this->type == 'memcache') {
+                    $data = $this->db->get($ckey);
+                }
+                else if ($this->type == 'apc') {
+                    $data = apc_fetch($ckey);
+                }
+
+                if ($this->debug) {
+                    $this->debug('get', $ckey, $data);
+                }
+            }
+
+            if ($data !== false) {
+                $md5sum = md5($data);
+                $data   = $this->unserialize($data);
+
+                if ($nostore) {
+                    return $data;
+                }
+
+                $this->cache_sums[$key] = $md5sum;
+                $this->cache[$key]      = $data;
+            }
+            else {
+                $this->cache[$key] = null;
+            }
+        }
+        else {
+            $sql_result = $this->db->query(
+                "SELECT `data`, `cache_key` FROM {$this->table}"
+                . " WHERE `cache_key` = ?",
+                $this->prefix . '.' . $key);
+
+            if ($sql_arr = $this->db->fetch_assoc($sql_result)) {
+                if (strlen($sql_arr['data']) > 0) {
+                    $md5sum = md5($sql_arr['data']);
+                    $data   = $this->unserialize($sql_arr['data']);
+                }
+
+                $this->db->reset();
+
+                if ($nostore) {
+                    return $data;
+                }
+
+                $this->cache[$key]      = $data;
+                $this->cache_sums[$key] = $md5sum;
+            }
+            else {
+                $this->cache[$key] = null;
+            }
+        }
+
+        return $this->cache[$key];
+    }
+
+    /**
+     * Writes single cache record into DB.
+     *
+     * @param string $key  Cache key name
+     * @param mixed  $data Serialized cache data
+     *
+     * @param boolean True on success, False on failure
+     */
+    private function write_record($key, $data)
+    {
+        if (!$this->db) {
+            return false;
+        }
+
+        // don't attempt to write too big data sets
+        if (strlen($data) > $this->max_packet_size()) {
+            trigger_error("rcube_cache: max_packet_size ($this->max_packet) exceeded for key $key. Tried to write " . strlen($data) . " bytes", E_USER_WARNING);
+            return false;
+        }
+
+        if ($this->type == 'memcache' || $this->type == 'apc') {
+            $result = $this->add_record($this->ckey($key), $data);
+
+            // make sure index will be updated
+            if ($result) {
+                if (!array_key_exists($key, $this->cache_sums)) {
+                    $this->cache_sums[$key] = true;
+                }
+
+                $this->load_index();
+
+                if (!$this->index_changed && !in_array($key, $this->index)) {
+                    $this->index_changed = true;
+                }
+            }
+
+            return $result;
+        }
+
+        $db_key = $this->prefix . '.' . $key;
+
+        // Remove NULL rows (here we don't need to check if the record exist)
+        if ($data == 'N;') {
+            $result = $this->db->query("DELETE FROM {$this->table} WHERE `cache_key` = ?", $db_key);
+
+            return !$this->db->is_error($result);
+        }
+
+        $key_exists = array_key_exists($key, $this->cache_sums);
+        $expires    = $this->ttl ? $this->db->now($this->ttl) : 'NULL';
+
+        if (!$key_exists) {
+            // Try INSERT temporarily ignoring "duplicate key" errors
+            $this->db->set_option('ignore_key_errors', true);
+
+            $result = $this->db->query(
+                "INSERT INTO {$this->table} (`expires`, `cache_key`, `data`)"
+                . " VALUES ($expires, ?, ?)",
+                $db_key, $data);
+
+            $this->db->set_option('ignore_key_errors', false);
+        }
+
+        // otherwise try UPDATE
+        if (!isset($result) || !($count = $this->db->affected_rows($result))) {
+            $result = $this->db->query(
+                "UPDATE {$this->table} SET `expires` = $expires, `data` = ?"
+                . " WHERE `cache_key` = ?",
+                $data, $db_key);
+
+            $count = $this->db->affected_rows($result);
+        }
+
+        return $count > 0;
+    }
+
+    /**
+     * Deletes the cache record(s).
+     *
+     * @param string  $key         Cache key name or pattern
+     * @param boolean $prefix_mode Enable it to clear all keys starting
+     *                             with prefix specified in $key
+     */
+    private function remove_record($key=null, $prefix_mode=false)
+    {
+        if (!$this->db) {
+            return;
+        }
+
+        if ($this->type != 'db') {
+            $this->load_index();
+
+            // Remove all keys
+            if ($key === null) {
+                foreach ($this->index as $key) {
+                    $this->delete_record($this->ckey($key));
+                }
+
+                $this->index = array();
+            }
+            // Remove keys by name prefix
+            else if ($prefix_mode) {
+                foreach ($this->index as $idx => $k) {
+                    if (strpos($k, $key) === 0) {
+                        $this->delete_record($this->ckey($k));
+                        unset($this->index[$idx]);
+                    }
+                }
+            }
+            // Remove one key by name
+            else {
+                $this->delete_record($this->ckey($key));
+                if (($idx = array_search($key, $this->index)) !== false) {
+                    unset($this->index[$idx]);
+                }
+            }
+
+            $this->index_changed = true;
+
+            return;
+        }
+
+        // Remove all keys (in specified cache)
+        if ($key === null) {
+            $where = " WHERE `cache_key` LIKE " . $this->db->quote($this->prefix.'.%');
+        }
+        // Remove keys by name prefix
+        else if ($prefix_mode) {
+            $where = " WHERE `cache_key` LIKE " . $this->db->quote($this->prefix.'.'.$key.'%');
+        }
+        // Remove one key by name
+        else {
+            $where = " WHERE `cache_key` = " . $this->db->quote($this->prefix.'.'.$key);
+        }
+
+        $this->db->query("DELETE FROM " . $this->table . $where);
+    }
+
+    /**
+     * Adds entry into memcache/apc DB.
+     *
+     * @param string $key  Cache internal key name
+     * @param mixed  $data Serialized cache data
+     *
+     * @param boolean True on success, False on failure
+     */
+    private function add_record($key, $data)
+    {
+        if ($this->type == 'memcache') {
+            $result = $this->db->replace($key, $data, MEMCACHE_COMPRESSED, $this->ttl);
+
+            if (!$result) {
+                $result = $this->db->set($key, $data, MEMCACHE_COMPRESSED, $this->ttl);
+            }
+        }
+        else if ($this->type == 'apc') {
+            if (apc_exists($key)) {
+                apc_delete($key);
+            }
+
+            $result = apc_store($key, $data, $this->ttl);
+        }
+
+        if ($this->debug) {
+            $this->debug('set', $key, $data, $result);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Deletes entry from memcache/apc DB.
+     *
+     * @param string $key Cache internal key name
+     *
+     * @param boolean True on success, False on failure
+     */
+    private function delete_record($key)
+    {
+        if ($this->type == 'memcache') {
+            // #1488592: use 2nd argument
+            $result = $this->db->delete($key, 0);
+        }
+        else {
+            $result = apc_delete($key);
+        }
+
+        if ($this->debug) {
+            $this->debug('delete', $key, null, $result);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Writes the index entry into memcache/apc DB.
+     */
+    private function write_index()
+    {
+        if (!$this->db || $this->type == 'db') {
+            return;
+        }
+
+        $this->load_index();
+
+        // Make sure index contains new keys
+        foreach ($this->cache as $key => $value) {
+            if ($value !== null && !in_array($key, $this->index)) {
+                $this->index[] = $key;
+            }
+        }
+
+        // new keys added using self::write()
+        foreach ($this->cache_sums as $key => $value) {
+            if ($value === true && !in_array($key, $this->index)) {
+                $this->index[] = $key;
+            }
+        }
+
+        $data = serialize($this->index);
+        $this->add_record($this->ikey(), $data);
+    }
+
+    /**
+     * Gets the index entry from memcache/apc DB.
+     */
+    private function load_index()
+    {
+        if (!$this->db || $this->type == 'db') {
+            return;
+        }
+
+        if ($this->index !== null) {
+            return;
+        }
+
+        $index_key = $this->ikey();
+
+        if ($this->type == 'memcache') {
+            $data = $this->db->get($index_key);
+        }
+        else if ($this->type == 'apc') {
+            $data = apc_fetch($index_key);
+        }
+
+        if ($this->debug) {
+            $this->debug('get', $index_key, $data);
+        }
+
+        $this->index = $data ? unserialize($data) : array();
+    }
+
+    /**
+     * Creates cache key name (for memcache and apc)
+     *
+     * @param string $key Cache key name
+     *
+     * @return string Cache key
+     */
+    private function ckey($key)
+    {
+        return $this->prefix . ':' . $key;
+    }
+
+    /**
+     * Creates index cache key name (for memcache and apc)
+     *
+     * @return string Cache key
+     */
+    private function ikey()
+    {
+        // This way each cache will have its own index
+        return $this->prefix . 'INDEX';
+    }
+
+    /**
+     * Serializes data for storing
+     */
+    private function serialize($data)
+    {
+        if ($this->type == 'db') {
+            return $this->db->encode($data, $this->packed);
+        }
+
+        return $this->packed ? serialize($data) : $data;
+    }
+
+    /**
+     * Unserializes serialized data
+     */
+    private function unserialize($data)
+    {
+        if ($this->type == 'db') {
+            return $this->db->decode($data, $this->packed);
+        }
+
+        return $this->packed ? @unserialize($data) : $data;
+    }
+
+    /**
+     * Determine the maximum size for cache data to be written
+     */
+    private function max_packet_size()
+    {
+        if ($this->max_packet < 0) {
+            $this->max_packet = 2097152; // default/max is 2 MB
+
+            if ($this->type == 'db') {
+                if ($value = $this->db->get_variable('max_allowed_packet', $this->max_packet)) {
+                    $this->max_packet = $value;
+                }
+                $this->max_packet -= 2000;
+            }
+            else {
+                $max_packet = rcube::get_instance()->config->get($this->type . '_max_allowed_packet');
+                $this->max_packet = parse_bytes($max_packet) ?: $this->max_packet;
+            }
+        }
+
+        return $this->max_packet;
+    }
+
+    /**
+     * Write memcache/apc debug info to the log
+     */
+    private function debug($type, $key, $data = null, $result = null)
+    {
+        $line = strtoupper($type) . ' ' . $key;
+
+        if ($data !== null) {
+            $line .= ' ' . ($this->packed ? $data : serialize($data));
+        }
+
+        rcube::debug($this->type, $line, $result);
+    }
+}