diff options
Diffstat (limited to 'program/include/rcube_cache.php')
-rw-r--r-- | program/include/rcube_cache.php | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/program/include/rcube_cache.php b/program/include/rcube_cache.php new file mode 100644 index 000000000..d38c237c8 --- /dev/null +++ b/program/include/rcube_cache.php @@ -0,0 +1,328 @@ +<?php + +/* + +-----------------------------------------------------------------------+ + | program/include/rcube_cache.php | + | | + | This file is part of the Roundcube Webmail client | + | Copyright (C) 2011, The Roundcube Dev Team | + | Copyright (C) 2011, Kolab Systems AG | + | Licensed under the GNU GPL | + | | + | PURPOSE: | + | Caching engine | + | | + +-----------------------------------------------------------------------+ + | Author: Thomas Bruederli <roundcube@gmail.com> | + | Author: Aleksander Machniak <alec@alec.pl> | + +-----------------------------------------------------------------------+ + + $Id$ + +*/ + + +/** + * Interface class for accessing Roundcube cache + * + * @package Cache + * @author Thomas Bruederli <roundcube@gmail.com> + * @author Aleksander Machniak <alec@alec.pl> + * @version 1.0 + */ +class rcube_cache +{ + /** + * Instance of rcube_mdb2 or Memcache class + * + * @var rcube_mdb2/Memcache + */ + private $db; + private $type; + private $userid; + private $prefix; + private $cache = array(); + private $cache_keys = array(); + private $cache_changes = array(); + private $cache_sums = array(); + + + + /** + * Object constructor. + * + * @param string $type Engine type ('db' or 'memcache') + * @param int $userid User identifier + * @param string $prefix Key name prefix + */ + function __construct($type, $userid, $prefix='') + { + $rcmail = rcmail::get_instance(); + + if (strtolower($type) == 'memcache') { + $this->type = 'memcache'; + $this->db = $rcmail->get_memcache(); + } + else { + $this->type = 'db'; + $this->db = $rcmail->get_dbh(); + } + + $this->userid = (int) $userid; + $this->prefix = $prefix; + } + + + /** + * Returns cached value. + * + * @param string $key Cache key + * + * @return mixed Cached value + */ + function get($key) + { + $key = $this->prefix.$key; + + if ($this->type == 'memcache') { + return $this->read_cache_record($key); + } + + // read cache (if it was not read before) + if (!count($this->cache)) { + $do_read = true; + } + else if (isset($this->cache[$key])) { + $do_read = false; + } + // Find cache prefix, we'll load data for all keys + // with specified (class) prefix into internal cache (memory) + else if ($pos = strpos($key, '.')) { + $prefix = substr($key, 0, $pos); + $regexp = '/^' . preg_quote($prefix, '/') . '/'; + if (!count(preg_grep($regexp, array_keys($this->cache_keys)))) { + $do_read = true; + } + } + + if ($do_read) { + return $this->read_cache_record($key); + } + + return $this->cache[$key]; + } + + + /** + * Sets (add/update) value in cache. + * + * @param string $key Cache key + * @param mixed $data Data + */ + function set($key, $data) + { + $key = $this->prefix.$key; + + $this->cache[$key] = $data; + $this->cache_changed = true; + $this->cache_changes[$key] = true; + } + + + /** + * Clears the cache. + * + * @param string $key Cache key name or pattern + * @param boolean $pattern_mode Enable it to clear all keys with name + * matching PREG pattern in $key + */ + function remove($key=null, $pattern_mode=false) + { + if ($key === null) { + foreach (array_keys($this->cache) as $key) + $this->clear_cache_record($key); + + $this->cache = array(); + $this->cache_changed = false; + $this->cache_changes = array(); + } + else if ($pattern_mode) { + $key = $this->prefix.$key; + + foreach (array_keys($this->cache) as $k) { + if (preg_match($key, $k)) { + $this->clear_cache_record($k); + $this->cache_changes[$k] = false; + unset($this->cache[$key]); + } + } + if (!count($this->cache)) { + $this->cache_changed = false; + } + } + else { + $key = $this->prefix.$key; + + $this->clear_cache_record($key); + $this->cache_changes[$key] = false; + unset($this->cache[$key]); + } + } + + + /** + * Writes the cache back to the DB. + */ + function close() + { + if (!$this->cache_changed) { + return; + } + + foreach ($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 + $data = serialize($data); + if (!$this->cache_sums[$key] || $this->cache_sums[$key] != md5($data)) { + $this->write_cache_record($key, $data); + } + } + } + } + + + /** + * Returns cached entry. + * + * @param string $key Cache key + * + * @return mixed Cached value + * @access private + */ + private function read_cache_record($key) + { + if (!$this->db) { + return null; + } + + if ($this->type == 'memcache') { + $data = $this->db->get($key); + + if ($data) { + $this->cache_sums[$key] = md5($data); + $data = unserialize($data); + } + return $this->cache[$key] = $data; + } + + // Find cache prefix, we'll load data for all keys + // with specified (class) prefix into internal cache (memory) + if ($pos = strpos($key, '.')) { + $prefix = substr($key, 0, $pos); + $where = " AND cache_key LIKE '$prefix%'"; + } + else { + $where = " AND cache_key = ".$this->db->quote($key); + } + + // get cached data from DB + $sql_result = $this->db->query( + "SELECT cache_id, data, cache_key". + " FROM ".get_table_name('cache'). + " WHERE user_id = ?".$where, + $this->userid); + + while ($sql_arr = $this->db->fetch_assoc($sql_result)) { + $sql_key = $sql_arr['cache_key']; + $this->cache_keys[$sql_key] = $sql_arr['cache_id']; + if (!isset($this->cache[$sql_key])) { + $md5sum = $sql_arr['data'] ? md5($sql_arr['data']) : null; + $data = $sql_arr['data'] ? unserialize($sql_arr['data']) : false; + $this->cache[$sql_key] = $data; + $this->cache_sums[$sql_key] = $md5sum; + } + } + + return $this->cache[$key]; + } + + + /** + * Writes single cache record. + * + * @param string $key Cache key + * @param mxied $data Cache value + * @access private + */ + private function write_cache_record($key, $data) + { + if (!$this->db) { + return false; + } + + if ($this->type == 'memcache') { + $result = $this->db->replace($key, $data, MEMCACHE_COMPRESSED); + if (!$result) + $result = $this->db->set($key, $data, MEMCACHE_COMPRESSED); + return $result; + } + + // update existing cache record + if ($this->cache_keys[$key]) { + $this->db->query( + "UPDATE ".get_table_name('cache'). + " SET created = ". $this->db->now().", data = ?". + " WHERE user_id = ?". + " AND cache_key = ?", + $data, $this->userid, $key); + } + // add new cache record + else { + $this->db->query( + "INSERT INTO ".get_table_name('cache'). + " (created, user_id, cache_key, data)". + " VALUES (".$this->db->now().", ?, ?, ?)", + $this->userid, $key, $data); + + // get cache entry ID for this key + $sql_result = $this->db->query( + "SELECT cache_id". + " FROM ".get_table_name('cache'). + " WHERE user_id = ?". + " AND cache_key = ?", + $this->userid, $key); + + if ($sql_arr = $this->db->fetch_assoc($sql_result)) + $this->cache_keys[$key] = $sql_arr['cache_id']; + } + } + + + /** + * Clears cache for single record. + * + * @param string $key Cache key + * @access private + */ + private function clear_cache_record($key) + { + if (!$this->db) { + return false; + } + + if ($this->type == 'memcache') { + return $this->db->delete($key); + } + + $this->db->query( + "DELETE FROM ".get_table_name('cache'). + " WHERE user_id = ?". + " AND cache_key = ?", + $this->userid, $key); + + unset($this->cache_keys[$key]); + } + +} |