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roundcubemail/program/include/rcube_cache.php

329 lines
9.4 KiB
PHP

<?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]);
}
}