| Current File : //var/webuzo-data/roundcube/program/lib/Roundcube/rcube_cache.php |
<?php
/**
+-----------------------------------------------------------------------+
| This file is part of the Roundcube Webmail client |
| |
| Copyright (C) The Roundcube Dev Team |
| Copyright (C) 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: |
| Caching engine |
+-----------------------------------------------------------------------+
| Author: Thomas Bruederli <roundcube@gmail.com> |
| Author: Aleksander Machniak <alec@alec.pl> |
+-----------------------------------------------------------------------+
*/
/**
* Interface class for accessing Roundcube cache
*
* @package Framework
* @subpackage Cache
*/
class rcube_cache
{
protected $type;
protected $userid;
protected $prefix;
protected $ttl;
protected $packed;
protected $indexed;
protected $index;
protected $index_update;
protected $cache = [];
protected $updates = [];
protected $exp_records = [];
protected $refresh_time = 0.5; // how often to refresh/save the index and cache entries
protected $debug = false;
protected $max_packet = -1;
const MAX_EXP_LEVEL = 2;
const DATE_FORMAT = 'Y-m-d H:i:s.u';
const DATE_FORMAT_REGEX = '[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{1,6}';
/**
* Object factory
*
* @param string $type Engine type ('db', 'memcache', 'apc', 'redis')
* @param int $userid User identifier
* @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
* @param bool $indexed Use indexed cache. Indexed cache is more appropriate for
* storing big data with possibility to remove it by a key prefix.
* Non-indexed cache does not remove data, but flags it for expiration,
* also stores it in memory until close() method is called.
*
* @return rcube_cache Cache object
*/
public static function factory($type, $userid, $prefix = '', $ttl = 0, $packed = true, $indexed = false)
{
$driver = strtolower($type) ?: 'db';
$class = "rcube_cache_$driver";
if (!$driver || !class_exists($class)) {
rcube::raise_error([
'code' => 600, 'type' => 'db',
'line' => __LINE__, 'file' => __FILE__,
'message' => "Configuration error. Unsupported cache driver: $driver"
],
true, true
);
}
return new $class($userid, $prefix, $ttl, $packed, $indexed);
}
/**
* Object constructor.
*
* @param int $userid User identifier
* @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
* @param bool $indexed Use indexed cache. Indexed cache is more appropriate for
* storing big data with possibility to remove it by key prefix.
* Non-indexed cache does not remove data, but flags it for expiration,
* also stores it in memory until close() method is called.
*/
public function __construct($userid, $prefix = '', $ttl = 0, $packed = true, $indexed = false)
{
$this->userid = (int) $userid;
$this->ttl = min(get_offset_sec($ttl), 2592000);
$this->prefix = $prefix;
$this->packed = $packed;
$this->indexed = $indexed;
}
/**
* Returns cached value.
*
* @param string $key Cache key name
*
* @return mixed Cached value
*/
public function get($key)
{
if (array_key_exists($key, $this->cache)) {
return $this->cache[$key];
}
return $this->read_record($key);
}
/**
* Sets (add/update) value in cache.
*
* @param string $key Cache key name
* @param mixed $data Cache data
*
* @return bool True on success, False on failure
*/
public function set($key, $data)
{
return $this->write_record($key, $data);
}
/**
* @deprecated Use self::get()
*/
public function read($key)
{
return $this->get($key);
}
/**
* @deprecated Use self::set()
*/
public function write($key, $data)
{
return $this->set($key, $data);
}
/**
* Clears the cache.
*
* @param string $key Cache key name or pattern
* @param bool $prefix_mode Enable it to clear all keys starting
* with prefix specified in $key
*/
public function remove($key = null, $prefix_mode = false)
{
// Remove record(s) from the backend
$this->remove_record($key, $prefix_mode);
}
/**
* Remove cache records older than ttl
*/
public function expunge()
{
// to be overwritten by engine class
}
/**
* Remove expired records of all caches
*/
public static function gc()
{
// Only DB cache requires an action to remove expired entries
rcube_cache_db::gc();
}
/**
* Writes the cache back to the DB.
*/
public function close()
{
$this->write_index(true);
$this->index = null;
$this->cache = [];
$this->updates = [];
$this->exp_records = [];
}
/**
* A helper to build cache key for specified parameters.
*
* @param string $prefix Key prefix (Max. length 64 characters)
* @param array $params Additional parameters
*
* @return string Key name
*/
public static function key_name($prefix, $params = [])
{
$cache_key = $prefix;
if (!empty($params)) {
$func = function($v) {
if (is_array($v)) {
sort($v);
}
return is_string($v) ? $v : serialize($v);
};
$params = array_map($func, $params);
$cache_key .= '.' . md5(implode(':', $params));
}
return $cache_key;
}
/**
* Reads cache entry.
*
* @param string $key Cache key name
*
* @return mixed Cached value
*/
protected function read_record($key)
{
$this->load_index();
// Consistency check (#1490390)
if (is_array($this->index) && !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.
return;
}
$ckey = $this->ckey($key);
$data = $this->get_item($ckey);
if ($this->indexed) {
return $data !== false ? $this->unserialize($data) : null;
}
if ($data !== false) {
$timestamp = 0;
$utc = new DateTimeZone('UTC');
// Extract timestamp from the data entry
if (preg_match('/^(' . self::DATE_FORMAT_REGEX . '):/', $data, $matches)) {
try {
$timestamp = new DateTime($matches[1], $utc);
$data = substr($data, strlen($matches[1]) + 1);
}
catch (Exception $e) {
// invalid date = no timestamp
}
}
// Check if the entry is still valid by comparing with EXP timestamps
// For example for key 'mailboxes.123456789' we check entries:
// 'EXP:*', 'EXP:mailboxes' and 'EXP:mailboxes.123456789'.
if ($timestamp) {
$path = explode('.', "*.$key");
$path_len = min(self::MAX_EXP_LEVEL + 1, count($path));
for ($x = 1; $x <= $path_len; $x++) {
$prefix = implode('.', array_slice($path, 0, $x));
if ($x > 1) {
$prefix = substr($prefix, 2); // remove "*." prefix
}
if (($ts = $this->get_exp_timestamp($prefix)) && $ts > $timestamp) {
$timestamp = 0;
break;
}
}
}
$data = $timestamp ? $this->unserialize($data) : null;
}
else {
$data = null;
}
return $this->cache[$key] = $data;
}
/**
* Writes single cache record into DB.
*
* @param string $key Cache key name
* @param mixed $data Serialized cache data
*
* @return bool True on success, False on failure
*/
protected function write_record($key, $data)
{
if ($this->indexed) {
$result = $this->store_record($key, $data);
if ($result) {
$this->load_index();
$this->index[] = $key;
if (!$this->index_update) {
$this->index_update = time();
}
}
}
else {
// In this mode we do not save the entry to the database immediately
// It's because we have cases where the same entry is updated
// multiple times in one request (e.g. 'messagecount' entry rcube_imap).
$this->updates[$key] = new DateTime('now', new DateTimeZone('UTC'));
$this->cache[$key] = $data;
$result = true;
}
$this->write_index();
return $result;
}
/**
* Deletes the cache record(s).
*
* @param string $key Cache key name or pattern
* @param bool $prefix_mode Enable it to clear all keys starting
* with prefix specified in $key
*/
protected function remove_record($key = null, $prefix_mode = false)
{
if ($this->indexed) {
return $this->remove_record_indexed($key, $prefix_mode);
}
// "Remove" all keys
if ($key === null) {
$ts = new DateTime('now', new DateTimeZone('UTC'));
$this->add_item($this->ekey('*'), $ts->format(self::DATE_FORMAT));
$this->exp_records['*'] = $ts;
$this->cache = [];
}
// "Remove" keys by name prefix
else if ($prefix_mode) {
$ts = new DateTime('now', new DateTimeZone('UTC'));
$prefix = implode('.', array_slice(explode('.', trim($key, '. ')), 0, self::MAX_EXP_LEVEL));
$this->add_item($this->ekey($prefix), $ts->format(self::DATE_FORMAT));
$this->exp_records[$prefix] = $ts;
foreach (array_keys($this->cache) as $k) {
if (strpos($k, $key) === 0) {
$this->cache[$k] = null;
}
}
}
// Remove one key by name
else {
$this->delete_item($this->ckey($key));
$this->cache[$key] = null;
}
}
/**
* @see self::remove_record()
*/
protected function remove_record_indexed($key = null, $prefix_mode = false)
{
$this->load_index();
// Remove all keys
if ($key === null) {
foreach ($this->index as $key) {
$this->delete_item($this->ckey($key));
if (!$this->index_update) {
$this->index_update = time();
}
}
$this->index = [];
}
// Remove keys by name prefix
else if ($prefix_mode) {
foreach ($this->index as $idx => $k) {
if (strpos($k, $key) === 0) {
$this->delete_item($this->ckey($k));
unset($this->index[$idx]);
if (!$this->index_update) {
$this->index_update = time();
}
}
}
}
// Remove one key by name
else {
$this->delete_item($this->ckey($key));
if (($idx = array_search($key, $this->index)) !== false) {
unset($this->index[$idx]);
if (!$this->index_update) {
$this->index_update = time();
}
}
}
$this->write_index();
}
/**
* Writes the index entry as well as updated entries into memcache/apc/redis DB.
*/
protected function write_index($force = null)
{
// Write updated/new entries when needed
if (!$this->indexed) {
$need_update = $force === true;
if (!$need_update && !empty($this->updates)) {
$now = new DateTime('now', new DateTimeZone('UTC'));
$need_update = floatval(min($this->updates)->format('U.u')) < floatval($now->format('U.u')) - $this->refresh_time;
}
if ($need_update) {
foreach ($this->updates as $key => $ts) {
if (isset($this->cache[$key])) {
$this->store_record($key, $this->cache[$key], $ts);
}
}
$this->updates = [];
}
}
// Write index entry when needed
else {
$need_update = $this->index_update && $this->index !== null
&& ($force === true || $this->index_update > time() - $this->refresh_time);
if ($need_update) {
$index = serialize(array_values(array_unique($this->index)));
$this->add_item($this->ikey(), $index);
$this->index_update = null;
$this->index = null;
}
}
}
/**
* Gets the index entry from memcache/apc/redis DB.
*/
protected function load_index()
{
if (!$this->indexed) {
return;
}
if ($this->index !== null) {
return;
}
$data = $this->get_item($this->ikey());
$this->index = $data ? unserialize($data) : [];
}
/**
* Write data entry into cache
*/
protected function store_record($key, $data, $ts = null)
{
$value = $this->serialize($data);
if (!$this->indexed) {
if (!$ts) {
$ts = new DateTime('now', new DateTimeZone('UTC'));
}
$value = $ts->format(self::DATE_FORMAT) . ':' . $value;
}
$size = strlen($value);
// don't attempt to write too big data sets
if ($size > $this->max_packet_size()) {
trigger_error("rcube_cache: max_packet_size ($this->max_packet) exceeded for key $key. Tried to write $size bytes", E_USER_WARNING);
return false;
}
return $this->add_item($this->ckey($key), $value);
}
/**
* Fetches cache entry.
*
* @param string $key Cache internal key name
*
* @return mixed Cached value
*/
protected function get_item($key)
{
// to be overwritten by engine class
}
/**
* Adds entry into memcache/apc/redis DB.
*
* @param string $key Cache internal key name
* @param mixed $data Serialized cache data
*
* @return bool True on success, False on failure
*/
protected function add_item($key, $data)
{
// to be overwritten by engine class
}
/**
* Deletes entry from memcache/apc/redis DB.
*
* @param string $key Cache internal key name
*
* @return bool True on success, False on failure
*/
protected function delete_item($key)
{
// to be overwritten by engine class
}
/**
* Get EXP:<key> record value from cache
*/
protected function get_exp_timestamp($key)
{
if (!array_key_exists($key, $this->exp_records)) {
$data = $this->get_item($this->ekey($key));
$this->exp_records[$key] = $data ? new DateTime($data, new DateTimeZone('UTC')) : null;
}
return $this->exp_records[$key];
}
/**
* Creates per-user index cache key name (for memcache, apc, redis)
*
* @return string Cache key
*/
protected function ikey()
{
$key = $this->prefix . 'INDEX';
if ($this->userid) {
$key = $this->userid . ':' . $key;
}
return $key;
}
/**
* Creates per-user cache key name (for memcache, apc, redis)
*
* @param string $key Cache key name
*
* @return string Cache key
*/
protected function ckey($key)
{
$key = $this->prefix . ':' . $key;
if ($this->userid) {
$key = $this->userid . ':' . $key;
}
return $key;
}
/**
* Creates per-user cache key name for expiration time entry
*
* @param string $key Cache key name
*
* @return string Cache key
*/
protected function ekey($key, $prefix = null)
{
$key = $this->prefix . 'EXP:' . $key;
if ($this->userid) {
$key = $this->userid . ':' . $key;
}
return $key;
}
/**
* Serializes data for storing
*/
protected function serialize($data)
{
return $this->packed ? serialize($data) : $data;
}
/**
* Unserializes serialized data
*/
protected function unserialize($data)
{
return $this->packed ? @unserialize($data) : $data;
}
/**
* Determine the maximum size for cache data to be written
*/
protected function max_packet_size()
{
if ($this->max_packet < 0) {
$config = rcube::get_instance()->config;
$max_packet = $config->get($this->type . '_max_allowed_packet');
$this->max_packet = parse_bytes($max_packet) ?: 2097152; // default/max is 2 MB
}
return $this->max_packet;
}
/**
* Write memcache/apc/redis debug info to the log
*/
protected function debug($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);
}
}