diff options
Diffstat (limited to 'program/lib/Roundcube/rcube_cache_shared.php')
| -rw-r--r-- | program/lib/Roundcube/rcube_cache_shared.php | 544 |
1 files changed, 544 insertions, 0 deletions
diff --git a/program/lib/Roundcube/rcube_cache_shared.php b/program/lib/Roundcube/rcube_cache_shared.php new file mode 100644 index 000000000..bef9e85f2 --- /dev/null +++ b/program/lib/Roundcube/rcube_cache_shared.php @@ -0,0 +1,544 @@ +<?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 +{ + /** + * Instance of database handler + * + * @var rcube_db|Memcache|bool + */ + private $db; + private $type; + private $prefix; + private $ttl; + private $packed; + private $index; + private $table; + private $cache = array(); + private $cache_changes = array(); + private $cache_sums = array(); + + + /** + * 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 = $rcube->get_memcache(); + } + else if ($type == 'apc') { + $this->type = 'apc'; + $this->db = function_exists('apc_exists'); // APC 3.1.4 required + } + else { + $this->type = 'db'; + $this->db = $rcube->get_dbh(); + $this->table = $this->db->table_name('cache_shared'); + } + + // 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_changed = true; + $this->cache_changes[$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, $this->packed ? serialize($data) : $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_changed = false; + $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->db->query( + "DELETE FROM " . $this->table + . " WHERE cache_key LIKE ?" + . " AND " . $this->db->unixtimestamp('created') . " < ?", + $this->prefix . '.%', + time() - $this->ttl); + } + } + + + /** + * Writes the cache back to the DB. + */ + function close() + { + if (!$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 = $this->packed ? serialize($data) : $data; + + if (!$this->cache_sums[$key] || $this->cache_sums[$key] != md5($data)) { + $this->write_record($key, $data); + } + } + } + + $this->write_index(); + } + + + /** + * 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 ($this->type != 'db') { + if ($this->type == 'memcache') { + $data = $this->db->get($this->ckey($key)); + } + else if ($this->type == 'apc') { + $data = apc_fetch($this->ckey($key)); + } + + if ($data) { + $md5sum = md5($data); + $data = $this->packed ? unserialize($data) : $data; + + if ($nostore) { + return $data; + } + + $this->cache_sums[$key] = $md5sum; + $this->cache[$key] = $data; + } + else { + $this->cache[$key] = null; + } + } + else { + $sql_result = $this->db->limitquery( + "SELECT data, cache_key". + " FROM " . $this->table . + " WHERE cache_key = ?". + // for better performance we allow more records for one key + // get the newer one + " ORDER BY created DESC", + 0, 1, $this->prefix . '.' . $key); + + if ($sql_arr = $this->db->fetch_assoc($sql_result)) { + $md5sum = $sql_arr['data'] ? md5($sql_arr['data']) : null; + if ($sql_arr['data']) { + $data = $this->packed ? unserialize($sql_arr['data']) : $sql_arr['data']; + } + + if ($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 mxied $data Serialized cache data + * + * @param boolean True on success, False on failure + */ + private function write_record($key, $data) + { + if (!$this->db) { + return false; + } + + if ($this->type == 'memcache' || $this->type == 'apc') { + return $this->add_record($this->ckey($key), $data); + } + + $key_exists = array_key_exists($key, $this->cache_sums); + $key = $this->prefix . '.' . $key; + + // Remove NULL rows (here we don't need to check if the record exist) + if ($data == 'N;') { + $this->db->query("DELETE FROM " . $this->table . " WHERE cache_key = ?", $key); + return true; + } + + // update existing cache record + if ($key_exists) { + $result = $this->db->query( + "UPDATE " . $this->table . + " SET created = " . $this->db->now() . ", data = ?" . + " WHERE cache_key = ?", + $data, $key); + } + // add new cache record + else { + // for better performance we allow more records for one key + // so, no need to check if record exist (see rcube_cache::read_record()) + $result = $this->db->query( + "INSERT INTO ".$this->table. + " (created, cache_key, data)". + " VALUES (".$this->db->now().", ?, ?)", + $key, $data); + } + + return $this->db->affected_rows($result); + } + + + /** + * 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) { + $this->delete_record($key, false); + } + $this->index = array(); + } + // Remove keys by name prefix + else if ($prefix_mode) { + foreach ($this->index as $k) { + if (strpos($k, $key) === 0) { + $this->delete_record($k); + } + } + } + // Remove one key by name + else { + $this->delete_record($key); + } + + 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 key name + * @param mxied $data Serialized cache data + * @param bollean $index Enables immediate index update + * + * @param boolean True on success, False on failure + */ + private function add_record($key, $data, $index=false) + { + if ($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, $this->ttl); + } + + // Update index + if ($index && $result) { + $this->load_index(); + + if (array_search($key, $this->index) === false) { + $this->index[] = $key; + $data = serialize($this->index); + $this->add_record($this->ikey(), $data); + } + } + + return $result; + } + + + /** + * Deletes entry from memcache/apc DB. + */ + private function delete_record($key, $index=true) + { + if ($this->type == 'memcache') { + // #1488592: use 2nd argument + $this->db->delete($this->ckey($key), 0); + } + else { + apc_delete($this->ckey($key)); + } + + if ($index) { + if (($idx = array_search($key, $this->index)) !== false) { + unset($this->index[$idx]); + } + } + } + + + /** + * Writes the index entry into memcache/apc DB. + */ + private function write_index() + { + if (!$this->db) { + return; + } + + if ($this->type == 'db') { + return; + } + + $this->load_index(); + + // Make sure index contains new keys + foreach ($this->cache as $key => $value) { + if ($value !== null) { + if (array_search($key, $this->index) === false) { + $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) { + 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); + } + + $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'; + } +} |