gnu-social/classes/Memcached_DataObject.php
Evan Prodromou 5a1ea0b9b2 Stop caching unfindable keys
There were some problems with the automated cache/uncache system
for data objects that made us cache unfindable keys (with null
attributes and sometimes null names). Fixed those problems and
refactored the encache() and decache() methods so they use a helper
to find the cache keys to use.
2010-01-04 08:59:19 -10:00

372 lines
10 KiB
PHP

<?php
/*
* StatusNet - the distributed open-source microblogging tool
* Copyright (C) 2008, 2009, StatusNet, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }
require_once INSTALLDIR.'/classes/Memcached_DataObject.php';
class Memcached_DataObject extends DB_DataObject
{
/**
* Destructor to free global memory resources associated with
* this data object when it's unset or goes out of scope.
* DB_DataObject doesn't do this yet by itself.
*/
function __destruct()
{
$this->free();
if (method_exists('DB_DataObject', '__destruct')) {
parent::__destruct();
}
}
/**
* Wrapper for DB_DataObject's static lookup using memcached
* as backing instead of an in-process cache array.
*
* @param string $cls classname of object type to load
* @param mixed $k key field name, or value for primary key
* @param mixed $v key field value, or leave out for primary key lookup
* @return mixed Memcached_DataObject subtype or false
*/
function &staticGet($cls, $k, $v=null)
{
if (is_null($v)) {
$v = $k;
# XXX: HACK!
$i = new $cls;
$keys = $i->keys();
$k = $keys[0];
unset($i);
}
$i = Memcached_DataObject::getcached($cls, $k, $v);
if ($i) {
return $i;
} else {
$i = DB_DataObject::factory($cls);
if (empty($i)) {
return false;
}
$result = $i->get($k, $v);
if ($result) {
$i->encache();
return $i;
} else {
return false;
}
}
}
function &pkeyGet($cls, $kv)
{
$i = Memcached_DataObject::multicache($cls, $kv);
if ($i) {
return $i;
} else {
$i = new $cls();
foreach ($kv as $k => $v) {
$i->$k = $v;
}
if ($i->find(true)) {
$i->encache();
} else {
$i = null;
}
return $i;
}
}
function insert()
{
$result = parent::insert();
return $result;
}
function update($orig=null)
{
if (is_object($orig) && $orig instanceof Memcached_DataObject) {
$orig->decache(); # might be different keys
}
$result = parent::update($orig);
if ($result) {
$this->encache();
}
return $result;
}
function delete()
{
$this->decache(); # while we still have the values!
return parent::delete();
}
static function memcache() {
return common_memcache();
}
static function cacheKey($cls, $k, $v) {
if (is_object($cls) || is_object($k) || is_object($v)) {
$e = new Exception();
common_log(LOG_ERR, __METHOD__ . ' object in param: ' .
str_replace("\n", " ", $e->getTraceAsString()));
}
return common_cache_key(strtolower($cls).':'.$k.':'.$v);
}
static function getcached($cls, $k, $v) {
$c = Memcached_DataObject::memcache();
if (!$c) {
return false;
} else {
return $c->get(Memcached_DataObject::cacheKey($cls, $k, $v));
}
}
function keyTypes()
{
global $_DB_DATAOBJECT;
if (!isset($_DB_DATAOBJECT['INI'][$this->_database][$this->__table."__keys"])) {
$this->databaseStructure();
}
return $_DB_DATAOBJECT['INI'][$this->_database][$this->__table."__keys"];
}
function encache()
{
$c = $this->memcache();
if (!$c) {
return false;
}
$keys = $this->_allCacheKeys();
foreach ($keys as $key) {
$c->set($key, $this);
}
}
function decache()
{
$c = $this->memcache();
if (!$c) {
return false;
}
$keys = $this->_allCacheKeys();
foreach ($keys as $key) {
$c->delete($key, $this);
}
}
function _allCacheKeys()
{
$ckeys = array();
$types = $this->keyTypes();
ksort($types);
$pkey = array();
$pval = array();
foreach ($types as $key => $type) {
assert(!empty($key));
if ($type == 'U') {
if (empty($this->$key)) {
continue;
}
$ckeys[] = $this->cacheKey($this->tableName(), $key, $this->$key);
} else if ($type == 'K' || $type == 'N') {
$pkey[] = $key;
$pval[] = $this->$key;
} else {
throw new Exception("Unknown key type $key => $type for " . $this->tableName());
}
}
assert(count($pkey) > 0);
// XXX: should work for both compound and scalar pkeys
$pvals = implode(',', $pval);
$pkeys = implode(',', $pkey);
$ckeys[] = $this->cacheKey($this->tableName(), $pkeys, $pvals);
return $ckeys;
}
function multicache($cls, $kv)
{
ksort($kv);
$c = Memcached_DataObject::memcache();
if (!$c) {
return false;
} else {
$pkeys = implode(',', array_keys($kv));
$pvals = implode(',', array_values($kv));
return $c->get(Memcached_DataObject::cacheKey($cls, $pkeys, $pvals));
}
}
function getSearchEngine($table)
{
require_once INSTALLDIR.'/lib/search_engines.php';
static $search_engine;
if (!isset($search_engine)) {
if (Event::handle('GetSearchEngine', array($this, $table, &$search_engine))) {
if ('mysql' === common_config('db', 'type')) {
$type = common_config('search', 'type');
if ($type == 'like') {
$search_engine = new MySQLLikeSearch($this, $table);
} else if ($type == 'fulltext') {
$search_engine = new MySQLSearch($this, $table);
} else {
throw new ServerException('Unknown search type: ' . $type);
}
} else {
$search_engine = new PGSearch($this, $table);
}
}
}
return $search_engine;
}
static function cachedQuery($cls, $qry, $expiry=3600)
{
$c = Memcached_DataObject::memcache();
if (!$c) {
$inst = new $cls();
$inst->query($qry);
return $inst;
}
$key_part = common_keyize($cls).':'.md5($qry);
$ckey = common_cache_key($key_part);
$stored = $c->get($ckey);
if ($stored) {
return new ArrayWrapper($stored);
}
$inst = new $cls();
$inst->query($qry);
$cached = array();
while ($inst->fetch()) {
$cached[] = clone($inst);
}
$inst->free();
$c->set($ckey, $cached, MEMCACHE_COMPRESSED, $expiry);
return new ArrayWrapper($cached);
}
// We overload so that 'SET NAMES "utf8"' is called for
// each connection
function _connect()
{
global $_DB_DATAOBJECT;
$sum = $this->_getDbDsnMD5();
if (!empty($_DB_DATAOBJECT['CONNECTIONS'][$sum]) &&
!PEAR::isError($_DB_DATAOBJECT['CONNECTIONS'][$sum])) {
$exists = true;
} else {
$exists = false;
}
$result = parent::_connect();
if ($result && !$exists) {
$DB = &$_DB_DATAOBJECT['CONNECTIONS'][$this->_database_dsn_md5];
if (common_config('db', 'type') == 'mysql' &&
common_config('db', 'utf8')) {
$conn = $DB->connection;
if (!empty($conn)) {
if ($DB instanceof DB_mysqli) {
mysqli_set_charset($conn, 'utf8');
} else if ($DB instanceof DB_mysql) {
mysql_set_charset('utf8', $conn);
}
}
}
}
return $result;
}
// XXX: largely cadged from DB_DataObject
function _getDbDsnMD5()
{
if ($this->_database_dsn_md5) {
return $this->_database_dsn_md5;
}
$dsn = $this->_getDbDsn();
if (is_string($dsn)) {
$sum = md5($dsn);
} else {
/// support array based dsn's
$sum = md5(serialize($dsn));
}
return $sum;
}
function _getDbDsn()
{
global $_DB_DATAOBJECT;
if (empty($_DB_DATAOBJECT['CONFIG'])) {
DB_DataObject::_loadConfig();
}
$options = &$_DB_DATAOBJECT['CONFIG'];
// if the databse dsn dis defined in the object..
$dsn = isset($this->_database_dsn) ? $this->_database_dsn : null;
if (!$dsn) {
if (!$this->_database) {
$this->_database = isset($options["table_{$this->__table}"]) ? $options["table_{$this->__table}"] : null;
}
if ($this->_database && !empty($options["database_{$this->_database}"])) {
$dsn = $options["database_{$this->_database}"];
} else if (!empty($options['database'])) {
$dsn = $options['database'];
}
}
if (!$dsn) {
throw new Exception("No database name / dsn found anywhere");
}
return $dsn;
}
}