Disk cache plugin

This commit is contained in:
Evan Prodromou 2010-01-02 22:46:13 -10:00
parent 7aeb11bb07
commit cde1f99838

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plugins/DiskCachePlugin.php Normal file
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<?php
/**
* StatusNet - the distributed open-source microblogging tool
* Copyright (C) 2009, StatusNet, Inc.
*
* Plugin to implement cache interface with disk files
*
* PHP version 5
*
* 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/>.
*
* @category Cache
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @copyright 2009 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
if (!defined('STATUSNET')) {
// This check helps protect against security problems;
// your code file can't be executed directly from the web.
exit(1);
}
/**
* A plugin to cache data on local disk
*
* @category Cache
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @copyright 2009 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
class DiskCachePlugin extends Plugin
{
var $root = '/tmp';
function keyToFilename($key)
{
return $this->root . '/' . str_replace(':', '/', $key);
}
/**
* Get a value associated with a key
*
* The value should have been set previously.
*
* @param string &$key in; Lookup key
* @param mixed &$value out; value associated with key
*
* @return boolean hook success
*/
function onStartCacheGet(&$key, &$value)
{
$filename = $this->keyToFilename($key);
if (file_exists($filename)) {
$this->log(LOG_INFO, "Cache hit on key '$key'");
$data = file_get_contents($filename);
$value = unserialize($data);
} else {
$this->log(LOG_INFO, "Cache miss on key '$key'");
}
Event::handle('EndCacheGet', array($key, &$value));
return false;
}
/**
* Associate a value with a key
*
* @param string &$key in; Key to use for lookups
* @param mixed &$value in; Value to associate
* @param integer &$flag in; Flag (passed through to Memcache)
* @param integer &$expiry in; Expiry (passed through to Memcache)
* @param boolean &$success out; Whether the set was successful
*
* @return boolean hook success
*/
function onStartCacheSet(&$key, &$value, &$flag, &$expiry, &$success)
{
$this->log(LOG_INFO, "Setting value for key '$key'");
$filename = $this->keyToFilename($key);
$parent = dirname($filename);
$sofar = '';
foreach (explode('/', $parent) as $part) {
if (empty($part)) {
continue;
}
$sofar .= '/' . $part;
if (!is_dir($sofar)) {
$this->debug("Creating new directory '$sofar'");
$success = mkdir($sofar, 0750);
if (!$success) {
$this->log(LOG_ERR, "Can't create directory '$sofar'");
return false;
}
}
}
if (is_dir($filename)) {
$success = false;
return false;
}
file_put_contents($filename, serialize($value));
Event::handle('EndCacheSet', array($key, $value, $flag,
$expiry));
return false;
}
/**
* Delete a value associated with a key
*
* @param string &$key in; Key to lookup
* @param boolean &$success out; whether it worked
*
* @return boolean hook success
*/
function onStartCacheDelete(&$key, &$success)
{
$this->log(LOG_INFO, "Deleting value for key '$key'");
$filename = $this->keyToFilename($key);
if (file_exists($filename) && !is_dir($filename)) {
unlink($filename);
}
Event::handle('EndCacheDelete', array($key));
return false;
}
}