mirror of
https://github.com/alextselegidis/easyappointments.git
synced 2024-11-29 19:32:46 +03:00
98 lines
2.7 KiB
PHP
98 lines
2.7 KiB
PHP
<?php
|
|
/*
|
|
* Copyright 2010 Google Inc.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
/**
|
|
* A persistent storage class based on the APC cache, which is not
|
|
* really very persistent, as soon as you restart your web server
|
|
* the storage will be wiped, however for debugging and/or speed
|
|
* it can be useful, kinda, and cache is a lot cheaper then storage.
|
|
*
|
|
* @author Chris Chabot <chabotc@google.com>
|
|
*/
|
|
class googleApcCache extends Google_Cache {
|
|
|
|
public function __construct() {
|
|
if (! function_exists('apc_add')) {
|
|
throw new Google_CacheException("Apc functions not available");
|
|
}
|
|
}
|
|
|
|
private function isLocked($key) {
|
|
if ((@apc_fetch($key . '.lock')) === false) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
private function createLock($key) {
|
|
// the interesting thing is that this could fail if the lock was created in the meantime..
|
|
// but we'll ignore that out of convenience
|
|
@apc_add($key . '.lock', '', 5);
|
|
}
|
|
|
|
private function removeLock($key) {
|
|
// suppress all warnings, if some other process removed it that's ok too
|
|
@apc_delete($key . '.lock');
|
|
}
|
|
|
|
private function waitForLock($key) {
|
|
// 20 x 250 = 5 seconds
|
|
$tries = 20;
|
|
$cnt = 0;
|
|
do {
|
|
// 250 ms is a long time to sleep, but it does stop the server from burning all resources on polling locks..
|
|
usleep(250);
|
|
$cnt ++;
|
|
} while ($cnt <= $tries && $this->isLocked($key));
|
|
if ($this->isLocked($key)) {
|
|
// 5 seconds passed, assume the owning process died off and remove it
|
|
$this->removeLock($key);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @inheritDoc
|
|
*/
|
|
public function get($key, $expiration = false) {
|
|
|
|
if (($ret = @apc_fetch($key)) === false) {
|
|
return false;
|
|
}
|
|
if (!$expiration || (time() - $ret['time'] > $expiration)) {
|
|
$this->delete($key);
|
|
return false;
|
|
}
|
|
return unserialize($ret['data']);
|
|
}
|
|
|
|
/**
|
|
* @inheritDoc
|
|
*/
|
|
public function set($key, $value) {
|
|
if (@apc_store($key, array('time' => time(), 'data' => serialize($value))) == false) {
|
|
throw new Google_CacheException("Couldn't store data");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @inheritDoc
|
|
* @param String $key
|
|
*/
|
|
public function delete($key) {
|
|
@apc_delete($key);
|
|
}
|
|
}
|