Given that these modules were written over two years ago and have had a few hundred downloads, many of which I suspect are now in operation on some of the heavily used phpBB boards, isn't it about time they were moved out of Area51 and into the mainstream product?I came across this topic when I was coding around some issues that we had on my forums with some bugs in the Solaris CSK 1.3.1 implementation of APC (see Sun Forums — APC change of behaviour on CSK upgrade). We have a pretty active site running a dozen forums on a common Apache instance, and sharing a common but otherwise reasonably standard phpBB code base (see phpBB3.0.4 Migration — Detailed Implementation Notes if you want more background). I also noticed that my APC cache was being expunged every hour or so, which should really be happening. I also had a problem with cron.php which meant that the cache tidying wasn't being triggered and I pretty quickly accumulated over a quarter of a million cache/sql_* files in just over a day! So I ended up adding the following to my php.ini:
- apc.cache_by_default=1
apc.filters="(/cache/sql_|/cache/data_)"
What I really question is the design choice of keeping the sql_* and data_* cache objects as PHP include fragments, as this has not performance gain and most PHP performance accelerators are simply not optimised to handle such a volume of tiny volatile code fragments. Why not just keep them in .data files as straight serialised text? With such an approach the main load logic in get:
Code: Select all
global $phpEx;
if (!$this->_exists($var_name))
{
return false;
}
@include($this->cache_dir . "data{$var_name}.$phpEx");
return (isset($data)) ? $data : false;Code: Select all
$temp = @unserialize(file_get_contents($this->cache_dir . 'data{$var_name}.data'));
return ($temp !== false && isset(temp[0]) && time() > $temp[0] && isset(temp[01) )
? $temp[1] : false; Code: Select all
if ($fp = @fopen($this->cache_dir . "data{$var_name}.$phpEx", 'wb'))
{
@flock($fp, LOCK_EX);
fwrite($fp, "<?php\n\$expired = (time() > " . (time() + $ttl) .
") ? true : false;\nif (\$expired) { return; }\n\n\$data = " .
(sizeof($var) ? "unserialize(" . var_export(serialize($var), true) . ");" : 'array();') . "\n\n?>");
@flock($fp, LOCK_UN);
fclose($fp);
if (!function_exists('phpbb_chmod'))
{
global $phpbb_root_path;
include($phpbb_root_path . 'includes/functions.' . $phpEx);
}
}
phpbb_chmod($this->cache_dir . "data{$var_name}.$phpEx", CHMOD_WRITE);
}Code: Select all
if (file_put_contents ($this->cache_dir . 'data_{$var_name}.data', serialize(array($ttl, $vars)), LOCK_EX) !== false )
{
if (!function_exists('phpbb_chmod'))
{
global $phpbb_root_path;
include($phpbb_root_path . 'includes/functions.' . $phpEx);
}
}Regards Terry
The one thing that you need to think about is whether the purge should instead be based on a delete enurating the apc_cache_info('user') cache_list on a filter of $this->store_prefix. In my case I don't mind doing a global purge so I haven't bothered.
