[Pmwiki-users] Cache system with PmWiki

[Alexandre Courbot]

Hello everybody,

A friend of mine has written a simple, yet efficient cache system for 
pmwiki 1.0.8 (the existing ones weren't what we expected, so he decided 
to write his own). We're running into a slight problem however: 
password-protected pages are displayed without any authentication if 
cached. Basically we redirected HandleActions["browse"] to our own 
function which looks like this:

function SmartCacheHandleBrowse($PageName)
{
    global $EnableSmartCache, $PmWikiBrowseAction;

    if (!$EnableSmartCache)
       return $PmWikiBrowseAction($PageName);

    // first check if the cache dir exists and if not, creates it
    if (!CheckAndCreateCacheDir())
       return CreatePageCache($PageName); // must create the page cache 
since it is the first call

    if (!AdditionalFilesAreUpToDate())
       InvalidateCache("");

    // check if all is up to date
    if (!PageIsUpToDate($PageName))
       return CreatePageCache($PageName);

    // the page is up to date, return the cached version
    return GetCachedPage($PageName);
}

And GetCachedPage:

function GetCachedPage($PageName)
{
    global $DebugSmartCache;
    $cache_file = GetCacheFile($PageName);
    $file_content = file($cache_file);
    if (!$file_content)
       return CreatePageCache($PageName);

    $content = implode("", $file_content);
    if ($DebugSmartCache)
       $content = str_replace("</title>", " [From Cache]</title>", 
$content);
    print $content;
    return true;
}

I fail to see how we could integrate authentication here. Actually I 
fail to understand how the authentication works exactly. Could someone 
give a pointer?

Also, I'd like to discuss some of the cache issues. There are lots of 
them (others pages the page being visited depends on, etc.), but I 
wonder if most of them couldn't be workarounded in PmWiki 2.0 by good 
design. Like, a page file could contain all the pages it depends on - 
and extensions could be provided a mechanism to register new 
dependancies. All in all the reason that motivated our cache was the 
general slowness of our site once switched to PmWiki, because it has 
some large, loaded pages and uses lots of extensions. This is a general 
problem with PHP since it doesn't have a compiled form (not even 
bytecode like Python) and at some point a site will face service issues 
when using too much extensions. Are there plans in 2.0 to deal with 
these problems? Are there tips to improve the general speed of the site?

Thanks,
Alex.