php "page caching" solution suggestions for CMS Applications

Question

Most examples use time-based cache expiration. I'd like to read more about file caches (where the database is called only when there is no file in a given directory). This is for a basic information site with CMS functions made with php/mysql. My searches are returning too many sites on web applications. Adding CMS to the search returns script repositories. I'd appreciate your suggestions.

Answer 1

It's not hard to write something like this yourself. Use file_exists() to check whether a specific file exists, or glob() how many files matching a given pattern there are.

Answer 2

I'm not quite sure what you're looking for.

If you're talking about generating a page (from the CMS) and placing it at the requested URI (so the next request bypasses even the CMS) - it's possible, but you make refreshing the 'cache' a little difficult.

However, what you may be looking for is just a server side cache (as opposed to telling the browser how long to cache a page). Those are usually file or memory based, and if you place the caching mechanism high in the CMS flow (perhaps where it processes the requests), you'll be caching a large portion of page creation.

Some cache libraries let you set an unlimited lifetime (for example Zend_Cache), leaving the cache maintenance up to you. That may be what you're looking for.

Answer 3

I use a page build system...

Each page created is given a guid - when a request comes in for the page check to see if a file in the cache named GUID.xxx serve it if not build the page and cache.

On editing a page (or if its expiration has passed) delete the file from the cache.

You can elaborate at will as to how the expiration is determined/administered and what protions of the page to cache and which to allow dynamic builds per request...