Caching PHP Simple HTML DOM Parser

Question

I am using the PHP HTML DOM Parser to pull data from an external website. To reduce load and speed up page rendering time I want to cache data I pull for a certain period. How can I do this?

Answer 1

You could create local files with the HTML and then keep track of the file paths in the $SESSION. If you have the disk space and can run a database, you could use a database to do the same thing. A database connection and query on the URL you're looking for won't add much overhead at all.

Answer 2

I wrote this file cache function which basically just replaces file_get_contents. You can specify the amount of time the cache should last for in $offset or completely override the cache with $override. If you don't want to use /tmp/, just change that directory to something you can read/write to.

function cache_get_contents($url, $offset = 600, $override = false) {
    $file = '/tmp/file_cache_' . md5($url);
    if (!$override && file_exists($file) && filemtime($file) > time() - $offset)
        return file_get_contents($file);

    $contents = file_get_contents($url);
    if ($contents === false)
        return false;

    file_put_contents($file, $contents);
    return $contents;
}

Answer 3

One way would be to save the data to a database or local file. You could then use a timestamp column or file modification time to determine whether to continue using the cache or pull and save a fresh copy.

If you have access to some kind of memory caching (e.g. memcached) that would be ideal.