Automatically create cache file with php

Question

I have been using a basic caching system on my site based on this link

It has so far worked well for everthing I want to do.

$cachefile = 'cache/'. basename($_SERVER['QUERY_STRING']) . '.html';
$cachetime = 1440 * 60; 

if (file_exists($cachefile) && (time() - $cachetime < filemtime($cachefile))) {
  include($cachefile);
  echo "<!-- Cached ".date('jS F Y H:i', filemtime($cachefile))." -->";
  exit;
}

ob_start();

// My html/php code here


$fp = fopen($cachefile, 'w'); // open the cache file for writing
fwrite($fp, ob_get_contents()); // save the contents of output buffer to the file
fclose($fp); // close
ob_end_flush(); // Send to browser

However I have a couple of pages with more detailed mysql queries, I have spent a fair bit of time optimising it however it still takes about 10 secs to run when I query it in mysql and even longer on the website. And sometimes it seems to time out as I get the below message.

The proxy server received an invalid response from an upstream server.
The proxy server could not handle the requestGET http://www.example.com

Reason: Error reading from remote server

This isn't a huge issue as because I am using the caching system above only the first person to click on it for the day gets the delay and the rest of the time the users get the cached page so it is actually quite fast for them.

I want to save myself from having to be the first person each day to go to the page and automate this process so at 17:00 (on the server) each day the file gets written to the cache.

How would I best achieve this?

Answer 1

I suggest you to use Php Speedy or this may help:

<?php
function getUrl () {
    if (!isset($_SERVER['REQUEST_URI'])) {
    $url = $_SERVER['REQUEST_URI'];
    } else {
    $url = $_SERVER['SCRIPT_NAME'];
    $url .= (!empty($_SERVER['QUERY_STRING']))? '?' . $_SERVER[ 'QUERY_STRING' ] : '';

    }
    return $url;
}

//getUrl gets the queried page with query string
function cache ($buffer) { //page's content is $buffer
    $url = getUrl();
    $filename = md5($url) . '.cache';
    $data = time() . '¦' . $buffer;
    $filew = fopen("cache/" . $filename, 'w');
    fwrite($filew, $data);
    fclose($filew);
    return $buffer;
}

function display () {
    $url = getUrl();
    $filename = md5($url) . '.cache';
    if (!file_exists("/cache/" . $filename)) {
    return false;
    }
    $filer = fopen("cache/" . $filename, 'r');
    $data = fread($filer, filesize("cache/" . $filename));
    fclose($filer);
    $content = explode('¦', $data, 2);
    if (count($content)!= 2 OR !is_numeric($content['0'])) {
        return false;
    }
    if (time()-(100) > $content['0']) { // 100 is the cache time here!!!
        return false;
    }
        echo $content['1'];
        die();
}

// Display cache (if any)
display();  // if it is displayed, die function will end the program here.

// if no cache, callback cache
ob_start ('cache');
?>

Just include this script anywhere you need caching and set a cron job for running it automated.