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Forked from JimWestergren/index-with-redis.php
Created December 11, 2012 16:54
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Redis as a Frontend Cache for WordPress
<?php
/*
Author: Jim Westergren & Jeedo Aquino
File: index-with-redis.php
Updated: 2012-10-25
This is a redis caching system for wordpress.
see more here: www.jimwestergren.com/wordpress-with-redis-as-a-frontend-cache/
Originally written by Jim Westergren but improved by Jeedo Aquino.
some caching mechanics are different from jim's script which is summarized below:
- cached pages do not expire not unless explicitly deleted or reset
- appending a ?c=y to a url deletes the entire cache of the domain, only works when you are logged in
- appending a ?r=y to a url deletes the cache of that url
- submitting a comment deletes the cache of that page
- refreshing (f5) a page deletes the cache of that page
- includes a debug mode, stats are displayed at the bottom most part after </html>
for setup and configuration see more here:
www.jeedo.net/lightning-fast-wordpress-with-nginx-redis/
use this script at your own risk. i currently use this albeit a slightly modified version
to display a redis badge whenever a cache is displayed.
*/
// change vars here
$cf = 1; // set to 1 if you are using cloudflare
$debug = 0; // set to 1 if you wish to see execution time and cache actions
$display_powered_by_redis = 1; // set to 1 if you want to display a powered by redis message with execution time, see below
$start = microtime(); // start timing page exec
// if cloudflare is enabled
if ($cf) {
if (isset($_SERVER['HTTP_CF_CONNECTING_IP'])) {
$_SERVER['REMOTE_ADDR'] = $_SERVER['HTTP_CF_CONNECTING_IP'];
}
}
// from wp
define('WP_USE_THEMES', true);
// init predis
include("predis.php");
$redis = new Predis\Client('');
// init vars
$domain = $_SERVER['HTTP_HOST'];
$url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
$url = str_replace('?r=y', '', $url);
$url = str_replace('?c=y', '', $url);
$dkey = md5($domain);
$ukey = md5($url);
// check if page isn't a comment submission
(($_SERVER['HTTP_CACHE_CONTROL'] == 'max-age=0') ? $submit = 1 : $submit = 0);
// check if logged in to wp
$cookie = var_export($_COOKIE, true);
$loggedin = preg_match("/wordpress_logged_in/", $cookie);
// check if a cache of the page exists
if ($redis->hexists($dkey, $ukey) && !$loggedin && !$submit && !strpos($url, '/feed/')) {
echo $redis->hget($dkey, $ukey);
$cached = 1;
$msg = 'this is a cache';
// if a comment was submitted or clear page cache request was made delete cache of page
} else if ($submit || substr($_SERVER['REQUEST_URI'], -4) == '?r=y') {
require('./wp-blog-header.php');
$redis->hdel($dkey, $ukey);
$msg = 'cache of page deleted';
// delete entire cache, works only if logged in
} else if ($loggedin && substr($_SERVER['REQUEST_URI'], -4) == '?c=y') {
require('./wp-blog-header.php');
if ($redis->exists($dkey)) {
$redis->del($dkey);
$msg = 'domain cache flushed';
} else {
$msg = 'no cache to flush';
}
// if logged in don't cache anything
} else if ($loggedin) {
require('./wp-blog-header.php');
$msg = 'not cached';
// cache the page
} else {
// turn on output buffering
ob_start();
require('./wp-blog-header.php');
// get contents of output buffer
$html = ob_get_contents();
// clean output buffer
ob_end_clean();
echo $html;
// Store to cache only if the page exist. Otherwise status code 200 is sent when 404 should be sent.
if (!is_404()) {
// store html contents to redis cache
$redis->hset($dkey, $ukey, $html);
$msg = 'cache is set';
}
}
$end = microtime(); // get end execution time
// show messages if debug is enabled
if ($debug) {
echo $msg.': ';
echo t_exec($start, $end);
}
if ($cached && $display_powered_by_redis) {
// You should move this CSS to your CSS file and change the: float:right;margin:20px 0;
echo "<style>#redis_powered{float:right;margin:20px 0;background:url(http://images.staticjw.com/jim/3959/redis.png) 10px no-repeat #fff;border:1px solid #D7D8DF;padding:10px;width:190px;}
#redis_powered div{width:190px;text-align:right;font:10px/11px arial,sans-serif;color:#000;}</style>";
echo "<a href=\"http://www.jimwestergren.com/wordpress-with-redis-as-a-frontend-cache/\" style=\"text-decoration:none;\"><div id=\"redis_powered\"><div>Page generated in<br/> ".t_exec($start, $end)." sec</div></div></a>";
}
// time diff
function t_exec($start, $end) {
$t = (getmicrotime($end) - getmicrotime($start));
return round($t,5);
}
// get time
function getmicrotime($t) {
list($usec, $sec) = explode(" ",$t);
return ((float)$usec + (float)$sec);
}
?>
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