php file cache example

cache.php

<?php

function get_cache($key) {
  $cacheFolder = '/tmp/wp-site/';
  $cacheFile = $cacheFolder+$key
  if(file_exists($cacheFile) {
    $contents = file_read($cacheFile);
    return json_decode($contents);
  } else {
    return false;
  }
}

function set_cache($key, $value="") {
  $cacheFolder = '/tmp/wp-site/';
  $cacheFile = $cacheFolder+$key;
  $contents = json_encode($value);
  file_write($cacheFile, $contents);
}

$cacheKey = 'sip-page-endpoint';
if (!$page = get_cache($cacheKey)) {
  $page = getPageStuff();
  set_cache($cacheKey, $page)
}

echo $page;