function getConversionRate($from, $to)
{
global $cache_tolerance, $cache_conversion, $webServiceURL;
$cache_file = $cache_conversion . md5($from) . "-" . md5($to);
if (isCacheValid($cache_file, $cache_tolerance)) {
return file_get_contents($cache_file);
}
$url = $webServiceURL . "?from=" . $from . "&to=" . $to;
$cache_contents = updateCache($cache_file, $url);
if (strlen($cache_contents) > 0) {
$cache_file_reverse = $cache_conversion . md5($to) . "-" . md5($from);
$reverse_response = getReverseResponse($cache_contents);
if (strlen($reverse_response) > 0) {
writeCache($cache_file_reverse, $reverse_response);
}
} else {
$cache_contents = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<response>\n<conversion-rate>0.0</conversion-rate>\n<date>:-(</date>\n</response>";
}
return $cache_contents;
}
}
//check if the file needs to be refreshed or not ?
$last_modified = new DateTime('@' . filemtime($cache));
$expire = new DateTime('-' . $ttl, new DateTimezone('UTC'));
return $last_modified > $expire;
}
function truncateCache()
{
global $cachefil;
$fh = fopen($cachefil, 'w');
fclose($fh);
}
// Cache-settings
// Recipe from: http://nyamsprod.com/blog/2014/tutorial-how-to-cache-a-resource-using-php/
$geojson = "";
if (!isCacheValid($cachefil, $ttl)) {
header('Hurtigbuffer: bom');
// if last cache hit was an error, invalidate immediately
// so that no more requests to source is triggered by request by another user
// happening before fetchData()-timeout.
if (filesize($cachefil) == 0) {
truncateCache();
}
$geojson = fetchData();
header('Content-Type: application/vnd.geo+json; charset=utf-8');
file_put_contents($cachefil, $geojson);
} else {
header('Hurtigbuffer: treff');
header('Content-Type: application/vnd.geo+json; charset=utf-8');
header('Hurtigbuffer-size: ' . filesize($cachefil));
if (filesize($cachefil) == 0) {