diff options
Diffstat (limited to 'app/lib/lib.http.php')
| -rw-r--r-- | app/lib/lib.http.php | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/app/lib/lib.http.php b/app/lib/lib.http.php new file mode 100644 index 0000000..5fa8193 --- /dev/null +++ b/app/lib/lib.http.php @@ -0,0 +1,52 @@ +<?php +/** + * Send HTTP 304 when needed, set ETag and Last-Modified else + * Source : http://annevankesteren.nl/2005/05/http-304 + */ +function http_modified($last_modified, $identifier){ + $etag = '"'.md5($last_modified.$identifier).'"'; + $client_etag = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? trim($_SERVER['HTTP_IF_NONE_MATCH']) : false; + $client_last_modified = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? trim($_SERVER['HTTP_IF_MODIFIED_SINCE']) : 0; + $client_last_modified_timestamp = strtotime($client_last_modified); + $last_modified_timestamp = strtotime($last_modified); + + if(($client_last_modified && $client_etag) ? (($client_last_modified_timestamp == $last_modified_timestamp) && ($client_etag == $etag)) : (($client_last_modified_timestamp == $last_modified_timestamp) || ($client_etag == $etag))){ + header('Not Modified',true,304); + exit(); + }else{ + header('Last-Modified:'.$last_modified); + header('ETag:'.$etag); + } +} + +//http://simonwillison.net/2003/Apr/23/conditionalGet/ +function doConditionalGet($timestamp) { + // A PHP implementation of conditional get, see + // http://fishbowl.pastiche.org/archives/001132.html + $last_modified = substr(date('r', $timestamp), 0, -5).'GMT'; + $etag = '"'.md5($last_modified).'"'; + // Send the headers + header("Last-Modified: $last_modified"); + header("ETag: $etag"); + // See if the client has provided the required headers + $if_modified_since = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? + stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']) : + false; + $if_none_match = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? + stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) : + false; + if (!$if_modified_since && !$if_none_match) { + return; + } + // At least one of the headers is there - check them + if ($if_none_match && $if_none_match != $etag) { + return; // etag is there but doesn't match + } + if ($if_modified_since && $if_modified_since != $last_modified) { + return; // if-modified-since is there but doesn't match + } + // Nothing has changed since their last request - serve a 304 and exit + header('HTTP/1.0 304 Not Modified'); + exit; +} +?>
\ No newline at end of file |