Convert <!-- timing data --> to a <script></script> block

This patch replaces:

  <!-- Served by mw1069 in 0.976 secs. -->

With:

  <script>mw.config.set({"wgBackendResponseTime":976,"wgHostname":"mw1069"});</script>

In the default HTML output of MediaWiki.

While the latter is a nearly twice as long, it is almost as readable for human
beings, while being substantially easy to get via JavaScript.

To get the values from the comment, you have to do something like:

  var comments, comment, hostname, duration;
  comments = $.grep( document.body.childNodes, function ( el ) {
	return el.nodeType === 8
  } );
  comment = comments.length
	? comments.pop().nodeValue.match( /(\S+) in ([\d.]+)/ ).slice( 1 )
	: [ null, null ];
  hostname = comment[0];
  respTime = parseFloat( comment[1] );

On the other hand, to get the values from the JavaScript code, you can simply:

  var hostname = mw.config.get( 'wgHostname' );
  var respTime = mw.config.get( 'wgBackendResponseTime' );

I believe that the ability to parse the number easily via JavaScript will make
it easier to include with other client-side measurements as part of reports on
site performance as experienced by users.

Change-Id: I895cd03f0968815484ff8cda4b23cc602ac555f0

diff --git a/includes/GlobalFunctions.php b/includes/GlobalFunctions.php
index 5174b32..cef19e1 100644 (file)
--- a/includes/GlobalFunctions.php
+++ b/includes/GlobalFunctions.php
@@ -1817,19 +1817,23 @@ function wfHostname() {
 }
 
 /**
- * Returns a HTML comment with the elapsed time since request.
- * This method has no side effects.
+ * Returns a script tag that stores the amount of time it took MediaWiki to
+ * handle the request in milliseconds as 'wgBackendResponseTime'.
+ *
+ * If $wgShowHostnames is true, the script will also set 'wgHostname' to the
+ * hostname of the server handling the request.
  *
  * @return string
  */
 function wfReportTime() {
        global $wgRequestTime, $wgShowHostnames;
 
-       $elapsed = microtime( true ) - $wgRequestTime;
-
-       return $wgShowHostnames
-               ? sprintf( '<!-- Served by %s in %01.3f secs. -->', wfHostname(), $elapsed )
-               : sprintf( '<!-- Served in %01.3f secs. -->', $elapsed );
+       $responseTime = round( ( microtime( true ) - $wgRequestTime ) * 1000 );
+       $reportVars = array( 'wgBackendResponseTime' => $responseTime );
+       if ( $wgShowHostnames ) {
+               $reportVars[ 'wgHostname' ] = wfHostname();
+       }
+       return Skin::makeVariablesScript( $reportVars );
 }
 
 /**