hgweb: add graph mode of ajax response processing

While the default mode appends all the new entries to a container on the page,
the graph mode resizes canvas correctly, and repaints the graph to include
newly received data.

mercurial/templates/static/mercurial.js

@@ -358,7 +358,8 b' function ajaxScrollInit(urlFormat,'
                         nextPageVar,
                         nextPageVarGet,
                         containerSelector,
-                        messageFormat) {
+                        messageFormat,
+                        mode) {
     updateInitiated = false;
     container = document.querySelector(containerSelector);
 
@@ -399,6 +400,16 b' function ajaxScrollInit(urlFormat,'
                 function onsuccess(htmlText) {
                     nextPageVar = nextPageVarGet(htmlText, nextPageVar);
 
+                    if (mode == 'graph') {
+                        var addHeight = htmlText.match(/^<canvas id="graph".*height="(\d+)"><\/canvas>$/m)[1];
+                        addHeight = parseInt(addHeight);
+                        graph.canvas.height = addHeight;
+
+                        var dataStr = htmlText.match(/^\s*var data = (.*);$/m)[1];
+                        var data = JSON.parse(dataStr)
+                        graph.reset();
+                        graph.render(data);
+                    } else {
                     var doc = docFromHTML(htmlText);
                     var nodes = doc.querySelector(containerSelector).children;
                     while (nodes.length) {
@@ -407,6 +418,7 b' function ajaxScrollInit(urlFormat,'
                         container.appendChild(node);
                     }
                     process_dates();
+                    }
                 },
                 function onerror(errorText) {
                     var message = {