reference client fixes (#290)

* reference client: fix issues with webkit browsers

webkit browsers tend to never leave the "sock.send()" loop. Make sure
they pause to post the AppInfo message. Change the timing to use
better source. Also exit the loop when it's time to increase the message size.

Co-authored-by: Peter Boothe <pboothe@google.com>

html/ndt7-download.js

@@ -10,12 +10,12 @@ onmessage = function (ev) {
     postMessage(null)
   }
   sock.onopen = function () {
-    const start = new Date().getTime()
+    const start = performance.now()
     let previous = start
     let total = 0
     sock.onmessage = function (ev) {
       total += (ev.data instanceof Blob) ? ev.data.size : ev.data.length
-      let now = new Date().getTime()
+      let now = performance.now()
       const every = 250  // ms
       if (now - previous > every) {
         postMessage({

html/ndt7-upload.js

@@ -11,8 +11,9 @@ onmessage = function (ev) {
     postMessage(null)
   }
   function uploader(socket, data, start, previous, total) {
-    let now = new Date().getTime()
+    let now = performance.now()
     const duration = 10000  // millisecond
+    const every = 250  // millisecond
     if (now - start > duration) {
       sock.close()
       return
@@ -22,11 +23,15 @@ onmessage = function (ev) {
       data = new Uint8Array(data.length * 2) // TODO(bassosimone): fill this message
     }
     const underbuffered = 7 * data.length
-    while (sock.bufferedAmount < underbuffered) {
+    while ((sock.bufferedAmount < underbuffered) &&
+	   (performance.now() - previous < every)) {
       sock.send(data)
       total += data.length
+      if (data.length < maxMessageSize && data.length < (total - sock.bufferedAmount)/16) {
+        break
+      }
     }
-    const every = 250  // millisecond
+    now = performance.now()
     if (now - previous > every) {
       postMessage({
         'AppInfo': {
@@ -42,11 +47,19 @@ onmessage = function (ev) {
       function() { uploader(sock, data, start, previous, total) },
       0)
   }
+  sock.onmessage = function (ev) {
+      if (!(ev.data instanceof Blob)) {
+          let m = JSON.parse(ev.data)
+          m.Origin = 'server'
+          m.Test = 'upload'
+          postMessage(m)
+      }
+  }
   sock.onopen = function () {
     const initialMessageSize = 8192 /* (1<<13) */
     const data = new Uint8Array(initialMessageSize) // TODO(bassosimone): fill this message
     sock.binarytype = 'arraybuffer'
-    const start = new Date().getTime()
+    const start = performance.now()
     uploader(sock, data, start, start, 0)
   }
 }