update museumsvictoria#258: Uptime can be misleading if start timesta…

…mp is inaccurate

Update thanks to automatic.com.au

nodel-framework/src/main/java/org/nodel/diagnostics/Diagnostics.java

@@ -43,10 +43,16 @@ public class Diagnostics {
     private final static int PERIOD = 2500;
 
     /**
-     * Start time.
+     * Start time based on the system wall clock time timestamp
      */
     private DateTime _startTime = DateTime.now();
-
+
+    /**
+     * The start instant of the framework used for uptime unaffected by wall clock accuracy
+     * (.nanoTime based, public for convenience)
+     */
+    public final static long START_INSTANT = System.nanoTime();
+
     /**
      * The permanent non-daemon thread to keep track of the counters.
      * (may not be started in thread-restricted environments)
@@ -128,11 +134,16 @@ public void run() {
         _logger.info("Environment dump: {}", Serialisation.serialise(this));
     } // (init)
 
-    @Value(name="startTime", title = "Start time", desc = "When this service was started.")
+    @Value(name="startTime", title = "Start time", desc = "When this service was started according to system's wall clock.")
     public DateTime startTime() {
         return _startTime;
     }
-
+
+    @Value(name="uptime", title = "Uptime", desc = "Uptime in milliseconds unaffected by wall clock accuracy.")
+    public long uptime() {
+        return (System.nanoTime() - START_INSTANT) / 1000000;
+    }
+
     @Value(name = "systemProperties", title = "System properties", desc = "The list of built-in system properties.")
     public Properties properties() {
         return System.getProperties();

nodel-webui-js/src/index.xsl

@@ -883,7 +883,7 @@
                 </tr>
                 <tr>
                   <th scope="row">Uptime</th>
-                  <td>{{>~fromtime(startTime)}}, started {{>~nicetime(startTime, false, 'llll')}}</td>
+                  <td>{{>~fromtime(uptime)}}, start timestamp {{>~nicetime(startTime, false, 'llll')}}</td>
                 </tr>
                 <tr>
                   <th scope="row">Host path</th>

nodel-webui-js/src/nodel.js

@@ -48,8 +48,12 @@ $.views.helpers({
     if (format) return moment(value).format(format);
     else return moment(value).format('Do MMM, h:mm a');
   },
-  fromtime: function(value){
-    return moment(value).from(moment(), true);
+  fromtime: function(value) {
+    now = moment();
+    if (typeof(value) == 'string') // treat value as an absolute timestamp
+      return moment(value).from(now, true);
+    else // treat value as a duration in millis
+      return moment(now).subtract(value, 'ms').from(now, true);
   },
   srcflt: function(item, i, items) {
     if(this.view.data.flt) {