Add more data to net-internals view of DNS cache

chrome/browser/resources/net_internals/dns_view.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * This view displays information on the host resolver:
  *
  *   - Shows the default address family.
  *   - Shows the current host cache contents.
  *   - Has a button to clear the host cache.
@@ skipping 37 matching lines @@
   DnsView.INTERNAL_DNS_ENABLED_SPAN_ID = 'dns-view-internal-dns-enabled';
   DnsView.INTERNAL_DNS_INVALID_CONFIG_SPAN_ID =
       'dns-view-internal-dns-invalid-config';
   DnsView.INTERNAL_DNS_CONFIG_TBODY_ID = 'dns-view-internal-dns-config-tbody';
 
   DnsView.CLEAR_CACHE_BUTTON_ID = 'dns-view-clear-cache';
   DnsView.CAPACITY_SPAN_ID = 'dns-view-cache-capacity';
 
   DnsView.ACTIVE_SPAN_ID = 'dns-view-cache-active';
   DnsView.EXPIRED_SPAN_ID = 'dns-view-cache-expired';
+  DnsView.NETWORK_SPAN_ID = 'dns-view-network-changes';
   DnsView.CACHE_TBODY_ID = 'dns-view-cache-tbody';
 
   cr.addSingletonGetter(DnsView);
 
   DnsView.prototype = {
     // Inherit the superclass's methods.
     __proto__: superClass.prototype,
 
     onLoadLogFinish: function(data) {
       return this.onHostResolverInfoChanged(data.hostResolverInfo);
     },
 
     onHostResolverInfoChanged: function(hostResolverInfo) {
       // Clear the existing values.
       $(DnsView.CAPACITY_SPAN_ID).innerHTML = '';
       $(DnsView.CACHE_TBODY_ID).innerHTML = '';
       $(DnsView.ACTIVE_SPAN_ID).innerHTML = '0';
       $(DnsView.EXPIRED_SPAN_ID).innerHTML = '0';
+      $(DnsView.NETWORK_SPAN_ID).innerHTML = '0';
 
       // Update fields containing async DNS configuration information.
       displayAsyncDnsConfig_(hostResolverInfo);
 
       // No info.
       if (!hostResolverInfo || !hostResolverInfo.cache)
         return false;
 
       // Fill in the basic cache information.
       var hostResolverCache = hostResolverInfo.cache;
       $(DnsView.CAPACITY_SPAN_ID).innerText = hostResolverCache.capacity;
+      $(DnsView.NETWORK_SPAN_ID).innerText =
+          valueOrDefault(hostResolverCache.network_changes, '');
 
       var expiredEntries = 0;
       // Date the cache was logged.  This will be either now, when actively
       // logging data, or the date the log dump was created.
       var logDate;
       if (MainView.isViewingLoadedLog()) {
         logDate = new Date(ClientInfo.numericDate);
       } else {
         logDate = new Date();
       }
 
       // Fill in the cache contents table.
       for (var i = 0; i < hostResolverCache.entries.length; ++i) {
         var e = hostResolverCache.entries[i];
         var tr = addNode($(DnsView.CACHE_TBODY_ID), 'tr');
+        var expired = false;
 
         var hostnameCell = addNode(tr, 'td');
         addTextNode(hostnameCell, e.hostname);
 
         var familyCell = addNode(tr, 'td');
         addTextNode(familyCell, addressFamilyToString(e.address_family));
 
         var addressesCell = addNode(tr, 'td');
 
         if (e.error != undefined) {
           var errorText = e.error + ' (' + netErrorToString(e.error) + ')';
           var errorNode = addTextNode(addressesCell, 'error: ' + errorText);
           addressesCell.classList.add('warning-text');
         } else {
           addListToNode_(addNode(addressesCell, 'div'), e.addresses);
         }
 
+        var ttlCell = addNode(tr, 'td');
+        addTextNode(ttlCell, valueOrDefault(e.ttl, ''));
+
         var expiresDate = timeutil.convertTimeTicksToDate(e.expiration);
         var expiresCell = addNode(tr, 'td');
         timeutil.addNodeWithDate(expiresCell, expiresDate);
         if (logDate > timeutil.convertTimeTicksToDate(e.expiration)) {
-          ++expiredEntries;
+          expired = true;
           var expiredSpan = addNode(expiresCell, 'span');
           expiredSpan.classList.add('warning-text');
           addTextNode(expiredSpan, ' [Expired]');
         }
+
+        // HostCache keeps track of how many network changes have happened since
+        // it was created, and entries store what that number was at the time
+        // they were created. If more network changes have happened since an
+        // entry was created, the entry is expired.
+        var networkChangesCell = addNode(tr, 'td');
+        addTextNode(networkChangesCell, valueOrDefault(e.network_changes, ''));
+        if (e.network_changes < hostResolverCache.network_changes) {
+          expired = true;
+          var expiredSpan = addNode(networkChangesCell, 'span');
+          expiredSpan.classList.add('warning-text');
+          addTextNode(expiredSpan, ' [Expired]');
+        }
+
+        if (expired) {
+          expiredEntries++;
+        }
       }
 
       $(DnsView.ACTIVE_SPAN_ID).innerText =
           hostResolverCache.entries.length - expiredEntries;
       $(DnsView.EXPIRED_SPAN_ID).innerText = expiredEntries;
       return true;
     },
   };
 
   /**
@@ skipping 47 matching lines @@
    * Takes a last of strings and adds them all to a DOM node, displaying them
    * on separate lines.
    * @param {DomNode} node The parent node.
    * @param {Array<string>} list List of strings to add to the node.
    */
   function addListToNode_(node, list) {
     for (var i = 0; i < list.length; ++i)
       addNodeWithText(node, 'div', list[i]);
   }
 
+  // TODO(mgersh): The |ttl| and |network_changes| properties were introduced in
+  // M59 and may not exist when loading older logs. This can be removed in M62.
+  function valueOrDefault(value, defaultValue) {
+    if (value != undefined)
+      return value;
+    return defaultValue;
+  }
+
   return DnsView;
 })();