Fixed bug with incorrect FILETIME conversion to DateTime for ETW and Performance Counter sources

Source/AssemblyInfo.cs

@@ -5,5 +5,5 @@ using System.Reflection;
 [assembly: AssemblyCompany("MS Open Tech")]
 [assembly: AssemblyProduct("Tx (LINQ to Logs and Traces)")]
 [assembly: AssemblyCopyright("Copyright © MS Open Tech 2012")]
-[assembly: AssemblyVersion("1.0.50917.0")]
-[assembly: AssemblyFileVersion("1.0.50917.0")]
+[assembly: AssemblyVersion("1.0.50930.0")]
+[assembly: AssemblyFileVersion("1.0.50930.0")]

Source/Tx.Windows/EtwNative/EtwNativeEvent.cs

@@ -64,7 +64,7 @@ namespace Tx.Windows
 
         public DateTimeOffset TimeStamp
         {
-            get { return DateTime.FromFileTimeUtc(record->EventHeader.TimeStamp); }
+            get { return TimeUtil.DateTimeOffsetFromFileTime(record->EventHeader.TimeStamp); }
         }
 
         public Int64 TimeStampRaw

Source/Tx.Windows/PerfCounters/PerfCounterFileReader.cs

@@ -55,7 +55,7 @@ namespace Tx.Windows
                             break;
 
                     PdhUtils.CheckStatus(status, PdhStatus.PDH_CSTATUS_VALID_DATA);
-                    DateTime timestamp = DateTime.FromFileTimeUtc(time);
+                    DateTime timestamp = TimeUtil.FromFileTime(time);
 
                     foreach (PerfCounterInfo counterInfo in _counters)
                     {

Source/Tx.Windows/PerfCounters/PerfCounterRealTimeProbe.cs

@@ -40,7 +40,7 @@ namespace Tx.Windows
                 long time;
                 PdhStatus status = PdhNativeMethods.PdhCollectQueryDataWithTime(_query, out time);
                 PdhUtils.CheckStatus(status, PdhStatus.PDH_CSTATUS_VALID_DATA);
-                DateTime timestamp = DateTime.FromFileTimeUtc(time);
+                DateTime timestamp = TimeUtil.FromFileTime(time);
 
                 foreach (PerfCounterInfo counterInfo in _counters)
                 {

Source/Tx.Windows/TimeUtil.cs

@@ -0,0 +1,40 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+using System;
+
+namespace Tx.Windows
+{
+    public sealed class TimeUtil
+    {
+        private const Int64 TicksPerMillisecond = 10000;
+        private const Int64 TicksPerSecond = TicksPerMillisecond * 1000;
+        private const Int64 TicksPerMinute = TicksPerSecond * 60;
+        private const Int64 TicksPerHour = TicksPerMinute * 60;
+        private const Int64 TicksPerDay = TicksPerHour * 24;
+
+        // Number of days in a non-leap year
+        private const int DaysPerYear = 365;
+        // Number of days in 4 years
+        const int DaysPer4Years = DaysPerYear * 4 + 1;
+        // Number of days in 100 years
+        private const int DaysPer100Years = DaysPer4Years * 25 - 1;
+        // Number of days in 400 years
+        private const int DaysPer400Years = DaysPer100Years * 4 + 1;
+
+        // Number of days from 1/1/0001 to 12/31/1600
+        private const int DaysTo1601 = DaysPer400Years * 4;
+
+        private const Int64 FileTimeOffset = DaysTo1601 * TicksPerDay;
+
+        public static DateTimeOffset DateTimeOffsetFromFileTime(Int64 fileTime)
+        {
+            return new DateTimeOffset(FileTimeOffset + fileTime, TimeSpan.Zero);
+        }
+
+        public static DateTime FromFileTime(Int64 fileTime)
+        {
+            return new DateTime(FileTimeOffset + fileTime, DateTimeKind.Local);
+        }
+    }
+}
+

Source/Tx.Windows/Tx.Windows.csproj

@@ -87,6 +87,7 @@
     <Compile Include="PerfCounters\PerformanceSample.cs" />
     <Compile Include="PerfMetadata.cs" />
     <Compile Include="SystemEvent.cs" />
+    <Compile Include="TimeUtil.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Tx.Core\Tx.Core.csproj">

Test/UnitTests/PerfCounterTest.cs

@@ -10,6 +10,8 @@ using Tx.Windows;
 
 namespace Tests.Tx
 {
+    using System.Globalization;
+
     [TestClass]
     public class PerfCounterTest
     {
@@ -140,6 +142,39 @@ namespace Tests.Tx
             Assert.AreEqual(600, disk.Count());
         }
 
+        [TestMethod]
+        public void PerformanceCounterProbeFirst()
+        {
+            PerformanceSample[] result;
+            var startTime = DateTimeOffset.UtcNow;
+
+            using (var playback = new Playback())
+            {
+                ((IPlaybackConfiguration)playback).AddInput(
+                    () => PerfCounterObservable.FromRealTime(TimeSpan.FromSeconds(1), @"\Processor(_Total)\% User Time").Take(1),
+                    typeof(PerfCounterPartitionTypeMap),
+                    typeof(PerfCounterTypeMap));
+
+                var query = playback.GetObservable<PerformanceSample>();
+
+                var enumerable = playback.BufferOutput(query);
+
+                playback.Run();
+
+                result = enumerable.ToArray();
+            }
+            var endTime = DateTimeOffset.UtcNow;
+
+            Assert.AreEqual(1, result.Length);
+
+            Assert.AreEqual("% User Time", result[0].CounterName, false, CultureInfo.InvariantCulture);
+            Assert.AreEqual("Processor", result[0].CounterSet, false, CultureInfo.InvariantCulture);
+            Assert.AreEqual("_Total", result[0].Instance, false, CultureInfo.InvariantCulture);
+            var dto = new DateTimeOffset(result[0].Timestamp);
+            Assert.IsTrue(dto >= startTime);
+            Assert.IsTrue(dto <= endTime);
+        }
+
         IEnumerable<InstanceCounterSnapshot> PivotToInstanceSnapshots(Playback playback, string counterSet)
         {
             var all = playback.GetObservable<PerformanceSample>();