TimeStamp tests and comments.

Author: LeeCampbell

src/HdrHistogram.UnitTests/HdrHistogram.UnitTests.csproj

@@ -69,6 +69,7 @@
     <Compile Include="Recording\RecorderTestWithLongHistogram.cs" />
     <Compile Include="Recording\RecorderTestWithLShortHistogram.cs" />
     <Compile Include="ShortHistogramTests.cs" />
+    <Compile Include="TimeStampTests.cs" />
   </ItemGroup>
   <ItemGroup>
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />

src/HdrHistogram.UnitTests/TimeStampTests.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Diagnostics;
+using System.Threading;
+using NUnit.Framework;
+
+namespace HdrHistogram.UnitTests
+{
+    [TestFixture]
+    public class TimeStampTests
+    {
+        [Test]
+        public void TimeStamp_values_are_accurate()
+        {
+            var delay = TimeSpan.FromSeconds(1);
+            var expected = TimeStamp.Seconds(delay.Seconds);
+
+            var start = Stopwatch.GetTimestamp();
+            Thread.Sleep(delay);
+            var end = Stopwatch.GetTimestamp();
+            var actual = end - start;
+            
+            Assert.AreEqual(expected, actual, expected * 0.05);
+            Assert.AreEqual(TimeStamp.Seconds(60), TimeStamp.Minutes(1));
+            Assert.AreEqual(TimeStamp.Minutes(60), TimeStamp.Hours(1));
+        }        
+    }
+}

src/HdrHistogram/HdrHistogram.csproj

@@ -83,6 +83,7 @@
     <Compile Include="Properties\AssemblyInfo.g.cs" />
     <Compile Include="Recorder.cs" />
     <Compile Include="ShortHistogram.cs" />
+    <Compile Include="TimeStamp.cs" />
     <Compile Include="Utilities\ArrayExtensions.cs" />
     <Compile Include="Utilities\Bitwise.cs" />
     <Compile Include="LongHistogram.cs" />

src/HdrHistogram/OutputScalingFactor.cs

@@ -35,21 +35,4 @@ public static class OutputScalingFactor
         /// </summary>
         public static readonly double TimeStampToSeconds = Stopwatch.Frequency;
     }
-
-    public static class TimeStamp
-    {
-        public static long Seconds(int seconds)
-        {
-            return Stopwatch.Frequency*seconds;
-        }
-
-        public static long Minutes(int minutes)
-        {
-            return Stopwatch.Frequency * minutes * 60L;
-        }
-        public static long Hours(int hours)
-        {
-            return Stopwatch.Frequency * hours * 60L * 60L;
-        }
-    }
 }

src/HdrHistogram/TimeStamp.cs

@@ -0,0 +1,40 @@
+using System.Diagnostics;
+
+namespace HdrHistogram
+{
+    /// <summary>
+    /// Helper methods to get time periods based in system stopwatch units.
+    /// </summary>
+    public static class TimeStamp
+    {
+        /// <summary>
+        /// Return a <see cref="long"/> representing the number system timer ticks that occur over the provided number of seconds.
+        /// </summary>
+        /// <param name="seconds">A number seconds to represent.</param>
+        /// <returns>The number of system timer ticks that represent the <paramref name="seconds"/>.</returns>
+        public static long Seconds(int seconds)
+        {
+            return Stopwatch.Frequency*seconds;
+        }
+
+        /// <summary>
+        /// Return a <see cref="long"/> representing the number system timer ticks that occur over the provided number of minutes.
+        /// </summary>
+        /// <param name="minutes">A number minutes to represent.</param>
+        /// <returns>The number of system timer ticks that represent the <paramref name="minutes"/>.</returns>
+        public static long Minutes(int minutes)
+        {
+            return Stopwatch.Frequency * minutes * 60L;
+        }
+
+        /// <summary>
+        /// Return a <see cref="long"/> representing the number system timer ticks that occur over the provided number of hours.
+        /// </summary>
+        /// <param name="hours">A number hours to represent.</param>
+        /// <returns>The number of system timer ticks that represent the <paramref name="hours"/>.</returns>
+        public static long Hours(int hours)
+        {
+            return Stopwatch.Frequency * hours * 60L * 60L;
+        }
+    }
+}