Send LogEvent timestamp as "time" in Http Collector json

src/Serilog.Sinks.Splunk.FullNetFx/Serilog.Sinks.Splunk.FullNetFx.csproj

@@ -65,6 +65,9 @@
     <Compile Include="..\Serilog.Sinks.Splunk\LoggerConfigurationSplunkPCLExtensions.cs">
       <Link>LoggerConfigurationSplunkPCLExtensions.cs</Link>
     </Compile>
+    <Compile Include="..\Serilog.Sinks.Splunk\Sinks\Splunk\Epoch.cs">
+      <Link>Sinks\Splunk\Epoch.cs</Link>
+    </Compile>
     <Compile Include="..\Serilog.Sinks.Splunk\Sinks\Splunk\EventCollectorClient.cs">
       <Link>Sinks\Splunk\EventCollectorClient.cs</Link>
     </Compile>

src/Serilog.Sinks.Splunk/Serilog.Sinks.Splunk.csproj

@@ -54,6 +54,7 @@
     <Compile Include="..\..\assets\CommonAssemblyInfo.cs">
       <Link>Properties\CommonAssemblyInfo.cs</Link>
     </Compile>
+    <Compile Include="Sinks\Splunk\Epoch.cs" />
     <Compile Include="Sinks\Splunk\EventCollectorClient.cs" />
     <Compile Include="Sinks\Splunk\EventCollectorRequest.cs" />
     <Compile Include="Sinks\Splunk\RepeatAction.cs" />

src/Serilog.Sinks.Splunk/Sinks/Splunk/Epoch.cs

@@ -0,0 +1,20 @@
+namespace Serilog.Sinks.Splunk
+{
+    using System;
+
+    internal static class EpochExtensions
+    {
+        private static DateTimeOffset Epoch = new DateTimeOffset(1970,1,1,0,0,0,TimeSpan.Zero);
+
+        public static double ToEpoch(this DateTimeOffset value)
+        {
+            // From Splunk HTTP Collector Protocol
+            // The default time format is epoch time format, in the format <sec>.<ms>. 
+            // For example, 1433188255.500 indicates 1433188255 seconds and 500 milliseconds after epoch, 
+            // or Monday, June 1, 2015, at 7:50:55 PM GMT.
+            // See: http://dev.splunk.com/view/SP-CAAAE6P
+
+            return Math.Round((value - Epoch).TotalSeconds, 3, MidpointRounding.AwayFromZero);
+        }
+    }
+}

src/Serilog.Sinks.Splunk/Sinks/Splunk/EventCollectorRequest.cs

@@ -8,7 +8,7 @@ internal class SplunkEvent
     {
         private string _payload;
 
-        internal SplunkEvent(string logEvent, string source, string sourceType, string host, string index)
+        internal SplunkEvent(string logEvent, string source, string sourceType, string host, string index, double time)
         {
             _payload = string.Empty;
 
@@ -32,6 +32,11 @@ internal SplunkEvent(string logEvent, string source, string sourceType, string h
                 jsonPayLoad = jsonPayLoad + @",""index"":""" + index + @"""";
             }
 
+            if (time > 0)
+            {
+                jsonPayLoad = jsonPayLoad + @",""time"":" + time;
+            }
+
             jsonPayLoad = jsonPayLoad + "}";
             _payload = jsonPayLoad;
         }

src/Serilog.Sinks.Splunk/Sinks/Splunk/EventCollectorSink.cs

@@ -176,8 +176,8 @@ private async Task Send(IEnumerable<LogEvent> events)
                 _jsonFormatter.Format(logEvent, sw);
 
                 var serialisedEvent = sw.ToString();
-
-                var splunkEvent = new SplunkEvent(serialisedEvent, _source, _sourceType, _host, _index);
+                
+                var splunkEvent = new SplunkEvent(serialisedEvent, _source, _sourceType, _host, _index, logEvent.Timestamp.ToEpoch());
 
                 allEvents = $"{allEvents}{splunkEvent.Payload}";
             }