Added support to set custom timestamp (#55)

* Added support to set custom timestamp

* Bumped version from 2.1.0 to 2.2.0

Author: rayabagi

README.md

@@ -177,7 +177,7 @@ Example:
 
 ```c#
 // Standard Resolution Example
-metrics.PutMetric("ProcessingLatency", 101, Unit.MILLISECONDS);
+logger.PutMetric("ProcessingLatency", 101, Unit.MILLISECONDS);
 
 // High Resolution Example
 logger.PutMetric("Memory.HeapUsed", "1600424.0", Unit.BYTES, StorageResolution.HIGH);
@@ -189,16 +189,16 @@ Adds or updates the value for a given property on this context. This value is no
 
 Example:
 ```c#
-metrics.PutProperty("AccountId", "123456789");
-metrics.PutProperty("RequestId", "422b1569-16f6-4a03-b8f0-fe3fd9b100f8");
+logger.PutProperty("AccountId", "123456789");
+logger.PutProperty("RequestId", "422b1569-16f6-4a03-b8f0-fe3fd9b100f8");
 
 Dictionary<string, object> payLoad = new Dictionary<string, object>
 {
   { "sampleTime", 123456789 },
   { "temperature", 273.0 },
   { "pressure", 101.3 }
 };
-metrics.PutProperty("Payload", payLoad);
+logger.PutProperty("Payload", payLoad);
 ```
 
 - MetricsLogger **PutDimensions**(DimensionSet dimensions)
@@ -217,7 +217,7 @@ Example:
 DimensionSet dimensionSet = new DimensionSet();
 dimensionSet.AddDimension("Service", "Aggregator");
 dimensionSet.AddDimension("Region", "us-west-2");
-metrics.PutDimensions(dimensionSet);
+logger.PutDimensions(dimensionSet);
 ```
 
 - MetricsLogger **SetDimensions**(params DimensionSet[] dimensionSets)
@@ -237,14 +237,14 @@ Examples:
 DimensionSet dimensionSet = new DimensionSet();
 dimensionSet.AddDimension("Service", "Aggregator");
 dimensionSet.AddDimension("Region", "us-west-2");
-metrics.SetDimensions(true, dimensionSet); // Will preserve default dimensions
+logger.SetDimensions(true, dimensionSet); // Will preserve default dimensions
 ```
 
 ```c#
 DimensionSet dimensionSet = new DimensionSet();
 dimensionSet.AddDimension("Service", "Aggregator");
 dimensionSet.AddDimension("Region", "us-west-2");
-metrics.SetDimensions(dimensionSet); // Will remove default dimensions
+logger.SetDimensions(dimensionSet); // Will remove default dimensions
 ```
 
 - MetricsLogger **ResetDimensions**(bool useDefault)
@@ -259,12 +259,23 @@ Namespaces must meet CloudWatch Namespace requirements, otherwise a `InvalidName
 Example:
 
 ```c#
-SetNamespace("MyApplication")
+logger.SetNamespace("MyApplication")
 ```
 
+- MetricsLogger **SetTimestamp**(DateTime dateTime)
+
+Sets the timestamp of the metrics. If not set, the current time of the client will be used.
+Timestamp must meet CloudWatch requirements, otherwise a `InvalidTimestampException` will be thrown. See [Timestamps](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch_concepts.html#about_timestamp) for valid values.
+
+Example:
+```c#
+ logger.SetTimestamp(DateTime.Now);
+```
+
+
 - **Flush**()
 
-Flushes the current MetricsContext to the configured sink and resets all properties and metric values. The namespace and default dimensions will be preserved across flushes. Custom dimensions are preserved by default, but this behavior can be changed by setting `flushPreserveDimensions = false` on the metrics logger.
+Flushes the current MetricsContext to the configured sink and resets all properties and metric values. The namespace and default dimensions will be preserved across flushes. Custom dimensions are preserved by default, but this behavior can be changed by setting `FlushPreserveDimensions = false` on the metrics logger.
 
 Examples:
 
@@ -273,12 +284,12 @@ flush();  // default dimensions and custom dimensions will be preserved after ea
 ```
 
 ```c#
-logger.setFlushPreserveDimensions = false;
+logger.FlushPreserveDimensions = false;
 flush();  // only default dimensions will be preserved after each flush()
 ```
 
 ```c#
-setFlushPreserveDimensions(false);
-resetDimensions(false);  // default dimensions are disabled; no dimensions will be preserved after each flush()
-flush();
+logger.FlushPreserveDimensions = false;
+logger.ResetDimensions(false);  // default dimensions are disabled; no dimensions will be preserved after each flush()
+logger.Flush();
 ```

examples/Amazon.CloudWatch.EMF.Examples.ConsoleApp/Program.cs

@@ -45,6 +45,7 @@ private static void EmitMetrics(ILogger logger, IMetricsLogger metrics)
         {
 
             var dimensionSet = new DimensionSet();
+            metrics.SetTimestamp(DateTime.Now);
             dimensionSet.AddDimension("Service", "Aggregator");
             dimensionSet.AddDimension("Region", "us-west-2");
             metrics.SetDimensions(dimensionSet);

examples/Amazon.CloudWatch.EMF.Examples.Lambda/Function.cs

@@ -5,7 +5,7 @@
 using Amazon.CloudWatch.EMF.Model;
 using Amazon.Lambda.Core;
 using System.Text;
-
+using System;
 // Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
 [assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]
 
@@ -27,6 +27,7 @@ public string FunctionHandler(string input, ILambdaContext context)
             var dimensionSet = new DimensionSet();
             dimensionSet.AddDimension("Service", "Aggregator");
             dimensionSet.AddDimension("Region", "us-west-2");
+            logger.SetTimestamp(DateTime.Now);
             logger.PutDimensions(dimensionSet);
             logger.SetNamespace("EMFLambda");
             logger.PutMetric("ProcessingLatency", 101, Unit.MILLISECONDS);

examples/Amazon.CloudWatch.EMF.Examples.Web/Controllers/WeatherForecastController.cs

@@ -37,7 +37,7 @@ public IEnumerable<WeatherForecast> Get()
             var rng = new Random();
             var temperature = rng.Next(-20, 55);
             var WindSpeed = rng.Next(10, 100);
-
+            _metrics.SetTimestamp(DateTime.Now);
             _metrics.PutMetric("Temperature", temperature, Unit.NONE);
             _metrics.PutMetric("WindSpeed", WindSpeed, Unit.NONE, StorageResolution.HIGH);
 

src/Amazon.CloudWatch.EMF/Amazon.CloudWatch.EMF.csproj

@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <PackageId>Amazon.CloudWatch.EMF</PackageId>
-        <VersionPrefix>2.1.0</VersionPrefix>
+        <VersionPrefix>2.2.0</VersionPrefix>
         <Authors>Amazon Web Services</Authors>
         <Description>Amazon CloudWatch Embedded Metric Format Client Library</Description>
         <Language>en-US</Language>

src/Amazon.CloudWatch.EMF/Constants.cs

@@ -16,5 +16,9 @@ public class Constants
         public const int MaxMetricsPerEvent = 100;
 
         public const string DefaultNamespace = "aws-embedded-metrics";
+
+        public const long MaxTimestampPastAgeDays = 14;
+
+        public const long MaxTimestampFutureAgeHours = 2;
     }
 }

src/Amazon.CloudWatch.EMF/Exception/InvalidTimestampException.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace Amazon.CloudWatch.EMF
+{
+    public class InvalidTimestampException : Exception
+    {
+        public InvalidTimestampException(string message)
+          : base(message)
+        {
+        }
+    }
+}

src/Amazon.CloudWatch.EMF/Logger/IMetricsLogger.cs

@@ -1,4 +1,5 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 using Amazon.CloudWatch.EMF.Model;
 
 namespace Amazon.CloudWatch.EMF.Logger
@@ -22,5 +23,7 @@ public interface IMetricsLogger
         public MetricsLogger PutMetadata(string key, object value);
 
         public MetricsLogger SetNamespace(string logNamespace);
+
+        public MetricsLogger SetTimestamp(DateTime dateTime);
     }
 }

src/Amazon.CloudWatch.EMF/Logger/MetricsLogger.cs

@@ -222,6 +222,18 @@ public void Dispose()
             this.Flush();
         }
 
+        /// <summary>
+        /// Sets the timestamp of the metrics. If not set, the current time of the client will be used.
+        /// </summary>
+        /// <param name="dateTime">Date and Time</param>
+        /// <returns>the current logger.</returns>
+        public MetricsLogger SetTimestamp(DateTime dateTime)
+        {
+            Validator.ValidateTimestamp(dateTime);
+            _context.SetTimestamp(dateTime);
+            return this;
+        }
+
         /// <summary>
         /// Shutdown the associated environment's sink.
         /// </summary>

src/Amazon.CloudWatch.EMF/Model/MetaData.cs

@@ -57,5 +57,15 @@ internal MetaData DeepCloneWithNewMetrics(List<MetricDefinition> metrics)
             clone.Timestamp = Timestamp;
             return clone;
         }
+
+        internal void SetTimestamp(DateTime dateTime)
+        {
+            Timestamp = dateTime;
+        }
+
+        internal DateTime GetTimeStamp()
+        {
+            return Timestamp;
+        }
     }
 }