Initial structure for running Processors

examples/Console/Program.cs

@@ -34,7 +34,7 @@ public class Program
         /// dotnet run -p Examples.Console.csproj prometheus -i 15 -p 9184 -d 2
         /// dotnet run -p Examples.Console.csproj otlp -e "http://localhost:4317"
         /// dotnet run -p Examples.Console.csproj zpages
-        /// dotnet run -p Examples.Console.csproj metrics -p 100
+        /// dotnet run -p Examples.Console.csproj metrics -p 100 -e 500
         ///
         /// The above must be run from the project root folder
         /// (eg: C:\repos\opentelemetry-dotnet\examples\Console\).
@@ -47,7 +47,7 @@ public static void Main(string[] args)
                     (JaegerOptions options) => TestJaegerExporter.Run(options.Host, options.Port),
                     (ZipkinOptions options) => TestZipkinExporter.Run(options.Uri),
                     (PrometheusOptions options) => TestPrometheusExporter.Run(options.Port, options.PushIntervalInSecs, options.DurationInMins),
-                    (MetricsOptions options) => TestMetrics.Run(options.ObservationPeriodMilliseconds),
+                    (MetricsOptions options) => TestMetrics.Run(options.ObservationPeriodMilliseconds, options.CollectionPeriodMilliseconds),
                     (GrpcNetClientOptions options) => TestGrpcNetClient.Run(),
                     (HttpClientOptions options) => TestHttpClient.Run(),
                     (RedisOptions options) => TestRedis.Run(options.Uri),
@@ -100,6 +100,9 @@ internal class MetricsOptions
     {
         [Option('p', "observationPeriodMilliseconds", Default = 100, HelpText = "Observation period.", Required = false)]
         public int ObservationPeriodMilliseconds { get; set; }
+
+        [Option('c', "collectionPeriodMilliseconds", Default = 500, HelpText = "Collection period.", Required = false)]
+        public int CollectionPeriodMilliseconds { get; set; }
     }
 
     [Verb("grpc", HelpText = "Specify the options required to test Grpc.Net.Client")]

examples/Console/TestMetrics.cs

@@ -25,11 +25,14 @@ namespace Examples.Console
 {
     internal class TestMetrics
     {
-        internal static object Run(int observationInterval)
+        internal static object Run(int observationInterval, int collectionInterval)
         {
             using var provider = Sdk.CreateMeterProviderBuilder()
                 .AddSource("TestMeter") // All instruments from this meter are enabled.
                 .SetObservationPeriod(observationInterval)
+                .SetCollectionPeriod(collectionInterval)
+                .AddProcessor(new TagEnrichmentProcessor())
+                .AddExportProcessor(new MetricConsoleExporter())
                 .Build();
 
             using var meter = new Meter("TestMeter", "0.0.1");
@@ -56,7 +59,7 @@ internal static object Run(int observationInterval)
                 };
             });
 
-            Task.Delay(50).Wait();
+            Task.Delay(5000).Wait();
             System.Console.WriteLine("Press Enter key to exit.");
             return null;
         }

src/OpenTelemetry/Metrics/AggregateState.cs

@@ -0,0 +1,39 @@
+// <copyright file="AggregateState.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    internal class AggregateState
+    {
+        internal long Count = 0;
+        internal long Sum = 0;
+
+        public virtual void Update(DataPoint? value)
+        {
+            long val = 0;
+
+            if (value is DataPoint<int> idp)
+            {
+                val = idp.Value;
+            }
+
+            this.Count++;
+            this.Sum += val;
+        }
+    }
+}

src/OpenTelemetry/Metrics/DataPoint.cs

@@ -0,0 +1,51 @@
+// <copyright file="DataPoint.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using System;
+using System.Collections.Generic;
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    public abstract class DataPoint
+    {
+        private KeyValuePair<string, object?>[] tags;
+
+        public DataPoint(ReadOnlySpan<KeyValuePair<string, object?>> tags)
+        {
+            this.tags = tags.ToArray();
+        }
+
+        public ReadOnlySpan<KeyValuePair<string, object?>> Tags
+        {
+            get
+            {
+                return new ReadOnlySpan<KeyValuePair<string, object?>>(this.tags);
+            }
+        }
+
+        public void SetTags(KeyValuePair<string, object?>[] tags)
+        {
+            this.tags = tags;
+        }
+
+        public virtual string ValueAsString()
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

src/OpenTelemetry/Metrics/DataPoint{T}.cs

@@ -0,0 +1,46 @@
+// <copyright file="DataPoint{T}.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using System;
+using System.Collections.Generic;
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    internal class DataPoint<T> : DataPoint
+        where T : unmanaged
+    {
+        internal readonly T Value;
+
+        public DataPoint(T value, params KeyValuePair<string, object?>[] tags)
+            : base(new ReadOnlySpan<KeyValuePair<string, object?>>(tags))
+        {
+            this.Value = value;
+        }
+
+        public DataPoint(T value, ReadOnlySpan<KeyValuePair<string, object?>> tags)
+            : base(tags)
+        {
+            this.Value = value;
+        }
+
+        public override string ValueAsString()
+        {
+            return this.Value.ToString();
+        }
+    }
+}

src/OpenTelemetry/Metrics/MeterProviderBuilderExtensions.cs

@@ -34,7 +34,55 @@ public static MeterProviderBuilder SetObservationPeriod(this MeterProviderBuilde
                 return meterProviderBuilderSdk.SetObservationPeriod(periodMilliseconds);
             }
 
-            return null;
+            return meterProviderBuilder;
+        }
+
+        /// <summary>
+        /// Sets collection period.
+        /// </summary>
+        /// <param name="meterProviderBuilder"><see cref="MeterProviderBuilder"/>.</param>
+        /// <param name="periodMilliseconds">Perion in milliseconds.</param>
+        /// <returns><see cref="MeterProvider"/>.</returns>
+        public static MeterProviderBuilder SetCollectionPeriod(this MeterProviderBuilder meterProviderBuilder, int periodMilliseconds)
+        {
+            if (meterProviderBuilder is MeterProviderBuilderSdk meterProviderBuilderSdk)
+            {
+                return meterProviderBuilderSdk.SetCollectionPeriod(periodMilliseconds);
+            }
+
+            return meterProviderBuilder;
+        }
+
+        /// <summary>
+        /// Add measurement processor.
+        /// </summary>
+        /// <param name="meterProviderBuilder"><see cref="MeterProviderBuilder"/>.</param>
+        /// <param name="processor">Measurement Processors.</param>
+        /// <returns><see cref="MeterProvider"/>.</returns>
+        public static MeterProviderBuilder AddProcessor(this MeterProviderBuilder meterProviderBuilder, MeasurementProcessor processor)
+        {
+            if (meterProviderBuilder is MeterProviderBuilderSdk meterProviderBuilderSdk)
+            {
+                return meterProviderBuilderSdk.AddMeasurementProcessor(processor);
+            }
+
+            return meterProviderBuilder;
+        }
+
+        /// <summary>
+        /// Add export processor.
+        /// </summary>
+        /// <param name="meterProviderBuilder"><see cref="MeterProviderBuilder"/>.</param>
+        /// <param name="processor">Measurement Processors.</param>
+        /// <returns><see cref="MeterProvider"/>.</returns>
+        public static MeterProviderBuilder AddExportProcessor(this MeterProviderBuilder meterProviderBuilder, MetricProcessor processor)
+        {
+            if (meterProviderBuilder is MeterProviderBuilderSdk meterProviderBuilderSdk)
+            {
+                return meterProviderBuilderSdk.AddExporter(processor);
+            }
+
+            return meterProviderBuilder;
         }
 
         /// <summary>

src/OpenTelemetry/Metrics/MeterProviderBuilderSdk.cs

@@ -22,12 +22,17 @@ namespace OpenTelemetry.Metrics
     internal class MeterProviderBuilderSdk : MeterProviderBuilder
     {
         private readonly List<string> meterSources = new List<string>();
-        private int observationPeriodMilliseconds;
+        private int observationPeriodMilliseconds = 1000;
+        private int collectionPeriodMilliseconds = 1000;
 
         internal MeterProviderBuilderSdk()
         {
         }
 
+        internal List<MeasurementProcessor> MeasurementProcessors { get; } = new List<MeasurementProcessor>();
+
+        internal List<MetricProcessor> ExportProcessors { get; } = new List<MetricProcessor>();
+
         public override MeterProviderBuilder AddSource(params string[] names)
         {
             if (names == null)
@@ -54,9 +59,33 @@ internal MeterProviderBuilderSdk SetObservationPeriod(int periodMilliseconds)
             return this;
         }
 
+        internal MeterProviderBuilderSdk SetCollectionPeriod(int periodMilliseconds)
+        {
+            this.collectionPeriodMilliseconds = periodMilliseconds;
+            return this;
+        }
+
+        internal MeterProviderBuilderSdk AddMeasurementProcessor(MeasurementProcessor processor)
+        {
+            this.MeasurementProcessors.Add(processor);
+            return this;
+        }
+
+        internal MeterProviderBuilderSdk AddExporter(MetricProcessor processor)
+        {
+            this.ExportProcessors.Add(processor);
+            return this;
+        }
+
         internal MeterProvider Build()
         {
-            return new MeterProviderSdk(this.meterSources, this.observationPeriodMilliseconds);
+            // TODO: Need to review using a struct for BuildOptions
+            return new MeterProviderSdk(
+                this.meterSources,
+                this.observationPeriodMilliseconds,
+                this.collectionPeriodMilliseconds,
+                this.MeasurementProcessors.ToArray(),
+                this.ExportProcessors.ToArray());
         }
     }
 }