Initial structure for running Processors

examples/AspNet/Examples.AspNet.csproj

@@ -79,6 +79,7 @@
     <PackageReference Include="Microsoft.AspNet.WebApi.WebHost" Version="$(MicrosoftAspNetWebApiWebHostPkgVer)" />
     <PackageReference Include="Microsoft.AspNet.Mvc" Version="$(MicrosoftAspNetMvcPkgVer)" />
     <PackageReference Include="Microsoft.AspNet.WebPages" Version="$(MicrosoftAspNetWebPagesPkgVer)" />
+    <PackageReference Include="Microsoft.VisualBasic" Version="10.3.0" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="$(RepoRoot)\src\OpenTelemetry.Api\OpenTelemetry.Api.csproj">

examples/Console/TestMetrics.cs

@@ -29,6 +29,8 @@ internal static object Run(int observationInterval)
         {
             using var provider = Sdk.CreateMeterProviderBuilder()
                 .AddSource("TestMeter") // All instruments from this meter are enabled.
+                .AddProcessor(new MeasurementProcessor())
+                .AddExportProcessor(new ExportMetricProcessor())
                 .SetObservationPeriod(observationInterval)
                 .Build();
 
@@ -56,7 +58,7 @@ 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/Aggregator/AggState.cs

@@ -0,0 +1,43 @@
+// <copyright file="AggState.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.Collections.Concurrent;
+using System.Diagnostics.Metrics;
+using System.Threading;
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    public class AggState
+    {
+        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/Aggregator/AggregateContext.cs

@@ -0,0 +1,34 @@
+// <copyright file="AggregateContext.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;
+using System.Diagnostics.Metrics;
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    public class AggregateContext
+    {
+        public AggregateContext(MeasurementContext measurment)
+        {
+            this.Measurment = measurment;
+        }
+
+        internal MeasurementContext Measurment { get; }
+    }
+}

src/OpenTelemetry/Metrics/Aggregator/AggregatorProcessor.cs

@@ -0,0 +1,40 @@
+// <copyright file="AggregatorProcessor.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.Collections.Concurrent;
+using System.Diagnostics.Metrics;
+using System.Threading;
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    public class AggregatorProcessor : BaseProcessor<MeasurementContext>
+    {
+        private ConcurrentDictionary<Instrument, AggState> states = new ConcurrentDictionary<Instrument, AggState>();
+
+        public override void OnEnd(MeasurementContext data)
+        {
+            var state = this.states.GetOrAdd(data.Instrument, (k) => new AggState());
+            state.Update(data.Point);
+        }
+
+        public ConcurrentDictionary<Instrument, AggState> Collect()
+        {
+            return Interlocked.Exchange(ref this.states, new ConcurrentDictionary<Instrument, AggState>());
+        }
+    }
+}

src/OpenTelemetry/Metrics/DataPoint.cs

@@ -0,0 +1,69 @@
+// <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 virtual string ValueAsString()
+        {
+            throw new NotImplementedException();
+        }
+    }
+
+    public 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/Exporter/ExportMetricContext.cs

@@ -0,0 +1,34 @@
+// <copyright file="ExportMetricContext.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.Concurrent;
+using System.Collections.Generic;
+using System.Diagnostics.Metrics;
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    public class ExportMetricContext
+    {
+        internal List<ConcurrentDictionary<Instrument, AggState>> Exports = new List<ConcurrentDictionary<Instrument, AggState>>();
+
+        public ExportMetricContext()
+        {
+        }
+    }
+}

src/OpenTelemetry/Metrics/Exporter/ExportMetricProcessor.cs

@@ -0,0 +1,40 @@
+// <copyright file="ExportMetricProcessor.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.Concurrent;
+using System.Diagnostics.Metrics;
+using System.Threading;
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    public class ExportMetricProcessor : BaseProcessor<ExportMetricContext>
+    {
+        public override void OnEnd(ExportMetricContext data)
+        {
+            foreach (var exports in data.Exports)
+            {
+                foreach (var item in exports)
+                {
+                    var msg = $"{item.Key.Meter.Name}:{item.Key.Name} = count:{item.Value.Count}, sum:{item.Value.Sum}";
+                    Console.WriteLine($"Export: {msg}");
+                }
+            }
+        }
+    }
+}

src/OpenTelemetry/Metrics/MeasurementContext.cs

@@ -0,0 +1,36 @@
+// <copyright file="MeasurementContext.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;
+using System.Diagnostics.Metrics;
+
+#nullable enable
+
+namespace OpenTelemetry.Metrics
+{
+    public class MeasurementContext
+    {
+        internal readonly Instrument Instrument;
+        internal DataPoint? Point;
+
+        public MeasurementContext(Instrument instrument, DataPoint point)
+        {
+            this.Instrument = instrument;
+            this.Point = point;
+        }
+    }
+}

src/OpenTelemetry/Metrics/MeasurementProcessor.cs

@@ -0,0 +1,51 @@
+// <copyright file="MeasurementProcessor.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 class MeasurementProcessor
+        : BaseProcessor<MeasurementContext>
+    {
+        public override void OnStart(MeasurementContext data)
+        {
+            // Console.WriteLine($"Start: {this.AsString(data)}");
+
+            // // Replace datapoint
+            // var oldArray = data.Point!.Tags.ToArray();
+            // var newArray = new KeyValuePair<string, object?>[oldArray.Length + 1];
+            // newArray[0] = new KeyValuePair<string, object?>("newLabel", "newValue");
+            // oldArray.CopyTo(newArray, 1);
+            // var dp = new DataPoint<int>(10000, newArray);
+            // data.Point = dp;
+        }
+
+        public override void OnEnd(MeasurementContext data)
+        {
+            // Console.WriteLine($"End: {this.AsString(data)}");
+        }
+
+        public string AsString(MeasurementContext data)
+        {
+            var tags = string.Join(",", data.Point!.Tags.ToArray());
+            return $"{data.Instrument.Meter.Name}:{data.Instrument.Name}{tags} = {data.Point!.ValueAsString()}";
+        }
+    }
+}