Make MetricPoint access from MetricPointAccessor readonly (#2736)

open-telemetry · Dec 14, 2021 · 33f3596 · 33f3596
1 parent 1e45e09
commit 33f3596
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Showing 9 changed files with 22 additions and 22 deletions.
diff --git a/src/OpenTelemetry.Exporter.Console/ConsoleMetricExporter.cs b/src/OpenTelemetry.Exporter.Console/ConsoleMetricExporter.cs
@@ -75,7 +75,7 @@ public override ExportResult Export(in Batch<Metric> batch)
 
                 Console.WriteLine(msg.ToString());
 
-                foreach (ref var metricPoint in metric.GetMetricPoints())
+                foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                 {
                     string valueDisplay = string.Empty;
                     StringBuilder tagsBuilder = new StringBuilder();

diff --git a/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/MetricItemExtensions.cs b/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/MetricItemExtensions.cs
@@ -148,7 +148,7 @@ internal static OtlpMetrics.Metric ToOtlpMetric(this Metric metric)
                         sum.IsMonotonic = true;
                         sum.AggregationTemporality = temporality;
 
-                        foreach (ref var metricPoint in metric.GetMetricPoints())
+                        foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                         {
                             var dataPoint = new OtlpMetrics.NumberDataPoint
                             {
@@ -172,7 +172,7 @@ internal static OtlpMetrics.Metric ToOtlpMetric(this Metric metric)
                         sum.IsMonotonic = true;
                         sum.AggregationTemporality = temporality;
 
-                        foreach (ref var metricPoint in metric.GetMetricPoints())
+                        foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                         {
                             var dataPoint = new OtlpMetrics.NumberDataPoint
                             {
@@ -193,7 +193,7 @@ internal static OtlpMetrics.Metric ToOtlpMetric(this Metric metric)
                 case MetricType.LongGauge:
                     {
                         var gauge = new OtlpMetrics.Gauge();
-                        foreach (ref var metricPoint in metric.GetMetricPoints())
+                        foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                         {
                             var dataPoint = new OtlpMetrics.NumberDataPoint
                             {
@@ -214,7 +214,7 @@ internal static OtlpMetrics.Metric ToOtlpMetric(this Metric metric)
                 case MetricType.DoubleGauge:
                     {
                         var gauge = new OtlpMetrics.Gauge();
-                        foreach (ref var metricPoint in metric.GetMetricPoints())
+                        foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                         {
                             var dataPoint = new OtlpMetrics.NumberDataPoint
                             {
@@ -237,7 +237,7 @@ internal static OtlpMetrics.Metric ToOtlpMetric(this Metric metric)
                         var histogram = new OtlpMetrics.Histogram();
                         histogram.AggregationTemporality = temporality;
 
-                        foreach (ref var metricPoint in metric.GetMetricPoints())
+                        foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                         {
                             var dataPoint = new OtlpMetrics.HistogramDataPoint
                             {

diff --git a/src/OpenTelemetry.Exporter.Prometheus/Implementation/PrometheusSerializerExt.cs b/src/OpenTelemetry.Exporter.Prometheus/Implementation/PrometheusSerializerExt.cs
@@ -40,7 +40,7 @@ public static int WriteMetric(byte[] buffer, int cursor, Metric metric)
 
             if (!metric.MetricType.IsHistogram())
             {
-                foreach (ref var metricPoint in metric.GetMetricPoints())
+                foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                 {
                     var tags = metricPoint.Tags;
                     var timestamp = metricPoint.EndTime.ToUnixTimeMilliseconds();
@@ -103,7 +103,7 @@ public static int WriteMetric(byte[] buffer, int cursor, Metric metric)
             }
             else
             {
-                foreach (ref var metricPoint in metric.GetMetricPoints())
+                foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                 {
                     var tags = metricPoint.Tags;
                     var timestamp = metricPoint.EndTime.ToUnixTimeMilliseconds();

diff --git a/src/OpenTelemetry/Metrics/MetricPointsAccessor.cs b/src/OpenTelemetry/Metrics/MetricPointsAccessor.cs
@@ -76,7 +76,7 @@ internal Enumerator(MetricPoint[] metricsPoints, int[] metricPointsToProcess, lo
             /// <summary>
             /// Gets the <see cref="MetricPoint"/> at the current position of the enumerator.
             /// </summary>
-            public ref MetricPoint Current
+            public ref readonly MetricPoint Current
             {
                 get
                 {

diff --git a/test/Benchmarks/Metrics/MetricCollectBenchmarks.cs b/test/Benchmarks/Metrics/MetricCollectBenchmarks.cs
@@ -69,7 +69,7 @@ void ProcessExport(Batch<Metric> batch)
                     if (this.UseWithRef)
                     {
                         // The performant way of iterating.
-                        foreach (ref var metricPoint in metric.GetMetricPoints())
+                        foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                         {
                             sum += metricPoint.GetSumDouble();
                         }

diff --git a/test/OpenTelemetry.Tests/Metrics/InMemoryExporterTests.cs b/test/OpenTelemetry.Tests/Metrics/InMemoryExporterTests.cs
@@ -48,7 +48,7 @@ public void InMemoryExporterShouldDeepCopyMetricPoints()
             var metric = exportedItems[0]; // Only one Metric object is added to the collection at this point
             var metricPointsEnumerator = metric.GetMetricPoints().GetEnumerator();
             Assert.True(metricPointsEnumerator.MoveNext()); // One MetricPoint is emitted for the Metric
-            ref var metricPointForFirstExport = ref metricPointsEnumerator.Current;
+            ref readonly var metricPointForFirstExport = ref metricPointsEnumerator.Current;
             Assert.Equal(10, metricPointForFirstExport.GetSumLong());
 
             // Emit 25 for the MetricPoint with a single key-vaue pair: ("tag1", "value1")

diff --git a/test/OpenTelemetry.Tests/Metrics/MetricAPITest.cs b/test/OpenTelemetry.Tests/Metrics/MetricAPITest.cs
@@ -58,7 +58,7 @@ public void ObserverCallbackTest()
             var metric = exportedItems[0];
             Assert.Equal("myGauge", metric.Name);
             List<MetricPoint> metricPoints = new List<MetricPoint>();
-            foreach (ref var mp in metric.GetMetricPoints())
+            foreach (ref readonly var mp in metric.GetMetricPoints())
             {
                 metricPoints.Add(mp);
             }
@@ -88,7 +88,7 @@ public void ObserverCallbackExceptionTest()
             var metric = exportedItems[0];
             Assert.Equal("myGauge", metric.Name);
             List<MetricPoint> metricPoints = new List<MetricPoint>();
-            foreach (ref var mp in metric.GetMetricPoints())
+            foreach (ref readonly var mp in metric.GetMetricPoints())
             {
                 metricPoints.Add(mp);
             }
@@ -450,7 +450,7 @@ int MetricPointCount()
 
                 foreach (var metric in exportedItems)
                 {
-                    foreach (ref var metricPoint in metric.GetMetricPoints())
+                    foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                     {
                         count++;
                     }
@@ -696,7 +696,7 @@ private static long GetLongSum(List<Metric> metrics)
             long sum = 0;
             foreach (var metric in metrics)
             {
-                foreach (ref var metricPoint in metric.GetMetricPoints())
+                foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                 {
                     if (metric.MetricType.IsSum())
                     {
@@ -717,7 +717,7 @@ private static double GetDoubleSum(List<Metric> metrics)
             double sum = 0;
             foreach (var metric in metrics)
             {
-                foreach (ref var metricPoint in metric.GetMetricPoints())
+                foreach (ref readonly var metricPoint in metric.GetMetricPoints())
                 {
                     if (metric.MetricType.IsSum())
                     {

diff --git a/test/OpenTelemetry.Tests/Metrics/MetricViewTests.cs b/test/OpenTelemetry.Tests/Metrics/MetricViewTests.cs
@@ -380,7 +380,7 @@ public void ViewToProduceCustomHistogramBound()
             Assert.Equal("MyHistogram", metricCustom.Name);
 
             List<MetricPoint> metricPointsDefault = new List<MetricPoint>();
-            foreach (ref var mp in metricDefault.GetMetricPoints())
+            foreach (ref readonly var mp in metricDefault.GetMetricPoints())
             {
                 metricPointsDefault.Add(mp);
             }
@@ -407,7 +407,7 @@ public void ViewToProduceCustomHistogramBound()
             Assert.Equal(Metric.DefaultHistogramBounds.Length + 1, actualCount);
 
             List<MetricPoint> metricPointsCustom = new List<MetricPoint>();
-            foreach (ref var mp in metricCustom.GetMetricPoints())
+            foreach (ref readonly var mp in metricCustom.GetMetricPoints())
             {
                 metricPointsCustom.Add(mp);
             }
@@ -465,7 +465,7 @@ public void ViewToSelectTagKeys()
             var metric = exportedItems[0];
             Assert.Equal("NameOnly", metric.Name);
             List<MetricPoint> metricPoints = new List<MetricPoint>();
-            foreach (ref var mp in metric.GetMetricPoints())
+            foreach (ref readonly var mp in metric.GetMetricPoints())
             {
                 metricPoints.Add(mp);
             }
@@ -476,7 +476,7 @@ public void ViewToSelectTagKeys()
             metric = exportedItems[1];
             Assert.Equal("SizeOnly", metric.Name);
             metricPoints.Clear();
-            foreach (ref var mp in metric.GetMetricPoints())
+            foreach (ref readonly var mp in metric.GetMetricPoints())
             {
                 metricPoints.Add(mp);
             }
@@ -487,7 +487,7 @@ public void ViewToSelectTagKeys()
             metric = exportedItems[2];
             Assert.Equal("NoTags", metric.Name);
             metricPoints.Clear();
-            foreach (ref var mp in metric.GetMetricPoints())
+            foreach (ref readonly var mp in metric.GetMetricPoints())
             {
                 metricPoints.Add(mp);
             }

diff --git a/test/OpenTelemetry.Tests/Metrics/MultipleReadersTests.cs b/test/OpenTelemetry.Tests/Metrics/MultipleReadersTests.cs
@@ -111,7 +111,7 @@ private void AssertLongSumValueForMetric(Metric metric, long value)
             var metricPoints = metric.GetMetricPoints();
             var metricPointsEnumerator = metricPoints.GetEnumerator();
             Assert.True(metricPointsEnumerator.MoveNext()); // One MetricPoint is emitted for the Metric
-            ref var metricPointForFirstExport = ref metricPointsEnumerator.Current;
+            ref readonly var metricPointForFirstExport = ref metricPointsEnumerator.Current;
             if (metric.MetricType.IsSum())
             {
                 Assert.Equal(value, metricPointForFirstExport.GetSumLong());