Added wildcard support for meter sources.

src/OpenTelemetry/Metrics/MeterProviderSdk.cs

@@ -19,6 +19,7 @@
 using System.Diagnostics;
 using System.Diagnostics.Metrics;
 using System.Linq;
+using System.Text.RegularExpressions;
 using OpenTelemetry.Internal;
 using OpenTelemetry.Resources;
 
@@ -87,10 +88,21 @@ internal MeterProviderSdk(
             }
 
             // Setup Listener
-            var meterSourcesToSubscribe = new Dictionary<string, bool>(StringComparer.OrdinalIgnoreCase);
-            foreach (var name in meterSources)
+            Func<Instrument, bool> shouldListenTo = null;
+            if (meterSources.Any(s => s.Contains('*')))
             {
-                meterSourcesToSubscribe[name] = true;
+                var regex = GetWildcardRegex(meterSources);
+                shouldListenTo = instrument => regex.IsMatch(instrument.Meter.Name);
+            }
+            else if (meterSources.Any())
+            {
+                var meterSourcesToSubscribe = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+                foreach (var meterSource in meterSources)
+                {
+                    meterSourcesToSubscribe.Add(meterSource);
+                }
+
+                shouldListenTo = instrument => meterSourcesToSubscribe.Contains(instrument.Meter.Name);
             }
 
             this.listener = new MeterListener();
@@ -99,7 +111,7 @@ internal MeterProviderSdk(
             {
                 this.listener.InstrumentPublished = (instrument, listener) =>
                 {
-                    if (meterSourcesToSubscribe.ContainsKey(instrument.Meter.Name))
+                    if (shouldListenTo != null && shouldListenTo(instrument))
                     {
                         // Creating list with initial capacity as the maximum
                         // possible size, to avoid any array resize/copy internally.
@@ -197,7 +209,7 @@ internal MeterProviderSdk(
             {
                 this.listener.InstrumentPublished = (instrument, listener) =>
                 {
-                    if (meterSourcesToSubscribe.ContainsKey(instrument.Meter.Name))
+                    if (shouldListenTo != null && shouldListenTo(instrument))
                     {
                         var metricName = instrument.Name;
                         Metric metric = null;
@@ -243,6 +255,12 @@ internal MeterProviderSdk(
 
             this.listener.MeasurementsCompleted = (instrument, state) => this.MeasurementsCompleted(instrument, state);
             this.listener.Start();
+
+            static Regex GetWildcardRegex(IEnumerable<string> collection)
+            {
+                var pattern = '^' + string.Join("|", from name in collection select "(?:" + Regex.Escape(name).Replace("\\*", ".*") + ')') + '$';
+                return new Regex(pattern, RegexOptions.Compiled | RegexOptions.IgnoreCase);
+            }
         }
 
         internal Resource Resource { get; }

test/OpenTelemetry.Tests/Metrics/MetricAPITest.cs

@@ -165,6 +165,89 @@ void ProcessExport(Batch<Metric> batch)
             Assert.Equal(1, metricCount);
         }
 
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void MeterSourcesWildcardSupportMatchTest(bool hasView)
+        {
+            var meterNames = new[]
+            {
+                "AbcCompany.XyzProduct.ComponentA",
+                "abcCompany.xYzProduct.componentC", // Wildcard match is case insensitive.
+                "DefCompany.AbcProduct.ComponentC",
+                "DefCompany.XyzProduct.ComponentC", // Wildcard match supports matching multiple patterns.
+                "GhiCompany.qweProduct.ComponentN",
+                "SomeCompany.SomeProduct.SomeComponent",
+            };
+
+            using var meter1 = new Meter(meterNames[0]);
+            using var meter2 = new Meter(meterNames[1]);
+            using var meter3 = new Meter(meterNames[2]);
+            using var meter4 = new Meter(meterNames[3]);
+            using var meter5 = new Meter(meterNames[4]);
+            using var meter6 = new Meter(meterNames[5]);
+
+            var exportedItems = new List<Metric>();
+            var meterProviderBuilder = Sdk.CreateMeterProviderBuilder()
+                .AddMeter("AbcCompany.XyzProduct.*")
+                .AddMeter("DefCompany.*.ComponentC")
+                .AddMeter("GhiCompany.qweProduct.ComponentN") // Mixing of non-wildcard meter name and wildcard meter name.
+                .AddInMemoryExporter(exportedItems);
+
+            if (hasView)
+            {
+                meterProviderBuilder.AddView("myGauge1", "newName");
+            }
+
+            using var meterProvider = meterProviderBuilder.Build();
+
+            var measurement = new Measurement<int>(100, new("name", "apple"), new("color", "red"));
+            meter1.CreateObservableGauge("myGauge1", () => measurement);
+            meter2.CreateObservableGauge("myGauge2", () => measurement);
+            meter3.CreateObservableGauge("myGauge3", () => measurement);
+            meter4.CreateObservableGauge("myGauge4", () => measurement);
+            meter5.CreateObservableGauge("myGauge5", () => measurement);
+            meter6.CreateObservableGauge("myGauge6", () => measurement);
+
+            meterProvider.ForceFlush(MaxTimeToAllowForFlush);
+
+            Assert.True(exportedItems.Count == 5); // "SomeCompany.SomeProduct.SomeComponent" will not be subscribed.
+
+            if (hasView)
+            {
+                Assert.Equal("newName", exportedItems[0].Name);
+            }
+            else
+            {
+                Assert.Equal("myGauge1", exportedItems[0].Name);
+            }
+
+            Assert.Equal("myGauge2", exportedItems[1].Name);
+            Assert.Equal("myGauge3", exportedItems[2].Name);
+            Assert.Equal("myGauge4", exportedItems[3].Name);
+            Assert.Equal("myGauge5", exportedItems[4].Name);
+        }
+
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public void MeterSourcesWildcardSupportWithoutAddingMeterToProvider(bool hasView)
+        {
+            var exportedItems = new List<Metric>();
+            var meterProviderBuilder = Sdk.CreateMeterProviderBuilder()
+                .AddInMemoryExporter(exportedItems);
+
+            if (hasView)
+            {
+                meterProviderBuilder.AddView("gauge1", "renamed");
+            }
+
+            using var meterProvider = meterProviderBuilder.Build();
+            var measurement = new Measurement<int>(100, new("name", "apple"), new("color", "red"));
+            meterProvider.ForceFlush(MaxTimeToAllowForFlush);
+            Assert.True(exportedItems.Count == 0);
+        }
+
         [Theory]
         [InlineData(true)]
         [InlineData(false)]