added ParentId to TelemetrySpan (#2740)

Author: Aaronontheweb

src/OpenTelemetry.Api/.publicApi/net461/PublicAPI.Unshipped.txt

@@ -23,3 +23,4 @@ static OpenTelemetry.Context.RuntimeContext.GetValue(string slotName) -> object
 static OpenTelemetry.Context.RuntimeContext.GetValue<T>(string slotName) -> T
 static OpenTelemetry.Context.RuntimeContext.SetValue(string slotName, object value) -> void
 static OpenTelemetry.Context.RuntimeContext.SetValue<T>(string slotName, T value) -> void
+OpenTelemetry.Trace.TelemetrySpan.ParentSpanId.get -> System.Diagnostics.ActivitySpanId

src/OpenTelemetry.Api/.publicApi/netstandard2.0/PublicAPI.Unshipped.txt

@@ -16,4 +16,5 @@ OpenTelemetry.Metrics.MeterProviderBuilder.MeterProviderBuilder() -> void
 static OpenTelemetry.Context.RuntimeContext.GetValue(string slotName) -> object
 static OpenTelemetry.Context.RuntimeContext.GetValue<T>(string slotName) -> T
 static OpenTelemetry.Context.RuntimeContext.SetValue(string slotName, object value) -> void
-static OpenTelemetry.Context.RuntimeContext.SetValue<T>(string slotName, T value) -> void
+static OpenTelemetry.Context.RuntimeContext.SetValue<T>(string slotName, T value) -> void
+OpenTelemetry.Trace.TelemetrySpan.ParentSpanId.get -> System.Diagnostics.ActivitySpanId

src/OpenTelemetry.Api/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+* Added `ParentSpanId` to `TelemetrySpan` ([#2740](https://github.com/open-telemetry/opentelemetry-dotnet/pull/2740))
+
 ## 1.2.0-rc1
 
 Released 2021-Nov-29

src/OpenTelemetry.Api/Trace/TelemetrySpan.cs

@@ -64,6 +64,24 @@ public bool IsRecording
             }
         }
 
+        /// <summary>
+        /// Gets the identity of the parent span id, if any.
+        /// </summary>
+        public ActivitySpanId ParentSpanId
+        {
+            get
+            {
+                if (this.Activity == null)
+                {
+                    return default;
+                }
+                else
+                {
+                    return this.Activity.ParentSpanId;
+                }
+            }
+        }
+
         /// <summary>
         /// Sets the status of the span execution.
         /// </summary>

test/OpenTelemetry.Tests/Trace/TelemetrySpanTest.cs

@@ -67,5 +67,21 @@ public void CheckRecordExceptionEmpty()
             telemetrySpan.RecordException(null);
             Assert.Empty(activity.Events);
         }
+
+        [Fact]
+        public void ParentIds()
+        {
+            using var parentActivity = new Activity("parentOperation");
+            parentActivity.Start(); // can't generate the Id until the operation is started
+            using var parentSpan = new TelemetrySpan(parentActivity);
+
+            // ParentId should be unset
+            Assert.Equal(default, parentSpan.ParentSpanId);
+
+            using var childActivity = new Activity("childOperation").SetParentId(parentActivity.Id);
+            using var childSpan = new TelemetrySpan(childActivity);
+
+            Assert.Equal(parentSpan.Context.SpanId, childSpan.ParentSpanId);
+        }
     }
 }