Creating CompositePropagator

src/OpenTelemetry.Api/CHANGELOG.md

@@ -16,6 +16,10 @@ changed to match the
  gets removed.
  ([#954](https://github.com/open-telemetry/opentelemetry-dotnet/pull/954)).
 * HttpStatusCode in all spans attribute (http.status_code) to use int value.
+* `ITextFormatActivity` got replaced by `ITextFormat` with an additional method
+ to be implemented (`IsInjected`)
+* Added `CompositePropagator` that accepts a list of `ITextFormat` following
+ [specification](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/context/api-propagators.md#create-a-composite-propagator)
 
 ## 0.4.0-beta.2
 

src/OpenTelemetry.Api/Context/Propagation/CompositePropagator.cs

@@ -0,0 +1,74 @@
+// <copyright file="CompositePropagator.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;
+using System.Linq;
+
+namespace OpenTelemetry.Context.Propagation
+{
+ /// <summary>
+ /// CompositePropagator provides a mechanism for combining multiple propagators into a single one.
+ /// </summary>
+ public class CompositePropagator : ITextFormat
+ {
+ private static readonly ISet<string> EmptyFields = new HashSet<string>();
+ private readonly List<ITextFormat> textFormats;
+
+ /// <summary>
+ /// Initializes a new instance of the <see cref="CompositePropagator"/> class.
+ /// </summary>
+ /// <param name="textFormats">List of <see cref="ITextFormat"/> wire context propagator.</param>
+ public CompositePropagator(List<ITextFormat> textFormats)
+ {
+ this.textFormats = textFormats ?? throw new ArgumentNullException(nameof(textFormats));
+ }
+
+ /// <inheritdoc/>
+ public ISet<string> Fields => EmptyFields;
+
+ /// <inheritdoc/>
+ public ActivityContext Extract<T>(ActivityContext activityContext, T carrier, Func<T, string, IEnumerable<string>> getter)
+ {
+ foreach (var textFormat in this.textFormats)
+ {
+ activityContext = textFormat.Extract(activityContext, carrier, getter);
+ if (activityContext.IsValid())
+ {
+ return activityContext;
+ }
+ }
+
+ return activityContext;
+ }
+
+ /// <inheritdoc/>
+ public void Inject<T>(ActivityContext activityContext, T carrier, Action<T, string, string> setter)
+ {
+ foreach (var textFormat in this.textFormats)
+ {
+ textFormat.Inject(activityContext, carrier, setter);
+ }
+ }
+
+ /// <inheritdoc/>
+ public bool IsInjected<T>(T carrier, Func<T, string, IEnumerable<string>> getter)
+ {
+ return this.textFormats.All(textFormat => textFormat.IsInjected(carrier, getter));
+ }
+ }
+}

src/OpenTelemetry.Api/Context/Propagation/ITextFormat.cs

@@ -45,10 +45,11 @@ public interface ITextFormat
  /// Extracts activity context from textual representation.
  /// </summary>
  /// <typeparam name="T">Type of object to extract context from. Typically HttpRequest or similar.</typeparam>
+ /// <param name="activityContext">The default activity context to be used if Extract fails.</param>
  /// <param name="carrier">Object to extract context from. Instance of this object will be passed to the getter.</param>
  /// <param name="getter">Function that will return string value of a key with the specified name.</param>
  /// <returns>Activity context from it's text representation.</returns>
- ActivityContext Extract<T>(T carrier, Func<T, string, IEnumerable<string>> getter);
+ ActivityContext Extract<T>(ActivityContext activityContext, T carrier, Func<T, string, IEnumerable<string>> getter);
 
  /// <summary>
  /// Tests if an activity context has been injected into a carrier.

src/OpenTelemetry.Api/Context/Propagation/TraceContextFormat.cs

@@ -30,7 +30,6 @@ public class TraceContextFormat : ITextFormat
  private const string TraceParent = "traceparent";
  private const string TraceState = "tracestate";
 
- private static readonly int VersionLength = "00".Length;
  private static readonly int VersionPrefixIdLength = "00-".Length;
  private static readonly int TraceIdLength = "0af7651916cd43dd8448eb211c80319c".Length;
  private static readonly int VersionAndTraceIdLength = "00-0af7651916cd43dd8448eb211c80319c-".Length;
@@ -74,18 +73,18 @@ public bool IsInjected<T>(T carrier, Func<T, string, IEnumerable<string>> getter
  }
 
  /// <inheritdoc/>
- public ActivityContext Extract<T>(T carrier, Func<T, string, IEnumerable<string>> getter)
+ public ActivityContext Extract<T>(ActivityContext activityContext, T carrier, Func<T, string, IEnumerable<string>> getter)
  {
  if (carrier == null)
  {
  OpenTelemetryApiEventSource.Log.FailedToInjectActivityContext("null carrier");
- return default;
+ return activityContext;
  }
 
  if (getter == null)
  {
  OpenTelemetryApiEventSource.Log.FailedToExtractContext("null getter");
- return default;
+ return activityContext;
  }
 
  try
@@ -95,22 +94,22 @@ public ActivityContext Extract<T>(T carrier, Func<T, string, IEnumerable<string>
  // There must be a single traceparent
  if (traceparentCollection == null || traceparentCollection.Count() != 1)
  {
- return default;
+ return activityContext;
  }
 
  var traceparent = traceparentCollection.First();
- var traceparentParsed = this.TryExtractTraceparent(traceparent, out var traceId, out var spanId, out var traceoptions);
+ var traceparentParsed = TryExtractTraceparent(traceparent, out var traceId, out var spanId, out var traceoptions);
 
  if (!traceparentParsed)
  {
- return default;
+ return activityContext;
  }
 
- string tracestate = null;
+ string tracestate = string.Empty;
  var tracestateCollection = getter(carrier, TraceState);
- if (tracestateCollection != null)
+ if (tracestateCollection?.Any() ?? false)
  {
- this.TryExtractTracestate(tracestateCollection.ToArray(), out tracestate);
+ TryExtractTracestate(tracestateCollection.ToArray(), out tracestate);
  }
 
  return new ActivityContext(traceId, spanId, traceoptions, tracestate, isRemote: true);
@@ -121,7 +120,7 @@ public ActivityContext Extract<T>(T carrier, Func<T, string, IEnumerable<string>
  }
 
  // in case of exception indicate to upstream that there is no parseable context from the top
- return default;
+ return activityContext;
  }
 
  /// <inheritdoc/>
@@ -157,7 +156,7 @@ public void Inject<T>(ActivityContext activityContext, T carrier, Action<T, stri
  }
  }
 
- private bool TryExtractTraceparent(string traceparent, out ActivityTraceId traceId, out ActivitySpanId spanId, out ActivityTraceFlags traceOptions)
+ internal static bool TryExtractTraceparent(string traceparent, out ActivityTraceId traceId, out ActivitySpanId spanId, out ActivityTraceFlags traceOptions)
  {
  // from https://github.com/w3c/distributed-tracing/blob/master/trace_context/HTTP_HEADER_FORMAT.md
  // traceparent: 00-0af7651916cd43dd8448eb211c80319c-00f067aa0ba902b7-01
@@ -179,8 +178,8 @@ private bool TryExtractTraceparent(string traceparent, out ActivityTraceId trace
  }
 
  // or version is not a hex (will throw)
- var version0 = this.HexCharToByte(traceparent[0]);
- var version1 = this.HexCharToByte(traceparent[1]);
+ var version0 = HexCharToByte(traceparent[0]);
+ var version1 = HexCharToByte(traceparent[1]);
 
  if (version0 == 0xf && version1 == 0xf)
  {
@@ -229,8 +228,8 @@ private bool TryExtractTraceparent(string traceparent, out ActivityTraceId trace
 
  try
  {
- options0 = this.HexCharToByte(traceparent[VersionAndTraceIdAndSpanIdLength]);
- options1 = this.HexCharToByte(traceparent[VersionAndTraceIdAndSpanIdLength + 1]);
+ options0 = HexCharToByte(traceparent[VersionAndTraceIdAndSpanIdLength]);
+ options1 = HexCharToByte(traceparent[VersionAndTraceIdAndSpanIdLength + 1]);
  }
  catch (ArgumentOutOfRangeException)
  {
@@ -259,27 +258,7 @@ private bool TryExtractTraceparent(string traceparent, out ActivityTraceId trace
  return true;
  }
 
- private byte HexCharToByte(char c)
- {
- if ((c >= '0') && (c <= '9'))
- {
- return (byte)(c - '0');
- }
-
- if ((c >= 'a') && (c <= 'f'))
- {
- return (byte)(c - 'a' + 10);
- }
-
- if ((c >= 'A') && (c <= 'F'))
- {
- return (byte)(c - 'A' + 10);
- }
-
- throw new ArgumentOutOfRangeException(nameof(c), $"Invalid character: {c}.");
- }
-
- private bool TryExtractTracestate(string[] tracestateCollection, out string tracestateResult)
+ internal static bool TryExtractTracestate(string[] tracestateCollection, out string tracestateResult)
  {
  tracestateResult = string.Empty;
 
@@ -304,5 +283,17 @@ private bool TryExtractTracestate(string[] tracestateCollection, out string trac
 
  return true;
  }
+
+ private static byte HexCharToByte(char c)
+ {
+ if (((c >= '0') && (c <= '9'))
+ || ((c >= 'a') && (c <= 'f'))
+ || ((c >= 'A') && (c <= 'F')))
+ {
+ return Convert.ToByte(c);
+ }
+
+ throw new ArgumentOutOfRangeException(nameof(c), $"Invalid character: {c}.");
+ }
  }
 }

src/OpenTelemetry.Api/Trace/SpanContext.cs

@@ -120,6 +120,12 @@ public IEnumerable<KeyValuePair<string, string>> TraceState
  }
  }
 
+ /// <summary>
+ /// Converts a <see cref="SpanContext"/> into an <see cref="ActivityContext"/>.
+ /// </summary>
+ /// <param name="spanContext"><see cref="SpanContext"/> source.</param>
+ public static implicit operator ActivityContext(SpanContext spanContext) => spanContext.ActivityContext;
+
  /// <summary>
  /// Compare two <see cref="SpanContext"/> for equality.
  /// </summary>

src/OpenTelemetry.Instrumentation.AspNet/Implementation/HttpInListener.cs

@@ -63,7 +63,7 @@ public override void OnStartActivity(Activity activity, object payload)
  {
  // This requires to ignore the current activity and create a new one
  // using the context extracted using the format TextFormat supports.
- var ctx = this.options.TextFormat.Extract(request, HttpRequestHeaderValuesGetter);
+ var ctx = this.options.TextFormat.Extract(default, request, HttpRequestHeaderValuesGetter);
 
  // Create a new activity with its parent set from the extracted context.
  // This makes the new activity as a "sibling" of the activity created by

src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs

@@ -50,9 +50,7 @@ public HttpInListener(string name, AspNetCoreInstrumentationOptions options, Act
 
  public override void OnStartActivity(Activity activity, object payload)
  {
- var context = this.startContextFetcher.Fetch(payload) as HttpContext;
-
- if (context == null)
+ if (!(this.startContextFetcher.Fetch(payload) is HttpContext context))
  {
  AspNetCoreInstrumentationEventSource.Log.NullPayload(nameof(HttpInListener), nameof(this.OnStartActivity));
  return;
@@ -72,7 +70,7 @@ public override void OnStartActivity(Activity activity, object payload)
  // using the context extracted from w3ctraceparent header or
  // using the format TextFormat supports.
 
- var ctx = this.options.TextFormat.Extract(request, HttpRequestHeaderValuesGetter);
+ var ctx = this.options.TextFormat.Extract(default, request, HttpRequestHeaderValuesGetter);
 
  // Create a new activity with its parent set from the extracted context.
  // This makes the new activity as a "sibling" of the activity created by

src/OpenTelemetry.Shims.OpenTracing/TracerShim.cs

@@ -81,7 +81,7 @@ IEnumerable<string> GetCarrierKeyValue(Dictionary<string, IEnumerable<string>> s
  return value;
  }
 
- activityContext = this.textFormat.Extract(carrierMap, GetCarrierKeyValue);
+ activityContext = this.textFormat.Extract(default, carrierMap, GetCarrierKeyValue);
  }
 
  return !activityContext.IsValid() ? null : new SpanContextShim(new Trace.SpanContext(activityContext));
@@ -115,8 +115,7 @@ public void Inject<TCarrier>(
 
  if ((format == BuiltinFormats.TextMap || format == BuiltinFormats.HttpHeaders) && carrier is ITextMap textMapCarrier)
  {
- // Remove comment after spanshim changes
- // this.textFormat.Inject(shim.SpanContext, textMapCarrier, (instrumentation, key, value) => instrumentation.Set(key, value));
+ this.textFormat.Inject(shim.SpanContext, textMapCarrier, (instrumentation, key, value) => instrumentation.Set(key, value));
  }
  }
  }