CorrelationContext -> Baggage

examples/MicroserviceExample/Utils/Messaging/MessageSender.cs

@@ -19,6 +19,7 @@
 using System.Diagnostics;
 using System.Text;
 using Microsoft.Extensions.Logging;
+using OpenTelemetry.Context;
 using OpenTelemetry.Context.Propagation;
 using RabbitMQ.Client;
 
@@ -61,7 +62,7 @@ public string SendMessage()
                     if (activity != null)
                     {
                         // Inject the ActivityContext into the message headers to propagate trace context to the receiving service.
-                        TextFormat.Inject(new PropagationContext(activity.Context, activity.Baggage), props, this.InjectTraceContextIntoBasicProperties);
+                        TextFormat.Inject(new PropagationContext(activity.Context, BaggageContext.Current), props, this.InjectTraceContextIntoBasicProperties);
 
                         // The OpenTelemetry messaging specification defines a number of attributes. These attributes are added here.
                         RabbitMqHelper.AddMessagingTags(activity);

src/OpenTelemetry.Api/Context/BaggageContext.cs

@@ -0,0 +1,241 @@
+// <copyright file="BaggageContext.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.Linq;
+
+namespace OpenTelemetry.Context
+{
+    /// <summary>
+    /// Baggage context.
+    /// </summary>
+    public readonly struct BaggageContext : IEquatable<BaggageContext>
+    {
+        private static readonly RuntimeContextSlot<BaggageContext> RuntimeContextSlot = RuntimeContext.RegisterSlot<BaggageContext>("otel.baggage_context");
+        private static readonly Dictionary<string, string> EmptyBaggage = new Dictionary<string, string>();
+
+        private readonly Dictionary<string, string> baggage;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BaggageContext"/> struct.
+        /// </summary>
+        /// <param name="baggage">Baggage key/value pairs.</param>
+        public BaggageContext(Dictionary<string, string> baggage = null)
+        {
+            this.baggage = baggage ?? EmptyBaggage;
+        }
+
+        /// <summary>
+        /// Gets or sets the current <see cref="BaggageContext"/>.
+        /// </summary>
+        public static BaggageContext Current
+        {
+            get => RuntimeContextSlot.Get();
+            set => RuntimeContextSlot.Set(value);
+        }
+
+        /// <summary>
+        /// Gets the number of key/value pairs in the baggage.
+        /// </summary>
+        public int Count => this.baggage.Count;
+
+        /// <summary>
+        /// Compare two entries of <see cref="BaggageContext"/> for equality.
+        /// </summary>
+        /// <param name="left">First Entry to compare.</param>
+        /// <param name="right">Second Entry to compare.</param>
+        public static bool operator ==(BaggageContext left, BaggageContext right) => left.Equals(right);
+
+        /// <summary>
+        /// Compare two entries of <see cref="BaggageContext"/> for not equality.
+        /// </summary>
+        /// <param name="left">First Entry to compare.</param>
+        /// <param name="right">Second Entry to compare.</param>
+        public static bool operator !=(BaggageContext left, BaggageContext right) => !(left == right);
+
+        /// <summary>
+        /// Returns the name/value pairs in the <see cref="BaggageContext"/>.
+        /// </summary>
+        /// <param name="baggageContext">Optional <see cref="BaggageContext"/>. <see cref="Current"/> is used if not specified.</param>
+        /// <returns>Baggage key/value pairs.</returns>
+        public static IReadOnlyDictionary<string, string> GetBaggage(BaggageContext baggageContext = default)
+            => baggageContext == default ? Current.GetBaggage() : baggageContext.GetBaggage();
+
+        /// <summary>
+        /// Returns the value associated with the given name, or <see langword="null"/> if the given name is not present.
+        /// </summary>
+        /// <param name="name">Baggage item name.</param>
+        /// <param name="baggageContext">Optional <see cref="BaggageContext"/>. <see cref="Current"/> is used if not specified.</param>
+        /// <returns>Baggage item or <see langword="null"/> if nothing was found.</returns>
+        public static object GetBaggage(string name, BaggageContext baggageContext = default)
+            => baggageContext == default ? Current.GetBaggage(name) : baggageContext.GetBaggage(name);
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> which contains the new key/value pair.
+        /// </summary>
+        /// <param name="name">Baggage item name.</param>
+        /// <param name="value">Baggage item value.</param>
+        /// <param name="baggageContext">Optional <see cref="BaggageContext"/>. <see cref="Current"/> is used if not specified.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public static BaggageContext SetBaggage(string name, string value, BaggageContext baggageContext = default)
+            => baggageContext == default ? Current.SetBaggage(name, value) : baggageContext.SetBaggage(name, value);
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> which contains the new key/value pair.
+        /// </summary>
+        /// <param name="baggageContext">Optional <see cref="BaggageContext"/>. <see cref="Current"/> is used if not specified.</param>
+        /// <param name="baggage">Baggage key/value pairs.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public static BaggageContext SetBaggage(BaggageContext baggageContext = default, params KeyValuePair<string, string>[] baggage)
+            => baggageContext == default ? Current.SetBaggage(baggage) : baggageContext.SetBaggage(baggage);
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> which contains the new key/value pair.
+        /// </summary>
+        /// <param name="baggage">Baggage key/value pairs.</param>
+        /// <param name="baggageContext">Optional <see cref="BaggageContext"/>. <see cref="Current"/> is used if not specified.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public static BaggageContext SetBaggage(IEnumerable<KeyValuePair<string, string>> baggage, BaggageContext baggageContext = default)
+           => baggageContext == default ? Current.SetBaggage(baggage) : baggageContext.SetBaggage(baggage);
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> with the key/value pair removed.
+        /// </summary>
+        /// <param name="name">Baggage item name.</param>
+        /// <param name="baggageContext">Optional <see cref="BaggageContext"/>. <see cref="Current"/> is used if not specified.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public static BaggageContext RemoveBaggage(string name, BaggageContext baggageContext = default)
+            => baggageContext == default ? Current.RemoveBaggage(name) : baggageContext.RemoveBaggage(name);
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> with all the key/value pairs removed.
+        /// </summary>
+        /// <param name="baggageContext">Optional <see cref="BaggageContext"/>. <see cref="Current"/> is used if not specified.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public static BaggageContext ClearBaggage(BaggageContext baggageContext = default)
+            => baggageContext == default ? Current.ClearBaggage() : baggageContext.ClearBaggage();
+
+        /// <summary>
+        /// Returns the name/value pairs in the <see cref="BaggageContext"/>.
+        /// </summary>
+        /// <returns>Baggage key/value pairs.</returns>
+        public IReadOnlyDictionary<string, string> GetBaggage()
+            => this.baggage;
+
+        /// <summary>
+        /// Returns the value associated with the given name, or <see langword="null"/> if the given name is not present.
+        /// </summary>
+        /// <param name="name">Baggage item name.</param>
+        /// <returns>Baggage item or <see langword="null"/> if nothing was found.</returns>
+        public object GetBaggage(string name)
+        {
+            return this.baggage.TryGetValue(name, out string value)
+                ? value
+                : null;
+        }
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> which contains the new key/value pair.
+        /// </summary>
+        /// <param name="name">Baggage item name.</param>
+        /// <param name="value">Baggage item value.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public BaggageContext SetBaggage(string name, string value)
+        {
+            var baggageContext = new BaggageContext(
+                new Dictionary<string, string>(this.baggage, StringComparer.OrdinalIgnoreCase)
+                {
+                    [name] = value,
+                });
+
+            Current = baggageContext;
+
+            return baggageContext;
+        }
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> which contains the new key/value pair.
+        /// </summary>
+        /// <param name="baggage">Baggage key/value pairs.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public BaggageContext SetBaggage(params KeyValuePair<string, string>[] baggage)
+            => this.SetBaggage((IEnumerable<KeyValuePair<string, string>>)baggage);
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> which contains the new key/value pair.
+        /// </summary>
+        /// <param name="baggage">Baggage key/value pairs.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public BaggageContext SetBaggage(IEnumerable<KeyValuePair<string, string>> baggage)
+        {
+            var newBaggage = new Dictionary<string, string>(this.baggage, StringComparer.OrdinalIgnoreCase);
+
+            foreach (var item in baggage)
+            {
+                newBaggage[item.Key] = item.Value;
+            }
+
+            var baggageContext = new BaggageContext(newBaggage);
+            Current = baggageContext;
+            return baggageContext;
+        }
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> with the key/value pair removed.
+        /// </summary>
+        /// <param name="name">Baggage item name.</param>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public BaggageContext RemoveBaggage(string name)
+        {
+            var baggage = new Dictionary<string, string>(this.baggage, StringComparer.OrdinalIgnoreCase);
+            baggage.Remove(name);
+            var baggageContext = new BaggageContext(baggage);
+            Current = baggageContext;
+            return baggageContext;
+        }
+
+        /// <summary>
+        /// Returns a new <see cref="BaggageContext"/> with all the key/value pairs removed.
+        /// </summary>
+        /// <returns>New <see cref="BaggageContext"/> containing the key/value pair.</returns>
+        public BaggageContext ClearBaggage()
+        {
+            var baggageContext = new BaggageContext(null);
+            Current = baggageContext;
+            return baggageContext;
+        }
+
+        /// <summary>
+        /// Returns an enumerator that iterates through the <see cref="BaggageContext"/>.
+        /// </summary>
+        /// <returns><see cref="Dictionary{TKey, TValue}.Enumerator"/>.</returns>
+        public Dictionary<string, string>.Enumerator GetEnumerator()
+            => this.baggage.GetEnumerator();
+
+        /// <inheritdoc/>
+        public bool Equals(BaggageContext other)
+            => this.baggage.SequenceEqual(other.baggage);
+
+        /// <inheritdoc/>
+        public override bool Equals(object obj)
+            => (obj is BaggageContext baggageContext) && this.Equals(baggageContext);
+
+        /// <inheritdoc/>
+        public override int GetHashCode()
+            => this.baggage.GetHashCode();
+    }
+}