Support ActivitySource in OPC UA client to enable tracing (.NET6) (#2251)

- Add traceable client session with factory to support ActivitySource on .NET 6
- Only traces the public API calls, inner calls are not yet supported.
- Uses the name: Opc.Ua.Client-TraceableSession-ActivitySource

Author: bhnaphade

Libraries/Opc.Ua.Client/DefaultSessionFactory.cs

@@ -29,6 +29,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -39,9 +40,21 @@ namespace Opc.Ua.Client
     /// </summary>
     public class DefaultSessionFactory : ISessionFactory
     {
+        /// <summary>
+        /// The default instance of the factory.
+        /// </summary>
+        public static readonly DefaultSessionFactory Instance = new DefaultSessionFactory();
+
+        /// <summary>
+        /// Force use of the default instance.
+        /// </summary>
+        protected DefaultSessionFactory()
+        {
+        }
+
         #region Public Methods
         /// <inheritdoc/>
-        public async Task<ISession> CreateAsync(
+        public async virtual Task<ISession> CreateAsync(
             ApplicationConfiguration configuration,
             ConfiguredEndpoint endpoint,
             bool updateBeforeConnect,
@@ -55,7 +68,7 @@ public async Task<ISession> CreateAsync(
         }
 
         /// <inheritdoc/>
-        public async Task<ISession> CreateAsync(
+        public async virtual Task<ISession> CreateAsync(
             ApplicationConfiguration configuration,
             ConfiguredEndpoint endpoint,
             bool updateBeforeConnect,
@@ -71,7 +84,7 @@ public async Task<ISession> CreateAsync(
         }
 
         /// <inheritdoc/>
-        public async Task<ISession> CreateAsync(
+        public async virtual Task<ISession> CreateAsync(
             ApplicationConfiguration configuration,
             ITransportWaitingConnection connection,
             ConfiguredEndpoint endpoint,
@@ -89,7 +102,7 @@ public async Task<ISession> CreateAsync(
         }
 
         /// <inheritdoc/>
-        public async Task<ISession> CreateAsync(
+        public async virtual Task<ISession> CreateAsync(
             ApplicationConfiguration configuration,
             ReverseConnectManager reverseConnectManager,
             ConfiguredEndpoint endpoint,
@@ -102,7 +115,6 @@ public async Task<ISession> CreateAsync(
             CancellationToken ct = default
             )
         {
-
             if (reverseConnectManager == null)
             {
                 return await CreateAsync(configuration, endpoint, updateBeforeConnect,
@@ -141,7 +153,25 @@ await endpoint.UpdateFromServerAsync(
         }
 
         /// <inheritdoc/>
-        public Task<ISession> RecreateAsync(ISession sessionTemplate)
+        public virtual ISession Create(
+           ApplicationConfiguration configuration,
+           ITransportChannel channel,
+           ConfiguredEndpoint endpoint,
+           X509Certificate2 clientCertificate,
+           EndpointDescriptionCollection availableEndpoints = null,
+           StringCollection discoveryProfileUris = null)
+        {
+            return Session.Create(configuration, channel, endpoint, clientCertificate, availableEndpoints, discoveryProfileUris);
+        }
+
+        /// <inheritdoc/>
+        public virtual Task<ITransportChannel> CreateChannelAsync(ApplicationConfiguration configuration, ITransportWaitingConnection connection, ConfiguredEndpoint endpoint, bool updateBeforeConnect, bool checkDomain)
+        {
+            return Session.CreateChannelAsync(configuration, connection, endpoint, updateBeforeConnect, checkDomain);
+        }
+
+        /// <inheritdoc/>
+        public virtual Task<ISession> RecreateAsync(ISession sessionTemplate)
         {
             if (!(sessionTemplate is Session template))
             {
@@ -152,7 +182,7 @@ public Task<ISession> RecreateAsync(ISession sessionTemplate)
         }
 
         /// <inheritdoc/>
-        public Task<ISession> RecreateAsync(ISession sessionTemplate, ITransportWaitingConnection connection)
+        public virtual Task<ISession> RecreateAsync(ISession sessionTemplate, ITransportWaitingConnection connection)
         {
             if (!(sessionTemplate is Session template))
             {

Libraries/Opc.Ua.Client/ISessionFactory.cs

@@ -28,6 +28,7 @@
  * ======================================================================*/
 
 using System.Collections.Generic;
+using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -131,6 +132,39 @@ Task<ISession> CreateAsync(
             IList<string> preferredLocales,
             CancellationToken ct = default);
 
+        /// <summary>
+        /// Creates a secure channel to the specified endpoint.
+        /// </summary>
+        /// <param name="configuration">The application configuration.</param>
+        /// <param name="connection">The client endpoint for the reverse connect.</param>
+        /// <param name="endpoint">A configured endpoint to connect to.</param> 
+        /// <param name="updateBeforeConnect">Update configuration based on server prior connect.</param>
+        /// <param name="checkDomain">Check that the certificate specifies a valid domain (computer) name.</param>
+        /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
+        Task<ITransportChannel> CreateChannelAsync(
+            ApplicationConfiguration configuration,
+            ITransportWaitingConnection connection,
+            ConfiguredEndpoint endpoint,
+            bool updateBeforeConnect,
+            bool checkDomain);
+
+        /// <summary>
+        /// Creates a new session with a server using the specified channel by invoking the CreateSession service.
+        /// </summary>
+        /// <param name="configuration">The configuration for the client application.</param>
+        /// <param name="channel">The channel for the server.</param>
+        /// <param name="endpoint">The endpoint for the server.</param>
+        /// <param name="clientCertificate">The certificate to use for the client.</param>
+        /// <param name="availableEndpoints">The list of available endpoints returned by server in GetEndpoints() response.</param>
+        /// <param name="discoveryProfileUris">The value of profileUris used in GetEndpoints() request.</param>
+        ISession Create(
+           ApplicationConfiguration configuration,
+           ITransportChannel channel,
+           ConfiguredEndpoint endpoint,
+           X509Certificate2 clientCertificate,
+           EndpointDescriptionCollection availableEndpoints = null,
+           StringCollection discoveryProfileUris = null);
+
         /// <summary>
         /// Recreates a session based on a specified template.
         /// </summary>

Libraries/Opc.Ua.Client/Session.cs

@@ -251,7 +251,7 @@ private void Initialize(
         /// </summary>
         private void Initialize()
         {
-            m_sessionFactory = new DefaultSessionFactory();
+            m_sessionFactory = DefaultSessionFactory.Instance;
             m_sessionTimeout = 0;
             m_namespaceUris = new NamespaceTable();
             m_serverUris = new StringTable();