Refactor client state persistence and add more tests (#3303)

* State handling and better serialization
* Nullable for almost everything  inclient library
* Additional testing of session

Author: marcschier

Applications/ConsoleReferenceClient/ClientSamples.cs

@@ -258,7 +258,7 @@ public async Task BrowseAsync(ISession session, CancellationToken ct = default)
             try
             {
                 // Create a Browser object
-                var browser = new Browser(session, m_telemetry)
+                var browser = new Browser(session)
                 {
                     // Set browse parameters
                     BrowseDirection = BrowseDirection.Forward,
@@ -1192,7 +1192,7 @@ private static Task FetchReferenceIdTypesAsync(
         /// <summary>
         /// Output all values as JSON.
         /// </summary>
-        public async Task<(DataValueCollection, IList<ServiceResult>)> ReadAllValuesAsync(
+        public async Task<ResultSet<DataValue>> ReadAllValuesAsync(
             IUAClient uaClient,
             NodeIdCollection variableIds,
             CancellationToken ct = default)
@@ -1278,7 +1278,7 @@ private static Task FetchReferenceIdTypesAsync(
                 }
             } while (retrySingleRead);
 
-            return (values, errors);
+            return ResultSet.From(values, errors);
         }
 
         /// <summary>

Applications/ConsoleReferenceClient/Program.cs

@@ -570,8 +570,10 @@ r is VariableNode v &&
 
                             if (jsonvalues && variableIds != null)
                             {
-                                (DataValueCollection allValues, IList<ServiceResult> results)
-                                    = await samples
+                                (
+                                    IReadOnlyList<DataValue> allValues,
+                                    IReadOnlyList<ServiceResult> results
+                                ) = await samples
                                     .ReadAllValuesAsync(uaClient, variableIds, ct)
                                     .ConfigureAwait(false);
                             }

Applications/ConsoleReferenceClient/UAClient.cs

@@ -245,7 +245,7 @@ public async Task<bool> ConnectAsync(
                         endpointConfiguration);
 
                     // Create the session factory. - we could take it as parameter or as member
-                    var sessionFactory = new TraceableSessionFactory(m_telemetry);
+                    var sessionFactory = new DefaultSessionFactory(m_telemetry);
 
                     // Create the session
                     ISession session = await sessionFactory

Libraries/Opc.Ua.Client.ComplexTypes/TypeResolver/NodeCacheResolver.cs

@@ -52,7 +52,9 @@ public class NodeCacheResolver : IComplexTypeResolver
         /// Initializes the type resolver with a session to load the custom type information.
         /// </summary>
         public NodeCacheResolver(ISession session, ITelemetryContext telemetry)
-            : this(new LruNodeCache(session, telemetry), telemetry)
+            : this(session, new LruNodeCache(
+                new NodeCacheContext(session),
+                telemetry), telemetry)
         {
         }
 
@@ -64,7 +66,10 @@ public NodeCacheResolver(
             ISession session,
             TimeSpan cacheExpiry,
             ITelemetryContext telemetry)
-            : this(new LruNodeCache(session, telemetry, cacheExpiry), telemetry)
+            : this(session, new LruNodeCache(
+                new NodeCacheContext(session),
+                telemetry,
+                cacheExpiry), telemetry)
         {
         }
 
@@ -76,17 +81,24 @@ public NodeCacheResolver(
             TimeSpan cacheExpiry,
             int capacity,
             ITelemetryContext telemetry)
-            : this(new LruNodeCache(session, telemetry, cacheExpiry, capacity), telemetry)
+            : this(session, new LruNodeCache(
+                new NodeCacheContext(session),
+                telemetry,
+                cacheExpiry,
+                capacity), telemetry)
         {
         }
 
         /// <summary>
         /// Initializes the type resolver with a session and lru cache to load the
         /// custom type information with the specified expiry and cache size.
         /// </summary>
-        public NodeCacheResolver(ILruNodeCache lruNodeCache, ITelemetryContext telemetry)
+        public NodeCacheResolver(
+            ISession session,
+            ILruNodeCache lruNodeCache,
+            ITelemetryContext telemetry)
         {
-            m_session = lruNodeCache.Session;
+            m_session = session;
             m_lruNodeCache = lruNodeCache;
             m_logger = telemetry.CreateLogger<NodeCacheResolver>();
             FactoryBuilder = m_session.Factory.Builder;