Fixed BsonDocumentWrapper and added comments

Author: papafe

src/MongoDB.Bson/ObjectModel/BsonDocumentWrapper.cs

@@ -37,14 +37,15 @@ public class BsonDocumentWrapper : MaterializedOnDemandBsonDocument
         // private fields
         private readonly object _wrapped;
         private readonly IBsonSerializer _serializer;
+        private readonly IBsonSerializationDomain _serializationDomain;
 
         // constructors
         /// <summary>
         /// Initializes a new instance of the <see cref="BsonDocumentWrapper"/> class.
         /// </summary>
         /// <param name="value">The value.</param>
         public BsonDocumentWrapper(object value)
-            : this(value, UndiscriminatedActualTypeSerializer<object>.Instance)
+            : this(value, UndiscriminatedActualTypeSerializer<object>.Instance, BsonSerializer.DefaultSerializationDomain)
         {
         }
 
@@ -54,14 +55,15 @@ public BsonDocumentWrapper(object value)
         /// <param name="value">The value.</param>
         /// <param name="serializer">The serializer.</param>
         public BsonDocumentWrapper(object value, IBsonSerializer serializer)
+            : this(value, serializer, BsonSerializer.DefaultSerializationDomain)
         {
-            if (serializer == null)
-            {
-                throw new ArgumentNullException("serializer");
-            }
+        }
 
+        internal BsonDocumentWrapper(object value, IBsonSerializer serializer, IBsonSerializationDomain serializationDomain)
+        {
+            _serializer = serializer ?? throw new ArgumentNullException(nameof(serializer));
+            _serializationDomain = serializationDomain;
             _wrapped = value;
-            _serializer = serializer;
         }
 
         // public properties
@@ -84,6 +86,7 @@ public object Wrapped
             get { return _wrapped; }
         }
 
+        // DOMAIN-API All the various Create methods are used only in testing, the version without the domain should be removed.
         // public static methods
         /// <summary>
         /// Creates a new instance of the BsonDocumentWrapper class.
@@ -111,7 +114,7 @@ public static BsonDocumentWrapper Create(Type nominalType, object value) =>
         internal static BsonDocumentWrapper Create(Type nominalType, object value, IBsonSerializationDomain domain)
         {
             var serializer = domain.LookupSerializer(nominalType);
-            return new BsonDocumentWrapper(value, serializer);
+            return new BsonDocumentWrapper(value, serializer, domain);
         }
 
         /// <summary>
@@ -139,7 +142,7 @@ internal static IEnumerable<BsonDocumentWrapper> CreateMultiple<TNominalType>(IE
             }
 
             var serializer = domain.LookupSerializer(typeof(TNominalType));
-            return values.Select(v => new BsonDocumentWrapper(v, serializer));
+            return values.Select(v => new BsonDocumentWrapper(v, serializer, domain));
         }
 
         /// <summary>
@@ -171,7 +174,7 @@ internal static IEnumerable<BsonDocumentWrapper> CreateMultiple(Type nominalType
             }
 
             var serializer = domain.LookupSerializer(nominalType);
-            return values.Cast<object>().Select(v => new BsonDocumentWrapper(v, serializer));
+            return values.Cast<object>().Select(v => new BsonDocumentWrapper(v, serializer, domain));
         }
 
         // public methods
@@ -191,7 +194,8 @@ public override BsonValue Clone()
             {
                 return new BsonDocumentWrapper(
                     _wrapped,
-                    _serializer);
+                    _serializer,
+                    _serializationDomain);
             }
         }
 
@@ -206,8 +210,7 @@ protected override IEnumerable<BsonElement> Materialize()
             var writerSettings = BsonDocumentWriterSettings.Defaults;
             using (var bsonWriter = new BsonDocumentWriter(bsonDocument, writerSettings))
             {
-                //QUESTION Is it correct we only need a default domain here?
-                var context = BsonSerializationContext.CreateRoot(bsonWriter, BsonSerializer.DefaultSerializationDomain);
+                var context = BsonSerializationContext.CreateRoot(bsonWriter, _serializationDomain);
                 _serializer.Serialize(context, _wrapped);
             }
 

src/MongoDB.Bson/Serialization/BsonSerializationInfo.cs

@@ -108,6 +108,20 @@ public Type NominalType
             get { return _nominalType; }
         }
 
+        /* DOMAIN-API Both DeserializeValue and SerializeValue should be changed to accept a domain as input.
+         * DeserializeValue is only used by BsonDocumentBackedClass
+         * SerializeValue is used by BsonDocumentBackedClass and also by GridFS buckets to serialize the Id field.
+         *
+         * BsonDocumentBackedClass is the base for a few classes in the driver (GridFSFileInfo, ChangeStreamPreAndPostImagesOptions, etc).
+         * For those classes we can use the default domain, as no custom serialization is expected.
+         *
+         * GridFS buckets on the other hand allow the user to specify a custom Id serializer, which may require a custom domain.
+         * But looking at the docs it seems that ObjectId is the preferred type for the Id field, and I suppose there won't need to be custom serialization.
+         *
+         * Thus for now I think it's acceptable to use the default domain in SerializeValue too, but we should revisit this decision at a later time.
+         */
+
+        //DOMAIN-API This method should be changed to accept a domain as input.
         /// <summary>
         /// Deserializes the value.
         /// </summary>
@@ -118,7 +132,6 @@ public object DeserializeValue(BsonValue value)
             var tempDocument = new BsonDocument("value", value);
             using (var reader = new BsonDocumentReader(tempDocument))
             {
-                //QUESTION Is it correct we only need a default domain here?
                 var context = BsonDeserializationContext.CreateRoot(reader, BsonSerializer.DefaultSerializationDomain);
                 reader.ReadStartDocument();
                 reader.ReadName("value");
@@ -145,6 +158,7 @@ obj is BsonSerializationInfo other &&
         /// <inheritdoc/>
         public override int GetHashCode() => 0;
 
+        //DOMAIN-API This method should be changed to accept a domain as input.
         /// <summary>
         /// Serializes the value.
         /// </summary>
@@ -155,7 +169,6 @@ public BsonValue SerializeValue(object value)
             var tempDocument = new BsonDocument();
             using (var bsonWriter = new BsonDocumentWriter(tempDocument))
             {
-                //QUESTION Is it correct we only need a default domain here?
                 var context = BsonSerializationContext.CreateRoot(bsonWriter, BsonSerializer.DefaultSerializationDomain);
                 bsonWriter.WriteStartDocument();
                 bsonWriter.WriteName("value");

src/MongoDB.Driver/Command.cs

@@ -221,12 +221,13 @@ public IBsonSerializer<TResult> ResultSerializer
             get { return _resultSerializer; }
         }
 
+        // DOMAIN-API: We need to pass also the domain here (or only the domain)
         /// <inheritdoc />
         public override RenderedCommand<TResult> Render(IBsonSerializerRegistry serializerRegistry)
         {
             var serializer = serializerRegistry.GetSerializer(_obj.GetType());
             return new RenderedCommand<TResult>(
-                new BsonDocumentWrapper(_obj, serializer),
+                new BsonDocumentWrapper(_obj, serializer, BsonSerializer.DefaultSerializationDomain),
                 _resultSerializer ?? serializerRegistry.GetSerializer<TResult>());
         }
     }

src/MongoDB.Driver/Core/WireProtocol/CommandUsingQueryMessageWireProtocol.cs

@@ -185,7 +185,7 @@ private BsonDocument CombineCommandWithPayloads(ConnectionDescription connection
             }
 
             var payloadAppendingSerializer = new ElementAppendingSerializer<BsonDocument>(BsonDocumentSerializer.Instance, extraElements);
-            return new BsonDocumentWrapper(_command, payloadAppendingSerializer);
+            return new BsonDocumentWrapper(_command, payloadAppendingSerializer, _serializationDomain);
         }
 
         private BsonArray CreatePayloadArray(Type1CommandMessageSection payload, ConnectionDescription connectionDescription)
@@ -200,7 +200,7 @@ private BsonArray CreatePayloadArray(Type1CommandMessageSection payload, Connect
                 payloadSerializer = CreateFixedCountPayloadSerializer(payload);
             }
 
-            var documents = new BsonDocumentWrapper(payload.Documents, payloadSerializer);
+            var documents = new BsonDocumentWrapper(payload.Documents, payloadSerializer, _serializationDomain);
             return new BsonArray { documents };
         }
 
@@ -377,7 +377,7 @@ private BsonDocument WrapCommandForQueryMessage(BsonDocument command, Connection
                 extraElements.Add(clusterTime);
             }
             var appendExtraElementsSerializer = new ElementAppendingSerializer<BsonDocument>(BsonDocumentSerializer.Instance, extraElements);
-            var commandWithExtraElements = new BsonDocumentWrapper(command, appendExtraElementsSerializer);
+            var commandWithExtraElements = new BsonDocumentWrapper(command, appendExtraElementsSerializer, _serializationDomain);
 
             var serverType = connectionDescription != null ? connectionDescription.HelloResult.ServerType : ServerType.Unknown;
             var readPreferenceDocument = QueryHelper.CreateReadPreferenceDocument(serverType, _readPreference, out secondaryOk);

src/MongoDB.Driver/Core/WireProtocol/Messages/Encoders/JsonEncoders/ReplyMessageJsonEncoder.cs

@@ -104,7 +104,7 @@ public void WriteMessage(ReplyMessage<TDocument> message)
             BsonArray documents = null;
             if (!message.QueryFailure)
             {
-                var wrappers = message.Documents.Select(d => new BsonDocumentWrapper(d, _serializer));
+                var wrappers = message.Documents.Select(d => new BsonDocumentWrapper(d, _serializer, _serializationDomain));
                 documents = new BsonArray(wrappers);
             }
 

src/MongoDB.Driver/FilterDefinition.cs

@@ -275,7 +275,7 @@ public object Object
         public override BsonDocument Render(RenderArgs<TDocument> args)
         {
             var serializer = args.SerializerRegistry.GetSerializer(_obj.GetType());
-            return new BsonDocumentWrapper(_obj, serializer);
+            return new BsonDocumentWrapper(_obj, serializer, args.SerializationDomain);
         }
     }
 }

src/MongoDB.Driver/MongoCollectionImpl.cs

@@ -679,7 +679,7 @@ private WriteRequest ConvertWriteModelToWriteRequest(WriteModel<TDocument> model
                     {
                         _documentSerializer.SetDocumentIdIfMissing(this, insertOneModel.Document, renderArgs.SerializationDomain);
                     }
-                    return new InsertRequest(new BsonDocumentWrapper(insertOneModel.Document, _documentSerializer))
+                    return new InsertRequest(new BsonDocumentWrapper(insertOneModel.Document, _documentSerializer, renderArgs.SerializationDomain))
                     {
                         CorrelationId = index
                     };
@@ -706,7 +706,7 @@ private WriteRequest ConvertWriteModelToWriteRequest(WriteModel<TDocument> model
                     return new UpdateRequest(
                         UpdateType.Replacement,
                         replaceOneModel.Filter.Render(renderArgs),
-                        new BsonDocumentWrapper(replaceOneModel.Replacement, _documentSerializer))
+                        new BsonDocumentWrapper(replaceOneModel.Replacement, _documentSerializer, renderArgs.SerializationDomain))
                     {
                         Collation = replaceOneModel.Collation,
                         CorrelationId = index,
@@ -1010,7 +1010,7 @@ private FindOneAndReplaceOperation<TProjection> CreateFindOneAndReplaceOperation
             return new FindOneAndReplaceOperation<TProjection>(
                 _collectionNamespace,
                 filter.Render(renderArgs),
-                new BsonDocumentWrapper(replacement, _documentSerializer),
+                new BsonDocumentWrapper(replacement, _documentSerializer, renderArgs.SerializationDomain),
                 new FindAndModifyValueDeserializer<TProjection>(renderedProjection.ProjectionSerializer),
                 _messageEncoderSettings,
                 _settings.SerializationDomain)

src/MongoDB.Driver/ProjectionDefinition.cs

@@ -393,7 +393,7 @@ public object Object
         public override BsonDocument Render(RenderArgs<TSource> args)
         {
             var serializer = args.SerializerRegistry.GetSerializer(_obj.GetType());
-            return new BsonDocumentWrapper(_obj, serializer);
+            return new BsonDocumentWrapper(_obj, serializer, args.SerializationDomain);
         }
     }
 
@@ -439,7 +439,7 @@ public override RenderedProjectionDefinition<TProjection> Render(RenderArgs<TSou
         {
             var serializer = args.SerializerRegistry.GetSerializer(_obj.GetType());
             return new RenderedProjectionDefinition<TProjection>(
-                new BsonDocumentWrapper(_obj, serializer),
+                new BsonDocumentWrapper(_obj, serializer, args.SerializationDomain),
                 _projectionSerializer ?? args.GetSerializer<TProjection>());
         }
     }

src/MongoDB.Driver/SortDefinition.cs

@@ -178,7 +178,7 @@ public object Object
         public override BsonDocument Render(RenderArgs<TDocument> args)
         {
             var serializer = args.SerializerRegistry.GetSerializer(_obj.GetType());
-            return new BsonDocumentWrapper(_obj, serializer);
+            return new BsonDocumentWrapper(_obj, serializer, args.SerializationDomain);
         }
     }
 }

src/MongoDB.Driver/UpdateDefinition.cs

@@ -241,7 +241,7 @@ public object Object
         public override BsonValue Render(RenderArgs<TDocument> args)
         {
             var serializer = args.SerializerRegistry.GetSerializer(_obj.GetType());
-            return new BsonDocumentWrapper(_obj, serializer);
+            return new BsonDocumentWrapper(_obj, serializer, args.SerializationDomain);
         }
     }
 }