public static IReadOnlyList <IFieldExpression> Gather(Expression node)
{
var gatherer = new SerializationExpressionGatherer();
gatherer.Visit(node);
return(gatherer._fieldExpressions);
}
public static RenderedProjectionDefinition <TProjection> Translate <TDocument, TProjection>(Expression <Func <TDocument, TProjection> > projector, IBsonSerializer <TDocument> parameterSerializer, IBsonSerializerRegistry serializerRegistry)
{
var bindingContext = new PipelineBindingContext(serializerRegistry);
var documentExpression = new DocumentExpression(parameterSerializer);
bindingContext.AddExpressionMapping(projector.Parameters[0], documentExpression);
var node = PartialEvaluator.Evaluate(projector.Body);
node = Transformer.Transform(node);
node = bindingContext.Bind(node, isClientSideProjection: true);
node = FieldExpressionFlattener.FlattenFields(node);
BsonDocument projectionDocument = null;
IBsonSerializer <TProjection> serializer;
if (node is DocumentExpression)
{
serializer = new ProjectingDeserializer <TDocument, TProjection>(parameterSerializer, projector.Compile());
}
else
{
var candidateFields = SerializationExpressionGatherer.Gather(node);
var fields = GetUniqueFieldsByHierarchy(candidateFields);
var serializationInfo = fields.Select(x => new BsonSerializationInfo(x.FieldName, x.Serializer, x.Serializer.ValueType)).ToList();
var projectedObjectExpression = Expression.Parameter(typeof(ProjectedObject), "document");
var translator = new FindProjectionTranslator(documentExpression, projectedObjectExpression, fields);
var translated = translator.Visit(node);
if (translator._fullDocument)
{
serializer = new ProjectingDeserializer <TDocument, TProjection>(parameterSerializer, projector.Compile());
}
else
{
var newProjector = Expression.Lambda <Func <ProjectedObject, TProjection> >(
translated,
projectedObjectExpression);
projectionDocument = GetProjectionDocument(serializationInfo);
var projectedObjectSerializer = new ProjectedObjectDeserializer(serializationInfo);
serializer = new ProjectingDeserializer <ProjectedObject, TProjection>(projectedObjectSerializer, newProjector.Compile());
}
}
return(new RenderedProjectionDefinition <TProjection>(projectionDocument, serializer));
}
protected override Expression VisitMethodCall(MethodCallExpression node)
{
if (!IsLinqMethod(node, "Select", "SelectMany"))
{
return(base.VisitMethodCall(node));
}
var source = node.Arguments[0] as SerializationExpression;
if (source != null)
{
var fields = SerializationExpressionGatherer.Gather(node.Arguments[1]);
if (fields.Any(x => x.SerializationInfo.ElementName.StartsWith(source.SerializationInfo.ElementName)))
{
_serializationExpressions.AddRange(fields);
return(node);
}
}
return(base.VisitMethodCall(node));
}
public static RenderedProjectionDefinition <TProjection> Translate <TDocument, TProjection>(Expression <Func <TDocument, TProjection> > projector, IBsonSerializer <TDocument> parameterSerializer)
{
var parameterSerializationInfo = new BsonSerializationInfo(null, parameterSerializer, parameterSerializer.ValueType);
var parameterExpression = new SerializationExpression(projector.Parameters[0], parameterSerializationInfo);
var binder = new SerializationInfoBinder(BsonSerializer.SerializerRegistry);
binder.RegisterParameterReplacement(projector.Parameters[0], parameterExpression);
var normalizedBody = Transformer.Transform(projector.Body);
var evaluatedBody = PartialEvaluator.Evaluate(normalizedBody);
var boundExpression = binder.Bind(evaluatedBody);
var candidateFields = SerializationExpressionGatherer.Gather(boundExpression);
var fields = GetUniqueFieldsByHierarchy(candidateFields);
var serializationInfo = fields.Select(x => x.SerializationInfo).ToList();
var replacementParameter = Expression.Parameter(typeof(ProjectedObject), "document");
var translator = new FindProjectionTranslator(projector.Parameters[0], replacementParameter, fields);
var newProjector = Expression.Lambda <Func <ProjectedObject, TProjection> >(
translator.Visit(boundExpression),
replacementParameter);
BsonDocument projectionDocument;
IBsonSerializer <TProjection> serializer;
if (translator._fullDocument)
{
projectionDocument = null;
serializer = new ProjectingDeserializer <TDocument, TProjection>(parameterSerializer, projector.Compile());
}
else
{
projectionDocument = GetProjectionDocument(serializationInfo);
var projectedObjectSerializer = new ProjectedObjectDeserializer(serializationInfo);
serializer = new ProjectingDeserializer <ProjectedObject, TProjection>(projectedObjectSerializer, newProjector.Compile());
}
return(new RenderedProjectionDefinition <TProjection>(projectionDocument, serializer));
}
