public override Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
// OfType is two operations in one. First we create WhereExpression
// for the test. Second, we want to issue a conversion projection
// using the selector parameter of a ProjectionExpression such that
// the conversion will be propogated to all future expressions.
var newType = node.Method.GetGenericArguments()[0];
var parameter = Expression.Parameter(projection.Projector.Type);
var predicate = Expression.Lambda(
Expression.TypeIs(parameter, newType),
parameter);
var source = BindPredicate(projection, context, projection.Source, predicate);
var serializer = context.SerializerRegistry.GetSerializer(newType);
var info = new BsonSerializationInfo(null, serializer, newType);
var projector = new SerializationExpression(
Expression.Convert(projection.Projector, newType),
info);
return new ProjectionExpression(
source,
projector);
}
public override Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
LambdaExpression aggregator;
if (node.Method.Name.EndsWith("Async"))
{
aggregator = CreateAsyncAggregator();
}
else
{
aggregator = CreateSyncAggregator();
}
var source = projection.Source;
var argument = arguments.FirstOrDefault();
if (argument != null && ExtensionExpressionVisitor.IsLambda(argument))
{
source = BindPredicate(projection, context, source, argument);
}
source = new TakeExpression(source, 1);
var serializer = context.SerializerRegistry.GetSerializer(typeof(int));
var accumulator = new AccumulatorExpression(typeof(int), AccumulatorType.Count, null);
var serializationAccumulator = new SerializationExpression(
accumulator,
new BsonSerializationInfo("__agg0", serializer, serializer.ValueType));
var rootAccumulator = new RootAccumulatorExpression(source, serializationAccumulator);
return new ProjectionExpression(
rootAccumulator,
serializationAccumulator,
aggregator);
}
public Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
return new ProjectionExpression(
new SkipExpression(
projection.Source,
(int)((ConstantExpression)arguments.Single()).Value),
projection.Projector,
projection.Aggregator);
}
public Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
var distinct = new DistinctExpression(projection.Source, projection.Projector);
var serializer = SerializerBuilder.Build(projection.Projector, context.SerializerRegistry);
var info = new BsonSerializationInfo("_id", serializer, serializer.ValueType);
var projector = new SerializationExpression(projection.Projector, info);
return new ProjectionExpression(
distinct,
projector);
}
public Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
var id = BindId(projection, context, arguments.First());
var selector = BindSelector(projection, context, id, arguments.Last());
var projector = BuildProjector(selector, context);
return new ProjectionExpression(
new GroupByWithResultSelectorExpression(
projection.Source,
selector),
projector);
}
protected static Expression BindPredicate(ProjectionExpression projection, ProjectionBindingContext context, Expression source, Expression argument)
{
// this is actually a predicate that needs to be rendered as a WhereExpression
var lambda = ExtensionExpressionVisitor.GetLambda(argument);
var binder = new AccumulatorBinder(context.GroupMap, context.SerializerRegistry);
binder.RegisterParameterReplacement(lambda.Parameters[0], projection.Projector);
var predicate = binder.Bind(lambda.Body);
source = new WhereExpression(
source,
predicate);
return source;
}
public Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
var collectionLambda = ExtensionExpressionVisitor.GetLambda(arguments.First());
var binder = new AccumulatorBinder(context.GroupMap, context.SerializerRegistry);
binder.RegisterParameterReplacement(collectionLambda.Parameters[0], projection.Projector);
var collectionSelector = binder.Bind(collectionLambda.Body) as SerializationExpression;
if (collectionSelector == null)
{
var message = string.Format("Unable to determine the collection selector in the tree: {0}", node.ToString());
throw new NotSupportedException(message);
}
var collectionArraySerializer = collectionSelector.SerializationInfo.Serializer as IBsonArraySerializer;
BsonSerializationInfo collectionItemSerializationInfo;
if (collectionArraySerializer == null || !collectionArraySerializer.TryGetItemSerializationInfo(out collectionItemSerializationInfo))
{
var message = string.Format("The collection selector's serializer must implement IBsonArraySerializer: {0}", node.ToString());
throw new NotSupportedException(message);
}
Expression resultSelector;
if (arguments.Count() == 2)
{
var resultLambda = ExtensionExpressionVisitor.GetLambda(arguments.Last());
binder.RegisterParameterReplacement(resultLambda.Parameters[0], projection.Projector);
binder.RegisterParameterReplacement(
resultLambda.Parameters[1],
new SerializationExpression(
resultLambda.Parameters[1],
collectionItemSerializationInfo.WithNewName(collectionSelector.SerializationInfo.ElementName)));
resultSelector = binder.Bind(resultLambda.Body);
}
else
{
resultSelector = new SerializationExpression(
collectionSelector,
collectionItemSerializationInfo.WithNewName(collectionSelector.SerializationInfo.ElementName));
}
var projector = BuildProjector(resultSelector, context);
return new ProjectionExpression(
new SelectManyExpression(
projection.Source,
collectionSelector,
resultSelector),
projector);
}
public Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
var lambda = ExtensionExpressionVisitor.GetLambda(arguments.Single());
var binder = new AccumulatorBinder(context.GroupMap, context.SerializerRegistry);
binder.RegisterParameterReplacement(lambda.Parameters[0], projection.Projector);
var predicate = binder.Bind(lambda.Body);
return new ProjectionExpression(
new WhereExpression(
projection.Source,
predicate),
projection.Projector,
projection.Aggregator);
}
public Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
List<KeyValuePair<Registration, IMethodCallBinder>> namedBinders;
if (!_binders.TryGetValue(node.Method.Name, out namedBinders))
{
return null;
}
var binder = namedBinders.Where(x => x.Key.Filter(node)).Select(x => x.Value).FirstOrDefault();
if (binder == null)
{
return null;
}
return binder.Bind(projection, context, node, arguments);
}
private GroupIdExpression BindId(ProjectionExpression projection, ProjectionBindingContext context, Expression node)
{
var lambda = ExtensionExpressionVisitor.GetLambda(node);
var binder = new AccumulatorBinder(context.GroupMap, context.SerializerRegistry);
binder.RegisterParameterReplacement(lambda.Parameters[0], projection.Projector);
var selector = binder.Bind(lambda.Body);
if (!(selector is ISerializationExpression))
{
var serializer = SerializerBuilder.Build(selector, context.SerializerRegistry);
selector = new SerializationExpression(
selector,
new BsonSerializationInfo(null, serializer, serializer.ValueType));
}
return new GroupIdExpression(selector, ((ISerializationExpression)selector).SerializationInfo);
}
public override Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
var aggregator = CreateAggregator(node.Method.Name, projection.Projector.Type);
var source = projection.Source;
var argument = arguments.FirstOrDefault();
if (argument != null && ExtensionExpressionVisitor.IsLambda(argument))
{
source = BindPredicate(projection, context, source, argument);
}
source = new TakeExpression(source, 2);
return new ProjectionExpression(
source,
projection.Projector,
aggregator);
}
protected internal override Expression VisitProjection(ProjectionExpression node)
{
var model = QueryableExecutionModelBuilder.Build(node, _serializerRegistry);
Expression executor;
if (_cancellationToken != null)
{
// we are async
executor = Expression.Call(
_provider,
"ExecuteAsync",
Type.EmptyTypes,
Expression.Constant(model, typeof(QueryableExecutionModel)),
_cancellationToken);
if (node.Aggregator != null)
{
executor = Expression.Invoke(
node.Aggregator,
Expression.Convert(executor, node.Aggregator.Parameters[0].Type),
_cancellationToken);
}
}
else
{
// we are sync
executor = Expression.Call(
_provider,
"Execute",
Type.EmptyTypes,
Expression.Constant(model, typeof(QueryableExecutionModel)));
if (node.Aggregator != null)
{
executor = Expression.Invoke(
node.Aggregator,
Expression.Convert(executor, node.Aggregator.Parameters[0].Type));
}
}
return executor;
}
public Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
var source = projection.Source;
var sortClauses = GatherPreviousSortClauses(projection.Source, out source);
var lambda = ExtensionExpressionVisitor.GetLambda(arguments.Single());
var binder = new AccumulatorBinder(context.GroupMap, context.SerializerRegistry);
binder.RegisterParameterReplacement(lambda.Parameters[0], projection.Projector);
var direction = GetDirection(node.Method.Name);
var ordering = binder.Bind(lambda.Body);
sortClauses.Add(new SortClause(ordering, direction));
return new ProjectionExpression(
new OrderByExpression(
source,
sortClauses),
projection.Projector,
projection.Aggregator);
}
public Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments)
{
var lambda = ExtensionExpressionVisitor.GetLambda(arguments.Single());
if (lambda.Body == lambda.Parameters[0])
{
// we can ignore identity projections
return projection;
}
var binder = new AccumulatorBinder(context.GroupMap, context.SerializerRegistry);
binder.RegisterParameterReplacement(lambda.Parameters[0], projection.Projector);
var selector = binder.Bind(lambda.Body);
var projector = BuildProjector(selector, context);
return new ProjectionExpression(
new SelectExpression(
projection.Source,
selector),
projector);
}
private Expression BindSelector(ProjectionExpression projection, ProjectionBindingContext context, Expression id, Expression node)
{
var lambda = ExtensionExpressionVisitor.GetLambda(node);
var binder = new AccumulatorBinder(context.GroupMap, context.SerializerRegistry);
var serializer = SerializerBuilder.Build(projection.Projector, context.SerializerRegistry);
var sequenceSerializer = (IBsonSerializer)Activator.CreateInstance(
typeof(ArraySerializer<>).MakeGenericType(projection.Projector.Type),
new object[] { serializer });
var sequenceInfo = new BsonSerializationInfo(
null,
sequenceSerializer,
sequenceSerializer.ValueType);
var sequenceExpression = new SerializationExpression(
lambda.Parameters[1],
sequenceInfo);
binder.RegisterParameterReplacement(lambda.Parameters[0], id);
binder.RegisterParameterReplacement(lambda.Parameters[1], sequenceExpression);
var correlationId = Guid.NewGuid();
context.GroupMap.Add(sequenceExpression, correlationId);
var bound = binder.Bind(lambda.Body);
return CorrelatedAccumulatorRemover.Remove(bound, correlationId);
}
private void VisitProjection(ProjectionExpression node)
{
Visit(node.Source);
var serializationExpression = node.Projector as ISerializationExpression;
if (serializationExpression != null)
{
var info = serializationExpression.SerializationInfo;
if (info.ElementName != null)
{
// We are projecting a field, however the server only responds
// with documents. So we'll create a projector that reads a document
// and then projects the field out of it.
var parameter = Expression.Parameter(typeof(ProjectedObject), "document");
var projector = Expression.Lambda(
Expression.Call(
parameter,
"GetValue",
new Type[] { info.Serializer.ValueType },
Expression.Constant(info.ElementName),
Expression.Constant(info.Serializer.ValueType.GetDefaultValue(), typeof(object))),
parameter);
var innerSerializer = new ProjectedObjectDeserializer(new[] { info });
_serializer = (IBsonSerializer)Activator.CreateInstance(
typeof(ProjectingDeserializer<,>).MakeGenericType(typeof(ProjectedObject), info.Serializer.ValueType),
new object[]
{
innerSerializer,
projector.Compile()
});
return;
}
}
_serializer = SerializerBuilder.Build(node.Projector, _serializerRegistry);
}
protected internal override Expression VisitProjection(ProjectionExpression node)
{
_lookup = AccumulatorGatherer.Gather(node.Source).ToLookup(x => x.CorrelationId);
return base.VisitProjection(node);
}
public abstract Expression Bind(ProjectionExpression projection, ProjectionBindingContext context, MethodCallExpression node, IEnumerable<Expression> arguments);
protected internal virtual Expression VisitProjection(ProjectionExpression node)
{
return node.Update(
Visit(node.Source),
Visit(node.Projector),
VisitAndConvert<LambdaExpression>(node.Aggregator, "VisitPipeline"));
}
