public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.Is(EnumerableMethod.Select))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
var selectorLambda = (LambdaExpression)arguments[1];
var selectorParameter = selectorLambda.Parameters[0];
var selectorParameterSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var selectorParameterSymbol = context.CreateSymbol(selectorParameter, selectorParameterSerializer);
var selectorContext = context.WithSymbol(selectorParameterSymbol);
var translatedSelector = ExpressionToAggregationExpressionTranslator.Translate(selectorContext, selectorLambda.Body);
var ast = AstExpression.Map(
sourceTranslation.Ast,
selectorParameterSymbol.Var,
translatedSelector.Ast);
var serializer = IEnumerableSerializer.Create(translatedSelector.Serializer);
return(new AggregationExpression(expression, ast, serializer));
}
throw new ExpressionNotSupportedException(expression);
}
private static AstPipeline TranslateSelectManyWithCollectionSelectorAndNonIdentityResultSelector(
TranslationContext context,
AstPipeline pipeline,
AggregationExpression collectionSelectorTranslation,
LambdaExpression resultSelectorLambda)
{
var sourceSerializer = pipeline.OutputSerializer;
var collectionItemSerializer = ArraySerializerHelper.GetItemSerializer(collectionSelectorTranslation.Serializer);
var resultSelectorSourceParameterExpression = resultSelectorLambda.Parameters[0];
var resultSelectorSourceAst = AstExpression.Var("ROOT", isCurrent: true);
var resultSelectorSourceParameterSymbol = context.CreateSymbol(resultSelectorSourceParameterExpression, resultSelectorSourceAst, sourceSerializer, isCurrent: true);
var resultSelectorCollectionItemParameterExpression = resultSelectorLambda.Parameters[1];
var resultSelectorCollectionItemParameterSymbol = context.CreateSymbol(resultSelectorCollectionItemParameterExpression, collectionItemSerializer);
var resultSelectorContext = context.WithSymbols(resultSelectorSourceParameterSymbol, resultSelectorCollectionItemParameterSymbol);
var resultSelectorTranslation = ExpressionToAggregationExpressionTranslator.Translate(resultSelectorContext, resultSelectorLambda.Body);
var resultValueSerializer = resultSelectorTranslation.Serializer;
var resultWrappedValueSerializer = WrappedValueSerializer.Create("_v", resultValueSerializer);
var resultAst = AstExpression.Map(
input: collectionSelectorTranslation.Ast,
@as: resultSelectorCollectionItemParameterSymbol.Var,
@in: resultSelectorTranslation.Ast);
return(pipeline.AddStages(
resultWrappedValueSerializer,
AstStage.Project(
AstProject.Set("_v", resultAst),
AstProject.ExcludeId()),
AstStage.Unwind("_v")));
}
public static AggregationExpression Translate(TranslationContext context, NewExpression expression)
{
var listType = expression.Type;
var listItemType = listType.GetGenericArguments()[0];
var arguments = expression.Arguments;
if (arguments.Count == 1)
{
var argument = arguments[0];
var argumentType = argument.Type;
if (argumentType.IsConstructedGenericType && argumentType.GetGenericTypeDefinition() == typeof(IEnumerable <>))
{
var argumentItemType = argumentType.GetGenericArguments()[0];
if (argumentItemType == listItemType)
{
var collectionExpression = argument;
var collectionTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, collectionExpression);
var listSerializerType = typeof(EnumerableInterfaceImplementerSerializer <,>).MakeGenericType(listType, listItemType);
var listItemSerializer = ArraySerializerHelper.GetItemSerializer(collectionTranslation.Serializer);
var listSerializer = (IBsonSerializer)Activator.CreateInstance(listSerializerType, listItemSerializer);
return(new AggregationExpression(expression, collectionTranslation.Ast, listSerializer));
}
}
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.Is(EnumerableMethod.All))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
var predicateLambda = (LambdaExpression)arguments[1];
var predicateParameter = predicateLambda.Parameters[0];
var predicateParameterSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var predicateSymbol = context.CreateSymbol(predicateParameter, predicateParameterSerializer);
var predicateContext = context.WithSymbol(predicateSymbol);
var predicateTranslation = ExpressionToAggregationExpressionTranslator.Translate(predicateContext, predicateLambda.Body);
var ast = AstExpression.AllElementsTrue(
AstExpression.Map(
input: sourceTranslation.Ast,
@as: predicateSymbol.Var,
@in: predicateTranslation.Ast));
return(new AggregationExpression(expression, ast, new BooleanSerializer()));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(EnumerableMethod.First, EnumerableMethod.FirstWithPredicate, EnumerableMethod.Last, EnumerableMethod.LastWithPredicate))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
var array = sourceTranslation.Ast;
var itemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
if (method.IsOneOf(EnumerableMethod.FirstWithPredicate, EnumerableMethod.LastWithPredicate))
{
var predicateLambda = (LambdaExpression)arguments[1];
var predicateTranslation = ExpressionToAggregationExpressionTranslator.TranslateLambdaBody(context, predicateLambda, itemSerializer, asRoot: false);
var predicateParameter = predicateLambda.Parameters[0];
array = AstExpression.Filter(
input: array,
cond: predicateTranslation.Ast,
@as: predicateParameter.Name);
}
var ast = method.Name == "First" ? AstExpression.First(array) : AstExpression.Last(array);
return(new AggregationExpression(expression, ast, itemSerializer));
}
if (WindowMethodToAggregationExpressionTranslator.CanTranslate(expression))
{
return(WindowMethodToAggregationExpressionTranslator.Translate(context, expression));
}
throw new ExpressionNotSupportedException(expression);
}
public static AstFilterField Translate(TranslationContext context, BinaryExpression expression)
{
if (expression.NodeType == ExpressionType.ArrayIndex)
{
var arrayExpression = expression.Left;
var arrayField = ExpressionToFilterFieldTranslator.Translate(context, arrayExpression);
var indexExpression = expression.Right;
var index = indexExpression.GetConstantValue <int>(containingExpression: expression);
if (index < 0)
{
var reason = "negative indexes are not valid";
if (index == -1)
{
reason += ". To use the positional operator $ use FirstMatchingElement instead of an index value of -1"; // closing period is added by exception
}
throw new ExpressionNotSupportedException(expression, because: reason);
}
var itemSerializer = ArraySerializerHelper.GetItemSerializer(arrayField.Serializer);
return(arrayField.SubField(index.ToString(), itemSerializer));
}
throw new ExpressionNotSupportedException(expression);
}
public static AstFilter Translate(TranslationContext context, Expression arrayFieldExpression, ConstantExpression arrayConstantExpression)
{
var arrayFieldTranslation = ExpressionToFilterFieldTranslator.Translate(context, arrayFieldExpression);
var itemSerializer = ArraySerializerHelper.GetItemSerializer(arrayFieldTranslation.Serializer);
var values = (IEnumerable)arrayConstantExpression.Value;
var serializedValues = SerializationHelper.SerializeValues(itemSerializer, values);
return(AstFilter.In(arrayFieldTranslation, serializedValues));
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(__averageMethods))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
AstExpression ast;
if (method.IsOneOf(__averageWithSelectorMethods))
{
var selectorLambda = (LambdaExpression)arguments[1];
var selectorParameter = selectorLambda.Parameters[0];
var sourceItemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var selectorSymbol = context.CreateSymbol(selectorParameter, sourceItemSerializer);
var selectorContext = context.WithSymbol(selectorSymbol);
var selectorTranslation = ExpressionToAggregationExpressionTranslator.Translate(selectorContext, selectorLambda.Body);
ast = AstExpression.Avg(
AstExpression.Map(
input: sourceTranslation.Ast,
@as: selectorSymbol.Var,
@in: selectorTranslation.Ast));
}
else
{
ast = AstExpression.Avg(sourceTranslation.Ast);
}
IBsonSerializer serializer = expression.Type switch
{
Type t when t == typeof(int) => new Int32Serializer(),
Type t when t == typeof(long) => new Int64Serializer(),
Type t when t == typeof(float) => new SingleSerializer(),
Type t when t == typeof(double) => new DoubleSerializer(),
Type t when t == typeof(decimal) => new DecimalSerializer(),
Type {
IsConstructedGenericType : true
} t when t.GetGenericTypeDefinition() == typeof(Nullable <>) => (IBsonSerializer)Activator.CreateInstance(typeof(NullableSerializer <>).MakeGenericType(t.GenericTypeArguments[0])),
_ => throw new ExpressionNotSupportedException(expression)
};
return(new AggregationExpression(expression, ast, serializer));
}
if (SetWindowFieldsMethodToAggregationExpressionTranslator.CanTranslate(expression))
{
return(SetWindowFieldsMethodToAggregationExpressionTranslator.Translate(context, expression));
}
throw new ExpressionNotSupportedException(expression);
}
}
public static AstFilter Translate(TranslationContext context, MethodCallExpression expression)
{
if (AllWithContainsInPredicateMethodToFilterTranslator.CanTranslate(expression, out var arrayFieldExpression, out var arrayConstantExpression))
{
return(AllWithContainsInPredicateMethodToFilterTranslator.Translate(context, arrayFieldExpression, arrayConstantExpression));
}
if (AnyWithContainsInPredicateMethodToFilterTranslator.CanTranslate(expression, out arrayFieldExpression, out arrayConstantExpression))
{
return(AnyWithContainsInPredicateMethodToFilterTranslator.Translate(context, arrayFieldExpression, arrayConstantExpression));
}
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(EnumerableMethod.All, EnumerableMethod.Any, EnumerableMethod.AnyWithPredicate))
{
var sourceExpression = arguments[0];
var(field, filter) = FilteredEnumerableFilterFieldTranslator.Translate(context, sourceExpression);
if (method.IsOneOf(EnumerableMethod.All, EnumerableMethod.AnyWithPredicate))
{
var predicateLambda = (LambdaExpression)arguments[1];
var parameterExpression = predicateLambda.Parameters.Single();
var elementSerializer = ArraySerializerHelper.GetItemSerializer(field.Serializer);
var parameterSymbol = context.CreateSymbol(parameterExpression, "@<elem>", elementSerializer); // @<elem> represents the implied element
var predicateContext = context.WithSingleSymbol(parameterSymbol); // @<elem> is the only symbol visible inside an $elemMatch
var predicateFilter = ExpressionToFilterTranslator.Translate(predicateContext, predicateLambda.Body, exprOk: false);
filter = AstFilter.Combine(filter, predicateFilter);
}
if (method.Is(EnumerableMethod.All))
{
return(AstFilter.Not(AstFilter.ElemMatch(field, AstFilter.Not(filter))));
}
else
{
if (filter == null)
{
return(AstFilter.And(AstFilter.Ne(field, BsonNull.Value), AstFilter.Not(AstFilter.Size(field, 0))));
}
else
{
return(AstFilter.ElemMatch(field, filter));
}
}
}
throw new ExpressionNotSupportedException(expression);
}
public static AstFilterField Translate(TranslationContext context, BinaryExpression expression)
{
if (expression.NodeType == ExpressionType.ArrayIndex)
{
var arrayExpression = expression.Left;
var arrayField = ExpressionToFilterFieldTranslator.Translate(context, arrayExpression);
var indexExpression = expression.Right;
var index = indexExpression.GetConstantValue <int>(containingExpression: expression);
var itemSerializer = ArraySerializerHelper.GetItemSerializer(arrayField.Serializer);
return(arrayField.SubField(index.ToString(), itemSerializer));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(__countMethods))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
AstExpression ast;
if (method.IsOneOf(__countWithPredicateMethods))
{
if (sourceExpression.Type == typeof(string))
{
throw new ExpressionNotSupportedException(expression);
}
var predicateLambda = (LambdaExpression)arguments[1];
var sourceItemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var predicateTranslation = ExpressionToAggregationExpressionTranslator.TranslateLambdaBody(context, predicateLambda, sourceItemSerializer, asRoot: false);
var filteredSourceAst = AstExpression.Filter(
input: sourceTranslation.Ast,
cond: predicateTranslation.Ast,
@as: predicateLambda.Parameters[0].Name);
ast = AstExpression.Size(filteredSourceAst);
}
else
{
if (sourceExpression.Type == typeof(string))
{
ast = AstExpression.StrLenCP(sourceTranslation.Ast);
}
else
{
ast = AstExpression.Size(sourceTranslation.Ast);
}
}
var serializer = GetSerializer(expression.Type);
return(new AggregationExpression(expression, ast, serializer));
}
if (WindowMethodToAggregationExpressionTranslator.CanTranslate(expression))
{
return(WindowMethodToAggregationExpressionTranslator.Translate(context, expression));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, BinaryExpression expression)
{
if (expression.NodeType == ExpressionType.ArrayIndex)
{
var arrayExpression = expression.Left;
var arrayTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, arrayExpression);
var indexExpression = expression.Right;
var indexTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, indexExpression);
var ast = AstExpression.ArrayElemAt(arrayTranslation.Ast, indexTranslation.Ast);
var itemSerializer = ArraySerializerHelper.GetItemSerializer(arrayTranslation.Serializer);
return(new AggregationExpression(expression, ast, itemSerializer));
}
throw new ExpressionNotSupportedException(expression);
}
private static AstPipeline TranslateSelectManyWithCollectionSelectorAndIdentityResultSelector(
AstPipeline pipeline,
AggregationExpression collectionSelectorTranslation)
{
var collectionItemSerializer = ArraySerializerHelper.GetItemSerializer(collectionSelectorTranslation.Serializer);
var resultValueSerializer = collectionItemSerializer;
var resultWrappedValueSerializer = WrappedValueSerializer.Create("_v", resultValueSerializer);
return(pipeline.AddStages(
resultWrappedValueSerializer,
AstStage.Project(
AstProject.Set("_v", collectionSelectorTranslation.Ast),
AstProject.ExcludeId()),
AstStage.Unwind("_v")));
}
public static (AstFilterField, AstFilter) Translate(TranslationContext context, Expression sourceExpression)
{
if (sourceExpression is MethodCallExpression sourceMethodCallExpression)
{
var method = sourceMethodCallExpression.Method;
var arguments = sourceMethodCallExpression.Arguments;
if (method.Is(EnumerableMethod.OfType))
{
var ofTypeSourceExpression = arguments[0];
var(sourceField, sourceFilter) = Translate(context, ofTypeSourceExpression);
var nominalType = ArraySerializerHelper.GetItemSerializer(sourceField.Serializer).ValueType;
var actualType = method.GetGenericArguments()[0];
var discriminatorConvention = BsonSerializer.LookupDiscriminatorConvention(actualType);
var discriminatorField = AstFilter.Field(discriminatorConvention.ElementName, BsonValueSerializer.Instance);
var discriminatorValue = discriminatorConvention.GetDiscriminator(nominalType, actualType);
var ofTypeFilter = AstFilter.Eq(discriminatorField, discriminatorValue);
var actualTypeSerializer = context.KnownSerializersRegistry.GetSerializer(sourceExpression);
var enumerableActualTypeSerializer = IEnumerableSerializer.Create(actualTypeSerializer);
var actualTypeSourceField = AstFilter.Field(sourceField.Path, enumerableActualTypeSerializer);
var combinedFilter = AstFilter.Combine(sourceFilter, ofTypeFilter);
return(actualTypeSourceField, combinedFilter);
}
if (method.Is(EnumerableMethod.Where))
{
var whereSourceExpression = arguments[0];
var(sourceField, sourceFilter) = Translate(context, whereSourceExpression);
var predicateLambda = (LambdaExpression)arguments[1];
var parameterExpression = predicateLambda.Parameters.Single();
var itemSerializer = ArraySerializerHelper.GetItemSerializer(sourceField.Serializer);
var parameterSymbol = context.CreateSymbol(parameterExpression, "@<elem>", itemSerializer); // @<elem> represents the implied element
var predicateContext = context.WithSingleSymbol(parameterSymbol); // @<elem> is the only symbol visible inside an $elemMatch
var whereFilter = ExpressionToFilterTranslator.Translate(predicateContext, predicateLambda.Body, exprOk: false);
var combinedFilter = AstFilter.Combine(sourceFilter, whereFilter);
return(sourceField, combinedFilter);
}
}
var field = ExpressionToFilterFieldTranslator.Translate(context, sourceExpression);
return(field, null);
}
private static AstFilter Translate(TranslationContext context, Expression expression, Expression sourceExpression, Expression itemExpression)
{
if (itemExpression.NodeType == ExpressionType.Constant)
{
var sourceField = ExpressionToFilterFieldTranslator.Translate(context, sourceExpression);
var itemSerializer = ArraySerializerHelper.GetItemSerializer(sourceField.Serializer);
var value = itemExpression.GetConstantValue <object>(containingExpression: expression);
var serializedValue = SerializationHelper.SerializeValue(itemSerializer, value);
return(AstFilter.ElemMatch(sourceField, AstFilter.Eq(AstFilter.Field("@<elem>", itemSerializer), serializedValue))); // @<elem> represents the implied element
}
var itemField = ExpressionToFilterFieldTranslator.Translate(context, itemExpression);
var sourceValues = sourceExpression.GetConstantValue <IEnumerable>(containingExpression: expression);
var serializedValues = SerializationHelper.SerializeValues(itemField.Serializer, sourceValues);
return(AstFilter.In(itemField, serializedValues));
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.Is(EnumerableMethod.Reverse))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
var ast = AstExpression.ReverseArray(sourceTranslation.Ast);
var itemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var serializer = IEnumerableSerializer.Create(itemSerializer);
return(new AggregationExpression(expression, ast, serializer));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.Is(EnumerableMethod.ToArray))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, sourceExpression);
var arrayItemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var arrayItemType = arrayItemSerializer.ValueType;
var arraySerializerType = typeof(ArraySerializer <>).MakeGenericType(arrayItemType);
var arraySerializer = (IBsonSerializer)Activator.CreateInstance(arraySerializerType, arrayItemSerializer);
return(new AggregationExpression(expression, sourceTranslation.Ast, arraySerializer));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(__sumMethods))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
var sourceItemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
AstExpression ast;
IBsonSerializer serializer;
if (arguments.Count == 1)
{
ast = AstExpression.Sum(sourceTranslation.Ast);
serializer = sourceItemSerializer;
}
else
{
var selectorLambda = (LambdaExpression)arguments[1];
var selectorParameter = selectorLambda.Parameters[0];
var selectorSymbol = context.CreateSymbol(selectorParameter, sourceItemSerializer);
var selectorContext = context.WithSymbol(selectorSymbol);
var selectorTranslation = ExpressionToAggregationExpressionTranslator.Translate(selectorContext, selectorLambda.Body);
ast = AstExpression.Sum(
AstExpression.Map(
input: sourceTranslation.Ast,
@as: selectorSymbol.Var,
@in: selectorTranslation.Ast));
serializer = selectorTranslation.Serializer;
}
return(new AggregationExpression(expression, ast, serializer));
}
if (SetWindowFieldsMethodToAggregationExpressionTranslator.CanTranslate(expression))
{
return(SetWindowFieldsMethodToAggregationExpressionTranslator.Translate(context, expression));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.DeclaringType == typeof(Enumerable) && (method.Name == "Max" || method.Name == "Min"))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
AstExpression ast;
IBsonSerializer serializer;
if (arguments.Count == 1)
{
var array = sourceTranslation.Ast;
ast = method.Name == "Max" ? AstExpression.Max(array) : AstExpression.Min(array);
serializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
}
else
{
var selectorLambda = (LambdaExpression)arguments[1];
var selectorParameter = selectorLambda.Parameters[0];
var selectorParameterSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var selectorParameterSymbol = context.CreateSymbol(selectorParameter, selectorParameterSerializer);
var selectorContext = context.WithSymbol(selectorParameterSymbol);
var selectorTranslation = ExpressionToAggregationExpressionTranslator.Translate(selectorContext, selectorLambda.Body);
var mappedArray =
AstExpression.Map(
input: sourceTranslation.Ast,
@as: selectorParameterSymbol.Var,
@in: selectorTranslation.Ast);
ast = method.Name == "Max" ? AstExpression.Max(mappedArray) : AstExpression.Min(mappedArray);
serializer = selectorTranslation.Serializer;
}
return(new AggregationExpression(expression, ast, serializer));
}
if (SetWindowFieldsMethodToAggregationExpressionTranslator.CanTranslate(expression))
{
return(SetWindowFieldsMethodToAggregationExpressionTranslator.Translate(context, expression));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
Expression sourceExpression, indexExpression, keyExpression;
if (IsBsonValueGetItemMethodWithIntIndex(expression, out sourceExpression, out indexExpression))
{
var sourceTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, sourceExpression);
var indexTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, indexExpression);
var ast = AstExpression.ArrayElemAt(sourceTranslation.Ast, indexTranslation.Ast);
var valueSerializer = BsonValueSerializer.Instance;
return(new AggregationExpression(expression, ast, valueSerializer));
}
if (IsBsonValueGetItemMethodWithStringKey(expression, out sourceExpression, out keyExpression))
{
var sourceTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, sourceExpression);
var keyTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, keyExpression);
var ast = AstExpression.GetField(sourceTranslation.Ast, keyTranslation.Ast);
var valueSerializer = BsonValueSerializer.Instance;
return(new AggregationExpression(expression, ast, valueSerializer));
}
if (IsEnumerableGetItemMethodWithIntIndex(expression, out sourceExpression, out indexExpression))
{
var sourceTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, sourceExpression);
var indexTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, indexExpression);
var ast = AstExpression.ArrayElemAt(sourceTranslation.Ast, indexTranslation.Ast);
var serializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
return(new AggregationExpression(expression, ast, serializer));
}
if (IsDictionaryGetItemMethodWithStringKey(expression, out sourceExpression, out keyExpression))
{
var sourceTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, sourceExpression);
var key = keyExpression.GetConstantValue <string>(containingExpression: expression);
var ast = AstExpression.GetField(sourceTranslation.Ast, key); // TODO: verify that dictionary is using Document representation
var valueSerializer = GetDictionaryValueSerializer(sourceTranslation.Serializer);
return(new AggregationExpression(expression, ast, valueSerializer));
}
throw new ExpressionNotSupportedException(expression);
}
private static AstPipeline TranslateSelectMany(
TranslationContext context,
AstPipeline pipeline,
ReadOnlyCollection <Expression> arguments)
{
var sourceSerializer = pipeline.OutputSerializer;
var selectorLambda = ExpressionHelper.UnquoteLambda(arguments[1]);
var selectorTranslation = ExpressionToAggregationExpressionTranslator.TranslateLambdaBody(context, selectorLambda, sourceSerializer, asRoot: true);
var resultValueSerializer = ArraySerializerHelper.GetItemSerializer(selectorTranslation.Serializer);
var resultWrappedValueSerializer = WrappedValueSerializer.Create("_v", resultValueSerializer);
pipeline = pipeline.AddStages(
resultWrappedValueSerializer,
AstStage.Project(
AstProject.Set("_v", selectorTranslation.Ast),
AstProject.ExcludeId()),
AstStage.Unwind("_v"));
return(pipeline);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (IsStandardDeviationMethod(method, out var stddevOperator))
{
if (arguments.Count == 1 || arguments.Count == 2)
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
if (arguments.Count == 2)
{
var selectorLambda = (LambdaExpression)arguments[1];
var selectorParameter = selectorLambda.Parameters[0];
var selectorParameterSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var selectorParameterSymbol = context.CreateSymbol(selectorParameter, selectorParameterSerializer);
var selectorContext = context.WithSymbol(selectorParameterSymbol);
var selectorTranslation = ExpressionToAggregationExpressionTranslator.Translate(selectorContext, selectorLambda.Body);
var selectorAst = AstExpression.Map(
input: sourceTranslation.Ast,
@as: selectorParameterSymbol.Var,
@in: selectorTranslation.Ast);
var selectorResultSerializer = BsonSerializer.LookupSerializer(selectorLambda.ReturnType);
sourceTranslation = new AggregationExpression(selectorLambda, selectorAst, selectorResultSerializer);
}
var ast = AstExpression.StdDev(stddevOperator, sourceTranslation.Ast);
var serializer = BsonSerializer.LookupSerializer(expression.Type);
return(new AggregationExpression(expression, ast, serializer));
}
}
if (SetWindowFieldsMethodToAggregationExpressionTranslator.CanTranslate(expression))
{
return(SetWindowFieldsMethodToAggregationExpressionTranslator.Translate(context, expression));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(EnumerableMethod.DefaultIfEmpty, EnumerableMethod.DefaultIfEmptyWithDefaultValue))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, sourceExpression);
var sourceVar = AstExpression.Var("source");
var sourceVarBinding = AstExpression.VarBinding(sourceVar, sourceTranslation.Ast);
AstExpression defaultValueAst;
if (method.Is(EnumerableMethod.DefaultIfEmpty))
{
var sourceItemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var defaultValue = Activator.CreateInstance(sourceItemSerializer.ValueType);
var serializedDefaultValue = SerializationHelper.SerializeValue(sourceItemSerializer, defaultValue);
defaultValueAst = AstExpression.Constant(new BsonArray {
serializedDefaultValue
});
}
else
{
var defaultValueExpression = arguments[1];
var defaultValueTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, defaultValueExpression);
defaultValueAst = AstExpression.ComputedArray(new[] { defaultValueTranslation.Ast });
}
var ast = AstExpression.Let(
sourceVarBinding,
AstExpression.Cond(
AstExpression.Eq(AstExpression.Size(sourceVar), 0),
defaultValueAst,
sourceVar));
return(new AggregationExpression(expression, ast, sourceTranslation.Serializer));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.Is(EnumerableMethod.Take))
{
var sourceExpression = arguments[0];
var countExpression = arguments[1];
Expression skipExpression = null;
if (sourceExpression is MethodCallExpression sourceSkipExpression && sourceSkipExpression.Method.Is(EnumerableMethod.Skip))
{
sourceExpression = sourceSkipExpression.Arguments[0];
skipExpression = sourceSkipExpression.Arguments[1];
}
var sourceTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, sourceExpression);
var countTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, countExpression);
AstExpression ast;
if (skipExpression == null)
{
ast = AstExpression.Slice(sourceTranslation.Ast, countTranslation.Ast);
}
else
{
var skipTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, skipExpression);
ast = AstExpression.Slice(sourceTranslation.Ast, skipTranslation.Ast, countTranslation.Ast);
}
var itemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var serializer = IEnumerableSerializer.Create(itemSerializer);
return(new AggregationExpression(expression, ast, serializer));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(EnumerableMethod.Where, MongoEnumerableMethod.WhereWithLimit))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
var itemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
var predicateLambda = (LambdaExpression)arguments[1];
var predicateParameter = predicateLambda.Parameters[0];
var predicateSymbol = context.CreateSymbol(predicateParameter, itemSerializer);
var predicateContext = context.WithSymbol(predicateSymbol);
var predicateTranslation = ExpressionToAggregationExpressionTranslator.Translate(predicateContext, predicateLambda.Body);
AggregationExpression limitTranslation = null;
if (method.Is(MongoEnumerableMethod.WhereWithLimit))
{
var limitExpression = arguments[2];
limitTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, limitExpression);
}
var ast = AstExpression.Filter(
sourceTranslation.Ast,
predicateTranslation.Ast,
predicateParameter.Name,
limitTranslation?.Ast);
var enumerableSerializer = IEnumerableSerializer.Create(itemSerializer);
return(new AggregationExpression(expression, ast, enumerableSerializer));
}
throw new ExpressionNotSupportedException(expression);
}
public static AggregationExpression Translate(TranslationContext context, MethodCallExpression expression)
{
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(__aggregateMethods))
{
var sourceExpression = arguments[0];
var sourceTranslation = ExpressionToAggregationExpressionTranslator.TranslateEnumerable(context, sourceExpression);
var itemSerializer = ArraySerializerHelper.GetItemSerializer(sourceTranslation.Serializer);
if (method.Is(EnumerableMethod.AggregateWithFunc))
{
var funcLambda = (LambdaExpression)arguments[1];
var funcParameters = funcLambda.Parameters;
var accumulatorParameter = funcParameters[0];
var accumulatorSymbol = context.CreateSymbolWithVarName(accumulatorParameter, varName: "value", itemSerializer); // note: MQL uses $$value for the accumulator
var itemParameter = funcParameters[1];
var itemSymbol = context.CreateSymbolWithVarName(itemParameter, varName: "this", itemSerializer); // note: MQL uses $$this for the item being processed
var funcContext = context.WithSymbols(accumulatorSymbol, itemSymbol);
var funcTranslation = ExpressionToAggregationExpressionTranslator.Translate(funcContext, funcLambda.Body);
var sourceVar = AstExpression.Var("source");
var ast = AstExpression.Let(
var: AstExpression.VarBinding(sourceVar, sourceTranslation.Ast),
@in: AstExpression.Cond(
@if: AstExpression.Lte(AstExpression.Size(sourceVar), 1),
@then: AstExpression.ArrayElemAt(sourceVar, 0),
@else: AstExpression.Reduce(
input: AstExpression.Slice(sourceVar, 1, int.MaxValue),
initialValue: AstExpression.ArrayElemAt(sourceVar, 0),
@in: funcTranslation.Ast)));
return(new AggregationExpression(expression, ast, itemSerializer));
}
else if (method.IsOneOf(EnumerableMethod.AggregateWithSeedAndFunc, EnumerableMethod.AggregateWithSeedFuncAndResultSelector))
{
var seedExpression = arguments[1];
var seedTranslation = ExpressionToAggregationExpressionTranslator.Translate(context, seedExpression);
var funcLambda = (LambdaExpression)arguments[2];
var funcParameters = funcLambda.Parameters;
var accumulatorParameter = funcParameters[0];
var accumulatorSerializer = context.KnownSerializersRegistry.GetSerializer(accumulatorParameter);
var accumulatorSymbol = context.CreateSymbolWithVarName(accumulatorParameter, varName: "value", accumulatorSerializer); // note: MQL uses $$value for the accumulator
var itemParameter = funcParameters[1];
var itemSymbol = context.CreateSymbolWithVarName(itemParameter, varName: "this", itemSerializer); // note: MQL uses $$this for the item being processed
var funcContext = context.WithSymbols(accumulatorSymbol, itemSymbol);
var funcTranslation = ExpressionToAggregationExpressionTranslator.Translate(funcContext, funcLambda.Body);
var ast = AstExpression.Reduce(
input: sourceTranslation.Ast,
initialValue: seedTranslation.Ast,
@in: funcTranslation.Ast);
var serializer = accumulatorSerializer;
if (method.Is(EnumerableMethod.AggregateWithSeedFuncAndResultSelector))
{
var resultSelectorLambda = (LambdaExpression)arguments[3];
var resultSelectorParameter = resultSelectorLambda.Parameters[0];
var resultSelectorParameterSerializer = context.KnownSerializersRegistry.GetSerializer(resultSelectorParameter);
var resultSelectorSymbol = context.CreateSymbol(resultSelectorParameter, resultSelectorParameterSerializer);
var resultSelectorContext = context.WithSymbol(resultSelectorSymbol);
var resultSelectorTranslation = ExpressionToAggregationExpressionTranslator.Translate(resultSelectorContext, resultSelectorLambda.Body);
ast = AstExpression.Let(
var: AstExpression.VarBinding(resultSelectorSymbol.Var, ast),
@in: resultSelectorTranslation.Ast);
serializer = context.KnownSerializersRegistry.GetSerializer(resultSelectorLambda);
}
return(new AggregationExpression(expression, ast, serializer));
}
}
throw new ExpressionNotSupportedException(expression);
}