private (NavigationExpansionExpression navigationExpression, Expression nullKeyExpression) CreateNullComparisonArguments(
NavigationBindingExpression navigationBindingExpression,
NavigationExpansionExpression navigationExpansionExpression)
{
var navigationKeyAccessExpression = NavigationExpansionHelpers.CreateKeyAccessExpression(
navigationBindingExpression,
new[] { navigationBindingExpression.EntityType.FindPrimaryKey().Properties.First() },
addNullCheck: true);
var nullKeyExpression = NavigationExpansionHelpers.CreateNullKeyExpression(
navigationKeyAccessExpression.Type,
keyCount: 1);
var newNavigationExpansionExpressionState = new NavigationExpansionExpressionState(
navigationExpansionExpression.State.CurrentParameter,
navigationExpansionExpression.State.SourceMappings,
Expression.Lambda(navigationKeyAccessExpression, navigationExpansionExpression.State.PendingSelector.Parameters[0]),
applyPendingSelector: true,
navigationExpansionExpression.State.PendingOrderings,
navigationExpansionExpression.State.PendingIncludeChain,
// we need to remap cardinality reducing operator since it's source type has now changed
navigationExpansionExpression.State.PendingCardinalityReducingOperator?.GetGenericMethodDefinition().MakeGenericMethod(navigationKeyAccessExpression.Type),
navigationExpansionExpression.State.CustomRootMappings,
navigationExpansionExpression.State.MaterializeCollectionNavigation);
var navigationExpression = new NavigationExpansionExpression(
navigationExpansionExpression.Operand,
newNavigationExpansionExpressionState,
navigationKeyAccessExpression.Type);
return(navigationExpression, nullKeyExpression);
}
public NavigationExpansionExpression(
Expression operand,
NavigationExpansionExpressionState state,
Type returnType)
{
Operand = operand;
State = state;
_returnType = returnType;
}
private (Expression Operand, NavigationExpansionExpressionState State) ApplyIncludes(
NavigationExpansionExpression navigationExpansionExpression)
{
var includeVisitor = new PendingSelectorIncludeVisitor();
var rewrittenBody = includeVisitor.Visit(navigationExpansionExpression.State.PendingSelector.Body);
if (navigationExpansionExpression.State.PendingSelector.Body != rewrittenBody)
{
navigationExpansionExpression.State.PendingSelector = Expression.Lambda(rewrittenBody, navigationExpansionExpression.State.PendingSelector.Parameters[0]);
navigationExpansionExpression.State.ApplyPendingSelector = true;
}
if (includeVisitor.PendingIncludes.Count > 0)
{
var result = (Source : navigationExpansionExpression.Operand, Parameter : navigationExpansionExpression.State.CurrentParameter);
foreach (var pendingIncludeNode in includeVisitor.PendingIncludes)
{
result = NavigationExpansionHelpers.AddNavigationJoin(
result.Source,
result.Parameter,
pendingIncludeNode.SourceMapping,
pendingIncludeNode.NavTreeNode,
navigationExpansionExpression.State,
new List <INavigation>(),
include: true);
}
var pendingSelector = navigationExpansionExpression.State.PendingSelector;
if (navigationExpansionExpression.State.CurrentParameter != result.Parameter)
{
var pendingSelectorBody = new ExpressionReplacingVisitor(navigationExpansionExpression.State.CurrentParameter, result.Parameter).Visit(navigationExpansionExpression.State.PendingSelector.Body);
pendingSelector = Expression.Lambda(pendingSelectorBody, result.Parameter);
}
var newState = new NavigationExpansionExpressionState(
result.Parameter,
navigationExpansionExpression.State.SourceMappings,
pendingSelector,
applyPendingSelector: true,
navigationExpansionExpression.State.PendingOrderings,
navigationExpansionExpression.State.PendingIncludeChain,
navigationExpansionExpression.State.PendingCardinalityReducingOperator,
navigationExpansionExpression.State.CustomRootMappings,
navigationExpansionExpression.State.MaterializeCollectionNavigation);
return(Operand : result.Source, newState);
}
return(navigationExpansionExpression.Operand, navigationExpansionExpression.State);
}
private Expression ProcessMemberPushdown(
Expression source,
NavigationExpansionExpression navigationExpansionExpression,
bool efProperty,
MemberInfo memberInfo,
string propertyName,
Type resultType)
{
// in case of nested FirstOrDefaults, we need to dig into the inner most - that's where the member finally gets pushed down to
if (navigationExpansionExpression.State.PendingSelector.Body is NavigationExpansionExpression navigationExpansionPendingSelector &&
navigationExpansionPendingSelector.State.PendingCardinalityReducingOperator != null)
{
var newPendingSelector = (NavigationExpansionExpression)ProcessMemberPushdown(source, navigationExpansionPendingSelector, efProperty, memberInfo, propertyName, resultType);
var newStateNested = new NavigationExpansionExpressionState(
navigationExpansionExpression.State.CurrentParameter,
navigationExpansionExpression.State.SourceMappings,
Expression.Lambda(newPendingSelector, navigationExpansionExpression.State.CurrentParameter),
applyPendingSelector: true,
navigationExpansionExpression.State.PendingOrderings,
navigationExpansionExpression.State.PendingIncludeChain,
// we need to remap cardinality reducing operator since it's source type has now changed
navigationExpansionExpression.State.PendingCardinalityReducingOperator.GetGenericMethodDefinition().MakeGenericMethod(newPendingSelector.Type),
navigationExpansionExpression.State.CustomRootMappings,
navigationExpansionExpression.State.MaterializeCollectionNavigation);
return(new NavigationExpansionExpression(
navigationExpansionExpression.Operand,
newStateNested,
resultType));
}
var selectorParameter = Expression.Parameter(source.Type, navigationExpansionExpression.State.CurrentParameter.Name);
var selectorBody = efProperty
? (Expression)Expression.Call(EF.PropertyMethod.MakeGenericMethod(resultType),
selectorParameter,
Expression.Constant(propertyName))
: Expression.MakeMemberAccess(selectorParameter, memberInfo);
if (navigationExpansionExpression.State.PendingCardinalityReducingOperator.MethodIsClosedFormOf(LinqMethodHelpers.QueryableFirstOrDefaultMethodInfo) ||
navigationExpansionExpression.State.PendingCardinalityReducingOperator.MethodIsClosedFormOf(LinqMethodHelpers.QueryableFirstOrDefaultPredicateMethodInfo) ||
navigationExpansionExpression.State.PendingCardinalityReducingOperator.MethodIsClosedFormOf(LinqMethodHelpers.QueryableSingleOrDefaultMethodInfo) ||
navigationExpansionExpression.State.PendingCardinalityReducingOperator.MethodIsClosedFormOf(LinqMethodHelpers.QueryableSingleOrDefaultPredicateMethodInfo) ||
navigationExpansionExpression.State.PendingCardinalityReducingOperator.MethodIsClosedFormOf(LinqMethodHelpers.EnumerableFirstOrDefaultMethodInfo) ||
navigationExpansionExpression.State.PendingCardinalityReducingOperator.MethodIsClosedFormOf(LinqMethodHelpers.EnumerableFirstOrDefaultPredicateMethodInfo) ||
navigationExpansionExpression.State.PendingCardinalityReducingOperator.MethodIsClosedFormOf(LinqMethodHelpers.EnumerableSingleOrDefaultMethodInfo) ||
navigationExpansionExpression.State.PendingCardinalityReducingOperator.MethodIsClosedFormOf(LinqMethodHelpers.EnumerableSingleOrDefaultPredicateMethodInfo))
{
if (!selectorBody.Type.IsNullableType())
{
selectorBody = Expression.Convert(selectorBody, selectorBody.Type.MakeNullable());
}
}
var selector = Expression.Lambda(selectorBody, selectorParameter);
var remappedSelectorBody = ReplacingExpressionVisitor.Replace(
selectorParameter, navigationExpansionExpression.State.PendingSelector.Body, selector.Body);
var binder = new NavigationPropertyBindingVisitor(
navigationExpansionExpression.State.CurrentParameter,
navigationExpansionExpression.State.SourceMappings);
var boundSelectorBody = binder.Visit(remappedSelectorBody);
if (boundSelectorBody is NavigationBindingExpression navigationBindingExpression &&
navigationBindingExpression.NavigationTreeNode.Navigation != null)
{
if (navigationBindingExpression.NavigationTreeNode.IsCollection)
{
var lastNavigation = navigationBindingExpression.NavigationTreeNode.Navigation;
var collectionNavigationElementType = lastNavigation.ForeignKey.DeclaringEntityType.ClrType;
var entityQueryable = NullAsyncQueryProvider.Instance.CreateEntityQueryableExpression(collectionNavigationElementType);
var outerParameter = Expression.Parameter(collectionNavigationElementType, collectionNavigationElementType.GenerateParameterName());
var outerKeyAccess = NavigationExpansionHelpers.CreateKeyAccessExpression(
outerParameter,
lastNavigation.ForeignKey.Properties);
var innerParameter = Expression.Parameter(navigationExpansionExpression.Type);
var innerKeyAccessLambda = Expression.Lambda(
NavigationExpansionHelpers.CreateKeyAccessExpression(
innerParameter,
lastNavigation.ForeignKey.PrincipalKey.Properties),
innerParameter);
var combinedKeySelectorBody = ReplacingExpressionVisitor.Replace(
innerKeyAccessLambda.Parameters[0], navigationExpansionExpression.State.PendingSelector.Body, innerKeyAccessLambda.Body);
if (outerKeyAccess.Type != combinedKeySelectorBody.Type)
{
if (combinedKeySelectorBody.Type.IsNullableType())
{
outerKeyAccess = Expression.Convert(outerKeyAccess, combinedKeySelectorBody.Type);
}
else
{
combinedKeySelectorBody = Expression.Convert(combinedKeySelectorBody, outerKeyAccess.Type);
}
}
var rewrittenState = new NavigationExpansionExpressionState(
navigationExpansionExpression.State.CurrentParameter,
navigationExpansionExpression.State.SourceMappings,
Expression.Lambda(combinedKeySelectorBody, navigationExpansionExpression.State.CurrentParameter),
applyPendingSelector: true,
navigationExpansionExpression.State.PendingOrderings,
navigationExpansionExpression.State.PendingIncludeChain,
// we need to remap cardinality reducing operator since it's source type has now changed
navigationExpansionExpression.State.PendingCardinalityReducingOperator.GetGenericMethodDefinition().MakeGenericMethod(combinedKeySelectorBody.Type),
navigationExpansionExpression.State.CustomRootMappings,
materializeCollectionNavigation: null);
var rewrittenNavigationExpansionExpression = new NavigationExpansionExpression(navigationExpansionExpression.Operand, rewrittenState, combinedKeySelectorBody.Type);
var inner = new NavigationExpansionReducingVisitor().Visit(rewrittenNavigationExpansionExpression);
var predicate = Expression.Lambda(
Expression.Equal(outerKeyAccess, inner),
outerParameter);
var whereMethodInfo = LinqMethodHelpers.QueryableWhereMethodInfo.MakeGenericMethod(collectionNavigationElementType);
var rewritten = Expression.Call(
whereMethodInfo,
entityQueryable,
predicate);
var entityType = lastNavigation.ForeignKey.DeclaringEntityType;
return(NavigationExpansionHelpers.CreateNavigationExpansionRoot(rewritten, entityType, materializeCollectionNavigation: null));
}
else
{
return(ProcessSelectCore(
navigationExpansionExpression.Operand,
navigationExpansionExpression.State,
selector,
selectorBody.Type));
}
}
var newState = new NavigationExpansionExpressionState(
navigationExpansionExpression.State.CurrentParameter,
navigationExpansionExpression.State.SourceMappings,
Expression.Lambda(boundSelectorBody, navigationExpansionExpression.State.CurrentParameter),
applyPendingSelector: true,
navigationExpansionExpression.State.PendingOrderings,
navigationExpansionExpression.State.PendingIncludeChain,
// we need to remap cardinality reducing operator since it's source type has now changed
navigationExpansionExpression.State.PendingCardinalityReducingOperator.GetGenericMethodDefinition().MakeGenericMethod(boundSelectorBody.Type),
navigationExpansionExpression.State.CustomRootMappings,
navigationExpansionExpression.State.MaterializeCollectionNavigation);
// TODO: expand navigations
var result = new NavigationExpansionExpression(
navigationExpansionExpression.Operand,
newState,
selectorBody.Type);
return(resultType != result.Type
? (Expression)Expression.Convert(result, resultType)
: result);
}
public static (Expression Source, ParameterExpression Parameter) AddNavigationJoin(
Expression sourceExpression,
ParameterExpression parameterExpression,
SourceMapping sourceMapping,
NavigationTreeNode navigationTree,
NavigationExpansionExpressionState state,
List <INavigation> navigationPath,
bool include)
{
var joinNeeded = include
? navigationTree.IncludeState == NavigationState.Pending
: navigationTree.ExpansionState == NavigationState.Pending;
if (joinNeeded)
{
var navigation = navigationTree.Navigation;
var sourceType = sourceExpression.Type.GetSequenceType();
var navigationTargetEntityType = navigation.GetTargetType();
var entityQueryable = NullAsyncQueryProvider.Instance.CreateEntityQueryableExpression(navigationTargetEntityType.ClrType);
var resultType = typeof(TransparentIdentifier <,>).MakeGenericType(sourceType, navigationTargetEntityType.ClrType);
var outerParameter = Expression.Parameter(sourceType, parameterExpression.Name);
var outerKeySelectorParameter = outerParameter;
var transparentIdentifierAccessorExpression = outerParameter.BuildPropertyAccess(navigationTree.Parent.ToMapping);
var outerKeySelectorBody = CreateKeyAccessExpression(
transparentIdentifierAccessorExpression,
navigation.IsDependentToPrincipal()
? navigation.ForeignKey.Properties
: navigation.ForeignKey.PrincipalKey.Properties,
addNullCheck: navigationTree.Parent != null && navigationTree.Parent.Optional);
var innerKeySelectorParameterType = navigationTargetEntityType.ClrType;
var innerKeySelectorParameter = Expression.Parameter(
innerKeySelectorParameterType,
parameterExpression.Name + "." + navigationTree.Navigation.Name);
var innerKeySelectorBody = CreateKeyAccessExpression(
innerKeySelectorParameter,
navigation.IsDependentToPrincipal()
? navigation.ForeignKey.PrincipalKey.Properties
: navigation.ForeignKey.Properties);
if (outerKeySelectorBody.Type.IsNullableType() &&
!innerKeySelectorBody.Type.IsNullableType())
{
innerKeySelectorBody = Expression.Convert(innerKeySelectorBody, outerKeySelectorBody.Type);
}
else if (innerKeySelectorBody.Type.IsNullableType() &&
!outerKeySelectorBody.Type.IsNullableType())
{
outerKeySelectorBody = Expression.Convert(outerKeySelectorBody, innerKeySelectorBody.Type);
}
var outerKeySelector = Expression.Lambda(
outerKeySelectorBody,
outerKeySelectorParameter);
var innerKeySelector = Expression.Lambda(
innerKeySelectorBody,
innerKeySelectorParameter);
if (!sourceExpression.Type.IsQueryableType())
{
var asQueryableMethodInfo = LinqMethodHelpers.AsQueryable.MakeGenericMethod(sourceType);
sourceExpression = Expression.Call(asQueryableMethodInfo, sourceExpression);
}
var joinMethodInfo = navigationTree.Optional
? _leftJoinMethodInfo.MakeGenericMethod(
sourceType,
navigationTargetEntityType.ClrType,
outerKeySelector.Body.Type,
resultType)
: LinqMethodHelpers.QueryableJoinMethodInfo.MakeGenericMethod(
sourceType,
navigationTargetEntityType.ClrType,
outerKeySelector.Body.Type,
resultType);
var resultSelectorOuterParameterName = outerParameter.Name;
var resultSelectorOuterParameter = Expression.Parameter(sourceType, resultSelectorOuterParameterName);
var resultSelectorInnerParameterName = innerKeySelectorParameter.Name;
var resultSelectorInnerParameter = Expression.Parameter(navigationTargetEntityType.ClrType, resultSelectorInnerParameterName);
var transparentIdentifierCtorInfo
= resultType.GetTypeInfo().GetConstructors().Single();
var transparentIdentifierOuterMemberInfo = resultType.GetTypeInfo().GetDeclaredField("Outer");
var transparentIdentifierInnerMemberInfo = resultType.GetTypeInfo().GetDeclaredField("Inner");
var resultSelector = Expression.Lambda(
Expression.New(
transparentIdentifierCtorInfo,
new[] { resultSelectorOuterParameter, resultSelectorInnerParameter },
new[] { transparentIdentifierOuterMemberInfo, transparentIdentifierInnerMemberInfo }),
resultSelectorOuterParameter,
resultSelectorInnerParameter);
var joinMethodCall = Expression.Call(
joinMethodInfo,
sourceExpression,
entityQueryable,
outerKeySelector,
innerKeySelector,
resultSelector);
sourceExpression = joinMethodCall;
var transparentIdentifierParameterName = resultSelectorInnerParameterName;
var transparentIdentifierParameter = Expression.Parameter(resultSelector.ReturnType, transparentIdentifierParameterName);
parameterExpression = transparentIdentifierParameter;
// remap navigation 'To' paths -> for this navigation prepend "Inner", for every other (already expanded) navigation prepend "Outer"
navigationTree.ToMapping.Insert(0, nameof(TransparentIdentifier <object, object> .Inner));
foreach (var mapping in state.SourceMappings)
{
var nodes = include
? mapping.NavigationTree.Flatten().Where(n => (n.IncludeState == NavigationState.Complete ||
n.ExpansionState == NavigationState.Complete ||
n.Navigation.ForeignKey.IsOwnership) &&
n != navigationTree)
: mapping.NavigationTree.Flatten().Where(n => (n.ExpansionState == NavigationState.Complete ||
n.Navigation.ForeignKey.IsOwnership) &&
n != navigationTree);
foreach (var navigationTreeNode in nodes)
{
navigationTreeNode.ToMapping.Insert(0, nameof(TransparentIdentifier <object, object> .Outer));
}
}
foreach (var customRootMapping in state.CustomRootMappings)
{
customRootMapping.Insert(0, nameof(TransparentIdentifier <object, object> .Outer));
}
if (include)
{
navigationTree.IncludeState = NavigationState.Complete;
}
else
{
navigationTree.ExpansionState = NavigationState.Complete;
}
navigationPath.Add(navigation);
}
else
{
navigationPath.Add(navigationTree.Navigation);
}
var result = (Source : sourceExpression, Parameter : parameterExpression);
foreach (var child in navigationTree.Children.Where(n => !n.IsCollection))
{
result = AddNavigationJoin(
result.Source,
result.Parameter,
sourceMapping,
child,
state,
navigationPath.ToList(),
include);
}
return(result);
}
public virtual NavigationExpansionExpression Update(Expression operand, NavigationExpansionExpressionState state)
=> operand != Operand || state != State
? new NavigationExpansionExpression(operand, state, Type)
: this;