protected override Expression VisitMember(MemberExpression expression)
{
var isIdentifier = _isEntityDecider.IsIdentifier(expression.Expression.Type, expression.Member.Name);
if (isIdentifier)
{
_hasIdentifier = true;
}
if (!isIdentifier)
{
_memberExpressionDepth++;
}
var result = base.VisitMember(expression);
if (!isIdentifier)
{
_memberExpressionDepth--;
}
if (_isEntityDecider.IsEntity(expression.Type) &&
((_requiresJoinForNonIdentifier && !_hasIdentifier) || _memberExpressionDepth > 0) &&
_joiner.CanAddJoin(expression))
{
var key = ExpressionKeyVisitor.Visit(expression, null);
return(_joiner.AddJoin(result, key));
}
_hasIdentifier = false;
return(result);
}
protected override Expression VisitMemberExpression(MemberExpression expression)
{
var isIdentifier = _isEntityDecider.IsIdentifier(expression.Expression.Type, expression.Member.Name);
if (!isIdentifier)
{
_memberExpressionDepth++;
}
var result = base.VisitMemberExpression(expression);
if (!isIdentifier)
{
_memberExpressionDepth--;
}
if (_isEntityDecider.IsEntity(expression.Type) &&
_memberExpressionDepth > 0 &&
_joiner.CanAddJoin(expression))
{
var key = ExpressionKeyVisitor.Visit(expression, null);
return(_joiner.AddJoin(result, key));
}
return(result);
}
// We would usually get NULL if one of our inner member expresions was null.
// However, it's possible a method call will convert the null value from the failed join into a non-null value.
// This could be optimized by actually checking what the method does. For example StartsWith("s") would leave null as null and would still allow us to inner join.
//protected override Expression VisitMethodCallExpression(MethodCallExpression expression)
//{
// Expression result = base.VisitMethodCallExpression(expression);
// return result;
//}
protected override Expression VisitMemberExpression(MemberExpression expression)
{
// The member expression we're visiting might be on the end of a variety of things, such as:
// a.B
// a.B.C
// (a.B ?? a.C).D
// I'm not sure what processing re-linq does to strange member expressions.
// TODO: I suspect this code doesn't add the right joins for the last case.
_memberExpressionDepth++;
var result = base.VisitMemberExpression(expression);
_memberExpressionDepth--;
ExpressionValues values = _values.Pop().Operation(pvs => pvs.MemberAccess(expression.Type));
if (_isEntityDecider.IsEntity(expression.Type))
{
// Don't add joins for things like a.B == a.C where B and C are entities.
// We only need to join B when there's something like a.B.D.
// TODO: Add an exception for the Id property.
if (_memberExpressionDepth > 0)
{
AddJoin(expression);
}
string key = ExpressionKeyVisitor.Visit(expression, null);
values.MemberExpressionValuesIfEmptyOuterJoined[key] = PossibleValueSet.CreateNull(expression.Type);
}
SetResultValues(values);
return(result);
}
protected override Expression VisitMemberExpression(MemberExpression expression)
{
if (_isEntityDecider.IsIdentifier(expression.Expression.Type, expression.Member.Name))
{
_hasIdentifier = true;
}
else if (_hasIdentifier)
{
_identifierMemberExpressionDepth++;
}
var result = base.VisitMemberExpression(expression);
if (_hasIdentifier)
{
_identifierMemberExpressionDepth--;
}
if (_isEntityDecider.IsEntity(expression.Type) &&
(!_hasIdentifier || _identifierMemberExpressionDepth > 0) &&
_joiner.CanAddJoin(expression))
{
var key = ExpressionKeyVisitor.Visit(expression, null);
return(_joiner.AddJoin(result, key));
}
_hasIdentifier = false;
return(result);
}
public static string Visit(Expression expression, IDictionary <ConstantExpression, NamedParameter> parameters)
{
var visitor = new ExpressionKeyVisitor(parameters);
visitor.VisitExpression(expression);
return(visitor.ToString());
}
/// <summary>
/// Generates the key for the expression.
/// </summary>
/// <param name="rootExpression">The expression.</param>
/// <param name="sessionFactory">The session factory.</param>
/// <param name="parameters">Parameters found in <paramref name="rootExpression"/>.</param>
/// <returns>The key for the expression.</returns>
public static string Visit(
Expression rootExpression,
IDictionary <ConstantExpression, NamedParameter> parameters,
ISessionFactoryImplementor sessionFactory)
{
var visitor = new ExpressionKeyVisitor(parameters, sessionFactory);
visitor.Visit(rootExpression);
return(visitor.ToString());
}
// We would usually get NULL if one of our inner member expressions was null.
// However, it's possible a method call will convert the null value from the failed join into a non-null value.
// This could be optimized by actually checking what the method does. For example StartsWith("s") would leave null as null and would still allow us to inner join.
//protected override Expression VisitMethodCall(MethodCallExpression expression)
//{
// Expression result = base.VisitMethodCall(expression);
// return result;
//}
protected override Expression VisitMember(MemberExpression expression)
{
// The member expression we're visiting might be on the end of a variety of things, such as:
// a.B
// a.B.C
// (a.B ?? a.C).D
// I'm not sure what processing re-linq does to strange member expressions.
// TODO: I suspect this code doesn't add the right joins for the last case.
// A static member expression such as DateTime.Now has a null Expression.
if (expression.Expression == null)
{
// A static member call is never a join, and it is not an instance member access either: leave
// the current value on stack, untouched.
return(base.VisitMember(expression));
}
var isIdentifier = _isEntityDecider.IsIdentifier(
expression.Expression.Type,
expression.Member.Name);
if (!isIdentifier)
{
_memberExpressionDepth++;
}
var result = base.VisitMember(expression);
if (!isIdentifier)
{
_memberExpressionDepth--;
}
ExpressionValues values = _values.Pop().Operation(pvs => pvs.MemberAccess(expression.Type));
if (_isEntityDecider.IsEntity(expression.Type))
{
// Don't add joins for things like a.B == a.C where B and C are entities.
// We only need to join B when there's something like a.B.D.
var key = ExpressionKeyVisitor.Visit(expression, null);
if (_memberExpressionDepth > 0 &&
_joiner.CanAddJoin(expression))
{
result = _joiner.AddJoin(result, key);
}
values.MemberExpressionValuesIfEmptyOuterJoined[key] = PossibleValueSet.CreateNull(expression.Type);
}
SetResultValues(values);
return(result);
}
private Expression AddJoin(MemberExpression expression)
{
string key = ExpressionKeyVisitor.Visit(expression, null);
LeftJoinClause join;
if (!_joins.TryGetValue(key, out join))
{
join = new LeftJoinClause(_nameGenerator.GetNewName(), expression.Type, expression);
_joins.Add(key, join);
}
return(new QuerySourceReferenceExpression(join));
}
protected internal Expression AddJoin(MemberExpression expression)
{
string key = ExpressionKeyVisitor.Visit(expression, null);
NhJoinClause join;
if (!_joins.TryGetValue(key, out join))
{
join = new NhJoinClause(_nameGenerator.GetNewName(), expression.Type, expression);
_joins.Add(key, join);
}
QuerySourceReferenceExpression newExpr = new QuerySourceReferenceExpression(join);
if (!_expressionMap.ContainsKey(expression))
{
_expressionMap.Add(expression, newExpr);
}
return(newExpr);
}
protected override Expression VisitMember(MemberExpression expression)
{
// A static member expression such as DateTime.Now has a null Expression.
if (expression.Expression == null)
{
// A static member call is never a join, and it is not an instance member access either.
return(base.VisitMember(expression));
}
var isIdentifier = _isEntityDecider.IsIdentifier(expression.Expression.Type, expression.Member.Name);
if (isIdentifier)
{
_hasIdentifier = true;
}
if (!isIdentifier)
{
_memberExpressionDepth++;
}
var result = base.VisitMember(expression);
if (!isIdentifier)
{
_memberExpressionDepth--;
}
if (_isEntityDecider.IsEntity(expression.Type) &&
((_requiresJoinForNonIdentifier && !_hasIdentifier) || _memberExpressionDepth > 0) &&
_joiner.CanAddJoin(expression))
{
var key = ExpressionKeyVisitor.Visit(expression, null);
return(_joiner.AddJoin(result, key));
}
_hasIdentifier = false;
return(result);
}
protected override Expression VisitMemberExpression(MemberExpression expression)
{
ArgumentUtility.CheckNotNull("expression", expression);
Expression newExpression;
try
{
_memberExpressionDepth++;
newExpression = base.VisitExpression(expression.Expression);
}
finally
{
_memberExpressionDepth--;
}
bool isEntity = _isEntityDecider.IsEntity(expression.Type);
if (isEntity)
{
// See (h) why we do not check for _memberExpressionDepth here!
AddPossibility(ExpressionKeyVisitor.Visit(expression, null), N);
}
if (_memberExpressionDepth > 0 && isEntity)
{
return(AddJoin(expression));
}
else
{
if (newExpression != expression.Expression)
{
return(Expression.MakeMemberAccess(newExpression, expression.Member));
}
return(expression);
}
}
