// OptimizeExpression will implement caching of the scopes of ScopedLifestyles which will optimize
// performance in case multiple scoped registrations are used within a single delegate. Here's an
// example of how the expression gets optimized:
// Before:
// Func<HomeController> factory = () =>
// {
// return new HomeController(
// reg1.GetInstance(), // Hits ThreadLocal, hits dictionary
// new SomeQueryHandler(reg1.GetInstance()), // Hits ThreadLocal, hits dictionary
// new SomeCommandHandler(reg2.GetInstance())); // Hits ThreadLocal, hits dictionary
// };
// After:
// Func<HomeController> factory = () =>
// {
// var scope1 = new LazyScope(scopeFactory1, container);
// var value1 = new LazyScopedRegistration<IRepository, RepositoryImpl>(reg1);
// var value2 = new LazyScopedRegistration<IService, ServiceImpl>(reg2);
//
// return new HomeController(
// value1.GetInstance(scope1.Value), // Hits ThreadLocal, hits dictionary
// new SomeQueryHandler(value1.GetInstance(scope1.Value)),
// new SomeCommandHandler(value2.GetInstance(scope1.Value))); // Hits dictionary
// };
private static Expression OptimizeExpression(Container container, Expression expression,
OptimizableLifestyleInfo[] lifestyleInfos)
{
var lifestyleAssigmentExpressions = (
from lifestyleInfo in lifestyleInfos
let scopeFactory = lifestyleInfo.Lifestyle.CreateCurrentScopeProvider(container)
let newExpression = CreateNewLazyScopeExpression(scopeFactory, container)
select Expression.Assign(lifestyleInfo.Variable, newExpression))
.ToArray();
var registrationInfos = (
from lifestyleInfo in lifestyleInfos
from registrationInfo in lifestyleInfo.Registrations
select registrationInfo)
.ToArray();
var registrationAssignmentExpressions = (
from registrationInfo in registrationInfos
let newExpression = CreateNewLazyScopedRegistration(registrationInfo.Registration)
select Expression.Assign(registrationInfo.Variable, newExpression))
.ToArray();
var optimizedExpression = ObjectGraphOptimizerExpressionVisitor.Optimize(expression, registrationInfos);
return(Expression.Block(
variables: lifestyleInfos.Select(l => l.Variable)
.Concat(registrationInfos.Select(r => r.Variable)),
expressions: lifestyleAssigmentExpressions
.Concat(registrationAssignmentExpressions
.Concat(new[] { optimizedExpression }))));
}
public static Expression Optimize(Expression expression,
OptimizableRegistrationInfo[] registrationsToOptimize)
{
var optimizer = new ObjectGraphOptimizerExpressionVisitor(registrationsToOptimize);
return(optimizer.Visit(expression));
}
