/// <summary>
/// Emits the instructions that will instantiate the current implementation.
/// </summary>
/// <param name="dependency">The dependency that describes the service to be instantiated.</param>
/// <param name="serviceMap">The service map that contains the list of dependencies in the application.</param>
/// <param name="targetMethod">The target method.</param>
public void Emit(IDependency dependency, IDictionary <IDependency, IImplementation> serviceMap, MethodDefinition targetMethod)
{
var declaringType = targetMethod.DeclaringType;
var module = declaringType.Module;
var body = targetMethod.Body;
var il = body.GetILProcessor();
// Emit the target implementation
_implementation.Emit(dependency, serviceMap, targetMethod);
// Determine the properties that need injection
Func <PropertyInfo, bool> propertyFilter = p => _propertyFilter(p) && _propertyDependencyResolver(p) != null && p.CanWrite;
var targetProperties = TargetType.GetProperties(BindingFlags.Public | BindingFlags.Instance);
foreach (var property in targetProperties)
{
if (!propertyFilter(property))
{
continue;
}
var curentDependency = _propertyDependencyResolver(property);
if (!serviceMap.ContainsKey(curentDependency))
{
continue;
}
EmitPropertySetter(serviceMap, targetMethod, module, il, property, curentDependency);
}
}
/// <summary>
/// Emits the instructions that will instantiate the cached service implementation.
/// </summary>
/// <param name="dependency">The dependency that describes the service to be instantiated.</param>
/// <param name="serviceMap">The service map that contains the list of dependencies in the application.</param>
/// <param name="targetMethod">The target method.</param>
public void Emit(IDependency dependency, IDictionary <IDependency, IImplementation> serviceMap, MethodDefinition targetMethod)
{
var declaringType = targetMethod.DeclaringType;
var module = declaringType.Module;
// Use the ICache instance that resides within the current container
var cacheType = module.ImportType <ICache>();
var methodBody = targetMethod.Body;
var locals = methodBody.Variables;
var cacheVariable = new VariableDefinition(cacheType);
locals.Add(cacheVariable);
var worker = methodBody.GetILProcessor();
// var cache = (ICache)container.GetInstance(cacheType, string.Empty);
var getCacheMethod = typeof(CacheRegistry).GetMethod("GetCache");
var getCacheInstanceMethod = module.Import(getCacheMethod);
worker.Emit(OpCodes.Ldarg_0);
worker.Emit(OpCodes.Call, getCacheInstanceMethod);
worker.Emit(OpCodes.Stloc, cacheVariable);
worker.Emit(OpCodes.Ldloc, cacheVariable);
var createInstance = worker.Create(OpCodes.Nop);
worker.Emit(OpCodes.Brfalse, createInstance);
// if (cache != null) {
var getItemMethod = module.ImportMethod <ICache>("get_Item");
var cacheKey = string.Format("Hiro Service Instance (ServiceName: {0}, ServiceType: {1}, Hash: {2})",
dependency.ServiceName,
dependency.ServiceType,
dependency.GetHashCode());
// cachedResult = cache[cacheKey];
worker.Emit(OpCodes.Ldloc, cacheVariable);
worker.Emit(OpCodes.Ldstr, cacheKey);
worker.Emit(OpCodes.Callvirt, getItemMethod);
worker.Emit(OpCodes.Brfalse, createInstance);
// if (cachedResult != null)
// return cachedResult;
var endLabel = worker.Create(OpCodes.Nop);
var objectType = module.ImportType(typeof(object));
var resultVariable = new VariableDefinition(objectType);
methodBody.Variables.Add(resultVariable);
worker.Emit(OpCodes.Ldloc, cacheVariable);
worker.Emit(OpCodes.Ldstr, cacheKey);
worker.Emit(OpCodes.Callvirt, getItemMethod);
worker.Emit(OpCodes.Stloc, resultVariable);
worker.Emit(OpCodes.Br, endLabel);
worker.Append(createInstance);
// Instantiate the actual service instance
_actualImplementation.Emit(dependency, serviceMap, targetMethod);
worker.Emit(OpCodes.Stloc, resultVariable);
// Cache the results
worker.Emit(OpCodes.Ldloc, cacheVariable);
worker.Emit(OpCodes.Brfalse, endLabel);
var setItemMethod = module.ImportMethod <ICache>("set_Item");
// cache[cacheKey] = result;
worker.Emit(OpCodes.Ldloc, cacheVariable);
worker.Emit(OpCodes.Ldstr, cacheKey);
worker.Emit(OpCodes.Ldloc, resultVariable);
worker.Emit(OpCodes.Callvirt, setItemMethod);
worker.Append(endLabel);
worker.Emit(OpCodes.Ldloc, resultVariable);
}
