Code:
/ FXUpdate3074 / FXUpdate3074 / 1.1 / DEVDIV / depot / DevDiv / releases / whidbey / QFE / ndp / fx / src / xsp / System / Web / Util / FactoryGenerator.cs / 1 / FactoryGenerator.cs
//------------------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
//-----------------------------------------------------------------------------
#if !DONTUSEFACTORYGENERATOR
using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Threading;
using System.Security;
using System.Security.Permissions;
namespace System.Web.Util {
/*
* Factory Generator class
* A factory generator is useful for cases where a large number of late-bound
* classes need to be instantiated.
*
* Normally, to create an instance of type t, you call the following code:
*
* ISomeInterface o = (ISomeInterface) Activator.CreateInstance(t);
*
* This assumes that the default constructor is used, and that the type t
* implements the interface ISomeInterface.
*
* The factory generator, on the other hand, can use reflection emit APIs
* to dynamically generate a class factory for t. The generated class has
* the equivalent of the following code:
*
* class X : ISomeInterfaceFactory {
* public ISomeInterface CreateInstance() {
* return new t();
* }
* }
*
* It then instantiates and returns an object of this type. You can then
* call CreateInstance to create an instance of the type, which is
* significantly faster.
*
* A single instance of a FactoryGenerator can generate factories for
* multiple types. However, it builds all these types into a single
* dynamically generated assembly. CLR implementation prevents this
* assembly from being unloaded until the process exits.
*
* The FactoryGenerator is (almost) a templated type. It takes two
* types in its constructor:
*
* returnedType is the type common to all classes for which factories
* are to be generated. In the example above, this would be
* ISomeInterface.
* factoryInterface is the interface implemented by the dynamically
* generated class factory, and should include a method named
* CreateInstance, that takes no parameters and returns an object
* of the type specified by returnedType. In the example above,
* this would be ISomeInterfaceFactory.
*
* Copyright (c) 2003 Microsoft Corporation
*/
internal class FactoryGenerator {
private Type _factoryInterface;
private Type _returnedType;
private MethodInfo _methodToOverride;
private ModuleBuilder _dynamicModule = null;
private Type[] _emptyParameterList = new Type[] { };
private Type[] _interfacesToImplement;
internal FactoryGenerator() : this(typeof(object), typeof(IWebObjectFactory)) {}
private FactoryGenerator(Type returnedType, Type factoryInterface) {
_returnedType = returnedType;
_factoryInterface = factoryInterface;
// Get the CreateInstance method, and make sure it has
// the correct signature.
_methodToOverride = factoryInterface.GetMethod("CreateInstance", new Type[0]);
if (_methodToOverride.ReturnType != _returnedType) {
throw new ArgumentException(SR.GetString(SR.FactoryInterface));
}
// This will be needed later, when building the dynamic class.
_interfacesToImplement = new Type[1];
_interfacesToImplement[0] = factoryInterface;
}
// A type must be public and have a parameterless constructor, in order for us to be able to
// create a factory for the type. Throws if either of these conditions are not true.
internal static void CheckPublicParameterlessConstructor(Type type) {
if (type == null) {
throw new ArgumentNullException("type");
}
if (!(type.IsPublic || type.IsNestedPublic)) {
throw new InvalidOperationException(SR.GetString(SR.FactoryGenerator_TypeNotPublic, type.Name));
}
ConstructorInfo constructor = type.GetConstructor(Type.EmptyTypes);
if (constructor == null) {
throw new InvalidOperationException(SR.GetString(SR.FactoryGenerator_TypeHasNoParameterlessConstructor, type.Name));
}
}
private static String GetUniqueCompilationName() {
return Guid.NewGuid().ToString().Replace('-', '_');
}
[ReflectionPermission(SecurityAction.Assert, Flags=ReflectionPermissionFlag.ReflectionEmit)]
Type GetFactoryTypeWithAssert(Type type) {
CheckPublicParameterlessConstructor(type);
// Create the dynamic assembly if needed.
Type factoryType;
if (_dynamicModule == null) {
lock (this) {
if (_dynamicModule == null) {
// Use a unique name for each assembly.
String name = GetUniqueCompilationName();
AssemblyName assemblyName = new AssemblyName();
assemblyName.Name = "A_" + name;
// Create a new assembly.
AssemblyBuilder newAssembly =
Thread.GetDomain().DefineDynamicAssembly(assemblyName,
AssemblyBuilderAccess.Run,
null, //directory to persist assembly
null, //evidence copied from caller
null, //requiredPermissions
null, //optionalPermissions
null, //refusedPermissions
true //isSynchronized
);
// Create a single module in the assembly.
_dynamicModule = newAssembly.DefineDynamicModule("M_" + name);
}
}
}
// Give the factory a unique name.
String typeName = GetUniqueCompilationName();
TypeBuilder factoryTypeBuilder = _dynamicModule.DefineType("T_" + typeName,
TypeAttributes.Public,
typeof(Object),
_interfacesToImplement);
// Define the CreateInstance method. It must be virtual to be an interface implementation.
MethodBuilder method = factoryTypeBuilder.DefineMethod("CreateInstance",
MethodAttributes.Public |
MethodAttributes.Virtual,
_returnedType,
null);
// Generate IL. The generated IL corresponds to "return new type()"
// newobj
// ret
ILGenerator il = method.GetILGenerator();
ConstructorInfo cons = type.GetConstructor(Type.EmptyTypes);
il.Emit(OpCodes.Newobj, cons);
il.Emit(OpCodes.Ret);
// Specify that this method implements CreateInstance from the inherited interface.
factoryTypeBuilder.DefineMethodOverride(method, _methodToOverride);
// Bake in the type.
factoryType = factoryTypeBuilder.CreateType();
return factoryType;
}
internal IWebObjectFactory CreateFactory(Type type) {
Debug.Trace("FactoryGenerator", "Creating generator for type " + type.FullName);
Type factoryType = GetFactoryTypeWithAssert(type);
// Create the type. This is the only place where Activator.CreateInstance is used,
// reducing the calls to it from 1 per instance to 1 per type.
return (IWebObjectFactory) Activator.CreateInstance(factoryType);
}
}
}
#endif
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
//------------------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
//-----------------------------------------------------------------------------
#if !DONTUSEFACTORYGENERATOR
using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Threading;
using System.Security;
using System.Security.Permissions;
namespace System.Web.Util {
/*
* Factory Generator class
* A factory generator is useful for cases where a large number of late-bound
* classes need to be instantiated.
*
* Normally, to create an instance of type t, you call the following code:
*
* ISomeInterface o = (ISomeInterface) Activator.CreateInstance(t);
*
* This assumes that the default constructor is used, and that the type t
* implements the interface ISomeInterface.
*
* The factory generator, on the other hand, can use reflection emit APIs
* to dynamically generate a class factory for t. The generated class has
* the equivalent of the following code:
*
* class X : ISomeInterfaceFactory {
* public ISomeInterface CreateInstance() {
* return new t();
* }
* }
*
* It then instantiates and returns an object of this type. You can then
* call CreateInstance to create an instance of the type, which is
* significantly faster.
*
* A single instance of a FactoryGenerator can generate factories for
* multiple types. However, it builds all these types into a single
* dynamically generated assembly. CLR implementation prevents this
* assembly from being unloaded until the process exits.
*
* The FactoryGenerator is (almost) a templated type. It takes two
* types in its constructor:
*
* returnedType is the type common to all classes for which factories
* are to be generated. In the example above, this would be
* ISomeInterface.
* factoryInterface is the interface implemented by the dynamically
* generated class factory, and should include a method named
* CreateInstance, that takes no parameters and returns an object
* of the type specified by returnedType. In the example above,
* this would be ISomeInterfaceFactory.
*
* Copyright (c) 2003 Microsoft Corporation
*/
internal class FactoryGenerator {
private Type _factoryInterface;
private Type _returnedType;
private MethodInfo _methodToOverride;
private ModuleBuilder _dynamicModule = null;
private Type[] _emptyParameterList = new Type[] { };
private Type[] _interfacesToImplement;
internal FactoryGenerator() : this(typeof(object), typeof(IWebObjectFactory)) {}
private FactoryGenerator(Type returnedType, Type factoryInterface) {
_returnedType = returnedType;
_factoryInterface = factoryInterface;
// Get the CreateInstance method, and make sure it has
// the correct signature.
_methodToOverride = factoryInterface.GetMethod("CreateInstance", new Type[0]);
if (_methodToOverride.ReturnType != _returnedType) {
throw new ArgumentException(SR.GetString(SR.FactoryInterface));
}
// This will be needed later, when building the dynamic class.
_interfacesToImplement = new Type[1];
_interfacesToImplement[0] = factoryInterface;
}
// A type must be public and have a parameterless constructor, in order for us to be able to
// create a factory for the type. Throws if either of these conditions are not true.
internal static void CheckPublicParameterlessConstructor(Type type) {
if (type == null) {
throw new ArgumentNullException("type");
}
if (!(type.IsPublic || type.IsNestedPublic)) {
throw new InvalidOperationException(SR.GetString(SR.FactoryGenerator_TypeNotPublic, type.Name));
}
ConstructorInfo constructor = type.GetConstructor(Type.EmptyTypes);
if (constructor == null) {
throw new InvalidOperationException(SR.GetString(SR.FactoryGenerator_TypeHasNoParameterlessConstructor, type.Name));
}
}
private static String GetUniqueCompilationName() {
return Guid.NewGuid().ToString().Replace('-', '_');
}
[ReflectionPermission(SecurityAction.Assert, Flags=ReflectionPermissionFlag.ReflectionEmit)]
Type GetFactoryTypeWithAssert(Type type) {
CheckPublicParameterlessConstructor(type);
// Create the dynamic assembly if needed.
Type factoryType;
if (_dynamicModule == null) {
lock (this) {
if (_dynamicModule == null) {
// Use a unique name for each assembly.
String name = GetUniqueCompilationName();
AssemblyName assemblyName = new AssemblyName();
assemblyName.Name = "A_" + name;
// Create a new assembly.
AssemblyBuilder newAssembly =
Thread.GetDomain().DefineDynamicAssembly(assemblyName,
AssemblyBuilderAccess.Run,
null, //directory to persist assembly
null, //evidence copied from caller
null, //requiredPermissions
null, //optionalPermissions
null, //refusedPermissions
true //isSynchronized
);
// Create a single module in the assembly.
_dynamicModule = newAssembly.DefineDynamicModule("M_" + name);
}
}
}
// Give the factory a unique name.
String typeName = GetUniqueCompilationName();
TypeBuilder factoryTypeBuilder = _dynamicModule.DefineType("T_" + typeName,
TypeAttributes.Public,
typeof(Object),
_interfacesToImplement);
// Define the CreateInstance method. It must be virtual to be an interface implementation.
MethodBuilder method = factoryTypeBuilder.DefineMethod("CreateInstance",
MethodAttributes.Public |
MethodAttributes.Virtual,
_returnedType,
null);
// Generate IL. The generated IL corresponds to "return new type()"
// newobj
// ret
ILGenerator il = method.GetILGenerator();
ConstructorInfo cons = type.GetConstructor(Type.EmptyTypes);
il.Emit(OpCodes.Newobj, cons);
il.Emit(OpCodes.Ret);
// Specify that this method implements CreateInstance from the inherited interface.
factoryTypeBuilder.DefineMethodOverride(method, _methodToOverride);
// Bake in the type.
factoryType = factoryTypeBuilder.CreateType();
return factoryType;
}
internal IWebObjectFactory CreateFactory(Type type) {
Debug.Trace("FactoryGenerator", "Creating generator for type " + type.FullName);
Type factoryType = GetFactoryTypeWithAssert(type);
// Create the type. This is the only place where Activator.CreateInstance is used,
// reducing the calls to it from 1 per instance to 1 per type.
return (IWebObjectFactory) Activator.CreateInstance(factoryType);
}
}
}
#endif
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- PropertyEmitterBase.cs
- AuthenticateEventArgs.cs
- _ReceiveMessageOverlappedAsyncResult.cs
- FrameworkElement.cs
- DataGridViewRowCollection.cs
- Material.cs
- CaseKeyBox.xaml.cs
- DataColumnCollection.cs
- HttpHandlerAction.cs
- ControlParameter.cs
- ViewGenerator.cs
- ExpressionHelper.cs
- RoleManagerSection.cs
- XmlNamespaceMapping.cs
- WebPartActionVerb.cs
- X509UI.cs
- _FtpDataStream.cs
- AddInToken.cs
- GraphicsContainer.cs
- Line.cs
- TimeSpan.cs
- ErrorProvider.cs
- MultipartIdentifier.cs
- ConditionChanges.cs
- TranslateTransform3D.cs
- ParserContext.cs
- UserControl.cs
- SudsWriter.cs
- SHA512.cs
- _Connection.cs
- SecuritySessionFilter.cs
- Debug.cs
- SrgsRulesCollection.cs
- VisualProxy.cs
- DataRecordInfo.cs
- DataStorage.cs
- QuadraticBezierSegment.cs
- ReverseInheritProperty.cs
- SetIterators.cs
- BmpBitmapEncoder.cs
- EnumBuilder.cs
- ToolboxCategoryItems.cs
- HandlerWithFactory.cs
- CryptoStream.cs
- ContainerAction.cs
- SafeViewOfFileHandle.cs
- PrintPreviewDialog.cs
- IpcPort.cs
- OpenFileDialog.cs
- CLRBindingWorker.cs
- Renderer.cs
- RuleDefinitions.cs
- Stylesheet.cs
- TaiwanCalendar.cs
- ExpressionStringBuilder.cs
- WebException.cs
- Membership.cs
- UnauthorizedAccessException.cs
- GenerateTemporaryTargetAssembly.cs
- DtcInterfaces.cs
- GotoExpression.cs
- DecodeHelper.cs
- OutputCacheProviderCollection.cs
- GatewayDefinition.cs
- ipaddressinformationcollection.cs
- PagerSettings.cs
- Exception.cs
- ConfigurationManagerHelperFactory.cs
- SqlCommand.cs
- TextContainerHelper.cs
- IssuanceLicense.cs
- CodeAttributeArgumentCollection.cs
- JsonDeserializer.cs
- ImportDesigner.xaml.cs
- XsltArgumentList.cs
- TranslateTransform.cs
- RuleSettingsCollection.cs
- PriorityItem.cs
- WebBrowserContainer.cs
- HostedTransportConfigurationManager.cs
- EntityProviderServices.cs
- TextBoxBase.cs
- CategoryNameCollection.cs
- MultipleViewPattern.cs
- DataBindingHandlerAttribute.cs
- DataGridViewBand.cs
- StructuredType.cs
- initElementDictionary.cs
- ObjectStateManagerMetadata.cs
- X509Certificate2Collection.cs
- XamlValidatingReader.cs
- ResourceIDHelper.cs
- CallbackValidator.cs
- WebPartsPersonalization.cs
- ValueSerializerAttribute.cs
- ConversionContext.cs
- SqlMetaData.cs
- ParameterCollectionEditorForm.cs
- TdsParserStateObject.cs
- ColorPalette.cs