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// <copyright>
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
namespace System.ServiceModel.Channels
{
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Configuration;
using System.Globalization;
using System.Net.Http;
using System.Reflection;
using System.Runtime;
using System.Runtime.CompilerServices;
using System.Security;
using System.Security.Permissions;
using System.ServiceModel.Configuration;
/// <summary>
/// Default HTTP message handler factory used by <see cref="HttpChannelListener"/> upon creation of an <see cref="HttpMessageHandler"/>
/// for instantiating a set of HTTP message handler types using their default constructors.
/// For more complex initialization scenarios, derive from <see cref="HttpMessageHandlerFactory"/>
/// and override the <see cref="HttpMessageHandlerFactory.OnCreate"/> method.
/// </summary>
public class HttpMessageHandlerFactory
{
static readonly Type delegatingHandlerType = typeof(DelegatingHandler);
Type[] httpMessageHandlers;
ConstructorInfo[] handlerCtors;
Func<IEnumerable<DelegatingHandler>> handlerFunc;
/// <summary>
/// Initializes a new instance of the <see cref="HttpMessageHandlerFactory"/> class given
/// a set of HTTP message handler types to instantiate using their default constructors.
/// </summary>
/// <param name="handlers">An ordered list of HTTP message handler types to be invoked as part of an
/// <see cref="HttpMessageHandler"/> instance.
/// HTTP message handler types must derive from <see cref="DelegatingHandler"/> and have a public constructor
/// taking exactly one argument of type <see cref="HttpMessageHandler"/>. The handlers are invoked in a
/// bottom-up fashion in the incoming path and top-down in the outgoing path. That is, the last entry is called first
/// for an incoming request messasge but invoked last for an outgoing response message.</param>
[PermissionSet(SecurityAction.Demand, Unrestricted = true), SecuritySafeCritical]
[MethodImpl(MethodImplOptions.NoInlining)]
public HttpMessageHandlerFactory(params Type[] handlers)
{
if (handlers == null)
{
throw FxTrace.Exception.ArgumentNull("handlers");
}
if (handlers.Length == 0)
{
throw FxTrace.Exception.Argument("handlers", SR.GetString(SR.InputTypeListEmptyError));
}
this.handlerCtors = new ConstructorInfo[handlers.Length];
for (int cnt = 0; cnt < handlers.Length; cnt++)
{
Type handler = handlers[cnt];
if (handler == null)
{
throw FxTrace.Exception.Argument(
string.Format(CultureInfo.InvariantCulture, "handlers[<<{0}>>]", cnt),
SR.GetString(SR.HttpMessageHandlerTypeNotSupported, "null", delegatingHandlerType.Name));
}
if (!delegatingHandlerType.IsAssignableFrom(handler) || handler.IsAbstract)
{
throw FxTrace.Exception.Argument(
string.Format(CultureInfo.InvariantCulture, "handlers[<<{0}>>]", cnt),
SR.GetString(SR.HttpMessageHandlerTypeNotSupported, handler.Name, delegatingHandlerType.Name));
}
ConstructorInfo ctorInfo = handler.GetConstructor(Type.EmptyTypes);
if (ctorInfo == null)
{
throw FxTrace.Exception.Argument(
string.Format(CultureInfo.InvariantCulture, "handlers[<<{0}>>]", cnt),
SR.GetString(SR.HttpMessageHandlerTypeNotSupported, handler.Name, delegatingHandlerType.Name));
}
this.handlerCtors[cnt] = ctorInfo;
}
this.httpMessageHandlers = handlers;
}
/// <summary>
/// Initializes a new instance of the <see cref="HttpMessageHandlerFactory"/> class given
/// a function to create a set of <see cref="DelegatingHandler"/> instances.
/// </summary>
/// <param name="handlers">A function to generate an ordered list of <see cref="DelegatingHandler"/> instances
/// to be invoked as part of an <see cref="HttpMessageHandler"/> instance.
/// The handlers are invoked in a bottom-up fashion in the incoming path and top-down in the outgoing path. That is,
/// the last entry is called first for an incoming request messasge but invoked last for an outgoing response message.</param>
[PermissionSet(SecurityAction.Demand, Unrestricted = true), SecuritySafeCritical]
[MethodImpl(MethodImplOptions.NoInlining)]
public HttpMessageHandlerFactory(Func<IEnumerable<DelegatingHandler>> handlers)
{
if (handlers == null)
{
throw FxTrace.Exception.ArgumentNull("handlers");
}
this.handlerFunc = handlers;
}
/// <summary>
/// Initializes a new instance of the <see cref="HttpMessageHandlerFactory"/> class.
/// </summary>
[PermissionSet(SecurityAction.Demand, Unrestricted = true), SecuritySafeCritical]
[MethodImpl(MethodImplOptions.NoInlining)]
protected HttpMessageHandlerFactory()
{
}
/// <summary>
/// Creates an instance of an <see cref="HttpMessageHandler"/> using the HTTP message handlers
/// provided in the constructor.
/// </summary>
/// <param name="innerChannel">The inner channel represents the destination of the HTTP message channel.</param>
/// <returns>The HTTP message channel.</returns>
[PermissionSet(SecurityAction.Demand, Unrestricted = true), SecuritySafeCritical]
[MethodImpl(MethodImplOptions.NoInlining)]
public HttpMessageHandler Create(HttpMessageHandler innerChannel)
{
if (innerChannel == null)
{
throw FxTrace.Exception.ArgumentNull("innerChannel");
}
return this.OnCreate(innerChannel);
}
internal static HttpMessageHandlerFactory CreateFromConfigurationElement(HttpMessageHandlerFactoryElement configElement)
{
Fx.Assert(configElement != null, "configElement should not be null.");
if (!string.IsNullOrWhiteSpace(configElement.Type))
{
if (configElement.Handlers != null && configElement.Handlers.Count > 0)
{
throw FxTrace.Exception.AsError(new ConfigurationErrorsException(SR.GetString(SR.HttpMessageHandlerFactoryConfigInvalid_WithBothTypeAndHandlerList, ConfigurationStrings.MessageHandlerFactory, ConfigurationStrings.Type, ConfigurationStrings.Handlers)));
}
Type factoryType = HttpChannelUtilities.GetTypeFromAssembliesInCurrentDomain(configElement.Type);
if (factoryType == null)
{
throw FxTrace.Exception.AsError(new ConfigurationErrorsException(SR.GetString(SR.CanNotLoadTypeGotFromConfig, configElement.Type)));
}
if (!typeof(HttpMessageHandlerFactory).IsAssignableFrom(factoryType) || factoryType.IsAbstract)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ConfigurationErrorsException(
SR.GetString(
SR.WebSocketElementConfigInvalidHttpMessageHandlerFactoryType,
typeof(HttpMessageHandlerFactory).Name,
factoryType,
typeof(HttpMessageHandlerFactory).AssemblyQualifiedName)));
}
return Activator.CreateInstance(factoryType) as HttpMessageHandlerFactory;
}
else
{
if (configElement.Handlers == null || configElement.Handlers.Count == 0)
{
return null;
}
Type[] handlerList = new Type[configElement.Handlers.Count];
for (int i = 0; i < configElement.Handlers.Count; i++)
{
Type handlerType = HttpChannelUtilities.GetTypeFromAssembliesInCurrentDomain(configElement.Handlers[i].Type);
if (handlerType == null)
{
throw FxTrace.Exception.AsError(new ConfigurationErrorsException(SR.GetString(SR.CanNotLoadTypeGotFromConfig, configElement.Handlers[i].Type)));
}
handlerList[i] = handlerType;
}
try
{
return new HttpMessageHandlerFactory(handlerList);
}
catch (ArgumentException ex)
{
throw FxTrace.Exception.AsError(new ConfigurationErrorsException(ex.Message, ex));
}
}
}
internal HttpMessageHandlerFactoryElement GenerateConfigurationElement()
{
if (this.handlerFunc != null)
{
throw FxTrace.Exception.AsError(new InvalidOperationException(SR.GetString(SR.HttpMessageHandlerFactoryWithFuncCannotGenerateConfig, typeof(HttpMessageHandlerFactory).Name, typeof(Func<IEnumerable<DelegatingHandler>>).Name)));
}
Type thisType = this.GetType();
if (thisType != typeof(HttpMessageHandlerFactory))
{
return new HttpMessageHandlerFactoryElement
{
Type = thisType.AssemblyQualifiedName
};
}
else
{
if (this.httpMessageHandlers != null)
{
DelegatingHandlerElementCollection handlerCollection = new DelegatingHandlerElementCollection();
for (int i = 0; i < this.httpMessageHandlers.Length; i++)
{
handlerCollection.Add(new DelegatingHandlerElement(this.httpMessageHandlers[i]));
}
return new HttpMessageHandlerFactoryElement
{
Handlers = handlerCollection
};
}
}
return null;
}
/// <summary>
/// Creates an instance of an <see cref="HttpMessageHandler"/> using the HTTP message handlers
/// provided in the constructor.
/// </summary>
/// <param name="innerChannel">The inner channel represents the destination of the HTTP message channel.</param>
/// <returns>The HTTP message channel.</returns>
protected virtual HttpMessageHandler OnCreate(HttpMessageHandler innerChannel)
{
if (innerChannel == null)
{
throw FxTrace.Exception.ArgumentNull("innerChannel");
}
// Get handlers either by constructing types or by calling Func
IEnumerable<DelegatingHandler> handlerInstances = null;
try
{
if (this.handlerFunc != null)
{
handlerInstances = this.handlerFunc.Invoke();
if (handlerInstances != null)
{
foreach (DelegatingHandler handler in handlerInstances)
{
if (handler == null)
{
throw FxTrace.Exception.Argument("handlers", SR.GetString(SR.DelegatingHandlerArrayFromFuncContainsNullItem, delegatingHandlerType.Name, GetFuncDetails(this.handlerFunc)));
}
}
}
}
else if (this.handlerCtors != null)
{
DelegatingHandler[] instances = new DelegatingHandler[this.handlerCtors.Length];
for (int cnt = 0; cnt < this.handlerCtors.Length; cnt++)
{
instances[cnt] = (DelegatingHandler)this.handlerCtors[cnt].Invoke(Type.EmptyTypes);
}
handlerInstances = instances;
}
}
catch (TargetInvocationException targetInvocationException)
{
throw FxTrace.Exception.AsError(targetInvocationException);
}
// Wire handlers up
HttpMessageHandler pipeline = innerChannel;
if (handlerInstances != null)
{
foreach (DelegatingHandler handler in handlerInstances)
{
if (handler.InnerHandler != null)
{
throw FxTrace.Exception.Argument("handlers", SR.GetString(SR.DelegatingHandlerArrayHasNonNullInnerHandler, delegatingHandlerType.Name, "InnerHandler", handler.GetType().Name));
}
handler.InnerHandler = pipeline;
pipeline = handler;
}
}
return pipeline;
}
static string GetFuncDetails(Func<IEnumerable<DelegatingHandler>> func)
{
Fx.Assert(func != null, "Func should not be null.");
MethodInfo m = func.Method;
Type t = m.DeclaringType;
return string.Format(CultureInfo.InvariantCulture, "{0}.{1}", t.FullName, m.Name);
}
}
}
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