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//------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
//------------------------------------------------------------
#pragma warning disable 1634, 1691
namespace System.ServiceModel.Description
{
using System.Collections.Generic;
using System.Linq;
using System.Net.Mime;
using System.Runtime;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Dispatcher;
using System.ServiceModel.Web;
using System.Diagnostics;
using System.ServiceModel.Diagnostics;
class FormatSelectingMessageInspector : IDispatchMessageInspector
{
static readonly IEnumerable<string> wildcardMediaTypes = new List<string>() { "application", "text" };
List<MultiplexingFormatMapping> mappings;
Dictionary<string, MultiplexingDispatchMessageFormatter> formatters;
Dictionary<string, NameValueCache<FormatContentTypePair>> caches;
bool automaticFormatSelectionEnabled;
// There are technically an infinite number of valid accept headers for just xml and json,
// but to prevent DOS attacks, we need to set an upper limit. It is assumed that there would
// never be more than two dozen valid accept headers actually used out in the wild.
static readonly int maxCachedAcceptHeaders = 25;
public FormatSelectingMessageInspector(WebHttpBehavior webHttpBehavior, List<MultiplexingFormatMapping> mappings)
{
if (webHttpBehavior == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("webHttpBehavior");
}
if (mappings == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("mappings");
}
this.automaticFormatSelectionEnabled = webHttpBehavior.AutomaticFormatSelectionEnabled;
this.formatters = new Dictionary<string, MultiplexingDispatchMessageFormatter>();
this.caches = new Dictionary<string, NameValueCache<FormatContentTypePair>>();
this.mappings = mappings;
}
public void RegisterOperation(string operationName, MultiplexingDispatchMessageFormatter formatter)
{
if (formatter == null)
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("formatter");
}
Fx.Assert(!this.formatters.ContainsKey(operationName), "An operation should only be registered once.");
this.formatters.Add(operationName, formatter);
this.caches.Add(operationName, new NameValueCache<FormatContentTypePair>(maxCachedAcceptHeaders));
}
public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
{
if (this.automaticFormatSelectionEnabled)
{
MessageProperties messageProperties = OperationContext.Current.IncomingMessageProperties;
if (messageProperties.ContainsKey(WebHttpDispatchOperationSelector.HttpOperationNamePropertyName))
{
string operationName = messageProperties[WebHttpDispatchOperationSelector.HttpOperationNamePropertyName] as string;
if (!string.IsNullOrEmpty(operationName) && this.formatters.ContainsKey(operationName))
{
string acceptHeader = WebOperationContext.Current.IncomingRequest.Accept;
if (!string.IsNullOrEmpty(acceptHeader))
{
if (TrySetFormatFromCache(operationName, acceptHeader) ||
TrySetFormatFromAcceptHeader(operationName, acceptHeader, true /* matchCharSet */) ||
TrySetFormatFromAcceptHeader(operationName, acceptHeader, false /* matchCharSet */))
{
return null;
}
}
if (TrySetFormatFromContentType(operationName))
{
return null;
}
SetFormatFromDefault(operationName);
}
}
}
return null;
}
public void BeforeSendReply(ref Message reply, object correlationState)
{
// do nothing
}
bool TrySetFormatFromCache(string operationName, string acceptHeader)
{
Fx.Assert(this.caches.ContainsKey(operationName), "The calling method is responsible for ensuring that the 'operationName' key exists in the caches dictionary.");
Fx.Assert(acceptHeader != null, "The calling method is responsible for ensuring that 'acceptHeader' is not null");
FormatContentTypePair pair = caches[operationName].Lookup(acceptHeader.ToUpperInvariant());
if (pair != null)
{
SetFormatAndContentType(pair.Format, pair.ContentType);
return true;
}
return false;
}
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Globalization", "CA1308:NormalizeStringsToUppercase", Justification = "Given that media types are generally in lowercase, it is awkward to normalize to uppercase.")]
bool TrySetFormatFromAcceptHeader(string operationName, string acceptHeader, bool matchCharSet)
{
Fx.Assert(this.formatters.ContainsKey(operationName), "The calling method is responsible for ensuring that the 'operationName' key exists in the formatters dictionary.");
IList<ContentType> acceptHeaderElements = WebOperationContext.Current.IncomingRequest.GetAcceptHeaderElements();
for (int i = 0; i < acceptHeaderElements.Count; i++)
{
string[] typeAndSubType = acceptHeaderElements[i].MediaType.Split('/');
string type = typeAndSubType[0].Trim().ToLowerInvariant();
string subType = typeAndSubType[1].Trim();
if ((subType[0] == '*' && subType.Length == 1) &&
((type[0] == '*' && type.Length == 1) ||
wildcardMediaTypes.Contains(type)))
{
SetFormatFromDefault(operationName, acceptHeader);
return true;
}
foreach (MultiplexingFormatMapping mapping in mappings)
{
ContentType contentType;
WebMessageFormat format = mapping.MessageFormat;
if (this.formatters[operationName].SupportsMessageFormat(format) &&
mapping.CanFormatResponse(acceptHeaderElements[i], matchCharSet, out contentType))
{
string contentTypeStr = contentType.ToString();
this.caches[operationName].AddOrUpdate(acceptHeader.ToUpperInvariant(), new FormatContentTypePair(format, contentTypeStr));
SetFormatAndContentType(format, contentTypeStr);
return true;
}
}
}
return false;
}
bool TrySetFormatFromContentType(string operationName)
{
Fx.Assert(this.formatters.ContainsKey(operationName), "The calling method is responsible for ensuring that the 'operationName' key exists in the formatters dictionary.");
string contentTypeStr = WebOperationContext.Current.IncomingRequest.ContentType;
if (contentTypeStr != null)
{
ContentType contentType = Web.Utility.GetContentType(contentTypeStr);
if (contentType != null)
{
foreach (MultiplexingFormatMapping mapping in mappings)
{
ContentType responseContentType;
if (this.formatters[operationName].SupportsMessageFormat(mapping.MessageFormat) &&
mapping.CanFormatResponse(contentType, false, out responseContentType))
{
SetFormatAndContentType(mapping.MessageFormat, responseContentType.ToString());
return true;
}
}
}
}
return false;
}
void SetFormatFromDefault(string operationName)
{
SetFormatFromDefault(operationName, null);
}
void SetFormatFromDefault(string operationName, string acceptHeader)
{
Fx.Assert(this.formatters.ContainsKey(operationName), "The calling method is responsible for ensuring that the 'operationName' key exists in the formatters dictionary.");
WebMessageFormat format = this.formatters[operationName].DefaultFormat;
if (!string.IsNullOrEmpty(acceptHeader))
{
this.caches[operationName].AddOrUpdate(acceptHeader.ToUpperInvariant(), new FormatContentTypePair(format, null));
}
WebOperationContext.Current.OutgoingResponse.Format = format;
if (DiagnosticUtility.ShouldTraceInformation)
{
TraceUtility.TraceEvent(TraceEventType.Information, TraceCode.AutomaticFormatSelectedOperationDefault, SR2.GetString(SR2.TraceCodeAutomaticFormatSelectedOperationDefault, format.ToString()));
}
}
void SetFormatAndContentType(WebMessageFormat format, string contentType)
{
OutgoingWebResponseContext outgoingResponse = WebOperationContext.Current.OutgoingResponse;
outgoingResponse.Format = format;
outgoingResponse.AutomatedFormatSelectionContentType = contentType;
if (DiagnosticUtility.ShouldTraceInformation)
{
TraceUtility.TraceEvent(TraceEventType.Information, TraceCode.AutomaticFormatSelectedRequestBased, SR2.GetString(SR2.TraceCodeAutomaticFormatSelectedRequestBased, format.ToString(), contentType));
}
}
class FormatContentTypePair
{
WebMessageFormat format;
string contentType;
public FormatContentTypePair(WebMessageFormat format, string contentType)
{
this.format = format;
this.contentType = contentType;
}
public WebMessageFormat Format
{
get { return this.format; }
}
public string ContentType
{
get { return this.contentType; }
}
}
}
}
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