/// <summary>Initializes a new <see cref="ResponseBodyWriter"/> that can write the body of a response.</summary>
/// <param name="service">Service for the request being processed.</param>
/// <param name="queryResults">Enumerator for results.</param>
/// <param name="requestDescription">Description of request made to the system.</param>
/// <param name="actualResponseMessageWhoseHeadersMayBeOverridden">IODataResponseMessage instance for the response.</param>
internal ResponseBodyWriter(
IDataService service,
QueryResultInfo queryResults,
RequestDescription requestDescription,
IODataResponseMessage actualResponseMessageWhoseHeadersMayBeOverridden)
{
Debug.Assert(service != null, "service != null");
Debug.Assert(requestDescription != null, "requestDescription != null");
Debug.Assert(actualResponseMessageWhoseHeadersMayBeOverridden != null, "actualResponseMessageWhoseHeadersMayBeOverridden != null");
this.service = service;
this.queryResults = queryResults;
this.requestDescription = requestDescription;
this.actualResponseMessageWhoseHeadersMayBeOverridden = actualResponseMessageWhoseHeadersMayBeOverridden;
Debug.Assert(this.PayloadKind != ODataPayloadKind.Unsupported, "payloadKind != ODataPayloadKind.Unsupported");
this.encoding = ContentTypeUtil.EncodingFromAcceptCharset(this.service.OperationContext.RequestMessage.GetRequestAcceptCharsetHeader());
if (this.PayloadKind == ODataPayloadKind.Entry ||
this.PayloadKind == ODataPayloadKind.Feed ||
this.PayloadKind == ODataPayloadKind.Property ||
this.PayloadKind == ODataPayloadKind.Collection ||
this.PayloadKind == ODataPayloadKind.EntityReferenceLink ||
this.PayloadKind == ODataPayloadKind.EntityReferenceLinks ||
this.PayloadKind == ODataPayloadKind.Error ||
this.PayloadKind == ODataPayloadKind.ServiceDocument ||
this.PayloadKind == ODataPayloadKind.Parameter)
{
AstoriaRequestMessage requestMessage = service.OperationContext.RequestMessage;
IODataResponseMessage responseMessageOnOperationContext = service.OperationContext.ResponseMessage;
Version effectiveMaxResponseVersion = VersionUtil.GetEffectiveMaxResponseVersion(service.Configuration.DataServiceBehavior.MaxProtocolVersion.ToVersion(), requestMessage.RequestMaxVersion);
bool isEntityOrFeed = this.PayloadKind == ODataPayloadKind.Entry || this.PayloadKind == ODataPayloadKind.Feed;
if (ContentTypeUtil.IsResponseMediaTypeJsonLight(requestMessage.GetAcceptableContentTypes(), isEntityOrFeed, effectiveMaxResponseVersion))
{
// If JSON light 'wins', then bump the version to V3.
requestDescription.VerifyAndRaiseResponseVersion(VersionUtil.Version4Dot0, service);
responseMessageOnOperationContext.SetHeader(XmlConstants.HttpODataVersion, XmlConstants.ODataVersion4Dot0 + ";");
}
}
if (this.requestDescription.TargetKind == RequestTargetKind.MediaResource)
{
Debug.Assert(this.PayloadKind == ODataPayloadKind.BinaryValue, "payloadKind == ODataPayloadKind.BinaryValue");
// Note that GetReadStream will set the ResponseETag before it returns
this.mediaResourceStream = service.StreamProvider.GetReadStream(
this.queryResults.Current,
this.requestDescription.StreamProperty,
this.service.OperationContext);
}
else if (this.PayloadKind != ODataPayloadKind.BinaryValue)
{
IEdmModel model;
if (this.PayloadKind == ODataPayloadKind.MetadataDocument)
{
model = MetadataSerializer.PrepareModelForSerialization(this.service.Provider, this.service.Configuration);
}
else
{
model = this.GetModelFromService();
}
// Create the message writer using which the response needs to be written.
this.messageWriterBuilder = MessageWriterBuilder.ForNormalRequest(
this.service,
this.requestDescription,
this.actualResponseMessageWhoseHeadersMayBeOverridden,
model);
this.messageWriter = this.messageWriterBuilder.CreateWriter();
try
{
// Make sure all the headers are written before the method returns.
this.contentFormat = ODataUtils.SetHeadersForPayload(this.messageWriter, this.PayloadKind);
}
catch (ODataContentTypeException contentTypeException)
{
throw new DataServiceException(415, null, Strings.DataServiceException_UnsupportedMediaType, null, contentTypeException);
}
Debug.Assert(requestDescription.ResponseFormat != null, "Response format should already have been determined.");
Debug.Assert(ReferenceEquals(this.contentFormat, requestDescription.ResponseFormat.Format), "Response format in request description did not match format when writing.");
if (this.PayloadKind == ODataPayloadKind.Value && !String.IsNullOrEmpty(this.requestDescription.MimeType))
{
this.actualResponseMessageWhoseHeadersMayBeOverridden.SetHeader(XmlConstants.HttpContentType, this.requestDescription.MimeType);
}
// EPM is currently removed, but this doesn't seem to be used for EPM only. The old comment was saying:
// In astoria, there is a bug in V1/V2 that while computing response version, we did not take
// epm into account. Hence while creating the writer, we need to pass the RequestDescription.ActualResponseVersion
// so that ODataLib can do the correct payload validation. But we need to write the response version without
// the epm into the response headers because of backward-compat issue. Hence over-writing the response version
// header with the wrong version value.
string responseVersion = this.requestDescription.ResponseVersion.ToString() + ";";
this.actualResponseMessageWhoseHeadersMayBeOverridden.SetHeader(XmlConstants.HttpODataVersion, responseVersion);
}
}