/// <summary>
/// Gets the default media type for a given payload kind in a given format.
/// </summary>
/// <param name="payloadKind">The kind of payload to write.</param>
/// <param name="specifiedFormat">The format in which to write the payload (can be ODataFormat.Default).</param>
/// <param name="actualFormat">The default format for the specified payload kind (is never ODataFormat.Default)</param>
/// <returns>The default media type for the given payload kind and format.</returns>
private static MediaType GetDefaultMediaType(ODataPayloadKind payloadKind, ODataFormat specifiedFormat, out ODataFormat actualFormat)
{
// get the supported and default media types for the specified payload kind
MediaTypeWithFormat[] supportedMediaTypes = mediaTypesForPayloadKind[(int)payloadKind];
for (int i = 0; i < supportedMediaTypes.Length; ++i)
{
// NOTE: the supportedMediaTypes are sorted (desc) by format and media type; so the
// default format and media type is the first entry in the array
MediaTypeWithFormat supportedMediaType = supportedMediaTypes[i];
if (specifiedFormat == ODataFormat.Default || supportedMediaType.Format == specifiedFormat)
{
actualFormat = supportedMediaType.Format;
return(supportedMediaType.MediaType);
}
}
throw new ODataException(Strings.ODataUtils_DidNotFindDefaultMediaType(specifiedFormat.ToString()));
}
/// <summary>
/// Matches the supported media types against the list of acceptable media types specified in the Accept header of the request. Matching follows the
/// rules for media type matching as described in RFC 2616.
/// </summary>
/// <param name="acceptableTypes">The set of acceptable media types specified in the Accept header of the request.</param>
/// <param name="supportedMediaTypes">The set of supported media types (sorted in descending precedence order).</param>
/// <param name="format">The <see cref="ODataFormat"/> for the selected media type.</param>
/// <returns>The media type that best matches the acceptable media types.</returns>
private static MediaType MatchMediaTypes(IList<MediaType> acceptableTypes, MediaTypeWithFormat[] supportedMediaTypes, out ODataFormat format)
{
Debug.Assert(supportedMediaTypes != null, "supportedMediaTypes != null");
MediaTypeWithFormat selectedContentType = null;
int selectedMatchingTypeNameParts = -1;
int selectedMatchingParameters = -2; // -2 is an invalid value; GetMatchingParameters returns values >= -1
int selectedQualityValue = 0;
int selectedPreferenceIndex = Int32.MaxValue;
bool selectedAcceptable = false;
if (acceptableTypes != null)
{
foreach (MediaType acceptableType in acceptableTypes)
{
for (int i = 0; i < supportedMediaTypes.Length; i++)
{
MediaTypeWithFormat supportedType = supportedMediaTypes[i];
// match the type name parts and parameters of the media type
int matchingParameters, matchingQualityValue, acceptableTypeParameterCount;
int matchingTypeNameParts = acceptableType.GetMatchingParts(supportedType.MediaType, out matchingParameters, out matchingQualityValue, out acceptableTypeParameterCount);
if (!IsValidCandidate(matchingTypeNameParts, matchingParameters, acceptableTypeParameterCount))
{
continue;
}
// only continue processing the type if it is acceptable or we don't have
// an acceptable type yet.
bool matchingAcceptable = matchingQualityValue != 0;
if (!matchingAcceptable && selectedAcceptable)
{
continue;
}
PrecedenceLevel precedence = ComputePrecedence(selectedAcceptable, matchingTypeNameParts, selectedMatchingTypeNameParts, matchingParameters, selectedMatchingParameters);
switch (precedence)
{
case PrecedenceLevel.Higher:
{
// A more specific type wins.
selectedContentType = supportedType;
selectedMatchingTypeNameParts = matchingTypeNameParts;
selectedMatchingParameters = matchingParameters;
selectedQualityValue = matchingQualityValue;
selectedPreferenceIndex = i;
selectedAcceptable = matchingAcceptable;
}
break;
case PrecedenceLevel.Same:
{
// A type with a higher q-value wins.
if (matchingQualityValue > selectedQualityValue)
{
selectedContentType = supportedType;
selectedQualityValue = matchingQualityValue;
selectedPreferenceIndex = i;
selectedAcceptable = selectedQualityValue != 0;
}
else if (matchingQualityValue == selectedQualityValue)
{
// A type that is earlier in the supportedMediaTypes array wins.
if (i < selectedPreferenceIndex)
{
selectedContentType = supportedType;
selectedPreferenceIndex = i;
}
}
}
break;
case PrecedenceLevel.Lower:
continue;
default:
throw new ODataException(Strings.General_InternalError(InternalErrorCodes.ODataUtils_MatchMediaTypes_UnreachableCodePath));
}
}
}
}
if (acceptableTypes == null || acceptableTypes.Count == 0)
{
// if not acceptable types are specified it means that all types are supported;
// take the first supported type (as they are oredered by priority/precedence)
selectedContentType = supportedMediaTypes[0];
}
else if (!selectedAcceptable)
{
format = ODataFormat.Default;
return null;
}
format = selectedContentType.Format;
return selectedContentType.MediaType;
}
/// <summary>
/// Matches the supported media types against the list of acceptable media types specified in the Accept header of the request. Matching follows the
/// rules for media type matching as described in RFC 2616.
/// </summary>
/// <param name="acceptableTypes">The set of acceptable media types specified in the Accept header of the request.</param>
/// <param name="supportedMediaTypes">The set of supported media types (sorted in descending precedence order).</param>
/// <param name="format">The <see cref="ODataFormat"/> for the selected media type.</param>
/// <returns>The media type that best matches the acceptable media types.</returns>
private static MediaType MatchMediaTypes(IList <MediaType> acceptableTypes, MediaTypeWithFormat[] supportedMediaTypes, out ODataFormat format)
{
Debug.Assert(supportedMediaTypes != null, "supportedMediaTypes != null");
MediaTypeWithFormat selectedContentType = null;
int selectedMatchingTypeNameParts = -1;
int selectedMatchingParameters = -2;// -2 is an invalid value; GetMatchingParameters returns values >= -1
int selectedQualityValue = 0;
int selectedPreferenceIndex = Int32.MaxValue;
bool selectedAcceptable = false;
if (acceptableTypes != null)
{
foreach (MediaType acceptableType in acceptableTypes)
{
for (int i = 0; i < supportedMediaTypes.Length; i++)
{
MediaTypeWithFormat supportedType = supportedMediaTypes[i];
// match the type name parts and parameters of the media type
int matchingParameters, matchingQualityValue, acceptableTypeParameterCount;
int matchingTypeNameParts = acceptableType.GetMatchingParts(supportedType.MediaType, out matchingParameters, out matchingQualityValue, out acceptableTypeParameterCount);
if (!IsValidCandidate(matchingTypeNameParts, matchingParameters, acceptableTypeParameterCount))
{
continue;
}
// only continue processing the type if it is acceptable or we don't have
// an acceptable type yet.
bool matchingAcceptable = matchingQualityValue != 0;
if (!matchingAcceptable && selectedAcceptable)
{
continue;
}
PrecedenceLevel precedence = ComputePrecedence(selectedAcceptable, matchingTypeNameParts, selectedMatchingTypeNameParts, matchingParameters, selectedMatchingParameters);
switch (precedence)
{
case PrecedenceLevel.Higher:
{
// A more specific type wins.
selectedContentType = supportedType;
selectedMatchingTypeNameParts = matchingTypeNameParts;
selectedMatchingParameters = matchingParameters;
selectedQualityValue = matchingQualityValue;
selectedPreferenceIndex = i;
selectedAcceptable = matchingAcceptable;
}
break;
case PrecedenceLevel.Same:
{
// A type with a higher q-value wins.
if (matchingQualityValue > selectedQualityValue)
{
selectedContentType = supportedType;
selectedQualityValue = matchingQualityValue;
selectedPreferenceIndex = i;
selectedAcceptable = selectedQualityValue != 0;
}
else if (matchingQualityValue == selectedQualityValue)
{
// A type that is earlier in the supportedMediaTypes array wins.
if (i < selectedPreferenceIndex)
{
selectedContentType = supportedType;
selectedPreferenceIndex = i;
}
}
}
break;
case PrecedenceLevel.Lower:
continue;
default:
throw new ODataException(Strings.General_InternalError(InternalErrorCodes.ODataUtils_MatchMediaTypes_UnreachableCodePath));
}
}
}
}
if (acceptableTypes == null || acceptableTypes.Count == 0)
{
// if not acceptable types are specified it means that all types are supported;
// take the first supported type (as they are oredered by priority/precedence)
selectedContentType = supportedMediaTypes[0];
}
else if (!selectedAcceptable)
{
format = ODataFormat.Default;
return(null);
}
format = selectedContentType.Format;
return(selectedContentType.MediaType);
}
