/// <summary>
/// Converts a CloudEvent to <see cref="HttpContent"/>.
/// </summary>
/// <param name="cloudEvent">The CloudEvent to convert. Must not be null, and must be a valid CloudEvent.</param>
/// <param name="contentMode">Content mode. Structured or binary.</param>
/// <param name="formatter">The formatter to use within the conversion. Must not be null.</param>
public static HttpContent ToHttpContent(this CloudEvent cloudEvent, ContentMode contentMode, CloudEventFormatter formatter)
{
Validation.CheckCloudEventArgument(cloudEvent, nameof(cloudEvent));
Validation.CheckNotNull(formatter, nameof(formatter));
ReadOnlyMemory <byte> content;
// The content type to include in the ContentType header - may be the data content type, or the formatter's content type.
ContentType?contentType;
switch (contentMode)
{
case ContentMode.Structured:
content = formatter.EncodeStructuredModeMessage(cloudEvent, out contentType);
break;
case ContentMode.Binary:
content = formatter.EncodeBinaryModeEventData(cloudEvent);
contentType = MimeUtilities.CreateContentTypeOrNull(formatter.GetOrInferDataContentType(cloudEvent));
break;
default:
throw new ArgumentOutOfRangeException(nameof(contentMode), $"Unsupported content mode: {contentMode}");
}
ByteArrayContent ret = ToByteArrayContent(content);
if (contentType is object)
{
ret.Headers.ContentType = MimeUtilities.ToMediaTypeHeaderValue(contentType);
}
else if (content.Length != 0)
{
throw new ArgumentException(Strings.ErrorContentTypeUnspecified, nameof(cloudEvent));
}
// Map headers in either mode.
// Including the headers in structured mode is optional in the spec (as they're already within the body) but
// can be useful.
ret.Headers.Add(HttpUtilities.SpecVersionHttpHeader, HttpUtilities.EncodeHeaderValue(cloudEvent.SpecVersion.VersionId));
foreach (var attributeAndValue in cloudEvent.GetPopulatedAttributes())
{
CloudEventAttribute attribute = attributeAndValue.Key;
string headerName = HttpUtilities.HttpHeaderPrefix + attribute.Name;
object value = attributeAndValue.Value;
// Skip the data content type attribute in binary mode, because it's already in the content type header.
if (attribute == cloudEvent.SpecVersion.DataContentTypeAttribute && contentMode == ContentMode.Binary)
{
continue;
}
else
{
string headerValue = HttpUtilities.EncodeHeaderValue(attribute.Format(value));
ret.Headers.Add(headerName, headerValue);
}
}
return(ret);
}
/// <summary>
/// Copies a <see cref="CloudEvent"/> into an <see cref="HttpResponse" />.
/// </summary>
/// <param name="cloudEvent">The CloudEvent to copy. Must not be null, and must be a valid CloudEvent.</param>
/// <param name="destination">The response to copy the CloudEvent to. Must not be null.</param>
/// <param name="contentMode">Content mode (structured or binary)</param>
/// <param name="formatter">The formatter to use within the conversion. Must not be null.</param>
/// <returns>A task representing the asynchronous operation.</returns>
public static async Task CopyToHttpResponseAsync(this CloudEvent cloudEvent, HttpResponse destination,
ContentMode contentMode, CloudEventFormatter formatter)
{
Validation.CheckCloudEventArgument(cloudEvent, nameof(cloudEvent));
Validation.CheckNotNull(destination, nameof(destination));
Validation.CheckNotNull(formatter, nameof(formatter));
ReadOnlyMemory <byte> content;
ContentType? contentType;
switch (contentMode)
{
case ContentMode.Structured:
content = formatter.EncodeStructuredModeMessage(cloudEvent, out contentType);
break;
case ContentMode.Binary:
content = formatter.EncodeBinaryModeEventData(cloudEvent);
contentType = MimeUtilities.CreateContentTypeOrNull(formatter.GetOrInferDataContentType(cloudEvent));
break;
default:
throw new ArgumentOutOfRangeException(nameof(contentMode), $"Unsupported content mode: {contentMode}");
}
if (contentType is object)
{
destination.ContentType = contentType.ToString();
}
else if (content.Length != 0)
{
throw new ArgumentException("The 'datacontenttype' attribute value must be specified", nameof(cloudEvent));
}
// Map headers in either mode.
// Including the headers in structured mode is optional in the spec (as they're already within the body) but
// can be useful.
destination.Headers.Add(HttpUtilities.SpecVersionHttpHeader, HttpUtilities.EncodeHeaderValue(cloudEvent.SpecVersion.VersionId));
foreach (var attributeAndValue in cloudEvent.GetPopulatedAttributes())
{
var attribute = attributeAndValue.Key;
var value = attributeAndValue.Value;
// The content type is already handled based on the content mode.
if (attribute != cloudEvent.SpecVersion.DataContentTypeAttribute)
{
string headerValue = HttpUtilities.EncodeHeaderValue(attribute.Format(value));
destination.Headers.Add(HttpUtilities.HttpHeaderPrefix + attribute.Name, headerValue);
}
}
destination.ContentLength = content.Length;
await BinaryDataUtilities.CopyToStreamAsync(content, destination.Body).ConfigureAwait(false);
}
/// <summary>
/// Converts a CloudEvent to <see cref="Message"/>.
/// </summary>
/// <param name="cloudEvent">The CloudEvent to convert. Must not be null, and must be a valid CloudEvent.</param>
/// <param name="contentMode">Content mode. Structured or binary.</param>
/// <param name="formatter">The formatter to use within the conversion. Must not be null.</param>
public static Message ToAmqpMessage(this CloudEvent cloudEvent, ContentMode contentMode, CloudEventFormatter formatter)
{
Validation.CheckCloudEventArgument(cloudEvent, nameof(cloudEvent));
Validation.CheckNotNull(formatter, nameof(formatter));
var applicationProperties = MapHeaders(cloudEvent);
RestrictedDescribed bodySection;
Properties properties;
switch (contentMode)
{
case ContentMode.Structured:
bodySection = new Data
{
Binary = BinaryDataUtilities.AsArray(formatter.EncodeStructuredModeMessage(cloudEvent, out var contentType))
};
// TODO: What about the other parts of the content type?
properties = new Properties {
ContentType = contentType.MediaType
};
break;
case ContentMode.Binary:
bodySection = new Data {
Binary = BinaryDataUtilities.AsArray(formatter.EncodeBinaryModeEventData(cloudEvent))
};
properties = new Properties {
ContentType = formatter.GetOrInferDataContentType(cloudEvent)
};
break;
default:
throw new ArgumentOutOfRangeException(nameof(contentMode), $"Unsupported content mode: {contentMode}");
}
return(new Message
{
ApplicationProperties = applicationProperties,
BodySection = bodySection,
Properties = properties
});
}
/// <summary>
/// Converts a CloudEvent to a Kafka message.
/// </summary>
/// <param name="cloudEvent">The CloudEvent to convert. Must not be null, and must be a valid CloudEvent.</param>
/// <param name="contentMode">Content mode. Structured or binary.</param>
/// <param name="formatter">The formatter to use within the conversion. Must not be null.</param>
public static Message <string?, byte[]> ToKafkaMessage(this CloudEvent cloudEvent, ContentMode contentMode, CloudEventFormatter formatter)
{
Validation.CheckCloudEventArgument(cloudEvent, nameof(cloudEvent));
Validation.CheckNotNull(formatter, nameof(formatter));
// TODO: Is this appropriate? Why can't we transport a CloudEvent without data in Kafka?
Validation.CheckArgument(cloudEvent.Data is object, nameof(cloudEvent), "Only CloudEvents with data can be converted to Kafka messages");
var headers = MapHeaders(cloudEvent);
string?key = (string?)cloudEvent[Partitioning.PartitionKeyAttribute];
byte[] value;
string?contentTypeHeaderValue;
switch (contentMode)
{
case ContentMode.Structured:
value = BinaryDataUtilities.AsArray(formatter.EncodeStructuredModeMessage(cloudEvent, out var contentType));
// TODO: What about the non-media type parts?
contentTypeHeaderValue = contentType.MediaType;
break;
case ContentMode.Binary:
value = BinaryDataUtilities.AsArray(formatter.EncodeBinaryModeEventData(cloudEvent));
contentTypeHeaderValue = formatter.GetOrInferDataContentType(cloudEvent);
break;
default:
throw new ArgumentOutOfRangeException(nameof(contentMode), $"Unsupported content mode: {contentMode}");
}
if (contentTypeHeaderValue is object)
{
headers.Add(KafkaContentTypeAttributeName, Encoding.UTF8.GetBytes(contentTypeHeaderValue));
}
return(new Message <string?, byte[]>
{
Headers = headers,
Value = value,
Key = key
});
}