eventstreamapi

package
v1.51.5 Latest Latest
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Published: Mar 21, 2024 License: Apache-2.0 Imports: 10 Imported by: 67

Documentation

Index

Constants

View Source
const (
	ChunkSignatureHeader = `:chunk-signature` // chunk signature for message
	DateHeader           = `:date`            // Date header for signature

	// Message header and values
	MessageTypeHeader    = `:message-type` // Identifies type of message.
	EventMessageType     = `event`
	ErrorMessageType     = `error`
	ExceptionMessageType = `exception`

	// Message Events
	EventTypeHeader = `:event-type` // Identifies message event type e.g. "Stats".

	// Message Error
	ErrorCodeHeader    = `:error-code`
	ErrorMessageHeader = `:error-message`

	// Message Exception
	ExceptionTypeHeader = `:exception-type`
)

EventStream headers with specific meaning to async API functionality.

View Source
const InputWriterCloseErrorCode = "EventStreamInputWriterCloseError"

InputWriterCloseErrorCode is used to denote an error occurred while closing the event stream input writer.

Variables

This section is empty.

Functions

func ApplyHTTPTransportFixes added in v1.43.4

func ApplyHTTPTransportFixes(r *request.Request)

ApplyHTTPTransportFixes is a no-op for Go 1.18 and above.

func GetHeaderString

func GetHeaderString(msg eventstream.Message, headerName string) (string, error)

GetHeaderString returns the value of the header as a string. If the header is not set or the value is not a string an error will be returned.

Types

type BufferEncoder added in v1.27.0

type BufferEncoder struct {
	// contains filtered or unexported fields
}

BufferEncoder is a utility that provides a buffered event stream encoder

func NewBufferEncoder added in v1.27.0

func NewBufferEncoder() *BufferEncoder

NewBufferEncoder returns a new BufferEncoder initialized with a 1024 byte buffer.

func (*BufferEncoder) Encode added in v1.27.0

func (e *BufferEncoder) Encode(msg eventstream.Message) ([]byte, error)

Encode returns the encoded message as a byte slice. The returned byte slice will be modified on the next encode call and should not be held onto.

type Encoder added in v1.27.0

type Encoder interface {
	Encode(eventstream.Message) error
}

Encoder is an stream encoder that will encode an event stream message for the transport.

type EventReader

type EventReader struct {
	// contains filtered or unexported fields
}

EventReader provides reading from the EventStream of an reader.

func NewEventReader

func NewEventReader(
	decoder *eventstream.Decoder,
	payloadUnmarshaler protocol.PayloadUnmarshaler,
	unmarshalerForEventType func(string) (Unmarshaler, error),
) *EventReader

NewEventReader returns a EventReader built from the reader and unmarshaler provided. Use ReadStream method to start reading from the EventStream.

func (*EventReader) ReadEvent

func (r *EventReader) ReadEvent() (event interface{}, err error)

ReadEvent attempts to read a message from the EventStream and return the unmarshaled event value that the message is for.

For EventStream API errors check if the returned error satisfies the awserr.Error interface to get the error's Code and Message components.

EventUnmarshalers called with EventStream messages must take copies of the message's Payload. The payload will is reused between events read.

type EventWriter added in v1.27.0

type EventWriter struct {
	// contains filtered or unexported fields
}

EventWriter provides a wrapper around the underlying event stream encoder for an io.WriteCloser.

func NewEventWriter added in v1.27.0

func NewEventWriter(encoder Encoder, pm protocol.PayloadMarshaler, eventTypeFor func(Marshaler) (string, error),
) *EventWriter

NewEventWriter returns a new event stream writer, that will write to the writer provided. Use the WriteEvent method to write an event to the stream.

func (*EventWriter) WriteEvent added in v1.27.0

func (w *EventWriter) WriteEvent(event Marshaler) error

WriteEvent writes an event to the stream. Returns an error if the event fails to marshal into a message, or writing to the underlying writer fails.

type Marshaler added in v1.27.0

type Marshaler interface {
	MarshalEvent(protocol.PayloadMarshaler) (eventstream.Message, error)
}

Marshaler provides a marshaling interface for event types to event stream messages.

type OnceError added in v1.27.0

type OnceError struct {
	// contains filtered or unexported fields
}

OnceError wraps the behavior of recording an error once and signal on a channel when this has occurred. Signaling is done by closing of the channel.

Type is safe for concurrent usage.

func NewOnceError added in v1.27.0

func NewOnceError() *OnceError

NewOnceError return a new OnceError

func (*OnceError) Err added in v1.27.0

func (e *OnceError) Err() error

Err acquires a read-lock and returns an error if one has been set.

func (*OnceError) ErrorSet added in v1.27.0

func (e *OnceError) ErrorSet() <-chan struct{}

ErrorSet returns a channel that will be used to signal that an error has been set. This channel will be closed when the error value has been set for OnceError.

func (*OnceError) SetError added in v1.27.0

func (e *OnceError) SetError(err error)

SetError acquires a write-lock and will set the underlying error value if one has not been set.

type SignEncoder added in v1.27.0

type SignEncoder struct {
	// contains filtered or unexported fields
}

SignEncoder envelopes event stream messages into an event stream message payload with included signature headers using the provided signer and encoder.

func NewSignEncoder added in v1.27.0

func NewSignEncoder(signer StreamSigner, encoder Encoder) *SignEncoder

NewSignEncoder returns a new SignEncoder using the provided stream signer and event stream encoder.

func (*SignEncoder) Close added in v1.27.0

func (s *SignEncoder) Close() error

Close encodes a final event stream signing envelope with an empty event stream payload. This final end-frame is used to mark the conclusion of the stream.

func (*SignEncoder) Encode added in v1.27.0

func (s *SignEncoder) Encode(msg eventstream.Message) error

Encode takes the provided message and add envelopes the message with the required signature.

type StreamSigner added in v1.27.0

type StreamSigner interface {
	GetSignature(headers, payload []byte, date time.Time) ([]byte, error)
}

StreamSigner defines an interface for the implementation of signing of event stream payloads

type StreamWriter added in v1.27.0

type StreamWriter struct {
	// contains filtered or unexported fields
}

StreamWriter provides concurrent safe writing to an event stream.

func NewStreamWriter added in v1.27.0

func NewStreamWriter(eventWriter *EventWriter, streamCloser io.Closer) *StreamWriter

NewStreamWriter returns a StreamWriter for the event writer, and stream closer provided.

func (*StreamWriter) Close added in v1.27.0

func (w *StreamWriter) Close() error

Close terminates the writers ability to write new events to the stream. Any future call to Send will fail with an error.

func (*StreamWriter) Err added in v1.27.0

func (w *StreamWriter) Err() error

Err returns any error that occurred while attempting to write an event to the stream.

func (*StreamWriter) ErrorSet added in v1.27.0

func (w *StreamWriter) ErrorSet() <-chan struct{}

ErrorSet returns a channel which will be closed if an error occurs.

func (*StreamWriter) Send added in v1.27.0

func (w *StreamWriter) Send(ctx aws.Context, event Marshaler) error

Send writes a single event to the stream returning an error if the write failed.

Send may be called concurrently. Events will be written to the stream safely.

type UnknownMessageTypeError added in v1.33.7

type UnknownMessageTypeError struct {
	Type    string
	Message eventstream.Message
}

UnknownMessageTypeError provides an error when a message is received from the stream, but the reader is unable to determine what kind of message it is.

func (*UnknownMessageTypeError) Error added in v1.33.7

func (e *UnknownMessageTypeError) Error() string

type Unmarshaler

type Unmarshaler interface {
	UnmarshalEvent(protocol.PayloadUnmarshaler, eventstream.Message) error
}

Unmarshaler provides the interface for unmarshaling a EventStream message into a SDK type.

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