codec

Documentation

Overview

Package codec is an interface for encoding messages

Index

• Variables
• type Codec
  • func NewCodec() Codec
• type Frame
• type Message
  • func NewMessage(t MessageType) *Message
• type MessageType
• type Option
  • func Logger(l logger.Logger) Option
  • func MaxMsgSize(n int) Option
  • func Meter(m meter.Meter) Option
  • func Tracer(t tracer.Tracer) Option
• type Options
  • func NewOptions(opts ...Option) Options

Variables

var (
	// ErrInvalidMessage returned when invalid messge passed to codec
	ErrInvalidMessage = errors.New("invalid message")
	// ErrUnknownContentType returned when content-type is unknown
	ErrUnknownContentType = errors.New("unknown content-type")
)

var (
	// DefaultMaxMsgSize specifies how much data codec can handle
	DefaultMaxMsgSize int = 1024 * 1024 * 4 // 4Mb
	// DefaultCodec is the global default codec
	DefaultCodec Codec = NewCodec()
)

Types

type Codec

type Codec interface {
	ReadHeader(io.Reader, *Message, MessageType) error
	ReadBody(io.Reader, interface{}) error
	Write(io.Writer, *Message, interface{}) error
	Marshal(interface{}) ([]byte, error)
	Unmarshal([]byte, interface{}) error
	String() string
}

Codec encodes/decodes various types of messages used within micro. ReadHeader and ReadBody are called in pairs to read requests/responses from the connection. Close is called when finished with the connection. ReadBody may be called with a nil argument to force the body to be read and discarded.

func NewCodec

func NewCodec() Codec

NewCodec returns new noop codec

type Frame

type Frame struct {
	Data []byte
}

Frame gives us the ability to define raw data to send over the pipes

type Message

type Message struct {
	Header   metadata.Metadata
	Target   string
	Method   string
	Endpoint string
	Error    string
	Id       string
	Body     []byte
	Type     MessageType
}

Message represents detailed information about the communication, likely followed by the body. In the case of an error, body may be nil.

func NewMessage

func NewMessage(t MessageType) *Message

NewMessage creates new codec message

type MessageType

type MessageType int

MessageType specifies message type for codec

const (
	Error MessageType = iota
	Request
	Response
	Event
)

Message types

type Option

type Option func(*Options)

Option func

func Logger

func Logger(l logger.Logger) Option

Logger sets the logger

func MaxMsgSize

func MaxMsgSize(n int) Option

MaxMsgSize sets the max message size

func Meter

func Meter(m meter.Meter) Option

Meter sets the meter

func Tracer

func Tracer(t tracer.Tracer) Option

Tracer to be used for tracing

type Options

type Options struct {
	// Meter used for metrics
	Meter meter.Meter
	// Logger used for logging
	Logger logger.Logger
	// Tracer used for tracing
	Tracer tracer.Tracer
	// MaxMsgSize specifies max messages size that reads by codec
	MaxMsgSize int
}

Options contains codec options

func NewOptions

func NewOptions(opts ...Option) Options

NewOptions returns new options