2016-12-14 15:41:48 +00:00
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// Package codec is an interface for encoding messages
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2015-11-27 00:17:36 +00:00
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package codec
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2015-11-28 11:22:29 +00:00
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import (
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2020-02-19 02:05:38 +03:00
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"errors"
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2015-11-28 11:22:29 +00:00
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"io"
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2020-11-18 16:50:41 +03:00
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"github.com/unistack-org/micro/v3/metadata"
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2015-11-28 11:22:29 +00:00
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)
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2021-02-13 15:35:56 +03:00
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// Message types
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2015-11-28 11:22:29 +00:00
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const (
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Error MessageType = iota
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Request
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Response
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2019-07-07 12:44:09 +01:00
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Event
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2015-11-28 11:22:29 +00:00
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)
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2020-02-19 02:05:38 +03:00
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var (
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2020-11-03 02:02:32 +03:00
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// ErrInvalidMessage returned when invalid messge passed to codec
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2020-02-19 02:05:38 +03:00
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ErrInvalidMessage = errors.New("invalid message")
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2020-11-23 16:18:47 +03:00
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// ErrUnknownContentType returned when content-type is unknown
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ErrUnknownContentType = errors.New("unknown content-type")
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2020-02-19 02:05:38 +03:00
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)
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2020-11-25 10:43:13 +03:00
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var (
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2020-12-08 00:38:37 +03:00
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// DefaultMaxMsgSize specifies how much data codec can handle
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2021-02-13 15:35:56 +03:00
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DefaultMaxMsgSize int = 1024 * 1024 * 4 // 4Mb
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// DefaultCodec is the global default codec
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DefaultCodec Codec = NewCodec()
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2020-11-25 10:43:13 +03:00
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)
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2021-02-14 11:28:50 +03:00
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// MessageType specifies message type for codec
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2015-11-28 11:22:29 +00:00
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type MessageType int
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2020-11-23 16:18:47 +03:00
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// Codec encodes/decodes various types of messages used within micro.
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2015-12-02 01:38:56 +00:00
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// ReadHeader and ReadBody are called in pairs to read requests/responses
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// from the connection. Close is called when finished with the
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// connection. ReadBody may be called with a nil argument to force the
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// body to be read and discarded.
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2015-11-27 00:17:36 +00:00
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type Codec interface {
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2020-12-20 23:53:29 +03:00
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ReadHeader(io.Reader, *Message, MessageType) error
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ReadBody(io.Reader, interface{}) error
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Write(io.Writer, *Message, interface{}) error
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2019-01-10 09:42:02 +00:00
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Marshal(interface{}) ([]byte, error)
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Unmarshal([]byte, interface{}) error
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String() string
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}
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2015-11-28 11:22:29 +00:00
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// Message represents detailed information about
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// the communication, likely followed by the body.
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// In the case of an error, body may be nil.
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type Message struct {
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2019-01-10 21:25:31 +00:00
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Id string
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Type MessageType
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Target string
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2019-01-18 10:12:57 +00:00
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Method string
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2019-01-10 21:25:31 +00:00
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Endpoint string
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Error string
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2019-01-09 16:20:57 +00:00
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// The values read from the socket
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2020-11-18 16:50:41 +03:00
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Header metadata.Metadata
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2019-01-09 19:28:13 +00:00
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Body []byte
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2015-11-28 11:22:29 +00:00
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}
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2020-11-24 15:14:47 +03:00
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2020-12-08 00:38:37 +03:00
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// NewMessage creates new codec message
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2020-11-24 15:14:47 +03:00
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func NewMessage(t MessageType) *Message {
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return &Message{Type: t, Header: metadata.New(0)}
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}
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