message

Documentation

Index

• Variables
• type ColumnDescription
• type Encoder
  • func (e *Encoder) BackendKeyData(pid, key int32) (Message, error)
  • func (e *Encoder) CommandComplete(tag string) (Message, error)
  • func (e *Encoder) Error(fields ...NoticeField) (Message, error)
  • func (e *Encoder) GoError(err error) (Message, error)
  • func (e *Encoder) NegotiateProtocolVersion(maxMinor int32, unrecognizedOptions ...string) (Message, error)
  • func (e *Encoder) ReadyForQuery(status TransactionStatus) (Message, error)
  • func (e *Encoder) RowDescription(cols ...ColumnDescription) (Message, error)
  • func (e *Encoder) TextRow(row ...string) (Message, error)
• type Message
• type NoticeField
• type NoticeFieldType
• type Reader
• type TransactionStatus
• type Type
• type WireReader
  • func NewWireReader(r *bufio.Reader) *WireReader
  • func (r *WireReader) ReadMessage() (Message, error)
• type WireWriter
  • func NewWireWriter(w *bufio.Writer) *WireWriter
  • func (w *WireWriter) Flush() error
  • func (w *WireWriter) WriteMessage(message Message) error
• type Writer

Variables

var AuthenticationOK = Message{
	Type: TypeAuthentication,
	Data: []byte{0, 0, 0, 0},
}

AuthenticationOK is a message indicating that authentication has completed.

var ErrMessageTooBig = errors.New("message is too big")

ErrMessageTooBig is an error indicating that a message is too big to be sent or received.

Types

type ColumnDescription

type ColumnDescription struct {
	Name         string
	TableID      int32 //either a table/col id or 0
	FieldID      int16 //either a table/col id or 0
	TypeID       int32 //field type
	TypeLen      int16 //size in bytes of field
	TypeModifier int32 //type modifer?
	Mode         int16 //0=text 1=binary
}

ColumnDescription is a description of a data column.

type Encoder

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

Encoder encodes messages.

func (*Encoder) BackendKeyData

func (e *Encoder) BackendKeyData(pid, key int32) (Message, error)

BackendKeyData encodes a Message with a cancellation key.

func (*Encoder) CommandComplete

func (e *Encoder) CommandComplete(tag string) (Message, error)

CommandComplete encodes a command completion message.

func (*Encoder) Error

func (e *Encoder) Error(fields ...NoticeField) (Message, error)

Error encodes a Postgres error message.

func (*Encoder) GoError

func (e *Encoder) GoError(err error) (Message, error)

GoError creates a simple Postgres error message from a Go error value.

func (*Encoder) NegotiateProtocolVersion

func (e *Encoder) NegotiateProtocolVersion(maxMinor int32, unrecognizedOptions ...string) (Message, error)

NegotiateProtocolVersion encodes a protocol negotiation packet.

func (*Encoder) ReadyForQuery

func (e *Encoder) ReadyForQuery(status TransactionStatus) (Message, error)

ReadyForQuery encodes a "ready for query" message.

func (*Encoder) RowDescription

func (e *Encoder) RowDescription(cols ...ColumnDescription) (Message, error)

RowDescription describes the response rows from a query.

func (*Encoder) TextRow

func (e *Encoder) TextRow(row ...string) (Message, error)

TextRow encodes a data row in textual format.

type Message

type Message struct {
	Type Type
	Data []byte
}

Message is a Postgres message value.

type NoticeField

type NoticeField struct {
	Type NoticeFieldType
	Data string
}

NoticeField is a field in an error or notice.

type NoticeFieldType

type NoticeFieldType byte

NoticeFieldType indicates the type of a notice/error field. https://www.postgresql.org/docs/9.3/protocol-error-fields.html

const (
	// NoticeFieldSeverity indicates the severity of a notice/error.
	NoticeFieldSeverity NoticeFieldType = 'S'

	// NoticeFieldMessage is a short human-readable error/notice message.
	NoticeFieldMessage NoticeFieldType = 'M'

	// NoticeFieldDetail is an optional extended description of the error.
	NoticeFieldDetail NoticeFieldType = 'D'

	// NoticeFieldHint is a suggestion of how to address the issue.
	NoticeFieldHint NoticeFieldType = 'H'
)

type Reader

type Reader interface {
	ReadMessage() (Message, error)
}

Reader reads messages.

type TransactionStatus

type TransactionStatus byte

TransactionStatus is the current transaction state.

const (
	// TransactionStatusIdle indicates that there is no active transaction.
	TransactionStatusIdle TransactionStatus = 'I'

	// TransactionStatusActive indicates that the connection currently has an active transaction.
	TransactionStatusActive TransactionStatus = 'T'

	// TransactionStatusFailed indicates that the connection currently has a failed transaction.
	TransactionStatusFailed TransactionStatus = 'E'
)

type Type

type Type byte

Type is a byte indicating the type of a Postgres message.

const (
	// TypeAuthentication is a message used to transfer authentication info.
	TypeAuthentication Type = 'R'

	// TypeReadyForQuery is a message used to indicate that the server is ready for another query.
	TypeReadyForQuery Type = 'Z'

	// TypeCommandComplete is a message used to indicate that a query has completed.
	TypeCommandComplete Type = 'C'

	// TypeError is an error message.
	TypeError Type = 'E'

	// TypeRowDescription is a message indicating the column types of the result rows from a query.
	TypeRowDescription Type = 'T'

	// TypeDataRow is a message with the contents of a single row.
	TypeDataRow Type = 'D'

	// TypeTermination is a message indicating a request to terminate a connection.
	TypeTermination Type = 'X'

	// TypeNegotiateProtocolVersion is a message used when a client attempts to connect with a newer minor version than the server supports.
	TypeNegotiateProtocolVersion Type = 'v'

	// TypeSimpleQuery is a simple query request.
	TypeSimpleQuery Type = 'Q'

	// TypeBackendKeyData contains a cancellation key for the client to use later.
	TypeBackendKeyData Type = 'K'
)

type WireReader

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

WireReader reads messages in Postgres wire protocol format.

func NewWireReader

func NewWireReader(r *bufio.Reader) *WireReader

NewWireReader returns a message reader that reads postgres wire protocol format.

func (*WireReader) ReadMessage

func (r *WireReader) ReadMessage() (Message, error)

ReadMessage reads a single message off of the wire. The returned message is only valid until the next read call, as the data buffer may be re-used.

type WireWriter

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

WireWriter writes messages in Postgres wire protocol.

func NewWireWriter

func NewWireWriter(w *bufio.Writer) *WireWriter

NewWireWriter returns a message writer that writes in postgres wire protocol format.

func (*WireWriter) Flush

func (w *WireWriter) Flush() error

Flush writes any buffered data to the underlying stream.

func (*WireWriter) WriteMessage

func (w *WireWriter) WriteMessage(message Message) error

WriteMessage writes a message onto the wire.

type Writer

type Writer interface {
	WriteMessage(Message) error
	Flush() error
}

Writer writes messages.