wire

Documentation

Overview

Package wire provides wire protocol implementation.

Index

• Constants
• Variables
• func ReadMessage(r *bufio.Reader) (*MsgHeader, MsgBody, error)
• func WriteMessage(w *bufio.Writer, header *MsgHeader, msg MsgBody) error
• type MsgBody
• type MsgHeader
  • func (msg *MsgHeader) MarshalBinary() ([]byte, error)
  • func (msg *MsgHeader) String() string
• type OpCode
  • func (i OpCode) String() string
• type OpMsg
  • func (msg *OpMsg) Document() (*types.Document, error)
  • func (msg *OpMsg) MarshalBinary() ([]byte, error)
  • func (msg *OpMsg) SetSections(sections ...OpMsgSection) error
  • func (msg *OpMsg) String() string
  • func (msg *OpMsg) UnmarshalBinary(b []byte) error
• type OpMsgFlagBit
  • func (i OpMsgFlagBit) String() string
• type OpMsgFlags
  • func (f OpMsgFlags) FlagSet(bit OpMsgFlagBit) bool
  • func (f OpMsgFlags) String() string
• type OpMsgSection
• type OpQuery
  • func (query *OpQuery) MarshalBinary() ([]byte, error)
  • func (query *OpQuery) String() string
  • func (query *OpQuery) UnmarshalBinary(b []byte) error
• type OpQueryFlagBit
  • func (i OpQueryFlagBit) String() string
• type OpQueryFlags
  • func (f OpQueryFlags) FlagSet(bit OpQueryFlagBit) bool
  • func (f OpQueryFlags) String() string
• type OpReply
  • func (reply *OpReply) MarshalBinary() ([]byte, error)
  • func (reply *OpReply) String() string
  • func (reply *OpReply) UnmarshalBinary(b []byte) error
• type OpReplyFlagBit
  • func (i OpReplyFlagBit) String() string
• type OpReplyFlags
  • func (f OpReplyFlags) FlagSet(bit OpReplyFlagBit) bool
  • func (f OpReplyFlags) String() string
• type ValidationError
  • func (v ValidationError) Error() string

Constants

const (
	// OpCodeReply is used for the initial handshake with old clients.
	// It is not used otherwise and is deprecated.
	OpCodeReply = OpCode(1) // OP_REPLY

	// OpCodeUpdate is deprecated.
	OpCodeUpdate = OpCode(2001) // OP_UPDATE

	// OpCodeInsert is deprecated and unused.
	OpCodeInsert = OpCode(2002) // OP_INSERT

	// OpCodeGetByOID is deprecated and unused.
	OpCodeGetByOID = OpCode(2003) // OP_GET_BY_OID

	// OpCodeQuery is used for the initial handshake with old clients.
	// It is not used otherwise and is deprecated.
	OpCodeQuery = OpCode(2004) // OP_QUERY

	// OpCodeGetMore is deprecated and unused.
	OpCodeGetMore = OpCode(2005) // OP_GET_MORE

	// OpCodeDelete is deprecated and unused.
	OpCodeDelete = OpCode(2006) // OP_DELETE

	// OpCodeKillCursors is deprecated and unused.
	OpCodeKillCursors = OpCode(2007) // OP_KILL_CURSORS

	// OpCodeCompressed is not implemented yet.
	OpCodeCompressed = OpCode(2012) // OP_COMPRESSED

	// OpCodeMsg is the main operation for client-server communication.
	OpCodeMsg = OpCode(2013) // OP_MSG
)

const (
	// MsgHeaderLen is an expected len of the header.
	MsgHeaderLen = 16

	// MaxMsgLen is the maximum message length.
	MaxMsgLen = 48000000
)

const (
	// OpMsgChecksumPresent indicates that there is a CRC-32C checksum in a message.
	OpMsgChecksumPresent = OpMsgFlagBit(1 << 0) // checksumPresent

	// OpMsgMoreToCome indicates that there is another message coming, no need to do anything for it.
	OpMsgMoreToCome = OpMsgFlagBit(1 << 1) // moreToCome

	// OpMsgExhaustAllowed indicates that client can handle multiple replies.
	OpMsgExhaustAllowed = OpMsgFlagBit(1 << 16) // exhaustAllowed
)

const (
	// OpQueryTailableCursor indicates that the cursor will not be closed.
	OpQueryTailableCursor = OpQueryFlagBit(1 << 1) // TailableCursor

	// OpQuerySlaveOk indicates that query can run on a replica slave.
	OpQuerySlaveOk = OpQueryFlagBit(1 << 2) // SlaveOk

	// OpQueryOplogReplay is deprecated.
	OpQueryOplogReplay = OpQueryFlagBit(1 << 3) // OplogReplay

	// OpQueryNoCursorTimeout disables cursor timeouts.
	OpQueryNoCursorTimeout = OpQueryFlagBit(1 << 4) // NoCursorTimeout

	// OpQueryAwaitData together with OpQueryTailableCursor, waits for data instead of returning it.
	OpQueryAwaitData = OpQueryFlagBit(1 << 5) // AwaitData

	// OpQueryExhaust indicates that server can divide data into multiple streams and expect that client can handle it.
	OpQueryExhaust = OpQueryFlagBit(1 << 6) // Exhaust

	// OpQueryPartial ignore error and give partial results.
	OpQueryPartial = OpQueryFlagBit(1 << 7) // Partial
)

const (
	// OpReplyCursorNotFound indicates that the cursor is no longer exist at the server.
	OpReplyCursorNotFound = OpReplyFlagBit(1 << 0) // CursorNotFound

	// OpReplyQueryFailure reports query has failed.
	OpReplyQueryFailure = OpReplyFlagBit(1 << 1) // QueryFailure

	// OpReplyShardConfigStale indicates that shard config is outdated.
	OpReplyShardConfigStale = OpReplyFlagBit(1 << 2) // ShardConfigStale

	// OpReplyAwaitCapable indicates server supports AwaitData Query option.
	OpReplyAwaitCapable = OpReplyFlagBit(1 << 3) // AwaitCapable
)

Variables

var ErrZeroRead = errors.New("zero bytes read")

ErrZeroRead is returned when zero bytes was read from connection, indicating that connection was closed by the client.

Functions

func ReadMessage

func ReadMessage(r *bufio.Reader) (*MsgHeader, MsgBody, error)

ReadMessage reads from reader and returns wire header and body.

Error is (possibly wrapped) ErrZeroRead if zero bytes was read.

func WriteMessage

func WriteMessage(w *bufio.Writer, header *MsgHeader, msg MsgBody) error

WriteMessage validates msg and headers and writes them to the writer.

Types

type MsgBody

type MsgBody interface {
	encoding.BinaryUnmarshaler
	encoding.BinaryMarshaler
	fmt.Stringer
	// contains filtered or unexported methods
}

MsgBody is a wire protocol message body.

type MsgHeader

type MsgHeader struct {
	MessageLength int32
	RequestID     int32
	ResponseTo    int32
	OpCode        OpCode
}

MsgHeader in general, each message consists of a standard message header followed by request-specific data.

func (*MsgHeader) MarshalBinary

func (msg *MsgHeader) MarshalBinary() ([]byte, error)

MarshalBinary writes a MsgHeader to a byte array.

func (*MsgHeader) String

func (msg *MsgHeader) String() string

String returns a string representation for logging.

type OpCode

type OpCode int32

OpCode represents wire operation code.

func (OpCode) String

func (i OpCode) String() string

type OpMsg

type OpMsg struct {
	FlagBits OpMsgFlags
	// contains filtered or unexported fields
}

OpMsg is an extensible message format designed to subsume the functionality of other opcodes.

func (*OpMsg) Document

func (msg *OpMsg) Document() (*types.Document, error)

Document returns the value of msg as a types.Document.

func (*OpMsg) MarshalBinary

func (msg *OpMsg) MarshalBinary() ([]byte, error)

MarshalBinary writes an OpMsg to a byte array.

func (*OpMsg) SetSections

func (msg *OpMsg) SetSections(sections ...OpMsgSection) error

SetSections of the OpMsg.

func (*OpMsg) String

func (msg *OpMsg) String() string

String returns a string representation for logging.

func (*OpMsg) UnmarshalBinary

func (msg *OpMsg) UnmarshalBinary(b []byte) error

UnmarshalBinary reads an OpMsg from a byte array.

type OpMsgFlagBit

type OpMsgFlagBit flagBit

OpMsgFlagBit integer is a bitmask encoding flags that modify the format and behavior of OpMsg.

func (OpMsgFlagBit) String

func (i OpMsgFlagBit) String() string

type OpMsgFlags

type OpMsgFlags flags

OpMsgFlags type unint32.

func (OpMsgFlags) FlagSet

func (f OpMsgFlags) FlagSet(bit OpMsgFlagBit) bool

FlagSet check if flag is set.

func (OpMsgFlags) String

func (f OpMsgFlags) String() string

String returns OpMsgFlags as a string.

type OpMsgSection

type OpMsgSection struct {
	Kind       byte
	Identifier string
	Documents  []*types.Document // TODO https://github.com/FerretDB/FerretDB/issues/274
}

OpMsgSection is one or more sections contained in an OpMsg.

type OpQuery

type OpQuery struct {
	Flags                OpQueryFlags
	FullCollectionName   string
	NumberToSkip         int32
	NumberToReturn       int32
	Query                *types.Document
	ReturnFieldsSelector *types.Document // may be nil
}

OpQuery is used to query the database for documents in a collection.

func (*OpQuery) MarshalBinary

func (query *OpQuery) MarshalBinary() ([]byte, error)

MarshalBinary writes an OpQuery to a byte array.

func (*OpQuery) String

func (query *OpQuery) String() string

String returns a string representation for logging.

func (*OpQuery) UnmarshalBinary

func (query *OpQuery) UnmarshalBinary(b []byte) error

UnmarshalBinary reads an OpQuery from a byte array.

type OpQueryFlagBit

type OpQueryFlagBit flagBit

OpQueryFlagBit an integer bitmask for the operation.

func (OpQueryFlagBit) String

func (i OpQueryFlagBit) String() string

type OpQueryFlags

type OpQueryFlags flags

OpQueryFlags enables String() and FlagSet methods for flags.

func (OpQueryFlags) FlagSet

func (f OpQueryFlags) FlagSet(bit OpQueryFlagBit) bool

FlagSet return true if flag set.

func (OpQueryFlags) String

func (f OpQueryFlags) String() string

String interface implementation for query flags.

type OpReply

type OpReply struct {
	ResponseFlags  OpReplyFlags
	CursorID       int64
	StartingFrom   int32
	NumberReturned int32
	Documents      []*types.Document
}

OpReply is a message sent by the MongoDB database in response to an OpQuery.

func (*OpReply) MarshalBinary

func (reply *OpReply) MarshalBinary() ([]byte, error)

MarshalBinary writes an OpReply to a byte array.

func (*OpReply) String

func (reply *OpReply) String() string

String returns a string representation for logging.

func (*OpReply) UnmarshalBinary

func (reply *OpReply) UnmarshalBinary(b []byte) error

UnmarshalBinary reads an OpReply from a byte array.

type OpReplyFlagBit

type OpReplyFlagBit flagBit

OpReplyFlagBit is a bit vector to specify OP_REPLY flags.

func (OpReplyFlagBit) String

func (i OpReplyFlagBit) String() string

type OpReplyFlags

type OpReplyFlags flags

OpReplyFlags are OP_REPLY flags.

func (OpReplyFlags) FlagSet

func (f OpReplyFlags) FlagSet(bit OpReplyFlagBit) bool

FlagSet returns true if the flag is set.

func (OpReplyFlags) String

func (f OpReplyFlags) String() string

String returns string value for OP_REPLY.

type ValidationError

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

ValidationError is used for reporting validation errors.

func (ValidationError) Error

func (v ValidationError) Error() string

Error implements error interface.