Documentation
¶
Index ¶
- Constants
- Variables
- type Handshake
- type Message
- func BackendKeyData(pid int32, secret int32) Message
- func CommandComplete(tag string) Message
- func DataRow(vals []string) Message
- func ErrorResponse(err error) Message
- func ParameterDescription(ps *nodes.PrepareStmt) (Message, error)
- func ParameterStatus(name, value string) Message
- func RowDescription(cols, types []string) Message
- func TLSResponse(supported bool) Message
- func (m Message) CancelKeyData() (int32, int32, error)
- func (m Message) ErrorResponse() (res *pgproto3.ErrorResponse, err error)
- func (m Message) IsCancel() bool
- func (m Message) IsError() bool
- func (m Message) IsTLSRequest() bool
- func (m Message) IsTerminate() bool
- func (m Message) StartupArgs() (map[string]interface{}, error)
- func (m Message) StartupVersion() (string, error)
- func (m Message) Type() byte
- type MessageReadWriter
- type TransactionState
- type Transport
Constants ¶
const ( DescribeStatement = 'S' DescribePortal = 'P' )
Describe message object types
const (
Terminate = 'X'
)
frontend message types
Variables ¶
var BindComplete = []byte{'2', 0, 0, 0, 4}
BindComplete is sent when backend prepared a portal and finished planning the query
var ParseComplete = []byte{'1', 0, 0, 0, 4}
ParseComplete is sent when backend parsed a prepared statement successfully
var ReadyForQuery = []byte{'Z', 0, 0, 0, 5, 'I'}
ReadyForQuery is sent whenever the backend is ready for a new query cycle.
var TypesOid = map[string]int{
"BOOL": 16,
"BYTEA": 17,
"CHAR": 18,
"INT8": 20,
"INT2": 21,
"INT4": 23,
"TEXT": 25,
"JSON": 114,
"XML": 142,
"FLOAT4": 700,
"FLOAT8": 701,
"VARCHAR": 1043,
"DATE": 1082,
"TIME": 1083,
"TIMESTAMP": 1114,
"TIMESTAMPZ": 1184,
"INTERVAL": 1186,
"NUMERIC": 1700,
"JSONB": 3802,
"ANY": 2276,
}
TypesOid maps between a type name to its corresponding OID
Functions ¶
This section is empty.
Types ¶
type Handshake ¶
type Handshake struct {
// contains filtered or unexported fields
}
Handshake handles the very first message passing of the protocol
func (*Handshake) Init ¶
Init receives and validates the very first message from the frontend per session. it may send message back to the frontend if needed to skip SSL request since it currently not supported.
once done, Init must not be called again, or error will be returned.
type Message ¶
type Message []byte
Message is just an alias for a slice of bytes that exposes common operations on Postgres' client-server protocol messages. see: https://www.postgresql.org/docs/current/protocol-message-formats.html for postgres specific list of message formats
func BackendKeyData ¶
BackendKeyData creates a new message providing the client with a process ID and secret key that it can later use to cancel running queries
func CommandComplete ¶
CommandComplete is sent when query was fully executed and cursor reached the end of the row set
func ErrorResponse ¶
ErrorResponse is sent whenever error has occurred
func ParameterDescription ¶
func ParameterDescription(ps *nodes.PrepareStmt) (Message, error)
ParameterDescription is sent when backend received Describe message from frontend with ObjectType = 'S' - requesting to describe prepared statement with a provided name
func ParameterStatus ¶
ParameterStatus creates a new message providing parameter name and value
func RowDescription ¶
RowDescription is a message indicating that DataRow messages are about to be transmitted and delivers their schema (column names/types)
func TLSResponse ¶
TLSResponse creates a new single byte message indicating if the server supports TLS or not. If it does, the client must immediately proceed to initiate the TLS handshake
func (Message) CancelKeyData ¶
CancelKeyData returns the key data of a cancel message
func (Message) ErrorResponse ¶
func (m Message) ErrorResponse() (res *pgproto3.ErrorResponse, err error)
ErrorResponse parses message of type error and returns an object describes it
func (Message) IsTLSRequest ¶
IsTLSRequest determines if this startup message is actually a request to open a TLS connection, in which case the version number is a special, predefined value of "1234.5679"
func (Message) IsTerminate ¶
IsTerminate determines if the current message is a notification that the client has terminated the connection upon user-request.
func (Message) StartupArgs ¶
StartupArgs parses the arguments delivered in the Startup and returns them as a key-value map. Startup messages contains a map of arguments, like the requested database name, user name, charset and additional connection defaults that may be used by the server. These arguments are encoded as pairs of key-values, terminated by a NULL character.
func (Message) StartupVersion ¶
StartupVersion returns the protocol version supported by the client. The version is encoded by two consecutive 2-byte integers, one for the major version, and the other for the minor version. Currently version 3.0 is the only valid version.
type MessageReadWriter ¶
MessageReadWriter describes objects that handle client-server communication. Objects implementing this interface are used by logic operations to send Message objects to frontend and receive Message back from it
type TransactionState ¶
type TransactionState int
TransactionState is used as a return with every message read for commit and rollback implementation
const ( // TransactionUnknown is the default/unset value of this enum TransactionUnknown TransactionState = iota // NotInTransaction states that transaction is not active and operations should auto-commit NotInTransaction // InTransaction states that transaction is active and operations should not commit InTransaction // TransactionEnded states that the current transaction has finished and has to commit TransactionEnded // TransactionFailed states that the current transaction has failed and has to roll-back TransactionFailed )
type Transport ¶
type Transport struct {
// contains filtered or unexported fields
}
Transport manages the underlying wire protocol between backend and frontend.
func (*Transport) NextFrontendMessage ¶
func (t *Transport) NextFrontendMessage() (msg pgproto3.FrontendMessage, ts TransactionState, err error)
NextFrontendMessage reads and returns a single message from the connection when available. if within a transaction, the transaction will read from the connection, otherwise a ReadyForQuery message will first be sent to the frontend and then reading a single message from the connection will happen
NextFrontendMessage expects to be called only after a call to Handshake without an error response otherwise, an error is returned
Source Files