Module protocol 

PostgreSQL wire protocol implementation.

PostgreSQL uses a simple message format with a type byte and length prefix. This module provides encoding/decoding for all frontend and backend messages.

Message Format

Standard Message (after startup)

+------+--------+------------------+
| Type | Length | Payload          |
| 1B   | 4B     | (Length-4) bytes |
+------+--------+------------------+

Length includes itself (4 bytes) but not the type byte.

Startup Message (first message from client)

+--------+------------------+
| Length | Payload          |
| 4B     | (Length-4) bytes |
+--------+------------------+

No type byte for startup message.

Modules

auth_type

Authentication method codes from the server.

backend_type

Message type bytes for backend messages.

frontend_type

Message type bytes for frontend messages.

Structs

ErrorFields

Error and notice response fields.

FieldDescription

Describes a single field (column) in a row description.

MessageReader

Incremental reader for PostgreSQL backend messages.

MessageWriter

Buffer for writing PostgreSQL protocol messages.

Enums

BackendMessage

Messages sent from the PostgreSQL server to the client.

DescribeKind

Kind for Describe/Close messages

FrontendMessage

Messages sent from the client to the PostgreSQL server.

TransactionStatus

Transaction status indicator from ReadyForQuery

Constants

CANCEL_REQUEST_CODE

Cancel request code.

PROTOCOL_VERSION

Protocol version 3.0.

SSL_REQUEST_CODE

SSL request code.