mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2025-10-31 12:22:24 -05:00
120 lines
3.4 KiB
Go
120 lines
3.4 KiB
Go
package pgproto3
|
|
|
|
import (
|
|
"encoding/hex"
|
|
"errors"
|
|
"fmt"
|
|
|
|
"github.com/jackc/pgx/v5/internal/pgio"
|
|
)
|
|
|
|
// maxMessageBodyLen is the maximum length of a message body in bytes. See PG_LARGE_MESSAGE_LIMIT in the PostgreSQL
|
|
// source. It is defined as (MaxAllocSize - 1). MaxAllocSize is defined as 0x3fffffff.
|
|
const maxMessageBodyLen = (0x3fffffff - 1)
|
|
|
|
// Message is the interface implemented by an object that can decode and encode
|
|
// a particular PostgreSQL message.
|
|
type Message interface {
|
|
// Decode is allowed and expected to retain a reference to data after
|
|
// returning (unlike encoding.BinaryUnmarshaler).
|
|
Decode(data []byte) error
|
|
|
|
// Encode appends itself to dst and returns the new buffer.
|
|
Encode(dst []byte) ([]byte, error)
|
|
}
|
|
|
|
// FrontendMessage is a message sent by the frontend (i.e. the client).
|
|
type FrontendMessage interface {
|
|
Message
|
|
Frontend() // no-op method to distinguish frontend from backend methods
|
|
}
|
|
|
|
// BackendMessage is a message sent by the backend (i.e. the server).
|
|
type BackendMessage interface {
|
|
Message
|
|
Backend() // no-op method to distinguish frontend from backend methods
|
|
}
|
|
|
|
type AuthenticationResponseMessage interface {
|
|
BackendMessage
|
|
AuthenticationResponse() // no-op method to distinguish authentication responses
|
|
}
|
|
|
|
type invalidMessageLenErr struct {
|
|
messageType string
|
|
expectedLen int
|
|
actualLen int
|
|
}
|
|
|
|
func (e *invalidMessageLenErr) Error() string {
|
|
return fmt.Sprintf("%s body must have length of %d, but it is %d", e.messageType, e.expectedLen, e.actualLen)
|
|
}
|
|
|
|
type invalidMessageFormatErr struct {
|
|
messageType string
|
|
details string
|
|
}
|
|
|
|
func (e *invalidMessageFormatErr) Error() string {
|
|
return fmt.Sprintf("%s body is invalid %s", e.messageType, e.details)
|
|
}
|
|
|
|
type writeError struct {
|
|
err error
|
|
safeToRetry bool
|
|
}
|
|
|
|
func (e *writeError) Error() string {
|
|
return fmt.Sprintf("write failed: %s", e.err.Error())
|
|
}
|
|
|
|
func (e *writeError) SafeToRetry() bool {
|
|
return e.safeToRetry
|
|
}
|
|
|
|
func (e *writeError) Unwrap() error {
|
|
return e.err
|
|
}
|
|
|
|
type ExceededMaxBodyLenErr struct {
|
|
MaxExpectedBodyLen int
|
|
ActualBodyLen int
|
|
}
|
|
|
|
func (e *ExceededMaxBodyLenErr) Error() string {
|
|
return fmt.Sprintf("invalid body length: expected at most %d, but got %d", e.MaxExpectedBodyLen, e.ActualBodyLen)
|
|
}
|
|
|
|
// getValueFromJSON gets the value from a protocol message representation in JSON.
|
|
func getValueFromJSON(v map[string]string) ([]byte, error) {
|
|
if v == nil {
|
|
return nil, nil
|
|
}
|
|
if text, ok := v["text"]; ok {
|
|
return []byte(text), nil
|
|
}
|
|
if binary, ok := v["binary"]; ok {
|
|
return hex.DecodeString(binary)
|
|
}
|
|
return nil, errors.New("unknown protocol representation")
|
|
}
|
|
|
|
// beginMessage begins a new message of type t. It appends the message type and a placeholder for the message length to
|
|
// dst. It returns the new buffer and the position of the message length placeholder.
|
|
func beginMessage(dst []byte, t byte) ([]byte, int) {
|
|
dst = append(dst, t)
|
|
sp := len(dst)
|
|
dst = pgio.AppendInt32(dst, -1)
|
|
return dst, sp
|
|
}
|
|
|
|
// finishMessage finishes a message that was started with beginMessage. It computes the message length and writes it to
|
|
// dst[sp]. If the message length is too large it returns an error. Otherwise it returns the final message buffer.
|
|
func finishMessage(dst []byte, sp int) ([]byte, error) {
|
|
messageBodyLen := len(dst[sp:])
|
|
if messageBodyLen > maxMessageBodyLen {
|
|
return nil, errors.New("message body too large")
|
|
}
|
|
pgio.SetInt32(dst[sp:], int32(messageBodyLen))
|
|
return dst, nil
|
|
}
|