42 lines
1 KiB
Go
42 lines
1 KiB
Go
package protocol
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"encoding/json"
|
|
"fmt"
|
|
"io"
|
|
)
|
|
|
|
// encode is a helper function that encodes any message with the given message type
|
|
func encode(w io.Writer, msgType MessageType, payload interface{}) error {
|
|
var payloadBytes []byte
|
|
var err error
|
|
|
|
// Only marshal if payload is not nil
|
|
if payload != nil {
|
|
payloadBytes, err = json.Marshal(payload)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to encode payload: %w", err)
|
|
}
|
|
}
|
|
|
|
// Write message type (1 byte)
|
|
if err := binary.Write(w, binary.BigEndian, msgType); err != nil {
|
|
return fmt.Errorf("failed to write message type: %w", err)
|
|
}
|
|
|
|
// Write payload length (4 bytes, big-endian)
|
|
if err := binary.Write(w, binary.BigEndian, uint32(len(payloadBytes))); err != nil {
|
|
return fmt.Errorf("failed to write payload length: %w", err)
|
|
}
|
|
|
|
// Write JSON payload if we have one
|
|
if len(payloadBytes) > 0 {
|
|
if _, err := w.Write(payloadBytes); err != nil {
|
|
return fmt.Errorf("failed to write payload: %w", err)
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|