Function ReadMessage

server/wire/protocol.go:156–184

readMessage reads a single message from the client

(r io.Reader)

		// with "slice bounds out of range". Mirrors the key-scan guard above.
		if valEnd >= len(data) {
			break
		}
		value := string(data[:valEnd])
		data = data[valEnd+1:]

		if key != "" {
			params[key] = value
		}
	}

	return StartupMessage{Params: params}, nil
}

// readMessage reads a single message from the client
func ReadMessage(r io.Reader) (byte, []byte, error) {
	// Read message type (1 byte)
	typeBuf := make([]byte, 1)
	if _, err := io.ReadFull(r, typeBuf); err != nil {
		return 0, nil, err
	}
	msgType := typeBuf[0]

	// Read message length (4 bytes, includes itself)
	var length int32
	if err := binary.Read(r, binary.BigEndian, &length); err != nil {
		return 0, nil, fmt.Errorf("failed to read message length: %w", err)
	}

	// Validate before allocating: minimum 4 = the length field itself.
	if length < 4 || length > maxMessageLength {
		return 0, nil, fmt.Errorf("invalid message length: %d", length)
	}