Coverage for melissa/utility/message.py: 89%

1#!/usr/bin/python3 

2 

3# Copyright (c) 2021-2022, Institut National de Recherche en Informatique et en Automatique (Inria) 

4# All rights reserved. 

5# 

6# Redistribution and use in source and binary forms, with or without 

7# modification, are permitted provided that the following conditions are met: 

8# 

9# * Redistributions of source code must retain the above copyright notice, this 

10# list of conditions and the following disclaimer. 

11# 

12# * Redistributions in binary form must reproduce the above copyright notice, 

13# this list of conditions and the following disclaimer in the documentation 

14# and/or other materials provided with the distribution. 

15# 

16# * Neither the name of the copyright holder nor the names of its 

17# contributors may be used to endorse or promote products derived from 

18# this software without specific prior written permission. 

19# 

20# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 

21# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 

22# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 

23# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE 

24# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 

25# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 

26# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 

27# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 

28# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 

29# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

30 

31 

32"""Defines parent classes for Message type of the launcher.""" 

33 

34 

35def int2bytes(x: int, num_bytes: int) -> bytes: 

36 """Returns bytes in little endian order.""" 

37 assert num_bytes > 0 

38 return x.to_bytes(num_bytes, byteorder="little") 

39 

40 

41def bytes2int(bs: bytes) -> int: 

42 """Returns int in little endian order.""" 

43 assert len(bs) > 0 

44 return int.from_bytes(bs, byteorder="little") 

45 

46 

47class Message: 

48 """Abstract class for basic serialization of bytes.""" 

49 def serialize(self) -> bytes: 

50 """Abstract method for serializing and returning bytes.""" 

51 bs = self._serialize() 

52 assert len(bs) > 0 

53 return bs 

54 

55 def _serialize(self) -> bytes: 

56 """Abstract method for serialization.""" 

57 raise NotImplementedError("Message.serialize not overridden") 

58 

59 

60class InvalidMessage(Message): 

61 """Abstract class for modifying string representation in case 

62 of an invalid message logging""" 

63 def __init__(self, raw_bytes: bytes, reason: str) -> None: 

64 self.raw_bytes = raw_bytes 

65 self.reason = reason 

66 

67 def __str__(self) -> str: 

68 return f"invalid message of {len(self.raw_bytes)} bytes: {self.reason}"