osm_common/msgbase.py

   1 # -*- coding: utf-8 -*-
   2
   3 # Copyright 2018 Telefonica S.A.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #    http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
  14 # implied.
  15 # See the License for the specific language governing permissions and
  16 # limitations under the License.
  17
  18 import logging
  19 from http import HTTPStatus
  20 from osm_common.common_utils import FakeLock
  21 from threading import Lock
  22
  23 __author__ = "Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>"
  24
  25
  26 class MsgException(Exception):
  27     """
  28     Base Exception class for all msgXXXX exceptions
  29     """
  30
  31     def __init__(self, message, http_code=HTTPStatus.SERVICE_UNAVAILABLE):
  32         """
  33         General exception
  34         :param message:  descriptive text
  35         :param http_code: <http.HTTPStatus> type. It contains ".value" (http error code) and ".name" (http error name
  36         """
  37         self.http_code = http_code
  38         Exception.__init__(self, "messaging exception " + message)
  39
  40
  41 class MsgBase(object):
  42     """
  43     Base class for all msgXXXX classes
  44     """
  45
  46     def __init__(self, logger_name="msg", lock=False):
  47         """
  48         Constructor of FsBase
  49         :param logger_name: logging name
  50         :param lock: Used to protect simultaneous access to the same instance class by several threads:
  51             False, None: Do not protect, this object will only be accessed by one thread
  52             True: This object needs to be protected by several threads accessing.
  53             Lock object. Use thi Lock for the threads access protection
  54         """
  55         self.logger = logging.getLogger(logger_name)
  56         if not lock:
  57             self.lock = FakeLock()
  58         elif lock is True:
  59             self.lock = Lock()
  60         elif isinstance(lock, Lock):
  61             self.lock = lock
  62         else:
  63             raise ValueError("lock parameter must be a Lock class or boolean")
  64
  65     def connect(self, config):
  66         pass
  67
  68     def disconnect(self):
  69         pass
  70
  71     def write(self, topic, key, msg):
  72         raise MsgException(
  73             "Method 'write' not implemented", http_code=HTTPStatus.INTERNAL_SERVER_ERROR
  74         )
  75
  76     def read(self, topic):
  77         raise MsgException(
  78             "Method 'read' not implemented", http_code=HTTPStatus.INTERNAL_SERVER_ERROR
  79         )
  80
  81     async def aiowrite(self, topic, key, msg, loop=None):
  82         raise MsgException(
  83             "Method 'aiowrite' not implemented",
  84             http_code=HTTPStatus.INTERNAL_SERVER_ERROR,
  85         )
  86
  87     async def aioread(
  88         self, topic, loop=None, callback=None, aiocallback=None, group_id=None, **kwargs
  89     ):
  90         raise MsgException(
  91             "Method 'aioread' not implemented",
  92             http_code=HTTPStatus.INTERNAL_SERVER_ERROR,
  93         )