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 from http import HTTPStatus
  19 import logging
  20 from threading import Lock
  21
  22 from osm_common.common_utils import FakeLock
  23
  24 __author__ = "Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>"
  25
  26
  27 class MsgException(Exception):
  28     """
  29     Base Exception class for all msgXXXX exceptions
  30     """
  31
  32     def __init__(self, message, http_code=HTTPStatus.SERVICE_UNAVAILABLE):
  33         """
  34         General exception
  35         :param message:  descriptive text
  36         :param http_code: <http.HTTPStatus> type. It contains ".value" (http error code) and ".name" (http error name
  37         """
  38         self.http_code = http_code
  39         Exception.__init__(self, "messaging exception " + message)
  40
  41
  42 class MsgBase(object):
  43     """
  44     Base class for all msgXXXX classes
  45     """
  46
  47     def __init__(self, logger_name="msg", lock=False):
  48         """
  49         Constructor of FsBase
  50         :param logger_name: logging name
  51         :param lock: Used to protect simultaneous access to the same instance class by several threads:
  52             False, None: Do not protect, this object will only be accessed by one thread
  53             True: This object needs to be protected by several threads accessing.
  54             Lock object. Use thi Lock for the threads access protection
  55         """
  56         self.logger = logging.getLogger(logger_name)
  57         if not lock:
  58             self.lock = FakeLock()
  59         elif lock is True:
  60             self.lock = Lock()
  61         elif isinstance(lock, Lock):
  62             self.lock = lock
  63         else:
  64             raise ValueError("lock parameter must be a Lock class or boolean")
  65
  66     def connect(self, config):
  67         pass
  68
  69     def disconnect(self):
  70         pass
  71
  72     def write(self, topic, key, msg):
  73         raise MsgException(
  74             "Method 'write' not implemented", http_code=HTTPStatus.INTERNAL_SERVER_ERROR
  75         )
  76
  77     def read(self, topic):
  78         raise MsgException(
  79             "Method 'read' not implemented", http_code=HTTPStatus.INTERNAL_SERVER_ERROR
  80         )
  81
  82     async def aiowrite(self, topic, key, msg):
  83         raise MsgException(
  84             "Method 'aiowrite' not implemented",
  85             http_code=HTTPStatus.INTERNAL_SERVER_ERROR,
  86         )
  87
  88     async def aioread(
  89         self, topic, callback=None, aiocallback=None, group_id=None, **kwargs
  90     ):
  91         raise MsgException(
  92             "Method 'aioread' not implemented",
  93             http_code=HTTPStatus.INTERNAL_SERVER_ERROR,
  94         )