common/python/rift/mano/dts/rpc/core.py

   1 """
   2 #
   3 #   Copyright 2016 RIFT.IO Inc
   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 implied.
  14 #   See the License for the specific language governing permissions and
  15 #   limitations under the License.
  16 #
  17
  18 @file core.py
  19 @author Varun Prasad (varun.prasad@riftio.com)
  20 @date 28-Sep-2016
  21
  22 """
  23
  24 import abc
  25 import asyncio
  26
  27 import gi
  28 gi.require_version("RwDts", "1.0")
  29
  30 from gi.repository import RwDts as rwdts
  31 import rift.tasklets
  32
  33 from ..core import DtsHandler
  34
  35
  36 class AbstractRpcHandler(DtsHandler):
  37     """Base class to simplify RPC implementation
  38     """
  39     def __init__(self, log, dts, loop, project=None):
  40         super().__init__(log, dts, loop, project)
  41
  42         if not asyncio.iscoroutinefunction(self.callback):
  43             raise ValueError('%s has to be a coroutine' % (self.callback))
  44
  45     @abc.abstractproperty
  46     def xpath(self):
  47         pass
  48
  49     @property
  50     def input_xpath(self):
  51         return "I,{}".format(self.xpath)
  52
  53     @property
  54     def output_xpath(self):
  55         return "O,{}".format(self.xpath)
  56
  57     def flags(self):
  58         return rwdts.Flag.PUBLISHER
  59
  60     @asyncio.coroutine
  61     def on_prepare(self, xact_info, action, ks_path, msg):
  62         assert action == rwdts.QueryAction.RPC
  63
  64         if self.project and not self.project.rpc_check(msg, xact_info=xact_info):
  65             return
  66
  67         try:
  68             rpc_op = yield from self.callback(ks_path, msg)
  69             xact_info.respond_xpath(
  70                 rwdts.XactRspCode.ACK,
  71                 self.output_xpath,
  72                 rpc_op)
  73
  74         except Exception as e:
  75             self.log.exception(e)
  76             xact_info.respond_xpath(
  77                 rwdts.XactRspCode.NACK,
  78                 self.output_xpath)
  79
  80     @asyncio.coroutine
  81     def register(self):
  82         if self.reg:
  83             self._log.warning("RPC already registered for project {}".
  84                               format(self._project.name))
  85             return
  86
  87         reg_event = asyncio.Event(loop=self.loop)
  88
  89         @asyncio.coroutine
  90         def on_ready(regh, status):
  91             reg_event.set()
  92
  93         handler = rift.tasklets.DTS.RegistrationHandler(
  94                 on_prepare=self.on_prepare,
  95                 on_ready=on_ready)
  96
  97         with self.dts.group_create() as group:
  98             self.reg = group.register(
  99                   xpath=self.input_xpath,
 100                   handler=handler,
 101                   flags=self.flags())
 102
 103         yield from reg_event.wait()
 104
 105     def deregister(self):
 106         self.reg.deregister()
 107         self.reg = None
 108
 109     @abc.abstractmethod
 110     @asyncio.coroutine
 111     def callback(self, ks_path, msg):
 112         """Subclass needs to override this method
 113
 114         Args:
 115             ks_path : Key spec path
 116             msg : RPC input
 117         """
 118         pass
 119