gns3-server/gns3server/notification_queue.py

71 lines
2.2 KiB
Python

#!/usr/bin/env python
#
# Copyright (C) 2016 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import asyncio
import json
import psutil
from gns3server.utils.cpu_percent import CpuPercent
class NotificationQueue(asyncio.Queue):
"""
Queue returned by the notification manager.
"""
def __init__(self):
super().__init__()
self._first = True
async def get(self, timeout):
"""
When timeout is expire we send a ping notification with server information
"""
# At first get we return a ping so the client immediately receives data
if self._first:
self._first = False
return ("ping", self._getPing(), {})
try:
(action, msg, kwargs) = await asyncio.wait_for(super().get(), timeout)
except asyncio.TimeoutError:
return ("ping", self._getPing(), {})
return (action, msg, kwargs)
def _getPing(self):
"""
Return the content of the ping notification
"""
msg = {}
# Non blocking call in order to get cpu usage. First call will return 0
msg["cpu_usage_percent"] = CpuPercent.get(interval=None)
msg["memory_usage_percent"] = psutil.virtual_memory().percent
return msg
async def get_json(self, timeout):
"""
Get a message as a JSON
"""
(action, msg, kwargs) = await self.get(timeout)
if hasattr(msg, "__json__"):
msg = {"action": action, "event": msg.__json__()}
else:
msg = {"action": action, "event": msg}
msg.update(kwargs)
return json.dumps(msg, sort_keys=True)