86 lines
2.5 KiB
Python
86 lines
2.5 KiB
Python
import json
|
|
import os
|
|
import time
|
|
import threading
|
|
|
|
from .. import Backend
|
|
|
|
from platypush.message import Message
|
|
from platypush.message.event import StopEvent
|
|
from platypush.message.request import Request
|
|
from platypush.message.response import Response
|
|
|
|
|
|
class LocalBackend(Backend):
|
|
"""
|
|
Sends and receive messages on two distinct local FIFOs, one for
|
|
the requests and one for the responses.
|
|
|
|
You can use this backend either to send local commands to push through
|
|
Pusher (or any other script), or debug. You can even send command on the
|
|
command line and read the responses in this way::
|
|
|
|
# Send the request. Remember: the JSON must be all on one line.
|
|
$ cat <<EOF > /tmp/platypush-requests.fifo
|
|
{"type": "request", "target": "node_name", "action": "shell.exec", "args": {"cmd":"echo ping"}, "origin": "node_name", "id": "put_an_id_here"}
|
|
EOF
|
|
$ cat /tmp/platypush-responses.fifo
|
|
ping
|
|
$
|
|
"""
|
|
|
|
def __init__(self, request_fifo, response_fifo, **kwargs):
|
|
super().__init__(**kwargs)
|
|
|
|
self.request_fifo = request_fifo
|
|
self.response_fifo = response_fifo
|
|
|
|
try: os.mkfifo(self.request_fifo)
|
|
except FileExistsError as e: pass
|
|
|
|
try: os.mkfifo(self.response_fifo)
|
|
except FileExistsError as e: pass
|
|
|
|
|
|
def send_message(self, msg):
|
|
fifo = self.response_fifo \
|
|
if isinstance(msg, Response) or self._request_context \
|
|
else self.request_fifo
|
|
|
|
msg = '{}\n'.format(str(msg)).encode('utf-8')
|
|
|
|
with open(fifo, 'wb') as f:
|
|
f.write(msg)
|
|
|
|
|
|
def _get_next_message(self):
|
|
fifo = self.response_fifo if self._request_context else self.request_fifo
|
|
with open(fifo, 'rb', 0) as f:
|
|
msg = f.readline()
|
|
|
|
return Message.build(msg) if len(msg) else None
|
|
|
|
|
|
def run(self):
|
|
super().run()
|
|
self.logger.info('Initialized local backend on {} and {}'.
|
|
format(self.request_fifo, self.response_fifo))
|
|
|
|
while not self.should_stop():
|
|
try:
|
|
msg = self._get_next_message()
|
|
if not msg: continue
|
|
except Exception as e:
|
|
self.logger.exception(e)
|
|
time.sleep(0.2)
|
|
continue
|
|
|
|
self.logger.debug('Received message on the local backend: {}, thread_id: '.format(msg, self.thread_id))
|
|
|
|
if self.should_stop(): break
|
|
self.on_message(msg)
|
|
|
|
|
|
# vim:sw=4:ts=4:et:
|
|
|