Psion-fanatic/platypush
1
0
Fork 0
forked from platypush/platypush
Code Pull requests Activity

Another major refactoring. Among the other things, reintroduced local backend, made requests and responses working in every case, and properly handling stop events

Browse source
This commit is contained in:
Fabio Manganiello 2017-12-22 00:49:03 +01:00
parent 7e79fa0418
commit 4b819d5460
9 changed files with 231 additions and 98 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

36
platypush/__init__.py
View file

@ -4,12 +4,10 @@ import sys
import traceback
from threading import Thread
from getopt import getopt
from .bus import Bus
from .config import Config
from .utils import get_or_load_plugin, init_backends, get_module_and_name_from_action
from .message.event import Event, StopEvent
from .message.request import Request
from .message.response import Response
@ -46,6 +44,7 @@ class Daemon(object):
"""
self.config_file = config_file
self.message_handler = message_handler
Config.init(self.config_file)
logging.basicConfig(level=Config.get('logging'), stream=sys.stdout)
@ -83,21 +82,6 @@ class Daemon(object):
return _f
def send_response(self, request, response):
""" Sends a response back.
Params:
request -- The platypush.message.request.Request object
response -- The platypush.message.response.Response object """
if request.backend and request.origin:
if request.id: response.id = request.id
response.target = request.origin
logging.info('Processing response: {}'.format(response))
request.backend.send_response(response)
else:
logging.info('Ignoring response as the request has no backend: '
.format(request))
def run_request(self):
""" Runs a request and returns the response """
@ -118,8 +102,12 @@ class Daemon(object):
# Run the action
response = plugin.run(method=method_name, **request.args)
if response and response.is_error():
logging.warning('Response processed with errors: {}'.format(response))
except Exception as e: # Retry mechanism
raise RuntimeError('Response processed with errors: {}'.format(response))
logging.info('Processed response from plugin {}: {}'.
format(plugin, response))
except Exception as e:
# Retry mechanism
response = Response(output=None, errors=[str(e), traceback.format_exc()])
logging.exception(e)
if n_tries:
@ -127,8 +115,12 @@ class Daemon(object):
get_or_load_plugin(module_name, reload=True)
_thread_func(request, n_tries=n_tries-1)
finally:
# Send the response on the backend that received the request
self.send_response(request, response)
# Send the response on the backend
if request.backend and request.origin:
request.backend.send_response(response=response, request=request)
else:
logging.info('Dropping response whose request has no ' +
'origin attached: {}'.format(request))
return _thread_func
@ -137,7 +129,7 @@ class Daemon(object):
self.bus = Bus(on_message=self.on_message())
# Initialize the backends and link them to the bus
self.backends = init_backends(self.bus)
self.backends = init_backends(bus=self.bus)
# Start the backend threads
for backend in self.backends.values():

114
platypush/backend/__init__.py
View file

@ -7,7 +7,7 @@ from threading import Thread
from platypush.bus import Bus
from platypush.config import Config
from platypush.utils import get_message_class_by_type
from platypush.utils import get_message_class_by_type, set_timeout, clear_timeout
from platypush.message import Message
from platypush.message.event import Event, StopEvent
from platypush.message.request import Request
@ -16,6 +16,8 @@ from platypush.message.response import Response
class Backend(Thread):
""" Parent class for backends """
_default_response_timeout = 5
def __init__(self, bus=None, **kwargs):
"""
Params:
@ -26,10 +28,16 @@ class Backend(Thread):
# If no bus is specified, create an internal queue where
# the received messages will be pushed
self.bus = bus if bus else Bus()
self.bus = bus or Bus()
self.device_id = Config.get('device_id')
self.thread_id = None
self._stop = False
self._kwargs = kwargs
# Internal-only, we set the request context on a backend if that
# backend is intended to react for a response to a specific request
self._request_context = kwargs['_req_ctx'] if '_req_ctx' in kwargs \
else None
Thread.__init__(self)
logging.basicConfig(stream=sys.stdout, level=Config.get('logging')
@ -50,59 +58,112 @@ class Backend(Thread):
object, or a string/byte UTF-8 encoded string
"""
msg = Message.parse(msg)
if 'type' not in msg:
logging.warning('Ignoring message with no type: {}'.format(msg))
return
msgtype = get_message_class_by_type(msg['type'])
msg = msgtype.build(msg)
msg = Message.build(msg)
if not getattr(msg, 'target') or msg.target != self.device_id:
return # Not for me
logging.info('Message received on the {} backend: {}'.format(
logging.debug('Message received on the {} backend: {}'.format(
self.__class__.__name__, msg))
msg.backend = self # Augment message
if self._is_expected_response(msg):
# Expected response, trigger the response handler
clear_timeout()
self._request_context['on_response'](msg)
self.stop()
return
if isinstance(msg, StopEvent) and msg.targets_me():
logging.info('Received STOP event on the {} backend: {}'.format(
self.__class__.__name__, msg))
logging.info('Received STOP event on {}'.format(self.__class__.__name__))
self._stop = True
else:
msg.backend = self # Augment message to be able to process responses
self.bus.post(msg)
def send_request(self, request):
def _is_expected_response(self, msg):
""" Internal only - returns true if we are expecting for a response
and msg is that response """
return self._request_context \
and isinstance(msg, Response) \
and msg.id == self._request_context['request'].id
def _get_backend_config(self):
config_name = 'backend.' + self.__class__.__name__.split('Backend')[0].lower()
return Config.get(config_name)
def _setup_response_handler(self, request, on_response, response_timeout):
def _timeout_hndl():
raise RuntimeError('Timed out while waiting for a response from {}'.
format(request.target))
req_ctx = {
'request': request,
'on_response': on_response,
'response_timeout': response_timeout,
}
resp_backend = self.__class__(bus=self.bus, _req_ctx=req_ctx,
**self._get_backend_config(), **self._kwargs)
# Set the response timeout
set_timeout(seconds=self._default_response_timeout,
on_timeout=_timeout_hndl)
resp_backend.start()
def send_request(self, request, on_response=None,
response_timeout=_default_response_timeout, **kwargs):
"""
Send a request message on the backend
Params:
request -- The request, either a dict, a string/bytes UTF-8 JSON,
or a platypush.message.request.Request object
request -- The request, either a dict, a string/bytes UTF-8 JSON,
or a platypush.message.request.Request object.
on_response -- Response handler, takes a platypush.message.response.Response
as argument. If set, the method will wait for a
response before exiting (default: None)
response_timeout -- If on_response is set, the backend will raise
an exception if the response isn't received
within this number of seconds (default: 5)
"""
request = Request.build(request)
assert isinstance(request, Request)
request.origin = self.device_id
self.send_message(request)
def send_response(self, response):
if on_response and response_timeout:
self._setup_response_handler(request, on_response, response_timeout)
self.send_message(request, **kwargs)
def send_response(self, response, request, **kwargs):
"""
Send a response message on the backend
Params:
response -- The response, either a dict, a string/bytes UTF-8 JSON,
or a platypush.message.response.Response object
request -- Associated request, used to set the response parameters
that will link them
"""
response = Response.build(response)
assert isinstance(response, Response)
assert isinstance(request, Request)
response.id = request.id
response.target = request.origin
response.origin = self.device_id
self.send_message(response)
self.send_message(response, **kwargs)
def send_message(self, msg):
def send_message(self, msg, **kwargs):
"""
Sends a platypush.message.Message to a node.
To be implemented in the derived classes.
@ -114,6 +175,7 @@ class Backend(Thread):
raise NotImplementedError("send_message should be implemented in a derived class")
def run(self):
""" Starts the backend thread. To be implemented in the derived classes """
self.thread_id = threading.get_ident()
@ -124,11 +186,13 @@ class Backend(Thread):
def stop(self):
""" Stops the backend thread by sending a STOP event on its bus """
evt = StopEvent(target=self.device_id, origin=self.device_id,
thread_id=self.thread_id)
def _async_stop():
evt = StopEvent(target=self.device_id, origin=self.device_id,
thread_id=self.thread_id)
self.send_message(evt)
self.on_stop()
self.send_message(evt)
self.on_stop()
Thread(target=_async_stop).start()
def should_stop(self):
return self._stop

19
platypush/backend/kafka/__init__.py
View file

@ -17,6 +17,8 @@ class KafkaBackend(Backend):
self.topic = self._topic_by_device_id(self.device_id)
self.producer = None
logging.getLogger('kafka').setLevel(logging.ERROR)
def _on_record(self, record):
if record.topic != self.topic: return
@ -25,7 +27,7 @@ class KafkaBackend(Backend):
except Exception as e:
logging.exception(e)
logging.debug('Received message: {}'.format(msg))
logging.debug('Received message on Kafka backend: {}'.format(msg))
self.on_message(msg)
def _init_producer(self):
@ -44,14 +46,12 @@ class KafkaBackend(Backend):
self.producer.flush()
def on_stop(self):
try:
if self.producer:
self.producer.flush()
self.producer.close()
if self.producer:
self.producer.flush()
self.producer.close()
if self.consumer:
self.consumer.close()
except: pass
if self.consumer:
self.consumer.close()
def run(self):
super().run()
@ -63,8 +63,7 @@ class KafkaBackend(Backend):
try:
for msg in self.consumer:
self._on_record(msg)
if self.should_stop():
break
if self.should_stop(): break
except ConnectionError:
logging.warning('Kafka connection error, retrying in {} seconds'.
format(self._conn_retry_secs))

77
platypush/backend/local/__init__.py Normal file
View file

@ -0,0 +1,77 @@
import logging
import json
import os
import time
from .. import Backend
from platypush.message import Message
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 """
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 on_stop(self):
try: os.remove(self.request_fifo)
except: pass
try: os.remove(self.response_fifo)
except: pass
def run(self):
super().run()
logging.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:
logging.exception(e)
time.sleep(0.2)
continue
# logging.debug('Received message on the local backend: {}'.format(msg))
logging.info('Received message on the local backend: {}'.format(msg))
if self.should_stop(): break
self.on_message(msg)
# vim:sw=4:ts=4:et:

1
platypush/backend/pushbullet/__init__.py
View file

@ -80,6 +80,7 @@ class PushbulletBackend(Backend):
push = data['push']
else: return # Not a push notification
if 'body' not in push: return
logging.debug('Received push: {}'.format(push))
body = push['body']

4
platypush/config.example.yaml
View file

@ -11,6 +11,10 @@ backend.pushbullet:
token: your_pushbullet_token_here
device: your_pushbullet_virtual_device_name
backend.local:
request_fifo: /tmp/platypush-requests.fifo
response_fifo: /tmp/platypush-responses.fifo
# device_id: <your_device_id> (default: current hostname)
# debug: True (default: False)

19
platypush/message/__init__.py
View file

@ -1,6 +1,8 @@
import logging
import inspect
import json
class Message(object):
""" Message generic class """
@ -15,7 +17,7 @@ class Message(object):
for attr in self.__dir__()
if not attr.startswith('_')
and not inspect.ismethod(getattr(self, attr))
})
}).replace('\n', ' ')
def __bytes__(self):
"""
@ -38,7 +40,10 @@ class Message(object):
if isinstance(msg, bytes) or isinstance(msg, bytearray):
msg = msg.decode('utf-8')
if isinstance(msg, str):
msg = json.loads(msg.strip())
try:
msg = json.loads(msg.strip())
except:
logging.warning('Invalid JSON message: {}'.format(msg))
assert isinstance(msg, dict)
return msg
@ -47,11 +52,15 @@ class Message(object):
def build(cls, msg):
"""
Builds a Message object from a dictionary.
To be implemented in the derived classes.
Params:
msg -- The message as a key-value dictionary
msg -- The message as a key-value dictionary, Message object or JSON string
"""
raise RuntimeError('build should be implemented in a derived class')
from platypush.utils import get_message_class_by_type
msg = cls.parse(msg)
msgtype = get_message_class_by_type(msg['type'])
if msgtype != cls: return msgtype.build(msg)
# vim:sw=4:ts=4:et:

46
platypush/pusher/__init__.py Executable file → Normal file
View file

@ -1,13 +1,13 @@
import argparse
import os
import logging
import re
import sys
from platypush.bus import Bus
from platypush.config import Config
from platypush.message.request import Request
from platypush.message.response import Response
from platypush.utils import init_backends, set_timeout, clear_timeout
from platypush.utils import init_backends
class Pusher(object):
"""
@ -49,6 +49,7 @@ class Pusher(object):
# Initialize the configuration
self.config_file = config_file
Config.init(config_file)
logging.basicConfig(level=Config.get('logging'), stream=sys.stdout)
self.on_response = on_response or self.default_on_response()
self.backend = backend or Config.get_default_pusher_backend()
@ -95,40 +96,19 @@ class Pusher(object):
def get_backend(self, name):
# Lazy init
if not self.backends: self.backends = init_backends(bus=self.bus)
if not self.backends:
self.backends = init_backends(bus=self.bus)
if name not in self.backends:
raise RuntimeError('No such backend configured: {}'.format(name))
return self.backends[name]
def on_timeout(self):
""" Default response timeout handle: raise RuntimeError """
def _f():
raise RuntimeError('Response timed out')
return _f
def default_on_response(self):
def _f(response):
print('Received response: {}'.format(response))
os._exit(0)
logging.info('Received response: {}'.format(response))
# self.backend_instance.stop()
return _f
def response_wait(self, request, timeout):
# Install the timeout handler
set_timeout(seconds=timeout, on_timeout=self.on_timeout())
# Loop on the bus until you get a response for your request ID
response_received = False
while not response_received:
msg = self.bus.get()
response_received = (
isinstance(msg, Response) and
hasattr(msg, 'id') and
msg.id == request.id)
if timeout: clear_timeout()
self.on_response(msg)
def push(self, target, action, backend=None, config_file=None,
timeout=default_response_wait_timeout, **kwargs):
"""
@ -161,11 +141,9 @@ class Pusher(object):
'args' : kwargs,
})
b = self.get_backend(backend)
b.start()
b.send_request(req)
if timeout: self.response_wait(request=req, timeout=timeout)
self.backend_instance = self.get_backend(backend)
self.backend_instance.send_request(req, on_response=self.on_response,
response_timeout=timeout)
def main(args=sys.argv[1:]):

13
platypush/utils/__init__.py
View file

@ -42,7 +42,16 @@ def get_or_load_plugin(plugin_name, reload=False):
return plugin
def init_backends(bus=None):
def init_backends(bus=None, **kwargs):
""" Initialize the backend objects based on the configuration and returns
a name -> backend_instance map.
Params:
bus -- If specific (it usually should), the messages processed by the
backends will be posted on this bus.
kwargs -- Any additional key-value parameters required to initialize the backends
"""
backends = {}
for k in Config.get_backends().keys():
@ -56,7 +65,7 @@ def init_backends(bus=None):
) + 'Backend'
try:
b = getattr(module, cls_name)(bus=bus, **cfg)
b = getattr(module, cls_name)(bus=bus, **cfg, **kwargs)
backends[k] = b
except AttributeError as e:
logging.warning('No such class in {}: {}'.format(