121 lines
4.0 KiB
Python
121 lines
4.0 KiB
Python
# -*- coding: utf-8 -*-
|
|
"""
|
|
proxy.py
|
|
~~~~~~~~
|
|
⚡⚡⚡ Fast, Lightweight, Pluggable, TLS interception capable proxy server focused on
|
|
Network monitoring, controls & Application development, testing, debugging.
|
|
|
|
:copyright: (c) 2013-present by Abhinav Singh and contributors.
|
|
:license: BSD, see LICENSE for more details.
|
|
"""
|
|
import queue
|
|
import threading
|
|
import multiprocessing
|
|
import logging
|
|
import uuid
|
|
|
|
from typing import Dict, Optional, Any, Callable
|
|
|
|
from ...common.types import DictQueueType
|
|
|
|
from .queue import EventQueue
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class EventSubscriber:
|
|
"""Core event subscriber.
|
|
|
|
Usage: Initialize one instance per CPU core for optimum performance.
|
|
|
|
EventSubscriber can run within various context. E.g. main thread,
|
|
another thread or a different process. EventSubscriber context
|
|
can be different from publishers. Publishers can even be processes
|
|
outside of the proxy.py core.
|
|
|
|
Note that, EventSubscriber cannot share the `multiprocessing.Manager`
|
|
with the EventManager. Because EventSubscriber can be started
|
|
in a different process than EventManager.
|
|
|
|
`multiprocessing.Manager` is used to initialize
|
|
a new Queue which is used for subscriptions. EventDispatcher
|
|
might be running in a separate process and hence
|
|
subscription queue must be multiprocess safe.
|
|
|
|
When `subscribe` method is called, EventManager will
|
|
start a relay thread which consumes using the multiprocess
|
|
safe queue passed to the relay thread.
|
|
"""
|
|
|
|
def __init__(self, event_queue: EventQueue) -> None:
|
|
self.manager: multiprocessing.managers.SyncManager = multiprocessing.Manager()
|
|
self.event_queue = event_queue
|
|
self.relay_thread: Optional[threading.Thread] = None
|
|
self.relay_shutdown: Optional[threading.Event] = None
|
|
self.relay_channel: Optional[DictQueueType] = None
|
|
self.relay_sub_id: Optional[str] = None
|
|
|
|
def subscribe(self, callback: Callable[[Dict[str, Any]], None]) -> None:
|
|
self._start_relay_thread(callback)
|
|
assert self.relay_sub_id and self.relay_channel
|
|
self.event_queue.subscribe(self.relay_sub_id, self.relay_channel)
|
|
logger.debug(
|
|
'Subscribed relay sub id %s from core events',
|
|
self.relay_sub_id,
|
|
)
|
|
|
|
def unsubscribe(self) -> None:
|
|
if self.relay_sub_id is None:
|
|
logger.warning('Unsubscribe called without existing subscription')
|
|
return
|
|
|
|
try:
|
|
self.event_queue.unsubscribe(self.relay_sub_id)
|
|
except BrokenPipeError:
|
|
pass
|
|
except EOFError:
|
|
pass
|
|
|
|
self._stop_relay_thread()
|
|
logger.debug(
|
|
'Un-subscribed relay sub id %s from core events',
|
|
self.relay_sub_id,
|
|
)
|
|
|
|
@staticmethod
|
|
def relay(
|
|
shutdown: threading.Event,
|
|
channel: DictQueueType,
|
|
callback: Callable[[Dict[str, Any]], None],
|
|
) -> None:
|
|
while not shutdown.is_set():
|
|
try:
|
|
ev = channel.get(timeout=1)
|
|
callback(ev)
|
|
except queue.Empty:
|
|
pass
|
|
except EOFError:
|
|
break
|
|
except KeyboardInterrupt:
|
|
break
|
|
|
|
def _start_relay_thread(self, callback: Callable[[Dict[str, Any]], None]) -> None:
|
|
self.relay_sub_id = uuid.uuid4().hex
|
|
self.relay_shutdown = threading.Event()
|
|
self.relay_channel = self.manager.Queue()
|
|
self.relay_thread = threading.Thread(
|
|
target=EventSubscriber.relay,
|
|
args=(self.relay_shutdown, self.relay_channel, callback),
|
|
)
|
|
self.relay_thread.start()
|
|
|
|
def _stop_relay_thread(self) -> None:
|
|
assert self.relay_thread and self.relay_shutdown and self.relay_channel and self.relay_sub_id
|
|
self.relay_shutdown.set()
|
|
self.relay_thread.join()
|
|
self.manager.shutdown()
|
|
self.relay_thread = None
|
|
self.relay_shutdown = None
|
|
self.relay_channel = None
|
|
self.relay_sub_id = None
|