import logging import asyncio from asyncio import CancelledError from itertools import cycle from time import time from torba.rpc import RPCSession as BaseClientSession, Connector, RPCError from torba import __version__ from torba.stream import StreamController log = logging.getLogger(__name__) class ClientSession(BaseClientSession): def __init__(self, *args, network, server, **kwargs): self.network = network self.server = server super().__init__(*args, **kwargs) self._on_disconnect_controller = StreamController() self.on_disconnected = self._on_disconnect_controller.stream self.bw_limit = self.framer.max_size = self.max_errors = 1 << 32 self.max_seconds_idle = 60 self.ping_task = None async def send_request(self, method, args=()): try: return await super().send_request(method, args) except RPCError as e: log.warning("Wallet server returned an error. Code: %s Message: %s", *e.args) raise e async def ping_forever(self): # TODO: change to 'ping' on newer protocol (above 1.2) while not self.is_closing(): if (time() - self.last_send) > self.max_seconds_idle: await self.send_request('server.banner') await asyncio.sleep(self.max_seconds_idle//3) async def create_connection(self, timeout=6): connector = Connector(lambda: self, *self.server) await asyncio.wait_for(connector.create_connection(), timeout=timeout) self.ping_task = asyncio.create_task(self.ping_forever()) async def handle_request(self, request): controller = self.network.subscription_controllers[request.method] controller.add(request.args) def connection_lost(self, exc): super().connection_lost(exc) self._on_disconnect_controller.add(True) if self.ping_task: self.ping_task.cancel() class BaseNetwork: def __init__(self, ledger): self.config = ledger.config self.client: ClientSession = None self.running = False self._on_connected_controller = StreamController() self.on_connected = self._on_connected_controller.stream self._on_header_controller = StreamController() self.on_header = self._on_header_controller.stream self._on_status_controller = StreamController() self.on_status = self._on_status_controller.stream self.subscription_controllers = { 'blockchain.headers.subscribe': self._on_header_controller, 'blockchain.address.subscribe': self._on_status_controller, } async def start(self): self.running = True delay = 0.0 connect_timeout = self.config.get('connect_timeout', 6) for server in cycle(self.config['default_servers']): self.client = ClientSession(network=self, server=server) connection_string = '{}:{}'.format(*server) try: await self.client.create_connection(connect_timeout) await self.ensure_server_version() log.info("Successfully connected to SPV wallet server: %s", connection_string) self._on_connected_controller.add(True) delay = 0.0 await self.client.on_disconnected.first except CancelledError: self.running = False except asyncio.TimeoutError: log.warning("Timed out connecting to: %s", connection_string) except Exception: # pylint: disable=broad-except log.exception("Connecting to %s raised an exception:", connection_string) if not self.running: return elif self.client: await self.client.close() self.client.connection.cancel_pending_requests() await asyncio.sleep(delay) delay = min(delay + 1.0, 10.0) async def stop(self): self.running = False if self.is_connected: disconnected = self.client.on_disconnected.first await self.client.close() await disconnected @property def is_connected(self): return self.client is not None and not self.client.is_closing() def rpc(self, list_or_method, *args): if self.is_connected: return self.client.send_request(list_or_method, args) else: raise ConnectionError("Attempting to send rpc request when connection is not available.") def ensure_server_version(self, required='1.2'): return self.rpc('server.version', __version__, required) def broadcast(self, raw_transaction): return self.rpc('blockchain.transaction.broadcast', raw_transaction) def get_history(self, address): return self.rpc('blockchain.address.get_history', address) def get_transaction(self, tx_hash): return self.rpc('blockchain.transaction.get', tx_hash) def get_merkle(self, tx_hash, height): return self.rpc('blockchain.transaction.get_merkle', tx_hash, height) def get_headers(self, height, count=10000): return self.rpc('blockchain.block.headers', height, count) def subscribe_headers(self): return self.rpc('blockchain.headers.subscribe', True) def subscribe_address(self, address): return self.rpc('blockchain.address.subscribe', address)