コード例 #1
0
class Subscriber(object):
    def __init__(self, validator_url):
        LOGGER.info('Connecting to validator: %s', validator_url)
        self._stream = Stream(validator_url)
        self._event_handlers = []

    def add_handler(self, handler):
        self._event_handlers.append(handler)

    def listen_to_event(self):
        self._stream.wait_for_ready()
        # Step 1: Construct a Subscription
        block_sub = EventSubscription(event_type='sawtooth/block-commit')

        # Step 2: Submit the Event Subscription
        request = ClientEventsSubscribeRequest(subscriptions=[block_sub])

        response_future = self._stream.send(
            Message.CLIENT_EVENTS_SUBSCRIBE_REQUEST,
            request.SerializeToString())

        response = ClientEventsSubscribeResponse()
        response.ParseFromString(response_future.result().content)

        # Listen for events in an infinite loop
        LOGGER.warning("Listening to events.")
        while True:
            msg = self._stream.receive()
            event_list = EventList()
            event_list.ParseFromString(msg.result().content)
            for handler in self._event_handlers:
                handler(event_list.events)
コード例 #2
0
ファイル: core.py プロジェクト: suparnadhar/SuparnaGit
class TransactionProcessor(object):
    def __init__(self, url):
        self._stream = Stream(url)
        self._url = url
        self._handlers = []

    @property
    def zmq_id(self):
        return self._stream.zmq_id

    def add_handler(self, handler):
        """Add a transaction family handler
        :param handler:
        """
        self._handlers.append(handler)

    def _matches(self, handler, header):
        return header.family_name == handler.family_name \
            and header.family_version in handler.family_versions \
            and header.payload_encoding in handler.encodings

    def _find_handler(self, header):
        """Find a handler for a particular (family_name,
        family_versions, payload_encoding)
        :param header transaction_pb2.TransactionHeader:
        :return: handler
        """
        try:
            return next(handler for handler in self._handlers
                        if self._matches(handler, header))
        except StopIteration:
            LOGGER.debug("Missing handler for header: %s", header)
            return None

    def _register_requests(self):
        """Returns all of the TpRegisterRequests for handlers

        :return (list): list of TpRegisterRequests
        """
        return itertools.chain.from_iterable(  # flattens the nested list
            [[
                TpRegisterRequest(family=n,
                                  version=v,
                                  encoding=e,
                                  namespaces=h.namespaces)
                for n, v, e in itertools.product(
                    [h.family_name], h.family_versions, h.encodings)
            ] for h in self._handlers])

    def _unregister_request(self):
        """Returns a single TP_UnregisterRequest that requests
        that the validator stop sending transactions for previously
        registered handlers.

        :return (processor_pb2.TpUnregisterRequest):
        """
        return TpUnregisterRequest()

    def _process(self, msg):
        if msg.message_type != Message.TP_PROCESS_REQUEST:
            LOGGER.debug(
                "Transaction Processor recieved invalid message type. "
                "Message type should be TP_PROCESS_REQUEST,"
                " but is %s", Message.MessageType.Name(msg.message_type))
            return

        request = TpProcessRequest()
        request.ParseFromString(msg.content)
        state = State(self._stream, request.context_id)
        header = TransactionHeader()
        header.ParseFromString(request.header)
        try:
            if not self._stream.is_ready():
                raise ValidatorConnectionError()
            handler = self._find_handler(header)
            if handler is None:
                return
            handler.apply(request, state)
            self._stream.send_back(
                message_type=Message.TP_PROCESS_RESPONSE,
                correlation_id=msg.correlation_id,
                content=TpProcessResponse(
                    status=TpProcessResponse.OK).SerializeToString())
        except InvalidTransaction as it:
            LOGGER.warning("Invalid Transaction %s", it)
            try:
                self._stream.send_back(
                    message_type=Message.TP_PROCESS_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpProcessResponse(
                        status=TpProcessResponse.INVALID_TRANSACTION,
                        message=str(it),
                        extended_data=it.extended_data).SerializeToString())
            except ValidatorConnectionError as vce:
                # TP_PROCESS_REQUEST has made it through the
                # handler.apply and an INVALID_TRANSACTION would have been
                # sent back but the validator has disconnected and so it
                # doesn't care about the response.
                LOGGER.warning("during invalid transaction response: %s", vce)
        except InternalError as ie:
            LOGGER.warning("internal error: %s", ie)
            try:
                self._stream.send_back(
                    message_type=Message.TP_PROCESS_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpProcessResponse(
                        status=TpProcessResponse.INTERNAL_ERROR,
                        message=str(ie),
                        extended_data=ie.extended_data).SerializeToString())
            except ValidatorConnectionError as vce:
                # Same as the prior except block, but an internal error has
                # happened, but because of the disconnect the validator
                # probably doesn't care about the response.
                LOGGER.warning("during internal error response: %s", vce)
        except ValidatorConnectionError as vce:
            # Somewhere within handler.apply a future resolved with an
            # error status that the validator has disconnected. There is
            # nothing left to do but reconnect.
            LOGGER.warning(
                "during handler.apply a future was resolved "
                "with error status: %s", vce)

    def _process_future(self, future, timeout=None, sigint=False):
        try:
            msg = future.result(timeout)
        except CancelledError:
            # This error is raised when Task.cancel is called on
            # disconnect from the validator in stream.py, for
            # this future.
            return
        if msg is RECONNECT_EVENT:
            if sigint is False:
                LOGGER.info("reregistering with validator")
                self._stream.wait_for_ready()
                self._register()
        else:
            LOGGER.debug('received message of type: %s',
                         Message.MessageType.Name(msg.message_type))
            if msg.message_type == Message.TP_PING:
                self._stream.send_back(
                    message_type=Message.TP_PING_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpPingResponse(
                        status=TpPingResponse.OK).SerializeToString())
                return
            self._process(msg)

    def _register(self):
        futures = []
        for message in self._register_requests():
            self._stream.wait_for_ready()
            future = self._stream.send(
                message_type=Message.TP_REGISTER_REQUEST,
                content=message.SerializeToString())
            futures.append(future)

        for future in futures:
            resp = TpRegisterResponse()
            try:
                resp.ParseFromString(future.result().content)
                LOGGER.info("register attempt: %s",
                            TpRegisterResponse.Status.Name(resp.status))
            except ValidatorConnectionError as vce:
                LOGGER.info("during waiting for response on registration: %s",
                            vce)

    def _unregister(self):
        message = self._unregister_request()
        self._stream.wait_for_ready()
        future = self._stream.send(message_type=Message.TP_UNREGISTER_REQUEST,
                                   content=message.SerializeToString())
        response = TpUnregisterResponse()
        try:
            response.ParseFromString(future.result(1).content)
            LOGGER.info("unregister attempt: %s",
                        TpUnregisterResponse.Status.Name(response.status))
        except ValidatorConnectionError as vce:
            LOGGER.info("during waiting for response on unregistration: %s",
                        vce)

    def start(self):
        fut = None
        try:
            self._register()
            while True:
                # During long running processing this
                # is where the transaction processor will
                # spend most of its time
                fut = self._stream.receive()
                self._process_future(fut)
        except KeyboardInterrupt:
            try:
                # tell the validator to not send any more messages
                self._unregister()
                while True:
                    if fut is not None:
                        # process futures as long as the tp has them,
                        # if the TP_PROCESS_REQUEST doesn't come from
                        # zeromq->asyncio in 1 second raise a
                        # concurrent.futures.TimeOutError and be done.
                        self._process_future(fut, 1, sigint=True)
                        fut = self._stream.receive()
            except concurrent.futures.TimeoutError:
                # Where the tp will usually exit after
                # a KeyboardInterrupt. Caused by the 1 second
                # timeout in _process_future.
                pass
            except FutureTimeoutError:
                # If the validator is not able to respond to the
                # unregister request, exit.
                pass

    def stop(self):
        self._stream.close()
class ZmqDriver(Driver):
    def __init__(self, engine):
        super().__init__(engine)
        self._engine = engine
        self._stream = None
        self._exit = False
        self._updates = None

    def start(self, endpoint):
        self._stream = Stream(endpoint)

        startup_state = self._register()

        # Validators version 1.1 send startup info with the registration
        # response; newer versions will send an activation message with the
        # startup info
        if startup_state is None:
            startup_state = self._wait_until_active()

        self._updates = Queue()

        driver_thread = Thread(
            target=self._driver_loop)
        driver_thread.start()

        try:
            self._engine.start(
                self._updates,
                ZmqService(
                    stream=self._stream,
                    timeout=SERVICE_TIMEOUT),
                startup_state)
        except Exception:  # pylint: disable=broad-except
            LOGGER.exception("Uncaught engine exception")

        self.stop()
        driver_thread.join()

    def _driver_loop(self):
        try:
            future = self._stream.receive()
            while True:
                if self._exit:
                    self._engine.stop()
                    break

                try:
                    message = future.result(1)
                    future = self._stream.receive()
                except concurrent.futures.TimeoutError:
                    continue
                try:
                    result = self._process(message)
                    # if message was a ping ignore
                    if result[0] == Message.PING_REQUEST:
                        continue

                    self._updates.put(result)

                except exceptions.ReceiveError as err:
                    LOGGER.warning("%s", err)
                    continue
        except Exception:  # pylint: disable=broad-except
            LOGGER.exception("Uncaught driver exception")

    def stop(self):
        self._exit = True
        self._engine.stop()
        self._stream.close()

    def _register(self):
        self._stream.wait_for_ready()

        request = consensus_pb2.ConsensusRegisterRequest(
            name=self._engine.name(),
            version=self._engine.version(),
        )

        for (name, version) in self._engine.additional_protocols():
            protocol = request.additional_protocols.add()
            protocol.name = name
            protocol.version = version

        while True:
            future = self._stream.send(
                message_type=Message.CONSENSUS_REGISTER_REQUEST,
                content=request.SerializeToString())
            response = consensus_pb2.ConsensusRegisterResponse()
            response.ParseFromString(future.result(REGISTER_TIMEOUT).content)

            if (
                response.status
                == consensus_pb2.ConsensusRegisterResponse.NOT_READY
            ):
                continue

            if response.status == consensus_pb2.ConsensusRegisterResponse.OK:
                if (
                    response.HasField('chain_head')
                    and response.HasField('local_peer_info')
                ):
                    return StartupState(
                        response.chain_head,
                        response.peers,
                        response.local_peer_info)

                return None

            raise exceptions.ReceiveError(
                'Registration failed with status {}'.format(response.status))

    def _wait_until_active(self):
        future = self._stream.receive()
        while True:
            try:
                message = future.result(1)
            except concurrent.futures.TimeoutError:
                continue

            if (
                message.message_type
                == Message.CONSENSUS_NOTIFY_ENGINE_ACTIVATED
            ):
                notification = \
                    consensus_pb2.ConsensusNotifyEngineActivated()
                notification.ParseFromString(message.content)

                startup_state = StartupState(
                    notification.chain_head,
                    notification.peers,
                    notification.local_peer_info)

                LOGGER.info(
                    'Received activation message with startup state: %s',
                    startup_state)

                self._stream.send_back(
                    message_type=Message.CONSENSUS_NOTIFY_ACK,
                    correlation_id=message.correlation_id,
                    content=consensus_pb2.ConsensusNotifyAck()
                                         .SerializeToString())

                return startup_state

            LOGGER.warning('Received message type %s while waiting for \
                activation message', message.message_type)
            future = self._stream.receive()

    def _process(self, message):
        type_tag = message.message_type

        if type_tag == Message.CONSENSUS_NOTIFY_PEER_CONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerConnected()
            notification.ParseFromString(message.content)

            data = notification.peer_info

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_DISCONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerDisconnected()
            notification.ParseFromString(message.content)

            data = notification.peer_id

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_MESSAGE:
            notification = consensus_pb2.ConsensusNotifyPeerMessage()
            notification.ParseFromString(message.content)

            header = consensus_pb2.ConsensusPeerMessageHeader()
            header.ParseFromString(notification.message.header)

            peer_message = PeerMessage(
                header=header,
                header_bytes=notification.message.header,
                header_signature=notification.message.header_signature,
                content=notification.message.content)

            data = peer_message, notification.sender_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_NEW:
            notification = consensus_pb2.ConsensusNotifyBlockNew()
            notification.ParseFromString(message.content)

            data = notification.block

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_VALID:
            notification = consensus_pb2.ConsensusNotifyBlockValid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_INVALID:
            notification = consensus_pb2.ConsensusNotifyBlockInvalid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_COMMIT:
            notification = consensus_pb2.ConsensusNotifyBlockCommit()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_ENGINE_DEACTIVATED:
            self.stop()
            data = None

        elif type_tag == Message.PING_REQUEST:
            data = None

        else:
            raise exceptions.ReceiveError(
                'Received unexpected message type: {}'.format(type_tag))

        self._stream.send_back(
            message_type=Message.CONSENSUS_NOTIFY_ACK,
            correlation_id=message.correlation_id,
            content=consensus_pb2.ConsensusNotifyAck().SerializeToString())

        return type_tag, data
コード例 #4
0
ファイル: zmq_driver.py プロジェクト: cianx/sawtooth-core
class ZmqDriver(Driver):
    def __init__(self, engine):
        super().__init__(engine)
        self._engine = engine
        self._stream = None
        self._exit = False
        self._updates = None

    def start(self, endpoint):
        self._stream = Stream(endpoint)

        startup_state = self._register()

        # Validators version 1.1 send startup info with the registration
        # response; newer versions will send an activation message with the
        # startup info
        if startup_state is None:
            startup_state = self._wait_until_active()

        self._updates = Queue()

        driver_thread = Thread(
            target=self._driver_loop)
        driver_thread.start()

        try:
            self._engine.start(
                self._updates,
                ZmqService(
                    stream=self._stream,
                    timeout=SERVICE_TIMEOUT),
                startup_state)
        except Exception:  # pylint: disable=broad-except
            LOGGER.exception("Uncaught engine exception")

        self.stop()
        driver_thread.join()

    def _driver_loop(self):
        try:
            future = self._stream.receive()
            while True:
                if self._exit:
                    self._engine.stop()
                    break

                try:
                    message = future.result(1)
                    future = self._stream.receive()
                except concurrent.futures.TimeoutError:
                    continue

                result = self._process(message)

                self._updates.put(result)
        except Exception:  # pylint: disable=broad-except
            LOGGER.exception("Uncaught driver exception")

    def stop(self):
        self._exit = True
        self._engine.stop()
        self._stream.close()

    def _register(self):
        self._stream.wait_for_ready()

        request = consensus_pb2.ConsensusRegisterRequest(
            name=self._engine.name(),
            version=self._engine.version(),
        ).SerializeToString()

        while True:
            future = self._stream.send(
                message_type=Message.CONSENSUS_REGISTER_REQUEST,
                content=request)
            response = consensus_pb2.ConsensusRegisterResponse()
            response.ParseFromString(future.result(REGISTER_TIMEOUT).content)

            if (
                response.status
                == consensus_pb2.ConsensusRegisterResponse.NOT_READY
            ):
                continue

            if response.status == consensus_pb2.ConsensusRegisterResponse.OK:
                if (
                    response.HasField('chain_head')
                    and response.HasField('local_peer_info')
                ):
                    return StartupState(
                        response.chain_head,
                        response.peers,
                        response.local_peer_info)

                return None

            raise exceptions.ReceiveError(
                'Registration failed with status {}'.format(response.status))

    def _wait_until_active(self):
        future = self._stream.receive()
        while True:
            try:
                message = future.result(1)
            except concurrent.futures.TimeoutError:
                continue

            if (
                message.message_type
                == Message.CONSENSUS_NOTIFY_ENGINE_ACTIVATED
            ):
                notification = \
                    consensus_pb2.ConsensusNotifyEngineActivated()
                notification.ParseFromString(message.content)

                startup_state = StartupState(
                    notification.chain_head,
                    notification.peers,
                    notification.local_peer_info)

                LOGGER.info(
                    'Received activation message with startup state: %s',
                    startup_state)

                self._stream.send_back(
                    message_type=Message.CONSENSUS_NOTIFY_ACK,
                    correlation_id=message.correlation_id,
                    content=consensus_pb2.ConsensusNotifyAck()
                                         .SerializeToString())

                return startup_state

            LOGGER.warning('Received message type %s while waiting for \
                activation message', message.message_type)
            future = self._stream.receive()

    def _process(self, message):
        type_tag = message.message_type

        if type_tag == Message.CONSENSUS_NOTIFY_PEER_CONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerConnected()
            notification.ParseFromString(message.content)

            data = notification.peer_info

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_DISCONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerDisconnected()
            notification.ParseFromString(message.content)

            data = notification.peer_id

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_MESSAGE:
            notification = consensus_pb2.ConsensusNotifyPeerMessage()
            notification.ParseFromString(message.content)

            header = consensus_pb2.ConsensusPeerMessageHeader()
            header.ParseFromString(notification.message.header)

            peer_message = PeerMessage(
                header=header,
                header_bytes=notification.message.header,
                header_signature=notification.message.header_signature,
                content=notification.message.content)

            data = peer_message, notification.sender_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_NEW:
            notification = consensus_pb2.ConsensusNotifyBlockNew()
            notification.ParseFromString(message.content)

            data = notification.block

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_VALID:
            notification = consensus_pb2.ConsensusNotifyBlockValid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_INVALID:
            notification = consensus_pb2.ConsensusNotifyBlockInvalid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_COMMIT:
            notification = consensus_pb2.ConsensusNotifyBlockCommit()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_ENGINE_DEACTIVATED:
            self.stop()
            data = None

        else:
            raise exceptions.ReceiveError(
                'Received unexpected message type: {}'.format(type_tag))

        self._stream.send_back(
            message_type=Message.CONSENSUS_NOTIFY_ACK,
            correlation_id=message.correlation_id,
            content=consensus_pb2.ConsensusNotifyAck().SerializeToString())

        return type_tag, data
コード例 #5
0
ファイル: zmq_driver.py プロジェクト: ywandy/sawtooth-core
class ZmqDriver(Driver):
    def __init__(self, engine):
        super().__init__(engine)
        self._engine = engine
        self._stream = None
        self._exit = False
        self._updates = None

    def start(self, endpoint):
        self._stream = Stream(endpoint)

        (chain_head, peers) = self._register()

        self._updates = Queue()

        engine_thread = Thread(
            target=self._engine.start,
            args=(self._updates,
                  ZmqService(stream=self._stream,
                             timeout=SERVICE_TIMEOUT,
                             name=self._engine.name(),
                             version=self._engine.version()), chain_head,
                  peers))

        engine_thread.start()

        while True:
            if self._exit:
                self._engine.stop()
                engine_thread.join()
                break

            try:
                message = self._stream.receive().result(0.1)
            except concurrent.futures.TimeoutError:
                continue

            result = self._process(message)

            self._updates.put(result)

    def stop(self):
        self._exit = True
        self._stream.close()

    def _register(self):
        self._stream.wait_for_ready()

        request = consensus_pb2.ConsensusRegisterRequest(
            name=self._engine.name(),
            version=self._engine.version(),
        ).SerializeToString()

        while True:
            future = self._stream.send(
                message_type=Message.CONSENSUS_REGISTER_REQUEST,
                content=request)
            response = consensus_pb2.ConsensusRegisterResponse()
            response.ParseFromString(future.result(REGISTER_TIMEOUT).content)

            if (response.status ==
                    consensus_pb2.ConsensusRegisterResponse.NOT_READY):
                continue

            if response.status == consensus_pb2.ConsensusRegisterResponse.OK:
                return (response.chain_head, response.peers)

            raise exceptions.ReceiveError(
                'Registration failed with status {}'.format(response.status))

    def _process(self, message):
        type_tag = message.message_type

        if type_tag == Message.CONSENSUS_NOTIFY_PEER_CONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerConnected()
            notification.ParseFromString(message.content)

            data = notification.peer_info

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_DISCONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerDisconnected()
            notification.ParseFromString(message.content)

            data = notification.peer_id

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_MESSAGE:
            notification = consensus_pb2.ConsensusNotifyPeerMessage()
            notification.ParseFromString(message.content)

            data = notification.message, notification.sender_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_NEW:
            notification = consensus_pb2.ConsensusNotifyBlockNew()
            notification.ParseFromString(message.content)

            data = notification.block

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_VALID:
            notification = consensus_pb2.ConsensusNotifyBlockValid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_INVALID:
            notification = consensus_pb2.ConsensusNotifyBlockInvalid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_COMMIT:
            notification = consensus_pb2.ConsensusNotifyBlockCommit()
            notification.ParseFromString(message.content)

            data = notification.block_id

        else:
            raise exceptions.ReceiveError(
                'Received unexpected message type: {}'.format(type_tag))

        self._stream.send_back(
            message_type=Message.CONSENSUS_NOTIFY_ACK,
            correlation_id=message.correlation_id,
            content=consensus_pb2.ConsensusNotifyAck().SerializeToString())

        return type_tag, data
コード例 #6
0
class Subscriber(object):
    """Creates an object that can subscribe to state delta events using the
    Sawtooth SDK's Stream class. Handler functions can be added prior to
    subscribing, and each will be called on each delta event received.
    """
    def __init__(self, validator_url):
        LOGGER.info("Connecting to validator: %s", validator_url)
        self._stream = Stream(validator_url)
        self._delta_handlers = []
        self._is_active = False

    def add_handler(self, event_handler):
        """Adds a handler which will be passed state delta events when they
        occur. Note that this event is mutable.
        """
        self._delta_handlers.append(event_handler)

    def clear_handlers(self):
        """Clears any delta handlers.
        """
        self._delta_handlers = []

    def start(self, known_ids=None):
        """Subscribes to state delta events, and then waits to receive deltas.
        Sends any events received to delta handlers.
        """
        self._stream.wait_for_ready()

        LOGGER.debug("Subscribing to client state events")
        request = client_event_pb2.ClientEventsSubscribeRequest(
            last_known_block_ids=known_ids,
            subscriptions=[
                events_pb2.EventSubscription(
                    event_type="sawtooth/block-commit"),
                events_pb2.EventSubscription(
                    event_type="sawtooth/state-delta",
                    filters=[
                        events_pb2.EventFilter(
                            key="address",
                            match_string="^" + addresser.NAMESPACE + ".*",
                            filter_type=events_pb2.EventFilter.REGEX_ANY,
                        )
                    ],
                ),
            ],
        )

        response_future = self._stream.send(
            Message.CLIENT_EVENTS_SUBSCRIBE_REQUEST,
            request.SerializeToString())
        response = client_event_pb2.ClientEventsSubscribeResponse()
        response.ParseFromString(response_future.result().content)

        # Forked all the way back to genesis, restart with no known_ids
        if (known_ids and response.status ==
                client_event_pb2.ClientEventsSubscribeResponse.UNKNOWN_BLOCK):
            return self.start()

        if response.status != client_event_pb2.ClientEventsSubscribeResponse.OK:
            raise RuntimeError("Subscription failed with status: {}".format(
                client_event_pb2.ClientEventsSubscribeResponse.Status.Name(
                    response.status)))

        self._is_active = True

        LOGGER.debug("Successfully subscribed to state delta events")
        while self._is_active:
            message_future = self._stream.receive()
            msg = message_future.result()

            if msg.message_type == Message.CLIENT_EVENTS:
                event_list = events_pb2.EventList()
                event_list.ParseFromString(msg.content)
                events = list(event_list.events)
                event = StateDeltaEvent(events)

                delta_count = len(event.state_changes)
                if delta_count > 0:
                    LOGGER.debug("Received %d deltas for block: %s",
                                 delta_count, event.block_id)

                    for handler in self._delta_handlers:
                        handler(event)

    def stop(self):
        """Stops the Subscriber, unsubscribing from state delta events and
        closing the the stream's connection.
        """
        self._is_active = False

        LOGGER.debug("Unsubscribing from client events")
        request = client_event_pb2.ClientEventsUnsubscribeResponse()
        response_future = self._stream.send(
            Message.CLIENT_EVENTS_UNSUBSCRIBE_REQUEST,
            request.SerializeToString())
        response = client_event_pb2.ClientEventsUnsubscribeResponse()
        response.ParseFromString(response_future.result().content)

        if response.status != client_event_pb2.ClientEventsUnsubscribeResponse.OK:
            LOGGER.warning(
                "Failed to unsubscribe with status: %s",
                client_event_pb2.ClientEventsUnsubscribeResponse.Status.Name(
                    response.status),
            )

        self._stream.close()
コード例 #7
0
ファイル: basic.py プロジェクト: mikalv/remme-core
class BasicClient:
    def __init__(self, family_handler, test_helper=None, keyfile=None):
        config = load_toml_with_defaults(
            '/config/remme-client-config.toml')['remme']['client']

        self.url = config['validator_rest_api_url']
        self._family_handler = family_handler
        self.test_helper = test_helper
        self._stream = Stream(
            f'tcp://{ config["validator_ip"] }:{ config["validator_port"] }')

        if keyfile is None:
            keyfile = PRIV_KEY_FILE

        try:
            self._signer = self.get_signer_priv_key_from_file(keyfile)
        except ClientException as e:
            LOGGER.warn('Could not set up signer from file, detailed: %s', e)
            self._signer = self.generate_signer(keyfile)

    @staticmethod
    def get_signer_priv_key_from_file(keyfile):
        try:
            with open(keyfile) as fd:
                private_key_str = fd.read().strip()
        except OSError as err:
            raise ClientException('Failed to read private key: {}'.format(
                str(err)))

        try:
            private_key = Secp256k1PrivateKey.from_hex(private_key_str)
        except ParseError as e:
            raise ClientException('Unable to load private key: {}'.format(
                str(e)))

        context = create_context('secp256k1')
        return CryptoFactory(context).new_signer(private_key)

    @staticmethod
    def generate_signer(keyfile=None):
        context = create_context('secp256k1')
        private_key = context.new_random_private_key()
        if keyfile:
            try:
                with open(keyfile, 'w') as fd:
                    fd.write(private_key.as_hex())
            except OSError as err:
                raise ClientException(f'Failed to write private key: {err}')
        return CryptoFactory(context).new_signer(private_key)

    def make_address(self, suffix):
        return self._family_handler.make_address(suffix)

    def make_address_from_data(self, data):
        return self._family_handler.make_address_from_data(data)

    def is_address(self, address):
        return self._family_handler.is_address(address)

    def get_value(self, address):
        result = self._send_request(f"state/{address}", conn_protocol='socket')
        return base64.b64decode(result['data'])

    def get_batch(self, batch_id):
        result = self._send_request(f"batch_statuses?id={batch_id}",
                                    conn_protocol='socket')
        return result['data'][0]

    def get_signer(self):
        return self._signer

    def get_public_key(self):
        return self.get_signer().get_public_key().as_hex()

    def _get_prefix(self):
        return self._family_handler.namespaces[-1]

    def _get_address(self, pub_key):
        if len(pub_key) > 64:
            raise ClientException("Wrong pub_key size: {}".format(pub_key))
        prefix = self._get_prefix()
        return prefix + pub_key

    def _send_request(self, suffix, data=None, conn_protocol='text', **kwargs):
        if conn_protocol == 'text':
            return self._text_request(suffix, data, **kwargs)
        elif conn_protocol == 'socket':
            return self._socket_request(suffix, data, **kwargs)
        raise ClientException('Unsupported connection protocol "%s"' %
                              conn_protocol)

    def _text_request(self, suffix, data=None, content_type=None):
        url = f"{self.url}/{suffix}"

        if not url.startswith("http://"):
            url = f"http://{url}"

        headers = {}
        if content_type is not None:
            headers['Content-Type'] = content_type

        try:
            if data is not None:
                with suppress(AttributeError):
                    data = data.SerializeToString()

                result = requests.post(url, headers=headers, data=data)
            else:
                result = requests.get(url, headers=headers)

            if result.status_code == 404:
                raise KeyNotFound("404")

            elif not result.ok:
                raise ClientException("Error {}: {}".format(
                    result.status_code, result.reason))

        except requests.ConnectionError as err:
            raise ClientException(
                'Failed to connect to REST API: {}'.format(err))

        return json.loads(result.text)

    def _socket_request(self, suffix, data=None):
        if suffix == 'batches':
            return self.submit_batches({'batches': data.batches})
        elif 'batch_statuses?id=' in suffix:
            _, batch_id = suffix.split('?id=')
            return self.get_batch_statuses({'batch_ids': [batch_id]})
        elif 'state/' in suffix:
            _, address = suffix.split('/')
            _, root = self.get_root_block()
            return self.fetch_state({'state_root': root, 'address': address})
        else:
            raise ClientException('Suffix "%s" not supported' % suffix)

    def _handle_response(self, msg_type, resp_proto, req):
        self._stream.wait_for_ready()
        future = self._stream.send(message_type=msg_type,
                                   content=req.SerializeToString())

        resp = resp_proto()
        try:
            resp.ParseFromString(future.result().content)
        except (DecodeError, AttributeError):
            raise ClientException(
                'Failed to parse "content" string from validator')
        except ValidatorConnectionError as vce:
            LOGGER.error('Error: %s' % vce)
            raise ClientException(
                'Failed with ZMQ interaction: {0}'.format(vce))

        data = message_to_dict(resp)

        # NOTE: Not all protos have this status
        with suppress(AttributeError):
            if resp.status == resp_proto.NO_RESOURCE:
                raise KeyNotFound("404")

        if resp.status != resp_proto.OK:
            raise ClientException("Error: %s" % data)

        return data

    def fetch_peers(self):
        resp = self._handle_response(Message.CLIENT_PEERS_GET_REQUEST,
                                     ClientPeersGetResponse,
                                     ClientPeersGetRequest())
        return {'data': resp['peers']}

    def get_root_block(self):
        resp = self._handle_response(
            Message.CLIENT_BLOCK_LIST_REQUEST, ClientBlockListResponse,
            ClientBlockListRequest(paging=ClientPagingControls(limit=1)))
        block = resp['blocks'][0]
        header = BlockHeader()
        try:
            header_bytes = base64.b64decode(block['header'])
            header.ParseFromString(header_bytes)
        except (KeyError, TypeError, ValueError, DecodeError):
            header = block.get('header', None)
            LOGGER.error(
                'The validator sent a resource with %s %s',
                'a missing header' if header is None else 'an invalid header:',
                header or '')
            raise ClientException()

        block['header'] = message_to_dict(header)

        return (
            block['header_signature'],
            block['header']['state_root_hash'],
        )

    def submit_batches(self, data):
        self._handle_response(
            Message.CLIENT_BATCH_SUBMIT_REQUEST, ClientBatchSubmitResponse,
            ClientBatchSubmitRequest(batches=data['batches']))

        id_string = ','.join(b.header_signature for b in data['batches'])
        link = f"{self.url}/batch_statuses?id={id_string}"
        return {'link': link}

    def fetch_state(self, data):
        resp = self._handle_response(
            Message.CLIENT_STATE_GET_REQUEST, ClientStateGetResponse,
            ClientStateGetRequest(state_root=data['state_root'],
                                  address=data['address']))

        return {'data': resp['value']}

    def get_batch_statuses(self, data):
        resp = self._handle_response(
            Message.CLIENT_BATCH_STATUS_REQUEST, ClientBatchStatusResponse,
            ClientBatchStatusRequest(batch_ids=data['batch_ids']))
        return {'data': resp['batch_statuses']}

    def make_batch_list(self, payload_pb, addresses_input, addresses_output):
        payload = payload_pb.SerializeToString()
        signer = self._signer
        header = TransactionHeader(
            signer_public_key=signer.get_public_key().as_hex(),
            family_name=self._family_handler.family_name,
            family_version=self._family_handler.family_versions[-1],
            inputs=addresses_input,
            outputs=addresses_output,
            dependencies=[],
            payload_sha512=hash512(payload),
            batcher_public_key=signer.get_public_key().as_hex(),
            nonce=time.time().hex().encode()).SerializeToString()

        signature = signer.sign(header)

        transaction = Transaction(header=header,
                                  payload=payload,
                                  header_signature=signature)

        return self._sign_batch_list(signer, [transaction])

    def set_signer(self, new_signer):
        self._signer = new_signer

    def get_user_address(self):
        return AccountHandler.make_address_from_data(
            self._signer.get_public_key().as_hex())

    def _send_transaction(self, method, data_pb, addresses_input,
                          addresses_output):
        '''
           Signs and sends transaction to the network using rest-api.

           :param str method: The method (defined in proto) for Transaction Processor to process the request.
           :param dict data: Dictionary that is required by TP to process the transaction.
           :param str addresses_input: list of addresses(keys) for which to get state.
           :param str addresses_output: list of addresses(keys) for which to save state.
        '''
        addresses_input_output = []
        addresses_input_output.extend(addresses_input)
        addresses_input_output.extend(addresses_output)
        addresses_input_output = list(set(addresses_input_output))
        # forward transaction to test helper
        if self.test_helper:
            self.test_helper.send_transaction(method, data_pb,
                                              addresses_input_output)
            return

        payload = TransactionPayload()
        payload.method = method
        payload.data = data_pb.SerializeToString()

        for address in addresses_input_output:
            if not is_address(address):
                raise ClientException(
                    'one of addresses_input_output {} is not an address'.
                    format(addresses_input_output))

        batch_list = self.make_batch_list(payload, addresses_input,
                                          addresses_output)

        return get_batch_id(self._send_request('batches', batch_list,
                                               'socket'))

    def _send_raw_transaction(self, transaction_pb):
        batch_list = self._sign_batch_list(self._signer, [transaction_pb])

        return get_batch_id(self._send_request('batches', batch_list,
                                               'socket'))

    def _sign_batch_list(self, signer, transactions):
        transaction_signatures = [t.header_signature for t in transactions]

        header = BatchHeader(
            signer_public_key=signer.get_public_key().as_hex(),
            transaction_ids=transaction_signatures).SerializeToString()

        signature = signer.sign(header)

        batch = Batch(header=header,
                      transactions=transactions,
                      header_signature=signature)
        return BatchList(batches=[batch])
コード例 #8
0
ファイル: core.py プロジェクト: cianx/sawtooth-core
class TransactionProcessor:
    """TransactionProcessor is a generic class for communicating with a
    validator and routing transaction processing requests to a registered
    handler. It uses ZMQ and channels to handle requests concurrently.
    """

    def __init__(self, url):
        """
        Args:
            url (string): The URL of the validator
        """
        self._stream = Stream(url)
        self._url = url
        self._handlers = []

    @property
    def zmq_id(self):
        return self._stream.zmq_id

    def add_handler(self, handler):
        """Adds a transaction family handler
        Args:
            handler (TransactionHandler): the handler to be added
        """
        self._handlers.append(handler)

    def _matches(self, handler, header):
        return header.family_name == handler.family_name \
            and header.family_version in handler.family_versions

    def _find_handler(self, header):
        """Find a handler for a particular (family_name, family_versions)
        :param header transaction_pb2.TransactionHeader:
        :return: handler
        """
        try:
            return next(
                handler for handler in self._handlers
                if self._matches(handler, header))
        except StopIteration:
            LOGGER.debug("Missing handler for header: %s", header)
            return None

    def _register_requests(self):
        """Returns all of the TpRegisterRequests for handlers

        :return (list): list of TpRegisterRequests
        """
        return itertools.chain.from_iterable(  # flattens the nested list
            [
                [TpRegisterRequest(
                    family=n,
                    version=v,
                    namespaces=h.namespaces)
                 for n, v in itertools.product(
                    [h.family_name],
                     h.family_versions,)] for h in self._handlers])

    def _unregister_request(self):
        """Returns a single TP_UnregisterRequest that requests
        that the validator stop sending transactions for previously
        registered handlers.

        :return (processor_pb2.TpUnregisterRequest):
        """
        return TpUnregisterRequest()

    def _process(self, msg):
        if msg.message_type != Message.TP_PROCESS_REQUEST:
            LOGGER.debug(
                "Transaction Processor recieved invalid message type. "
                "Message type should be TP_PROCESS_REQUEST,"
                " but is %s", Message.MessageType.Name(msg.message_type))
            return

        request = TpProcessRequest()
        request.ParseFromString(msg.content)
        state = Context(self._stream, request.context_id)
        header = request.header
        try:
            if not self._stream.is_ready():
                raise ValidatorConnectionError()
            handler = self._find_handler(header)
            if handler is None:
                return
            handler.apply(request, state)
            self._stream.send_back(
                message_type=Message.TP_PROCESS_RESPONSE,
                correlation_id=msg.correlation_id,
                content=TpProcessResponse(
                    status=TpProcessResponse.OK
                ).SerializeToString())
        except InvalidTransaction as it:
            LOGGER.warning("Invalid Transaction %s", it)
            try:
                self._stream.send_back(
                    message_type=Message.TP_PROCESS_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpProcessResponse(
                        status=TpProcessResponse.INVALID_TRANSACTION,
                        message=str(it),
                        extended_data=it.extended_data
                    ).SerializeToString())
            except ValidatorConnectionError as vce:
                # TP_PROCESS_REQUEST has made it through the
                # handler.apply and an INVALID_TRANSACTION would have been
                # sent back but the validator has disconnected and so it
                # doesn't care about the response.
                LOGGER.warning("during invalid transaction response: %s", vce)
        except InternalError as ie:
            LOGGER.warning("internal error: %s", ie)
            try:
                self._stream.send_back(
                    message_type=Message.TP_PROCESS_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpProcessResponse(
                        status=TpProcessResponse.INTERNAL_ERROR,
                        message=str(ie),
                        extended_data=ie.extended_data
                    ).SerializeToString())
            except ValidatorConnectionError as vce:
                # Same as the prior except block, but an internal error has
                # happened, but because of the disconnect the validator
                # probably doesn't care about the response.
                LOGGER.warning("during internal error response: %s", vce)
        except ValidatorConnectionError as vce:
            # Somewhere within handler.apply a future resolved with an
            # error status that the validator has disconnected. There is
            # nothing left to do but reconnect.
            LOGGER.warning("during handler.apply a future was resolved "
                           "with error status: %s", vce)
        except AuthorizationException as ae:
            LOGGER.warning("AuthorizationException: %s", ae)
            try:
                self._stream.send_back(
                    message_type=Message.TP_PROCESS_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpProcessResponse(
                        status=TpProcessResponse.INVALID_TRANSACTION,
                        message=str(ae),
                    ).SerializeToString())
            except ValidatorConnectionError as vce:
                # TP_PROCESS_REQUEST has made it through the
                # handler.apply and an INVALID_TRANSACTION would have been
                # sent back but the validator has disconnected and so it
                # doesn't care about the response.
                LOGGER.warning("during invalid transaction response: %s", vce)

    def _process_future(self, future, timeout=None, sigint=False):
        try:
            msg = future.result(timeout)
        except CancelledError:
            # This error is raised when Task.cancel is called on
            # disconnect from the validator in stream.py, for
            # this future.
            return
        if msg is RECONNECT_EVENT:
            if sigint is False:
                LOGGER.info("reregistering with validator")
                self._stream.wait_for_ready()
                self._register()
        else:
            LOGGER.debug(
                'received message of type: %s',
                Message.MessageType.Name(msg.message_type))
            if msg.message_type == Message.PING_REQUEST:
                self._stream.send_back(
                    message_type=Message.PING_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=PingResponse().SerializeToString())
                return
            self._process(msg)

    def _register(self):
        futures = []
        for message in self._register_requests():
            self._stream.wait_for_ready()
            future = self._stream.send(
                message_type=Message.TP_REGISTER_REQUEST,
                content=message.SerializeToString())
            futures.append(future)

        for future in futures:
            resp = TpRegisterResponse()
            try:
                resp.ParseFromString(future.result().content)
                LOGGER.info("register attempt: %s",
                            TpRegisterResponse.Status.Name(resp.status))
            except ValidatorConnectionError as vce:
                LOGGER.info("during waiting for response on registration: %s",
                            vce)

    def _unregister(self):
        message = self._unregister_request()
        self._stream.wait_for_ready()
        future = self._stream.send(
            message_type=Message.TP_UNREGISTER_REQUEST,
            content=message.SerializeToString())
        response = TpUnregisterResponse()
        try:
            response.ParseFromString(future.result(1).content)
            LOGGER.info("unregister attempt: %s",
                        TpUnregisterResponse.Status.Name(response.status))
        except ValidatorConnectionError as vce:
            LOGGER.info("during waiting for response on unregistration: %s",
                        vce)

    def start(self):
        """Connects the transaction processor to a validator and starts
        listening for requests and routing them to an appropriate
        transaction handler.
        """
        fut = None
        try:
            self._register()
            while True:
                # During long running processing this
                # is where the transaction processor will
                # spend most of its time
                fut = self._stream.receive()
                self._process_future(fut)
        except KeyboardInterrupt:
            try:
                # tell the validator to not send any more messages
                self._unregister()
                while True:
                    if fut is not None:
                        # process futures as long as the tp has them,
                        # if the TP_PROCESS_REQUEST doesn't come from
                        # zeromq->asyncio in 1 second raise a
                        # concurrent.futures.TimeOutError and be done.
                        self._process_future(fut, 1, sigint=True)
                        fut = self._stream.receive()
            except concurrent.futures.TimeoutError:
                # Where the tp will usually exit after
                # a KeyboardInterrupt. Caused by the 1 second
                # timeout in _process_future.
                pass
            except FutureTimeoutError:
                # If the validator is not able to respond to the
                # unregister request, exit.
                pass

    def stop(self):
        """Closes the connection between the TransactionProcessor and the
        validator.
        """
        self._stream.close()
コード例 #9
0
ファイル: subscriber.py プロジェクト: celiojpeg/bev
class Subscriber(object):
    """Creates an object that can subscribe to state delta events using the
    Sawtooth SDK's Stream class. Handler functions can be added prior to
    subscribing, and each will be called on each delta event received.
    """
    def __init__(self, validator_url):
        LOGGER.info('Connecting to validator: %s', validator_url)
        self._stream = Stream(validator_url)
        self._event_handlers = []
        self._is_active = False

    def add_handler(self, handler):
        """Adds a handler which will be passed state delta events when they
        occur. Note that this event is mutable.
        """
        self._event_handlers.append(handler)

    def clear_handlers(self):
        """Clears any delta handlers.
        """
        self._event_handlers = []

    def start(self, known_ids=None):
        """Subscribes to state delta events, and then waits to receive deltas.
        Sends any events received to delta handlers.
        """
        if not known_ids:
            known_ids = [NULL_BLOCK_ID]

        self._stream.wait_for_ready()
        LOGGER.debug('Subscribing to state delta events')

        block_sub = EventSubscription(event_type='sawtooth/block-commit')
        delta_sub = EventSubscription(
            event_type='sawtooth/state-delta',
            filters=[
                EventFilter(key='address',
                            match_string='^{}.*'.format(NAMESPACE),
                            filter_type=EventFilter.REGEX_ANY)
            ])

        request = ClientEventsSubscribeRequest(
            last_known_block_ids=known_ids,
            subscriptions=[block_sub, delta_sub])
        response_future = self._stream.send(
            Message.CLIENT_EVENTS_SUBSCRIBE_REQUEST,
            request.SerializeToString())
        response = ClientEventsSubscribeResponse()
        response.ParseFromString(response_future.result().content)

        # Forked all the way back to genesis, restart with no known_ids
        if (response.status == ClientEventsSubscribeResponse.UNKNOWN_BLOCK
                and known_ids):
            return self.start()

        if response.status != ClientEventsSubscribeResponse.OK:
            raise RuntimeError('Subscription failed with status: {}'.format(
                ClientEventsSubscribeResponse.Status.Name(response.status)))

        self._is_active = True

        LOGGER.debug('Successfully subscribed to state delta events')
        while self._is_active:
            message_future = self._stream.receive()

            event_list = EventList()
            event_list.ParseFromString(message_future.result().content)
            for handler in self._event_handlers:
                handler(event_list.events)

    def stop(self):
        """Stops the Subscriber, unsubscribing from state delta events and
        closing the the stream's connection.
        """
        self._is_active = False

        LOGGER.debug('Unsubscribing from state delta events')
        request = ClientEventsUnsubscribeRequest()
        response_future = self._stream.send(
            Message.CLIENT_EVENTS_UNSUBSCRIBE_REQUEST,
            request.SerializeToString())
        response = ClientEventsUnsubscribeResponse()
        response.ParseFromString(response_future.result().content)

        if response.status != ClientEventsUnsubscribeResponse.OK:
            LOGGER.warning(
                'Failed to unsubscribe with status: %s',
                ClientEventsUnsubscribeResponse.Status.Name(response.status))

        self._stream.close()
コード例 #10
0
class SyncProcessor:
    future: Optional["Future"] = None
    _stream: Stream

    def __init__(self, url=None):
        self._stream = Stream(url or VALIDATOR_URL)
        self._handlers = []

    def add_handler(self, handler: Type["HandlerBase"]):
        if handler not in self._handlers:
            LOG.info(f"Add handler {handler.__name__}")
            self._handlers.append(handler)

    def start(self):
        LOG.info("Start SyncProcessor")

        future = None
        try:
            self._register()
            while True:
                future = self._stream.receive()
                self._process_future(future)
        except KeyboardInterrupt:
            LOG.warning("break")
            try:
                # tell the validator to not send any more messages
                self._unregister()
                while True:
                    if future is not None:
                        # process futures as long as the tp has them,
                        # if the TP_PROCESS_REQUEST doesn't come from
                        # zeromq->asyncio in 1 second raise a
                        # concurrent.futures.TimeOutError and be done.
                        self._process_future(future, 1, sigint=True)
                        future = self._stream.receive()
            except ConcurrentTimeoutError:
                # Where the tp will usually exit after
                # a KeyboardInterrupt. Caused by the 1 second
                # timeout in _process_future.
                pass
            except FutureTimeoutError:
                # If the validator is not able to respond to the
                # unregister request, exit.
                pass

    def _unregister(self):
        LOG.warning("unregister")
        pass

    def _register(self):
        LOG.debug(f"Register handlers")
        self._stream.wait_for_ready()
        future = self._stream.send(
            message_type=Message.CLIENT_EVENTS_SUBSCRIBE_REQUEST,
            content=ClientEventsSubscribeRequest(
                last_known_block_ids=[NULL_BLOCK_ID],
                subscriptions=[
                    EventSubscription(event_type="sawtooth/block-commit"),
                    EventSubscription(
                        event_type="sawtooth/state-delta",
                        filters=[
                            EventFilter(
                                key="address",
                                match_string=f"^{Namespaces.GA_NAMESPACE}.*",
                                filter_type=EventFilter.REGEX_ANY,
                            )
                        ],
                    ),
                ],
            ).SerializeToString(),
        )

        resp = TpRegisterResponse()
        try:
            resp.ParseFromString(future.result().content)
            LOG.info("Register response: %s",
                     TpRegisterResponse.Status.Name(resp.status))
        except ValidatorConnectionError as vce:
            LOG.info("During waiting for response on registration: %s", vce)
        except Exception as e:
            LOG.info("During waiting for response on registration: %s", e)

    def _process_future(self,
                        future: "Future",
                        timeout=None,
                        sigint=False) -> None:
        try:
            msg = future.result(timeout)
        except CancelledError:
            # This error is raised when Task.cancel is called on
            # disconnect from the validator in stream.py, for
            # this future.
            LOG.error("Cancelled")
            return

        if msg is RECONNECT_EVENT:
            if sigint is False:
                LOG.info("Reregistering with validator")
                self._stream.wait_for_ready()
                self._register()
        else:
            LOG.debug(f"Received message of type: "
                      f"{Message.MessageType.Name(msg.message_type)}")

            if msg.message_type == Message.PING_REQUEST:
                self._stream.send_back(
                    message_type=Message.PING_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=PingResponse().SerializeToString(),
                )
                return
            elif msg.message_type == Message.CLIENT_EVENTS:
                self._process(msg)
                return

            LOG.warning(f"SyncProcessor got wrong message type: "
                        f"{Message.MessageType.Name(msg.message_type)}")

    def _process(self, msg: Message) -> None:
        event_list = EventList()
        event_list.ParseFromString(msg.content)
        events = event_list.events
        raw_block = next(
            (e for e in events if e.event_type == "sawtooth/block-commit"), [])
        block = {b.key: b.value for b in raw_block.attributes}
        LOG.debug(f"Block: {block}")
        event = next(
            (e for e in events if e.event_type == "sawtooth/state-delta"),
            None)
        if event:
            state_changes = StateChangeList()
            state_changes.ParseFromString(event.data)
            changes = list(state_changes.state_changes)
            LOG.debug(f"Found {len(changes)} state changes")
            self._handle_changes(block, changes)

    def _handle_changes(self, block: dict, changes: list):
        # r.table(Tbl.BLOCKS).insert(block).run()
        for change in changes:
            for handler in self._handlers:
                if change.address.startswith(handler.prefix):
                    handler.process(change)
コード例 #11
0
class ZmqDriver(Driver):
    def __init__(self, engine):
        super().__init__(engine)
        self._engine = engine
        self._stream = None
        self._exit = False
        self._updates = None

    def start(self, endpoint):
        self._stream = Stream(endpoint)

        startup_state = self._register()

        self._updates = Queue()

        driver_thread = Thread(
            target=self._driver_loop)
        driver_thread.start()

        try:
            self._engine.start(
                self._updates,
                ZmqService(
                    stream=self._stream,
                    timeout=SERVICE_TIMEOUT,
                    name=self._engine.name(),
                    version=self._engine.version()),
                startup_state)
        except Exception:  # pylint: disable=broad-except
            LOGGER.exception("Uncaught engine exception")

        self.stop()
        driver_thread.join()

    def _driver_loop(self):
        try:
            future = self._stream.receive()
            while True:
                if self._exit:
                    self._engine.stop()
                    break

                try:
                    message = future.result(1)
                    future = self._stream.receive()
                except concurrent.futures.TimeoutError:
                    continue

                result = self._process(message)

                self._updates.put(result)
        except Exception:  # pylint: disable=broad-except
            LOGGER.exception("Uncaught driver exception")

    def stop(self):
        self._exit = True
        self._engine.stop()
        self._stream.close()

    def _register(self):
        self._stream.wait_for_ready()

        request = consensus_pb2.ConsensusRegisterRequest(
            name=self._engine.name(),
            version=self._engine.version(),
        ).SerializeToString()

        while True:
            future = self._stream.send(
                message_type=Message.CONSENSUS_REGISTER_REQUEST,
                content=request)
            response = consensus_pb2.ConsensusRegisterResponse()
            response.ParseFromString(future.result(REGISTER_TIMEOUT).content)

            if (
                response.status
                == consensus_pb2.ConsensusRegisterResponse.NOT_READY
            ):
                continue

            if response.status == consensus_pb2.ConsensusRegisterResponse.OK:
                return StartupState(
                    response.chain_head,
                    response.peers,
                    response.local_peer_info)

            raise exceptions.ReceiveError(
                'Registration failed with status {}'.format(response.status))

    def _process(self, message):
        type_tag = message.message_type

        if type_tag == Message.CONSENSUS_NOTIFY_PEER_CONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerConnected()
            notification.ParseFromString(message.content)

            data = notification.peer_info

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_DISCONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerDisconnected()
            notification.ParseFromString(message.content)

            data = notification.peer_id

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_MESSAGE:
            notification = consensus_pb2.ConsensusNotifyPeerMessage()
            notification.ParseFromString(message.content)

            data = notification.message, notification.sender_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_NEW:
            notification = consensus_pb2.ConsensusNotifyBlockNew()
            notification.ParseFromString(message.content)

            data = notification.block

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_VALID:
            notification = consensus_pb2.ConsensusNotifyBlockValid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_INVALID:
            notification = consensus_pb2.ConsensusNotifyBlockInvalid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_COMMIT:
            notification = consensus_pb2.ConsensusNotifyBlockCommit()
            notification.ParseFromString(message.content)

            data = notification.block_id

        else:
            raise exceptions.ReceiveError(
                'Received unexpected message type: {}'.format(type_tag))

        self._stream.send_back(
            message_type=Message.CONSENSUS_NOTIFY_ACK,
            correlation_id=message.correlation_id,
            content=consensus_pb2.ConsensusNotifyAck().SerializeToString())

        return type_tag, data
コード例 #12
0
class TransactionProcessor:
    """TransactionProcessor is a generic class for communicating with a
    validator and routing transaction processing requests to a registered
    handler. It uses ZMQ and channels to handle requests concurrently.
    """

    # This is the version used by SDK to match if validator supports feature
    # it requested during registration. It should only be incremented when
    # there are changes in TpRegisterRequest. Remember to sync this
    # information in validator if changed.
    # Note: SDK_PROTOCOL_VERSION is the highest version the SDK supports
    class _FeatureVersion(Enum):
        FEATURE_UNUSED = 0
        FEATURE_CUSTOM_HEADER_STYLE = 1
        SDK_PROTOCOL_VERSION = 1

    def __init__(self, url):
        """
        Args:
            url (string): The URL of the validator
        """
        self._stream = Stream(url)
        self._url = url
        self._handlers = []
        self._highest_sdk_feature_requested = \
            self._FeatureVersion.FEATURE_UNUSED
        self._header_style = TpRegisterRequest.HEADER_STYLE_UNSET

    @property
    def zmq_id(self):
        return self._stream.zmq_id

    def add_handler(self, handler):
        """Adds a transaction family handler
        Args:
            handler (TransactionHandler): the handler to be added
        """
        self._handlers.append(handler)

    def set_header_style(self, style):
        """Sets a flag to request the validator for custom transaction header
        style in TpProcessRequest.
        Args:
            style (TpProcessRequestHeaderStyle): enum value to set header style
        """
        if self._FeatureVersion.FEATURE_CUSTOM_HEADER_STYLE.value > \
                self._highest_sdk_feature_requested.value:
            self._highest_sdk_feature_requested = \
                self._FeatureVersion.FEATURE_CUSTOM_HEADER_STYLE
        self._header_style = style

    def _matches(self, handler, header):
        return header.family_name == handler.family_name \
            and header.family_version in handler.family_versions

    def _find_handler(self, header):
        """Find a handler for a particular (family_name, family_versions)
        :param header transaction_pb2.TransactionHeader:
        :return: handler
        """
        try:
            return next(handler for handler in self._handlers
                        if self._matches(handler, header))
        except StopIteration:
            LOGGER.debug("Missing handler for header: %s", header)
            return None

    def _register_requests(self):
        """Returns all of the TpRegisterRequests for handlers

        :return (list): list of TpRegisterRequests
        """
        return itertools.chain.from_iterable(  # flattens the nested list
            [[
                TpRegisterRequest(
                    family=n,
                    version=v,
                    namespaces=h.namespaces,
                    protocol_version=self._highest_sdk_feature_requested.value,
                    request_header_style=self._header_style)
                for n, v in itertools.product(
                    [h.family_name],
                    h.family_versions,
                )
            ] for h in self._handlers])

    def _unregister_request(self):
        """Returns a single TP_UnregisterRequest that requests
        that the validator stop sending transactions for previously
        registered handlers.

        :return (processor_pb2.TpUnregisterRequest):
        """
        return TpUnregisterRequest()

    def _process(self, msg):
        if msg.message_type != Message.TP_PROCESS_REQUEST:
            LOGGER.debug(
                "Transaction Processor recieved invalid message type. "
                "Message type should be TP_PROCESS_REQUEST,"
                " but is %s", Message.MessageType.Name(msg.message_type))
            return

        request = TpProcessRequest()
        request.ParseFromString(msg.content)
        state = Context(self._stream, request.context_id)
        if self._header_style == TpRegisterRequest.RAW:
            header = TransactionHeader()
            header.ParseFromString(request.header_bytes)
        else:
            header = request.header
        try:
            if not self._stream.is_ready():
                raise ValidatorConnectionError()
            handler = self._find_handler(header)
            if handler is None:
                return
            handler.apply(request, state)
            self._stream.send_back(
                message_type=Message.TP_PROCESS_RESPONSE,
                correlation_id=msg.correlation_id,
                content=TpProcessResponse(
                    status=TpProcessResponse.OK).SerializeToString())
        except InvalidTransaction as it:
            LOGGER.warning("Invalid Transaction %s", it)
            try:
                self._stream.send_back(
                    message_type=Message.TP_PROCESS_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpProcessResponse(
                        status=TpProcessResponse.INVALID_TRANSACTION,
                        message=str(it),
                        extended_data=it.extended_data).SerializeToString())
            except ValidatorConnectionError as vce:
                # TP_PROCESS_REQUEST has made it through the
                # handler.apply and an INVALID_TRANSACTION would have been
                # sent back but the validator has disconnected and so it
                # doesn't care about the response.
                LOGGER.warning("during invalid transaction response: %s", vce)
        except InternalError as ie:
            LOGGER.warning("internal error: %s", ie)
            try:
                self._stream.send_back(
                    message_type=Message.TP_PROCESS_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpProcessResponse(
                        status=TpProcessResponse.INTERNAL_ERROR,
                        message=str(ie),
                        extended_data=ie.extended_data).SerializeToString())
            except ValidatorConnectionError as vce:
                # Same as the prior except block, but an internal error has
                # happened, but because of the disconnect the validator
                # probably doesn't care about the response.
                LOGGER.warning("during internal error response: %s", vce)
        except ValidatorConnectionError as vce:
            # Somewhere within handler.apply a future resolved with an
            # error status that the validator has disconnected. There is
            # nothing left to do but reconnect.
            LOGGER.warning(
                "during handler.apply a future was resolved "
                "with error status: %s", vce)
        except AuthorizationException as ae:
            LOGGER.warning("AuthorizationException: %s", ae)
            try:
                self._stream.send_back(
                    message_type=Message.TP_PROCESS_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=TpProcessResponse(
                        status=TpProcessResponse.INVALID_TRANSACTION,
                        message=str(ae),
                    ).SerializeToString())
            except ValidatorConnectionError as vce:
                # TP_PROCESS_REQUEST has made it through the
                # handler.apply and an INVALID_TRANSACTION would have been
                # sent back but the validator has disconnected and so it
                # doesn't care about the response.
                LOGGER.warning("during invalid transaction response: %s", vce)

    def _process_future(self, future, timeout=None, sigint=False):
        try:
            msg = future.result(timeout)
        except CancelledError:
            # This error is raised when Task.cancel is called on
            # disconnect from the validator in stream.py, for
            # this future.
            return
        if msg is RECONNECT_EVENT:
            if sigint is False:
                LOGGER.info("reregistering with validator")
                self._stream.wait_for_ready()
                self._register()
        else:
            LOGGER.debug('received message of type: %s',
                         Message.MessageType.Name(msg.message_type))
            if msg.message_type == Message.PING_REQUEST:
                self._stream.send_back(
                    message_type=Message.PING_RESPONSE,
                    correlation_id=msg.correlation_id,
                    content=PingResponse().SerializeToString())
                return
            self._process(msg)

    def _register(self):
        futures = []
        for message in self._register_requests():
            self._stream.wait_for_ready()
            future = self._stream.send(
                message_type=Message.TP_REGISTER_REQUEST,
                content=message.SerializeToString())
            futures.append(future)

        for future in futures:
            resp = TpRegisterResponse()
            try:
                resp.ParseFromString(future.result().content)
                if resp.protocol_version != \
                        self._highest_sdk_feature_requested.value:
                    LOGGER.error(
                        "Validator version %s does not support "
                        "requested feature by SDK version %s. "
                        "Unregistering with the validator.",
                        str(resp.protocol_version),
                        str(self._highest_sdk_feature_requested.value))
                    raise ValidatorVersionError()
                LOGGER.info("register attempt: %s",
                            TpRegisterResponse.Status.Name(resp.status))
                if resp.status == TpRegisterResponse.ERROR:
                    raise RuntimeError("Transaction processor registration "
                                       "failed")
            except ValidatorConnectionError as vce:
                LOGGER.info("during waiting for response on registration: %s",
                            vce)

    def _unregister(self):
        message = self._unregister_request()
        self._stream.wait_for_ready()
        future = self._stream.send(message_type=Message.TP_UNREGISTER_REQUEST,
                                   content=message.SerializeToString())
        response = TpUnregisterResponse()
        try:
            response.ParseFromString(future.result(1).content)
            LOGGER.info("unregister attempt: %s",
                        TpUnregisterResponse.Status.Name(response.status))
        except ValidatorConnectionError as vce:
            LOGGER.info("during waiting for response on unregistration: %s",
                        vce)

    def start(self):
        """Connects the transaction processor to a validator and starts
        listening for requests and routing them to an appropriate
        transaction handler.
        """
        fut = None
        try:
            self._register()
            while True:
                # During long running processing this
                # is where the transaction processor will
                # spend most of its time
                fut = self._stream.receive()
                self._process_future(fut)
        except (KeyboardInterrupt, ValidatorVersionError):
            try:
                # tell the validator to not send any more messages
                self._unregister()
                while True:
                    if fut is not None:
                        # process futures as long as the tp has them,
                        # if the TP_PROCESS_REQUEST doesn't come from
                        # zeromq->asyncio in 1 second raise a
                        # concurrent.futures.TimeOutError and be done.
                        self._process_future(fut, 1, sigint=True)
                        fut = self._stream.receive()
            except concurrent.futures.TimeoutError:
                # Where the tp will usually exit after
                # a KeyboardInterrupt. Caused by the 1 second
                # timeout in _process_future.
                pass
            except FutureTimeoutError:
                # If the validator is not able to respond to the
                # unregister request, exit.
                pass
        except RuntimeError as e:
            LOGGER.error("Error: %s", e)
            self.stop()

    def stop(self):
        """Closes the connection between the TransactionProcessor and the
        validator.
        """
        self._stream.close()
コード例 #13
0
class ZmqDriver(Driver):
    def __init__(self, engine):
        super().__init__(engine)
        self._engine = engine
        self._stream = None
        self._exit = False
        self._updates = None

    def start(self, endpoint):
        LOGGER.debug('ZmqDriver: start endpoint=%s', endpoint)
        self._stream = Stream(endpoint)

        startup_state = self._register()

        self._updates = Queue()

        driver_thread = Thread(target=self._driver_loop)
        driver_thread.start()

        try:
            self._engine.start(
                self._updates,
                ZmqService(stream=self._stream,
                           timeout=SERVICE_TIMEOUT,
                           name=self._engine.name(),
                           version=self._engine.version()), startup_state)
        except Exception as ex:  # pylint: disable=broad-except
            LOGGER.exception("Uncaught engine exception(%s)", ex)

        self.stop()
        driver_thread.join()

    def _driver_loop(self):
        try:
            future = self._stream.receive()
            LOGGER.debug('ZmqDriver: _driver_loop future=%s', future)
            while True:
                if self._exit:
                    self._engine.stop()
                    break

                try:
                    message = future.result(1)
                    future = self._stream.receive()
                except concurrent.futures.TimeoutError:
                    continue
                #LOGGER.debug('ZmqDriver: _driver_loop _process')
                result = self._process(message)

                self._updates.put(result)
        except Exception:  # pylint: disable=broad-except
            LOGGER.exception("Uncaught driver exception")

    def stop(self):
        self._exit = True
        self._engine.stop()
        self._stream.close()

    def _register(self):
        self._stream.wait_for_ready()

        request = consensus_pb2.ConsensusRegisterRequest(
            name=self._engine.name(),
            version=self._engine.version(),
        ).SerializeToString()

        while True:
            future = self._stream.send(
                message_type=Message.CONSENSUS_REGISTER_REQUEST,
                content=request)
            response = consensus_pb2.ConsensusRegisterResponse()
            response.ParseFromString(future.result(REGISTER_TIMEOUT).content)

            if (response.status ==
                    consensus_pb2.ConsensusRegisterResponse.NOT_READY):
                #LOGGER.debug('ZmqDriver:register NOT_READY: url=%s',self._stream._url)
                continue

            if response.status == consensus_pb2.ConsensusRegisterResponse.OK:
                LOGGER.debug('ZmqDriver:register DONE: url=%s',
                             self._stream._url)
                return StartupState(response.chain_head, response.peers,
                                    response.local_peer_info,
                                    response.peering_mode)

            raise exceptions.ReceiveError(
                'Registration failed with status {}'.format(response.status))

    def _process(self, message):
        type_tag = message.message_type

        if type_tag == Message.CONSENSUS_NOTIFY_PEER_CONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerConnected()
            notification.ParseFromString(message.content)

            data = notification.peer_info, notification.status, notification.mode, notification.info

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_DISCONNECTED:
            notification = consensus_pb2.ConsensusNotifyPeerDisconnected()
            notification.ParseFromString(message.content)

            data = notification.peer_id

        elif type_tag == Message.CONSENSUS_NOTIFY_PEER_MESSAGE:
            notification = consensus_pb2.ConsensusNotifyPeerMessage()
            notification.ParseFromString(message.content)

            data = notification.message, notification.sender_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_NEW:
            notification = consensus_pb2.ConsensusNotifyBlockNew()
            notification.ParseFromString(message.content)

            data = notification.block

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_VALID:
            notification = consensus_pb2.ConsensusNotifyBlockValid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_INVALID:
            notification = consensus_pb2.ConsensusNotifyBlockInvalid()
            notification.ParseFromString(message.content)

            data = notification.block_id

        elif type_tag == Message.CONSENSUS_NOTIFY_BLOCK_COMMIT:
            notification = consensus_pb2.ConsensusNotifyBlockCommit()
            notification.ParseFromString(message.content)

            data = notification.block_id

        else:
            raise exceptions.ReceiveError(
                'Received unexpected message type: {}'.format(type_tag))

        self._stream.send_back(
            message_type=Message.CONSENSUS_NOTIFY_ACK,
            correlation_id=message.correlation_id,
            content=consensus_pb2.ConsensusNotifyAck().SerializeToString())

        return type_tag, data
コード例 #14
0
class Subscriber(object):
    """Creates an object that can subscribe to state delta events using the
    Sawtooth SDK's Stream class. Handler functions can be added prior to
    subscribing, and each will be called on each delta event received.
    """
    def __init__(self, validator_url):
        LOGGER.info('Connecting to validator: %s', validator_url)
        self._stream = Stream(validator_url)
        self._delta_handlers = []
        self._is_active = False

    def add_handler(self, event_handler):
        """Adds a handler which will be passed state delta events when they
        occur. Note that this event is mutable.
        """
        self._delta_handlers.append(event_handler)

    def clear_handlers(self):
        """Clears any delta handlers.
        """
        self._delta_handlers = []

    def start(self, known_ids=None):
        """Subscribes to state delta events, and then waits to receive deltas.
        Sends any events received to delta handlers.
        """
        self._stream.wait_for_ready()

        LOGGER.debug('Subscribing to state delta events')
        request = StateDeltaSubscribeRequest(last_known_block_ids=known_ids,
                                             address_prefixes=[NAMESPACE])
        response_future = self._stream.send(
            Message.STATE_DELTA_SUBSCRIBE_REQUEST, request.SerializeToString())
        response = StateDeltaSubscribeResponse()
        response.ParseFromString(response_future.result().content)

        # Forked all the way back to genesis, restart with no known_ids
        if (known_ids and response.status
                == StateDeltaSubscribeResponse.UNKNOWN_BLOCK):
            return self.start()

        if response.status != StateDeltaSubscribeResponse.OK:
            raise RuntimeError('Subscription failed with status: {}'.format(
                StateDeltaSubscribeResponse.Status.Name(response.status)))

        self._is_active = True

        LOGGER.debug('Successfully subscribed to state delta events')
        while self._is_active:
            message_future = self._stream.receive()

            event = StateDeltaEvent()
            event.ParseFromString(message_future.result().content)
            LOGGER.debug('Received deltas for block: %s', event.block_id)

            for handler in self._delta_handlers:
                handler(event)

    def stop(self):
        """Stops the Subscriber, unsubscribing from state delta events and
        closing the the stream's connection.
        """
        self._is_active = False

        LOGGER.debug('Unsubscribing from state delta events')
        request = StateDeltaUnsubscribeRequest()
        response_future = self._stream.send(
            Message.STATE_DELTA_UNSUBSCRIBE_REQUEST,
            request.SerializeToString())
        response = StateDeltaUnsubscribeResponse()
        response.ParseFromString(response_future.result().content)

        if response.status != StateDeltaUnsubscribeResponse.OK:
            LOGGER.warning(
                'Failed to unsubscribe with status: %s',
                StateDeltaUnsubscribeResponse.Status.Name(response.status))

        self._stream.close()
コード例 #15
0
class Subscriber(object):
    """Creates an object that can subscribe to state delta events using the
    Sawtooth SDK's Stream class. Handler functions can be added prior to
    subscribing, and each will be called on each delta event received.
    """
    def __init__(self, validator_url):
        LOGGER.info('Connecting to validator: %s', validator_url)
        self._stream = Stream(validator_url)
        self._event_handlers = []
        self._is_active = False

    def add_handler(self, handler):
        """Adds a handler which will be passed state delta events when they
        occur. Note that this event is mutable.
        """
        self._event_handlers.append(handler)

    def clear_handlers(self):
        """Clears any delta handlers.
        """
        self._event_handlers = []

    def start(self, known_ids=None):
        """Subscribes to state delta events, and then waits to receive deltas.
        Sends any events received to delta handlers.
        """
        if not known_ids:
            known_ids = [NULL_BLOCK_ID]

        self._stream.wait_for_ready()
        LOGGER.debug('Subscribing to state delta events')

        block_sub = EventSubscription(event_type='sawtooth/block-commit')
        delta_sub = EventSubscription(
            event_type='sawtooth/state-delta',
            filters=[EventFilter(
                key='address',
                match_string='^{}.*'.format(NAMESPACE),
                filter_type=EventFilter.REGEX_ANY)])

        request = ClientEventsSubscribeRequest(
            last_known_block_ids=known_ids,
            subscriptions=[block_sub, delta_sub])
        response_future = self._stream.send(
            Message.CLIENT_EVENTS_SUBSCRIBE_REQUEST,
            request.SerializeToString())
        response = ClientEventsSubscribeResponse()
        response.ParseFromString(response_future.result().content)

        # Forked all the way back to genesis, restart with no known_ids
        if (response.status == ClientEventsSubscribeResponse.UNKNOWN_BLOCK
                and known_ids):
            self.start()

        if response.status != ClientEventsSubscribeResponse.OK:
            raise RuntimeError(
                'Subscription failed with status: {}'.format(
                    ClientEventsSubscribeResponse.Status.Name(
                        response.status)))

        self._is_active = True

        LOGGER.debug('Successfully subscribed to state delta events')
        while self._is_active:
            message_future = self._stream.receive()

            event_list = EventList()
            event_list.ParseFromString(message_future.result().content)
            for handler in self._event_handlers:
                handler(event_list.events)

    def stop(self):
        """Stops the Subscriber, unsubscribing from state delta events and
        closing the the stream's connection.
        """
        self._is_active = False

        LOGGER.debug('Unsubscribing from state delta events')
        request = ClientEventsUnsubscribeRequest()
        response_future = self._stream.send(
            Message.CLIENT_EVENTS_UNSUBSCRIBE_REQUEST,
            request.SerializeToString())
        response = ClientEventsUnsubscribeResponse()
        response.ParseFromString(response_future.result().content)

        if response.status != ClientEventsUnsubscribeResponse.OK:
            LOGGER.warning(
                'Failed to unsubscribe with status: %s',
                ClientEventsUnsubscribeResponse.Status.Name(response.status))

        self._stream.close()