#------------------------------------------------------------------------- # Copyright (c) Microsoft Corporation. All rights reserved. # Licensed under the MIT License. See License.txt in the project root for # license information. #-------------------------------------------------------------------------- import logging import uuid from uamqp import c_uamqp, constants, errors, utils _logger = logging.getLogger(__name__) class MessageSender(object): """A Message Sender that opens its own exclsuive Link on an existing Session. :ivar send_settle_mode: The mode by which to settle message send operations. If set to `Unsettled`, the client will wait for a confirmation from the service that the message was successfully send. If set to 'Settled', the client will not wait for confirmation and assume success. :vartype send_settle_mode: ~uamqp.constants.SenderSettleMode :ivar receive_settle_mode: The mode by which to settle message receive operations. If set to `PeekLock`, the receiver will lock a message once received until the client accepts or rejects the message. If set to `ReceiveAndDelete`, the service will assume successful receipt of the message and clear it from the queue. The default is `PeekLock`. :vartype receive_settle_mode: ~uamqp.constants.ReceiverSettleMode :ivar max_message_size: The maximum allowed message size negotiated for the Link. :vartype max_message_size: int :param session: The underlying Session with which to send. :type session: ~uamqp.session.Session :param source: The name of source (i.e. the client). :type source: str or bytes :param target: The AMQP endpoint to send to. :type target: ~uamqp.address.Target :param name: A unique name for the sender. If not specified a GUID will be used. :type name: str or bytes :param send_settle_mode: The mode by which to settle message send operations. If set to `Unsettled`, the client will wait for a confirmation from the service that the message was successfully sent. If set to 'Settled', the client will not wait for confirmation and assume success. :type send_settle_mode: ~uamqp.constants.SenderSettleMode :param receive_settle_mode: The mode by which to settle message receive operations. If set to `PeekLock`, the receiver will lock a message once received until the client accepts or rejects the message. If set to `ReceiveAndDelete`, the service will assume successful receipt of the message and clear it from the queue. The default is `PeekLock`. :type receive_settle_mode: ~uamqp.constants.ReceiverSettleMode :param desired_capabilities: The extension capabilities desired from the peer endpoint. To create a desired_capabilities object, please do as follows: - 1. Create an array of desired capability symbols: `capabilities_symbol_array = [types.AMQPSymbol(string)]` - 2. Transform the array to AMQPValue object: `utils.data_factory(types.AMQPArray(capabilities_symbol_array))` :type desired_capabilities: ~uamqp.c_uamqp.AMQPValue :param max_message_size: The maximum allowed message size negotiated for the Link. :type max_message_size: int :param link_credit: The sender Link credit that determines how many messages the Link will attempt to handle per connection iteration. :type link_credit: int :param properties: Metadata to be sent in the Link ATTACH frame. :type properties: dict :param error_policy: A policy for parsing errors on link, connection and message disposition to determine whether the error should be retryable. :type error_policy: ~uamqp.errors.ErrorPolicy :param debug: Whether to turn on network trace logs. If `True`, trace logs will be logged at INFO level. Default is `False`. :type debug: bool :param encoding: The encoding to use for parameters supplied as strings. Default is 'UTF-8' :type encoding: str """ def __init__(self, session, source, target, name=None, send_settle_mode=constants.SenderSettleMode.Unsettled, receive_settle_mode=constants.ReceiverSettleMode.PeekLock, max_message_size=constants.MAX_MESSAGE_LENGTH_BYTES, link_credit=None, properties=None, error_policy=None, debug=False, encoding='UTF-8', desired_capabilities=None): # pylint: disable=protected-access if name: self.name = name.encode(encoding) if isinstance(name, str) else name else: self.name = str(uuid.uuid4()).encode(encoding) source = source.encode(encoding) if isinstance(source, str) else source role = constants.Role.Sender self.source = c_uamqp.Messaging.create_source(source) self.target = target._address.value self.error_policy = error_policy or errors.ErrorPolicy() self._conn = session._conn self._session = session self._link = c_uamqp.create_link(session._session, self.name, role.value, self.source, self.target) self._link.max_message_size = max_message_size self._link.subscribe_to_detach_event(self) if link_credit: self._link.set_prefetch_count(link_credit) if properties: self._link.set_attach_properties(utils.data_factory(properties, encoding=encoding)) if send_settle_mode: self.send_settle_mode = send_settle_mode if receive_settle_mode: self.receive_settle_mode = receive_settle_mode if max_message_size: self.max_message_size = max_message_size if desired_capabilities: self._link.set_desired_capabilities(desired_capabilities) self._sender = c_uamqp.create_message_sender(self._link, self) self._sender.set_trace(debug) self._state = constants.MessageSenderState.Idle self._error = None def __enter__(self): """Open the MessageSender in a context manager.""" self.open() return self def __exit__(self, *args): """Close the MessageSender when exiting a context manager.""" self.destroy() def _detach_received(self, error): """Callback called when a link DETACH frame is received. This callback will process the received DETACH error to determine if the link is recoverable or whether it should be shutdown. :param error: The error information from the detach frame. :type error: ~uamqp.errors.ErrorResponse """ # pylint: disable=protected-access if error: condition = error.condition description = error.description info = error.info else: condition = b"amqp:unknown-error" description = None info = None self._error = errors._process_link_error(self.error_policy, condition, description, info) _logger.info("Received Link detach event: %r\nLink: %r\nDescription: %r" "\nDetails: %r\nRetryable: %r\nConnection: %r", condition, self.name, description, info, self._error.action.retry, self._session._connection.container_id) def _state_changed(self, previous_state, new_state): """Callback called whenever the underlying Sender undergoes a change of state. This function wraps the states as Enums to prepare for calling the public callback. :param previous_state: The previous Sender state. :type previous_state: int :param new_state: The new Sender state. :type new_state: int """ try: try: _previous_state = constants.MessageSenderState(previous_state) except ValueError: _previous_state = previous_state try: _new_state = constants.MessageSenderState(new_state) except ValueError: _new_state = new_state if _previous_state == constants.MessageSenderState.Opening \ and _new_state == constants.MessageSenderState.Error: _logger.info("Sender link failed to open - expecting to receive DETACH frame.") elif self._session._link_error: # pylint: disable=protected-access _logger.info("Sender link ATTACH frame invalid - expecting to receive DETACH frame.") else: self.on_state_changed(_previous_state, _new_state) except KeyboardInterrupt: _logger.error("Received shutdown signal while updating sender state from {} to {}".format( previous_state, new_state)) self._error = errors.AMQPClientShutdown() def get_state(self): """Get the state of the MessageSender and its underlying Link. :rtype: ~uamqp.constants.MessageSenderState """ try: raise self._error except TypeError: pass except Exception as e: _logger.warning("%r", e) raise return self._state def work(self): """Update the link status.""" self._link.do_work() def destroy(self): """Close both the Sender and the Link. Clean up any C objects.""" self._sender.destroy() self._link.destroy() def open(self): """Open the MessageSender in order to start processing messages. :raises: ~uamqp.errors.AMQPConnectionError if the Sender raises an error on opening. This can happen if the target URI is invalid or the credentials are rejected. """ try: self._sender.open() except ValueError: raise errors.AMQPConnectionError( "Failed to open Message Sender. " "Please confirm credentials and target URI.") def close(self): """Close the sender, leaving the link intact.""" self._sender.close() def send(self, message, callback, timeout=0): """Add a single message to the internal pending queue to be processed by the Connection without waiting for it to be sent. :param message: The message to send. :type message: ~uamqp.message.Message :param callback: The callback to be run once a disposition is received in receipt of the message. The callback must take three arguments, the message, the send result and the optional delivery condition (exception). :type callback: callable[~uamqp.message.Message, ~uamqp.constants.MessageSendResult, ~uamqp.errors.MessageException] :param timeout: An expiry time for the message added to the queue. If the message is not sent within this timeout it will be discarded with an error state. If set to 0, the message will not expire. The default is 0. """ # pylint: disable=protected-access try: raise self._error except TypeError: pass except Exception as e: _logger.warning("%r", e) raise c_message = message.get_message() message._on_message_sent = callback try: self._session._connection.lock(timeout=-1) return self._sender.send(c_message, timeout, message) finally: self._session._connection.release() def on_state_changed(self, previous_state, new_state): """Callback called whenever the underlying Sender undergoes a change of state. This function can be overridden. :param previous_state: The previous Sender state. :type previous_state: ~uamqp.constants.MessageSenderState :param new_state: The new Sender state. :type new_state: ~uamqp.constants.MessageSenderState """ # pylint: disable=protected-access _logger.info("Message sender %r state changed from %r to %r on connection: %r", self.name, previous_state, new_state, self._session._connection.container_id) self._state = new_state @property def send_settle_mode(self): return self._link.send_settle_mode @send_settle_mode.setter def send_settle_mode(self, value): self._link.send_settle_mode = value.value @property def receive_settle_mode(self): return self._link.receive_settle_mode @receive_settle_mode.setter def receive_settle_mode(self, value): self._link.receive_settle_mode = value.value @property def max_message_size(self): return self._link.max_message_size @max_message_size.setter def max_message_size(self, value): self._link.max_message_size = int(value)