def receive(self, max_batch_size=None, timeout=None):
# type:(int, float) -> List[EventData]
"""
Receive events from the EventHub.
:param max_batch_size: Receive a batch of events. Batch size will
be up to the maximum specified, but will return as soon as service
returns no new events. If combined with a timeout and no events are
retrieve before the time, the result will be empty. If no batch
size is supplied, the prefetch size will be the maximum.
:type max_batch_size: int
:param timeout: The maximum wait time to build up the requested message count for the batch.
If not specified, the default wait time specified when the consumer was created will be used.
:type timeout: float
:rtype: list[~azure.eventhub.common.EventData]
:raises: ~azure.eventhub.AuthenticationError, ~azure.eventhub.ConnectError, ~azure.eventhub.ConnectionLostError,
~azure.eventhub.EventHubError
Example:
.. literalinclude:: ../examples/test_examples_eventhub.py
:start-after: [START eventhub_client_sync_receive]
:end-before: [END eventhub_client_sync_receive]
:language: python
:dedent: 4
:caption: Receive events from the EventHub.
"""
self._check_closed()
self._open()
max_batch_size = min(
self.client.config.max_batch_size,
self.prefetch) if max_batch_size is None else max_batch_size
timeout = self.client.config.receive_timeout if timeout is None else timeout
data_batch = [] # type: List[EventData]
max_retries = self.client.config.max_retries
connecting_count = 0
while True:
connecting_count += 1
try:
timeout_ms = 1000 * timeout if timeout else 0
message_batch = self._handler.receive_message_batch(
max_batch_size=max_batch_size -
(len(data_batch) if data_batch else 0),
timeout=timeout_ms)
for message in message_batch:
event_data = EventData(message=message)
self.offset = EventPosition(event_data.offset)
data_batch.append(event_data)
return data_batch
except errors.AuthenticationException as auth_error:
if connecting_count < max_retries:
log.info(
"EventHubConsumer disconnected due to token error. Attempting reconnect."
)
self._reconnect()
else:
log.info(
"EventHubConsumer authentication failed. Shutting down."
)
error = AuthenticationError(str(auth_error), auth_error)
self.close(auth_error)
raise error
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info(
"EventHubConsumer detached. Attempting reconnect.")
self._reconnect()
else:
log.info("EventHubConsumer detached. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubConsumer detached. Attempting reconnect.")
self._reconnect()
else:
log.info("EventHubConsumer detached. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(error)
raise error
except errors.AMQPConnectionError as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubConsumer connection lost. Attempting reconnect."
)
self._reconnect()
else:
log.info(
"EventHubConsumer connection lost. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(error)
raise error
except compat.TimeoutException as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubConsumer timed out receiving event data. Attempting reconnect."
)
self._reconnect()
else:
log.info("EventHubConsumer timed out. Shutting down.")
self.close(shutdown)
raise ConnectionLostError(str(shutdown), shutdown)
except KeyboardInterrupt:
log.info("EventHubConsumer stops due to keyboard interrupt")
self.close()
raise
except Exception as e:
log.error("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Receive failed: {}".format(e), e)
self.close(exception=error)
raise error
def _build_connection(self, is_reconnect=False):
"""
:param is_reconnect: True - trying to reconnect after fail to connect or a connection is lost.
False - the 1st time to connect
:return: True - connected. False - not connected
"""
# pylint: disable=protected-access
if is_reconnect:
alt_creds = {
"username": self.client._auth_config.get("iot_username"),
"password": self.client._auth_config.get("iot_password")
}
self._handler.close()
source = Source(self.source)
if self.offset is not None:
source.set_filter(self.offset._selector())
self._handler = ReceiveClient(
source,
auth=self.client.get_auth(**alt_creds),
debug=self.client.config.network_tracing,
prefetch=self.prefetch,
link_properties=self.properties,
timeout=self.timeout,
error_policy=self.retry_policy,
keep_alive_interval=self.keep_alive,
client_name=self.name,
properties=self.client._create_properties(
self.client.config.user_agent)) # pylint: disable=protected-access
self.messages_iter = None
try:
self._handler.open()
while not self._handler.client_ready():
time.sleep(0.05)
return True
except errors.AuthenticationException as shutdown:
if is_reconnect:
log.info(
"EventHubConsumer couldn't authenticate. Shutting down. (%r)",
shutdown)
error = AuthenticationError(str(shutdown), shutdown)
self.close(exception=error)
raise error
else:
log.info(
"EventHubConsumer couldn't authenticate. Attempting reconnect."
)
return False
except errors.LinkRedirect as redirect:
self._redirect(redirect)
return True
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry:
log.info("EventHubConsumer detached. Attempting reconnect.")
return False
else:
log.info("EventHubConsumer detached. Shutting down.")
error = ConnectError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if is_reconnect:
log.info("EventHubConsumer detached. Shutting down.")
error = ConnectError(str(shutdown), shutdown)
self.close(exception=error)
raise error
else:
log.info("EventHubConsumer detached. Attempting reconnect.")
return False
except errors.AMQPConnectionError as shutdown:
if is_reconnect:
log.info(
"EventHubConsumer connection error (%r). Shutting down.",
shutdown)
error = AuthenticationError(str(shutdown), shutdown)
self.close(exception=error)
raise error
else:
log.info(
"EventHubConsumer couldn't authenticate. Attempting reconnect."
)
return False
except compat.TimeoutException as shutdown:
if is_reconnect:
log.info(
"EventHubConsumer authentication timed out. Shutting down."
)
error = AuthenticationError(str(shutdown), shutdown)
self.close(exception=error)
raise error
else:
log.info(
"EventHubConsumer authentication timed out. Attempting reconnect."
)
return False
except Exception as e:
log.error(
"Unexpected error occurred when building connection (%r). Shutting down.",
e)
error = EventHubError(
"Unexpected error occurred when building connection", e)
self.close(exception=error)
raise error
def _send_event_data(self):
self._open()
max_retries = self.client.config.max_retries
connecting_count = 0
while True:
connecting_count += 1
try:
if self.unsent_events:
self._handler.queue_message(*self.unsent_events)
self._handler.wait()
self.unsent_events = self._handler.pending_messages
if self._outcome != constants.MessageSendResult.Ok:
EventHubProducer._error(self._outcome, self._condition)
return
except (errors.MessageAccepted, errors.MessageAlreadySettled,
errors.MessageModified, errors.MessageRejected,
errors.MessageReleased,
errors.MessageContentTooLarge) as msg_error:
raise EventDataError(str(msg_error), msg_error)
except errors.MessageException as failed:
log.error("Send event data error (%r)", failed)
error = EventDataSendError(str(failed), failed)
self.close(exception=error)
raise error
except errors.AuthenticationException as auth_error:
if connecting_count < max_retries:
log.info(
"EventHubProducer disconnected due to token error. Attempting reconnect."
)
self._reconnect()
else:
log.info(
"EventHubProducer authentication failed. Shutting down."
)
error = AuthenticationError(str(auth_error), auth_error)
self.close(auth_error)
raise error
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry:
log.info(
"EventHubProducer detached. Attempting reconnect.")
self._reconnect()
else:
log.info("EventHubProducer detached. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubProducer detached. Attempting reconnect.")
self._reconnect()
else:
log.info("EventHubProducer detached. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(error)
raise error
except errors.AMQPConnectionError as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubProducer connection lost. Attempting reconnect."
)
self._reconnect()
else:
log.info(
"EventHubProducer connection lost. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(error)
raise error
except compat.TimeoutException as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubProducer timed out sending event data. Attempting reconnect."
)
self._reconnect()
else:
log.info("EventHubProducer timed out. Shutting down.")
self.close(shutdown)
raise ConnectionLostError(str(shutdown), shutdown)
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Send failed: {}".format(e), e)
self.close(exception=error)
raise error
def __next__(self):
self._open()
max_retries = self.client.config.max_retries
connecting_count = 0
while True:
connecting_count += 1
try:
if not self.messages_iter:
self.messages_iter = self._handler.receive_messages_iter()
message = next(self.messages_iter)
event_data = EventData(message=message)
self.offset = EventPosition(event_data.offset, inclusive=False)
return event_data
except errors.AuthenticationException as auth_error:
if connecting_count < max_retries:
log.info(
"EventHubConsumer disconnected due to token error. Attempting reconnect."
)
self._reconnect()
else:
log.info(
"EventHubConsumer authentication failed. Shutting down."
)
error = AuthenticationError(str(auth_error), auth_error)
self.close(auth_error)
raise error
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info(
"EventHubConsumer detached. Attempting reconnect.")
self._reconnect()
else:
log.info("EventHubConsumer detached. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubConsumer detached. Attempting reconnect.")
self._reconnect()
else:
log.info("EventHubConsumer detached. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(error)
raise error
except errors.AMQPConnectionError as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubConsumer connection lost. Attempting reconnect."
)
self._reconnect()
else:
log.info(
"EventHubConsumer connection lost. Shutting down.")
error = ConnectionLostError(str(shutdown), shutdown)
self.close(error)
raise error
except compat.TimeoutException as shutdown:
if connecting_count < max_retries:
log.info(
"EventHubConsumer timed out receiving event data. Attempting reconnect."
)
self._reconnect()
else:
log.info("EventHubConsumer timed out. Shutting down.")
self.close(shutdown)
raise ConnectionLostError(str(shutdown), shutdown)
except StopIteration:
raise
except KeyboardInterrupt:
log.info("EventHubConsumer stops due to keyboard interrupt")
self.close()
raise
except Exception as e:
log.error("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Receive failed: {}".format(e), e)
self.close(exception=error)
raise error
def _build_connection(self, is_reconnect=False):
"""
:param is_reconnect: True - trying to reconnect after fail to connect or a connection is lost.
False - the 1st time to connect
:return: True - connected. False - not connected
"""
# pylint: disable=protected-access
if is_reconnect:
self._handler.close()
self._handler = SendClient(
self.target,
auth=self.client.get_auth(),
debug=self.client.config.network_tracing,
msg_timeout=self.timeout,
error_policy=self.retry_policy,
keep_alive_interval=self.keep_alive,
client_name=self.name,
properties=self.client._create_properties(
self.client.config.user_agent))
try:
self._handler.open()
while not self._handler.client_ready():
time.sleep(0.05)
return True
except errors.AuthenticationException as shutdown:
if is_reconnect:
log.info(
"EventHubProducer couldn't authenticate. Shutting down. (%r)",
shutdown)
error = AuthenticationError(str(shutdown), shutdown)
self.close(exception=error)
raise error
else:
log.info(
"EventHubProducer couldn't authenticate. Attempting reconnect."
)
return False
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry:
log.info("EventHubProducer detached. Attempting reconnect.")
return False
else:
log.info("EventHubProducer detached. Shutting down.")
error = ConnectError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if is_reconnect:
log.info("EventHubProducer detached. Shutting down.")
error = ConnectError(str(shutdown), shutdown)
self.close(exception=error)
raise error
else:
log.info("EventHubProducer detached. Attempting reconnect.")
return False
except errors.AMQPConnectionError as shutdown:
if is_reconnect:
log.info(
"EventHubProducer connection error (%r). Shutting down.",
shutdown)
error = AuthenticationError(str(shutdown), shutdown)
self.close(exception=error)
raise error
else:
log.info(
"EventHubProducer couldn't authenticate. Attempting reconnect."
)
return False
except compat.TimeoutException as shutdown:
if is_reconnect:
log.info(
"EventHubProducer authentication timed out. Shutting down."
)
error = AuthenticationError(str(shutdown), shutdown)
self.close(exception=error)
raise error
else:
log.info(
"EventHubProducer authentication timed out. Attempting reconnect."
)
return False
except Exception as e:
log.info(
"Unexpected error occurred when building connection (%r). Shutting down.",
e)
error = EventHubError(
"Unexpected error occurred when building connection", e)
self.close(exception=error)
raise error