class Receiver:
"""
Implements a Receiver.
"""
timeout = 0
_epoch = b'com.microsoft:epoch'
def __init__(self, client, source, prefetch=300, epoch=None):
"""
Instantiate a receiver.
:param client: The parent EventHubClient.
:type client: ~azure.eventhub.client.EventHubClient
:param source: The source EventHub from which to receive events.
:type source: ~uamqp.address.Source
:param prefetch: The number of events to prefetch from the service
for processing. Default is 300.
:type prefetch: int
:param epoch: An optional epoch value.
:type epoch: int
"""
self.offset = None
self.prefetch = prefetch
self.epoch = epoch
self.properties = None
self.redirected = None
self.debug = client.debug
self.error = None
if epoch:
self.properties = {
types.AMQPSymbol(self._epoch): types.AMQPLong(int(epoch))
}
self._handler = ReceiveClient(source,
auth=client.auth,
debug=self.debug,
prefetch=self.prefetch,
link_properties=self.properties,
timeout=self.timeout)
def open(self, connection):
"""
Open the Receiver using the supplied conneciton.
If the handler has previously been redirected, the redirect
context will be used to create a new handler before opening it.
:param connection: The underlying client shared connection.
:type: connection: ~uamqp.connection.Connection
"""
if self.redirected:
self._handler = ReceiveClient(self.redirected.address,
auth=None,
debug=self.debug,
prefetch=self.prefetch,
link_properties=self.properties,
timeout=self.timeout)
self._handler.open(connection)
def get_handler_state(self):
"""
Get the state of the underlying handler with regards to start
up processes.
:rtype: ~uamqp.constants.MessageReceiverState
"""
# pylint: disable=protected-access
return self._handler._message_receiver.get_state()
def has_started(self):
"""
Whether the handler has completed all start up processes such as
establishing the connection, session, link and authentication, and
is not ready to process messages.
:rtype: bool
"""
# pylint: disable=protected-access
timeout = False
auth_in_progress = False
if self._handler._connection.cbs:
timeout, auth_in_progress = self._handler._auth.handle_token()
if timeout:
raise EventHubError("Authorization timeout.")
elif auth_in_progress:
return False
elif not self._handler._client_ready():
return False
else:
return True
def close(self, exception=None):
"""
Close down the handler. If the handler has already closed,
this will be a no op. An optional exception can be passed in to
indicate that the handler was shutdown due to error.
:param exception: An optional exception if the handler is closing
due to an error.
:type exception: Exception
"""
if self.error:
return
elif isinstance(exception, errors.LinkRedirect):
self.redirected = exception
elif isinstance(exception, EventHubError):
self.error = exception
elif exception:
self.error = EventHubError(str(exception))
else:
self.error = EventHubError("This receive handler is now closed.")
self._handler.close()
@property
def queue_size(self):
"""
The current size of the unprocessed Event queue.
:rtype: int
"""
# pylint: disable=protected-access
if self._handler._received_messages:
return self._handler._received_messages.qsize()
return 0
def receive(self, max_batch_size=None, timeout=None):
"""
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
:rtype: list[~azure.eventhub.common.EventData]
"""
if self.error:
raise self.error
try:
timeout_ms = 1000 * timeout if timeout else 0
message_batch = self._handler.receive_message_batch(
max_batch_size=max_batch_size, timeout=timeout_ms)
data_batch = []
for message in message_batch:
event_data = EventData(message=message)
self.offset = event_data.offset
data_batch.append(event_data)
return data_batch
except errors.LinkDetach as detach:
error = EventHubError(str(detach))
self.close(exception=error)
raise error
except Exception as e:
error = EventHubError("Receive failed: {}".format(e))
self.close(exception=error)
raise error
def selector(self, default):
"""
Create a selector for the current offset if it is set.
:param default: The fallback receive offset.
:type default: ~azure.eventhub.common.Offset
:rtype: ~azure.eventhub.common.Offset
"""
if self.offset is not None:
return Offset(self.offset).selector()
return default
class Receiver(object):
"""
Implements a Receiver.
"""
timeout = 0
_epoch = b'com.microsoft:epoch'
def __init__(self, client, source, offset=None, prefetch=300, epoch=None, keep_alive=None, auto_reconnect=True):
"""
Instantiate a receiver.
:param client: The parent EventHubClient.
:type client: ~azure.eventhub.client.EventHubClient
:param source: The source EventHub from which to receive events.
:type source: str
:param prefetch: The number of events to prefetch from the service
for processing. Default is 300.
:type prefetch: int
:param epoch: An optional epoch value.
:type epoch: int
"""
self.running = False
self.client = client
self.source = source
self.offset = offset
self.prefetch = prefetch
self.epoch = epoch
self.keep_alive = keep_alive
self.auto_reconnect = auto_reconnect
self.retry_policy = errors.ErrorPolicy(max_retries=3, on_error=_error_handler)
self.reconnect_backoff = 1
self.properties = None
self.redirected = None
self.error = None
partition = self.source.split('/')[-1]
self.name = "EHReceiver-{}-partition{}".format(uuid.uuid4(), partition)
source = Source(self.source)
if self.offset is not None:
source.set_filter(self.offset.selector())
if epoch:
self.properties = {types.AMQPSymbol(self._epoch): types.AMQPLong(int(epoch))}
self._handler = ReceiveClient(
source,
auth=self.client.get_auth(),
debug=self.client.debug,
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())
def open(self):
"""
Open the Receiver using the supplied conneciton.
If the handler has previously been redirected, the redirect
context will be used to create a new handler before opening it.
:param connection: The underlying client shared connection.
:type: connection: ~uamqp.connection.Connection
"""
# pylint: disable=protected-access
self.running = True
if self.redirected:
self.source = self.redirected.address
source = Source(self.source)
if self.offset is not None:
source.set_filter(self.offset.selector())
alt_creds = {
"username": self.client._auth_config.get("iot_username"),
"password":self.client._auth_config.get("iot_password")}
self._handler = ReceiveClient(
source,
auth=self.client.get_auth(**alt_creds),
debug=self.client.debug,
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._handler.open()
while not self._handler.client_ready():
time.sleep(0.05)
def _reconnect(self): # pylint: disable=too-many-statements
# pylint: disable=protected-access
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.debug,
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())
try:
self._handler.open()
while not self._handler.client_ready():
time.sleep(0.05)
return True
except errors.TokenExpired as shutdown:
log.info("Receiver disconnected due to token expiry. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
return False
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
return False
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.AMQPConnectionError as shutdown:
if str(shutdown).startswith("Unable to open authentication session") and self.auto_reconnect:
log.info("Receiver couldn't authenticate. Attempting reconnect.")
return False
log.info("Receiver connection error (%r). Shutting down.", shutdown)
error = EventHubError(str(shutdown))
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Receiver reconnect failed: {}".format(e))
self.close(exception=error)
raise error
def reconnect(self):
"""If the Receiver was disconnected from the service with
a retryable error - attempt to reconnect."""
while not self._reconnect():
time.sleep(self.reconnect_backoff)
def get_handler_state(self):
"""
Get the state of the underlying handler with regards to start
up processes.
:rtype: ~uamqp.constants.MessageReceiverState
"""
# pylint: disable=protected-access
return self._handler._message_receiver.get_state()
def has_started(self):
"""
Whether the handler has completed all start up processes such as
establishing the connection, session, link and authentication, and
is not ready to process messages.
**This function is now deprecated and will be removed in v2.0+.**
:rtype: bool
"""
# pylint: disable=protected-access
timeout = False
auth_in_progress = False
if self._handler._connection.cbs:
timeout, auth_in_progress = self._handler._auth.handle_token()
if timeout:
raise EventHubError("Authorization timeout.")
if auth_in_progress:
return False
if not self._handler._client_ready():
return False
return True
def close(self, exception=None):
"""
Close down the handler. If the handler has already closed,
this will be a no op. An optional exception can be passed in to
indicate that the handler was shutdown due to error.
:param exception: An optional exception if the handler is closing
due to an error.
:type exception: Exception
"""
self.running = False
if self.error:
return
if isinstance(exception, errors.LinkRedirect):
self.redirected = exception
elif isinstance(exception, EventHubError):
self.error = exception
elif exception:
self.error = EventHubError(str(exception))
else:
self.error = EventHubError("This receive handler is now closed.")
self._handler.close()
@property
def queue_size(self):
"""
The current size of the unprocessed Event queue.
:rtype: int
"""
# pylint: disable=protected-access
if self._handler._received_messages:
return self._handler._received_messages.qsize()
return 0
def receive(self, max_batch_size=None, timeout=None):
"""
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
:rtype: list[~azure.eventhub.common.EventData]
"""
if self.error:
raise self.error
if not self.running:
raise ValueError("Unable to receive until client has been started.")
data_batch = []
try:
timeout_ms = 1000 * timeout if timeout else 0
message_batch = self._handler.receive_message_batch(
max_batch_size=max_batch_size,
timeout=timeout_ms)
for message in message_batch:
event_data = EventData(message=message)
self.offset = event_data.offset
data_batch.append(event_data)
return data_batch
except (errors.TokenExpired, errors.AuthenticationException):
log.info("Receiver disconnected due to token error. Attempting reconnect.")
self.reconnect()
return data_batch
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
self.reconnect()
return data_batch
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
self.reconnect()
return data_batch
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Receive failed: {}".format(e))
self.close(exception=error)
raise error
class Receiver(object):
"""
Implements a Receiver.
Example:
.. literalinclude:: ../examples/test_examples_eventhub.py
:start-after: [START create_eventhub_client_receiver_instance]
:end-before: [END create_eventhub_client_receiver_instance]
:language: python
:dedent: 4
:caption: Create a new instance of the Receiver.
"""
timeout = 0
_epoch = b'com.microsoft:epoch'
def __init__(self, client, source, offset=None, prefetch=300, epoch=None, keep_alive=None, auto_reconnect=True):
"""
Instantiate a receiver.
:param client: The parent EventHubClient.
:type client: ~azure.eventhub.client.EventHubClient
:param source: The source EventHub from which to receive events.
:type source: str
:param prefetch: The number of events to prefetch from the service
for processing. Default is 300.
:type prefetch: int
:param epoch: An optional epoch value.
:type epoch: int
"""
self.running = False
self.client = client
self.source = source
self.offset = offset
self.prefetch = prefetch
self.epoch = epoch
self.keep_alive = keep_alive
self.auto_reconnect = auto_reconnect
self.retry_policy = errors.ErrorPolicy(max_retries=3, on_error=_error_handler)
self.reconnect_backoff = 1
self.properties = None
self.redirected = None
self.error = None
partition = self.source.split('/')[-1]
self.name = "EHReceiver-{}-partition{}".format(uuid.uuid4(), partition)
source = Source(self.source)
if self.offset is not None:
source.set_filter(self.offset.selector())
if epoch:
self.properties = {types.AMQPSymbol(self._epoch): types.AMQPLong(int(epoch))}
self._handler = ReceiveClient(
source,
auth=self.client.get_auth(),
debug=self.client.debug,
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())
def open(self):
"""
Open the Receiver using the supplied conneciton.
If the handler has previously been redirected, the redirect
context will be used to create a new handler before opening it.
:param connection: The underlying client shared connection.
:type: connection: ~uamqp.connection.Connection
Example:
.. literalinclude:: ../examples/test_examples_eventhub.py
:start-after: [START eventhub_client_receiver_open]
:end-before: [END eventhub_client_receiver_open]
:language: python
:dedent: 4
:caption: Open the Receiver using the supplied conneciton.
"""
# pylint: disable=protected-access
self.running = True
if self.redirected:
self.source = self.redirected.address
source = Source(self.source)
if self.offset is not None:
source.set_filter(self.offset.selector())
alt_creds = {
"username": self.client._auth_config.get("iot_username"),
"password":self.client._auth_config.get("iot_password")}
self._handler = ReceiveClient(
source,
auth=self.client.get_auth(**alt_creds),
debug=self.client.debug,
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._handler.open()
while not self._handler.client_ready():
time.sleep(0.05)
def _reconnect(self): # pylint: disable=too-many-statements
# pylint: disable=protected-access
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.debug,
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())
try:
self._handler.open()
while not self._handler.client_ready():
time.sleep(0.05)
return True
except errors.TokenExpired as shutdown:
log.info("Receiver disconnected due to token expiry. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
return False
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
return False
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.AMQPConnectionError as shutdown:
if str(shutdown).startswith("Unable to open authentication session") and self.auto_reconnect:
log.info("Receiver couldn't authenticate. Attempting reconnect.")
return False
log.info("Receiver connection error (%r). Shutting down.", shutdown)
error = EventHubError(str(shutdown))
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Receiver reconnect failed: {}".format(e))
self.close(exception=error)
raise error
def reconnect(self):
"""If the Receiver was disconnected from the service with
a retryable error - attempt to reconnect."""
while not self._reconnect():
time.sleep(self.reconnect_backoff)
def get_handler_state(self):
"""
Get the state of the underlying handler with regards to start
up processes.
:rtype: ~uamqp.constants.MessageReceiverState
"""
# pylint: disable=protected-access
return self._handler._message_receiver.get_state()
def has_started(self):
"""
Whether the handler has completed all start up processes such as
establishing the connection, session, link and authentication, and
is not ready to process messages.
**This function is now deprecated and will be removed in v2.0+.**
:rtype: bool
"""
# pylint: disable=protected-access
timeout = False
auth_in_progress = False
if self._handler._connection.cbs:
timeout, auth_in_progress = self._handler._auth.handle_token()
if timeout:
raise EventHubError("Authorization timeout.")
if auth_in_progress:
return False
if not self._handler._client_ready():
return False
return True
def close(self, exception=None):
"""
Close down the handler. If the handler has already closed,
this will be a no op. An optional exception can be passed in to
indicate that the handler was shutdown due to error.
:param exception: An optional exception if the handler is closing
due to an error.
:type exception: Exception
Example:
.. literalinclude:: ../examples/test_examples_eventhub.py
:start-after: [START eventhub_client_receiver_close]
:end-before: [END eventhub_client_receiver_close]
:language: python
:dedent: 4
:caption: Close down the handler.
"""
self.running = False
if self.error:
return
if isinstance(exception, errors.LinkRedirect):
self.redirected = exception
elif isinstance(exception, EventHubError):
self.error = exception
elif exception:
self.error = EventHubError(str(exception))
else:
self.error = EventHubError("This receive handler is now closed.")
self._handler.close()
@property
def queue_size(self):
"""
The current size of the unprocessed Event queue.
:rtype: int
"""
# pylint: disable=protected-access
if self._handler._received_messages:
return self._handler._received_messages.qsize()
return 0
def receive(self, max_batch_size=None, timeout=None):
"""
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
:rtype: list[~azure.eventhub.common.EventData]
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.
"""
if self.error:
raise self.error
if not self.running:
raise ValueError("Unable to receive until client has been started.")
data_batch = []
try:
timeout_ms = 1000 * timeout if timeout else 0
message_batch = self._handler.receive_message_batch(
max_batch_size=max_batch_size,
timeout=timeout_ms)
for message in message_batch:
event_data = EventData(message=message)
self.offset = event_data.offset
data_batch.append(event_data)
return data_batch
except (errors.TokenExpired, errors.AuthenticationException):
log.info("Receiver disconnected due to token error. Attempting reconnect.")
self.reconnect()
return data_batch
except (errors.LinkDetach, errors.ConnectionClose) as shutdown:
if shutdown.action.retry and self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
self.reconnect()
return data_batch
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except errors.MessageHandlerError as shutdown:
if self.auto_reconnect:
log.info("Receiver detached. Attempting reconnect.")
self.reconnect()
return data_batch
log.info("Receiver detached. Shutting down.")
error = EventHubError(str(shutdown), shutdown)
self.close(exception=error)
raise error
except Exception as e:
log.info("Unexpected error occurred (%r). Shutting down.", e)
error = EventHubError("Receive failed: {}".format(e))
self.close(exception=error)
raise error