eii package¶

Submodules¶

Custom exceptions used in the Python module

exception eii.exc.Disconnected¶

Bases: Exception

Error raised when a receive context has been disconnected.

exception eii.exc.MessageBusAuthenticationFailed¶

Bases: Exception

Error raised when the message bus authentication for a receive context fails.

exception eii.exc.MessageBusError¶

Bases: Exception

Generic exception used when an issue occurs in a message bus method

exception eii.exc.ReceiveTimeout¶

Bases: Exception

Exception raised when a timeout has occurred while attempting to receive a message.

EII Message Envelope utility functions

class eii.msg_envelope.MsgEnvelope(meta_data=None, blob=None, name=None)¶

Bases: object

EII Message Envelope

get_blob()¶

Get the blob data in the message envelope.

Returns: Blob data in the message if any exists
Return type: Union[None, bytes]

get_meta_data()¶

Get the meta-data in the message envelope if any exists.

Returns: Meta-data in the message envelope
Return type: Union[None, dict]

get_name()¶

Get the topic string or service name in the message envelope.

Note

This will only be assigned if the MsgEnvelope was received over the message bus.

Returns: Topic string or service name, will be None if not set
Return type: Union[None, str]

EII Message Bus Python mapping

class eii.msgbus.MsgbusContext¶

Bases: object

EII Message Bus context object

get_service()¶

Create a new service context for issuing requests to a service.

Note that this method will expect to find the configuration attributes needed to communicate with the specified service in the configuration given to the constructor.

Parameters: service_name – Name of the service
Type: str
Returns: Service object
Return type: Service

new_publisher()¶

Create a new publisher object.

Parameters: topic – Publisher’s topic
Type: str
Returns: Publisher object
Return type: Publisher

new_service()¶

Create a new service context for receiving requests.

Note that this method will expect to find the configuration attributes needed to communicate with the specified service in the configuration given to the constructor.

Parameters: service_name – Name of the service
Type: str
Returns: Service object
Return type: Service

new_subscriber()¶

Create a new subscriber object.

Parameters: topic – Topic to subscribe to
Type: str
Returns: Subscriber object
Return type: Subscriber

EII Message Bus Publisher wrapper object

class eii.publisher.Publisher¶

Bases: object

EII Message Bus Publisher object

close()¶

Close the publisher.

This MUST be called before the program exists. If it is not your program may hang.

Note that this method is not thread-safe.

publish()¶

Publish message on the publisher object.

The message object passed to this method can be either a Python bytes object or a Python dictionary. When a bytes object is given to be published, then this method will construct a message envelope for a blob. If a dictionary is given, then a JSON message envelope will be constructed and published.

Parameters: message – Message to publish
Type: bytes or dict

EII Message Bus Python receive context wrapper

class eii.receive_context.ReceiveContext¶

Bases: object

EII Message Bus receive context wrapper object

close()¶

Close the receive context.

This MUST be called before the program exists. If it is not your program may hang.

Note that this method is not thread-safe.

recv()¶

Receive a message on the message bus for the given receive context. Note that the receive context can be a Subscriber or a Service object.

Additionally, if the timeout is set to -1, then this method will operate based on whether blocking is set to True or False (i.e. block or do not block). However, it the timeout is set to anything > -1, then this method will ignore whether blocking is set and use operate on a timeout.

Parameters

blocking – (Optional) Block until message received, or return immediately.
timeout – (Optional) Timeout in milliseconds to receive a message

Type

bool

Type

int

Returns

Received message

Return type

dict or bytes

EII Message Bus service wrapper object for receiving requests

class eii.service.Service¶

Bases: eii.receive_context.ReceiveContext

EII Message Bus service wrapper object for receiving requests

response()¶

Issue a response over the message bus.

Parameters: resp – Response data
Type: bytes or dict

EII Message Bus service wrapper object to issue requests

class eii.service_requester.ServiceRequester¶

Bases: eii.receive_context.ReceiveContext

EII Message Bus service wrapper object to issue requests

request()¶

Issue a request to the service.

Parameters: request – Request to issue to the service
Type: bytes or dict

Module contents¶

EII Message Bus