Struct MessageBus

pub struct MessageBus {
    pub trader_id: TraderId,
    pub instance_id: UUID4,
    pub name: String,
    pub has_backing: bool,
    pub switchboard: MessagingSwitchboard,
    /* private fields */
}

A generic message bus to facilitate various messaging patterns.

The bus provides both a producer and consumer API for Pub/Sub, Req/Rep, as well as direct point-to-point messaging to registered endpoints.

Pub/Sub wildcard patterns for hierarchical topics are possible:

• * asterisk represents one or more characters in a pattern.
• ? question mark represents a single character in a pattern.

Given a topic and pattern potentially containing wildcard characters, i.e. * and ?, where ? can match any single character in the topic, and * can match any number of characters including zero characters.

The asterisk in a wildcard matches any character zero or more times. For example, comp* matches anything beginning with comp which means comp, complete, and computer are all matched.

A question mark matches a single character once. For example, c?mp matches camp and comp. The question mark can also be used more than once. For example, c??p would match both of the above examples and coop.

Fields

trader_id: TraderId

The trader ID associated with the message bus.

instance_id: UUID4

The instance ID associated with the message bus.

name: String

The name for the message bus.

has_backing: bool

If the message bus is backed by a database.

switchboard: MessagingSwitchboard

The switchboard for built-in endpoints.

Implementations

impl MessageBus

pub fn new( trader_id: TraderId, instance_id: UUID4, name: Option<String>, _config: Option<HashMap<String, Value>>, ) -> Self

Creates a new MessageBus instance.

pub fn memory_address(&self) -> String

Returns the message bus instances memory address.

pub fn endpoints(&self) -> Vec<&str>

Returns the registered endpoint addresses.

pub fn topics(&self) -> Vec<&str>

Returns the topics for active subscriptions.

pub fn has_subscribers<T: AsRef<str>>(&self, pattern: T) -> bool

Returns whether there are subscribers for the given pattern.

pub fn subscriptions_count<T: AsRef<str>>(&self, pattern: T) -> usize

Returns the count of subscribers for the given pattern.

pub fn subscriptions(&self) -> Vec<&Subscription>

Returns whether there are subscribers for the given pattern.

pub fn subscription_handler_ids(&self) -> Vec<&str>

Returns whether there are subscribers for the given pattern.

pub fn is_registered<T: AsRef<str>>(&self, endpoint: T) -> bool

Returns whether there is a registered endpoint for the given pattern.

pub fn is_subscribed<T: AsRef<str>>( &self, topic: T, handler: ShareableMessageHandler, ) -> bool

Returns whether there are subscribers for the given pattern.

pub const fn close(&self) -> Result<()>

Close the message bus which will close the sender channel and join the thread.

pub fn register<T: AsRef<str>>( &mut self, endpoint: T, handler: ShareableMessageHandler, )

Registers the given handler for the endpoint address.

pub fn deregister(&mut self, endpoint: &Ustr)

Deregisters the given handler for the endpoint address.

pub fn subscribe<T: AsRef<str>>( &mut self, topic: T, handler: ShareableMessageHandler, priority: Option<u8>, )

Subscribes the given handler to the topic.

pub fn unsubscribe<T: AsRef<str>>( &mut self, topic: T, handler: ShareableMessageHandler, )

Unsubscribes the given handler from the topic.

pub fn get_endpoint<T: AsRef<str>>( &self, endpoint: T, ) -> Option<&ShareableMessageHandler>

Returns the handler for the given endpoint.

pub fn matching_subscriptions<'a>( &'a self, pattern: &'a Ustr, ) -> Vec<&'a Subscription>

pub fn send(&self, endpoint: &Ustr, message: &dyn Any)

Sends a message to an endpoint.

pub fn publish(&self, topic: &Ustr, message: &dyn Any)

Publish a message to a topic.

impl MessageBus

Data specific functions.

pub fn send_response(&self, message: DataResponse)

Send a DataResponse to an endpoint that must be an actor.

pub fn publish_data(&self, topic: &Ustr, message: Data)

Publish [Data] to a topic.

impl MessageBus

pub fn send_py(&self, endpoint: &str, message: PyObject)

Sends a message to a an endpoint.

pub fn publish_py(&self, topic: &str, message: PyObject)

Publish a message to a topic.

pub fn register_py(&mut self, endpoint: &str, handler: PythonMessageHandler)

Registers the given handler for the endpoint address.

pub fn subscribe_py( slf: PyRefMut<'_, Self>, topic: &str, handler: PythonMessageHandler, priority: Option<u8>, )

Subscribes the given handler to the topic.

The priority for the subscription determines the ordering of handlers receiving messages being processed, higher priority handlers will receive messages before lower priority handlers.

Safety: Priority should be between 0 and 255

Warnings

Assigning priority handling is an advanced feature which shouldn’t normally be needed by most users. Only assign a higher priority to the subscription if you are certain of what you’re doing. If an inappropriate priority is assigned then the handler may receive messages before core system components have been able to process necessary calculations and produce potential side effects for logically sound behavior.

pub fn is_subscribed_py( &self, topic: &str, handler: PythonMessageHandler, ) -> bool

Returns whether there are subscribers for the given pattern.

pub fn unsubscribe_py(&mut self, topic: &str, handler: PythonMessageHandler)

Unsubscribes the given handler from the topic.

pub fn is_registered_py(&self, endpoint: &str) -> bool

Returns whether there are subscribers for the given pattern.

pub fn deregister_py(&mut self, endpoint: &str)

Deregisters the given handler for the endpoint address.

Trait Implementations

impl Default for MessageBus

fn default() -> Self

Creates a new default MessageBus instance.

impl IntoPy<Py<PyAny>> for MessageBus

fn into_py(self, py: Python<'_>) -> PyObject

Performs the conversion.

impl PyClass for MessageBus

type Frozen = False

Whether the pyclass is frozen.

impl PyClassImpl for MessageBus

const IS_BASETYPE: bool = false

#[pyclass(subclass)]

const IS_SUBCLASS: bool = false

#[pyclass(extends=…)]

const IS_MAPPING: bool = false

#[pyclass(mapping)]

const IS_SEQUENCE: bool = false

#[pyclass(sequence)]

type BaseType = PyAny

Base class

type ThreadChecker = SendablePyClass<MessageBus>

This handles following two situations:

type PyClassMutability = <<PyAny as PyClassBaseType>::PyClassMutability as PyClassMutability>::MutableChild

Immutable or mutable

type Dict = PyClassDummySlot

Specify this class has #[pyclass(dict)] or not.

type WeakRef = PyClassDummySlot

Specify this class has #[pyclass(weakref)] or not.

type BaseNativeType = PyAny

The closest native ancestor. This is PyAny by default, and when you declare #[pyclass(extends=PyDict)], it’s PyDict.

fn items_iter() -> PyClassItemsIter

fn doc(py: Python<'_>) -> PyResult<&'static CStr>

Rendered class doc

fn lazy_type_object() -> &'static LazyTypeObject<Self>

fn dict_offset() -> Option<isize>

fn weaklist_offset() -> Option<isize>

impl<'a, 'py> PyFunctionArgument<'a, 'py> for &'a MessageBus

type Holder = Option<PyRef<'py, MessageBus>>

fn extract( obj: &'a Bound<'py, PyAny>, holder: &'a mut Self::Holder, ) -> PyResult<Self>

impl<'a, 'py> PyFunctionArgument<'a, 'py> for &'a mut MessageBus

type Holder = Option<PyRefMut<'py, MessageBus>>

fn extract( obj: &'a Bound<'py, PyAny>, holder: &'a mut Self::Holder, ) -> PyResult<Self>

impl PyMethods<MessageBus> for PyClassImplCollector<MessageBus>

fn py_methods(self) -> &'static PyClassItems

impl PyTypeInfo for MessageBus

const NAME: &'static str = "MessageBus"

Class name.

const MODULE: Option<&'static str> = _

Module name, if any.

fn type_object_raw(py: Python<'_>) -> *mut PyTypeObject

Returns the PyTypeObject instance for this type.

fn type_object_bound(py: Python<'_>) -> Bound<'_, PyType>

Returns the safe abstraction over the type object.

fn is_type_of_bound(object: &Bound<'_, PyAny>) -> bool

Checks if object is an instance of this type or a subclass of this type.

fn is_exact_type_of_bound(object: &Bound<'_, PyAny>) -> bool

Checks if object is an instance of this type.

impl DerefToPyAny for MessageBus

impl Send for MessageBus

impl Sync for MessageBus