Components
The parts of ruststream-pulsar a Pulsar service uses, one page per component, grouped by the
part of the service they belong to.
The broker, PulsarBroker, holds the
connection.
A subscription names its topics with a descriptor, and a handler's
outcome becomes an acknowledgement.
A handler reads where its delivery sits through its context, and moves its
subscription to a position in the log.
A service publishes through a policy, with a key and headers per message.
The Pulsar bindings describe the service in its AsyncAPI document, and a
TestApp test runs it on an in-process transport.