Crate polkadot_node_subsystem::gen

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Orchestra

orchestra provides a global information flow of what a token of information. The token is arbitrary, but is used to notify all Subsystems of what is relevant and what is not.

For the motivations behind implementing the orchestra itself you should check out that guide, documentation in this crate will focus and be of technical nature.

An Orchestra is something that allows spawning/stopping and orchestrating asynchronous tasks as well as establishing a well-defined and easy to use protocol that the tasks can use to communicate with each other. It is desired that this protocol is the only way tasks communicate with each other, however at this moment there are no foolproof guards against other ways of communication.

The Orchestra is instantiated with a pre-defined set of Subsystems that share the same behavior from Orchestra’s point of view.

                             +-----------------------------+
                             |         Orchesta            |
                             +-----------------------------+

            ................|  Orchestra "holds" these and uses |.............
            .                  them to (re)start things                      .
            .                                                                .
            .  +-------------------+                +---------------------+  .
            .  |   Subsystem1      |                |   Subsystem2        |  .
            .  +-------------------+                +---------------------+  .
            .           |                                       |            .
            ..................................................................
                        |                                       |
                      start()                                 start()
                        V                                       V
            ..................| Orchestra "runs" these |.......................
            .  +--------------------+               +---------------------+  .
            .  | SubsystemInstance1 | <-- bidir --> | SubsystemInstance2  |  .
            .  +--------------------+               +---------------------+  .
            ..................................................................

Modules

futures
Abstractions for asynchronous programming.
metered
Metered variant of mpsc channels to be able to extract metrics.
tracing
A scoped, structured logging and diagnostics system.

Macros

poll
A macro which returns the result of polling a future once within the current async context.
select
Polls multiple futures and streams simultaneously, executing the branch for the future that finishes first. If multiple futures are ready, one will be pseudo-randomly selected at runtime. Futures directly passed to select! must be Unpin and implement FusedFuture.

Structs

Context
The context of an asynchronous task.
Delay
A future representing the notification that an elapsed duration has occurred.
Duration
A Duration type to represent a span of time, typically used for system timeouts.
Fuse
Future for the fuse method.
FuturesUnordered
A set of futures which may complete in any order.
MessagePacket
A wrapping type for messages.
Pin
A pinned pointer.
SignalsReceived
Watermark to track the received signals.
SpawnedSubsystem
An asynchronous subsystem task..
SubsystemInstance
A running instance of some Subsystem.
SubsystemMeterReadouts
Set of readouts of the Meters of a subsystem.
SubsystemMeters
Collection of meters related to a subsystem.
Timeout
A future that wraps another future with a Delay allowing for time-limited futures.

Enums

FromOrchestra
A message type that a subsystem receives from an orchestra. It wraps signals from an orchestra and messages that are circulating between subsystems.
OrchestraError
An error type that describes faults that may happen
Poll
Indicates whether a value is available or if the current task has been scheduled to receive a wakeup instead.
PollNext
Type to tell SelectWithStrategy which stream to poll next.
ToOrchestra
A type of messages that are sent from a Subsystem to the declared orchestra.

Traits

AnnotateErrorOrigin
A trait to support the origin annotation such that errors across subsystems can be easier tracked.
Future
A future represents an asynchronous computation obtained by use of async.
FutureExt
An extension trait for Futures that provides a variety of convenient adapters.
MapSubsystem
A helper trait to map a subsystem to smth. else.
Spawner
A spawner
StreamExt
An extension trait for Streams that provides a variety of convenient combinator functions.
Subsystem
A trait that describes the Subsystems that can run on the Orchestra.
SubsystemContext
A context type that is given to the Subsystem upon spawning. It can be used by Subsystem to communicate with other Subsystems or spawn jobs.
SubsystemSender
Sender end of a channel to interface with a subsystem.
TimeoutExt
Extends Future to allow time-limited futures.

Functions

make_packet
Create a packet from its parts.
select
This function will attempt to pull items from both streams. Each stream will be polled in a round-robin fashion, and whenever a stream is ready to yield an item that item is yielded.
select_message_channel_strategy
A functor to specify strategy of the channels selection in the SubsystemIncomingMessages
select_with_strategy
This function will attempt to pull items from both streams. You provide a closure to tell SelectWithStrategy which stream to poll. The closure can store state on SelectWithStrategy to which it will receive a &mut on every invocation. This allows basing the strategy on prior choices.

Type Definitions

BoxFuture
An owned dynamically typed Future for use in cases where you can’t statically type your result or need to add some indirection.
OrchestraResult
Alias for a result with error type OrchestraError.
SubsystemIncomingMessages
Incoming messages from both the bounded and unbounded channel.

Attribute Macros

async_trait
contextbounds
orchestra
subsystem