Crate polkadot_node_subsystem_util

Utility module for subsystems

Many subsystems have common interests such as canceling a bunch of spawned jobs, or determining what their validator ID is. These common interests are factored into this module.

This crate also reexports Prometheus metric types which are expected to be implemented by subsystems.

Re-exports

pub use metered_channel as metered;

Modules

metrics

This module reexports Prometheus types and defines the [Metrics] trait.

reexports

These reexports are required so that external crates can use the delegated_subsystem macro properly.

rolling_session_window

A rolling session window cache. A rolling window of sessions and cached session info, updated by the state of newly imported blocks.

runtime

Convenient and efficient runtime info access. Convenient interface to runtime information.

Structs

JobSender

A sender for messages from jobs, as well as commands to the overseer.

JobSubsystem

A subsystem which wraps jobs.

Metronome

Create a stream of ticks with a defined cycle duration.

Timeout

A future that wraps another future with a Delay allowing for time-limited futures.

Validator

Local validator information

Enums

Error

Utility errors

FromJobCommand

Commands from a job to the broader subsystem.

JobsError

Error which can be returned by the jobs manager

OverseerError

An error type that describes faults that may happen

Constants

JOB_CHANNEL_CAPACITY

Capacity of channels to and from individual jobs

JOB_GRACEFUL_STOP_DURATION

Duration a job will wait after sending a stop signal before hard-aborting.

MIN_GOSSIP_PEERS

The minimum amount of peers to send gossip messages to.

Traits

JobTrait

This trait governs jobs.

Subsystem

A trait that describes the Subsystems that can run on the Overseer.

TimeoutExt

Extends Future to allow time-limited futures.

Functions

choose_random_subset

Choose a random subset of min elements. But always include is_priority elements.

determine_new_blocks

Given a new chain-head hash, this determines the hashes of all new blocks we should track metadata for, given this head.

find_validator_group

Find the validator group the given validator index belongs to.

gen_ratio

Returns a bool with a probability of a / b of being true.

request_assumed_validation_data

Request AssumedValidationData from the runtime

request_authorities

Request Authorities from the runtime

request_availability_cores

Request AvailabilityCores from the runtime

request_candidate_events

Request CandidateEvents from the runtime

request_candidate_pending_availability

Request CandidatePendingAvailability from the runtime

request_from_runtime

Request some data from the RuntimeApi.

request_persisted_validation_data

Request PersistedValidationData from the runtime

request_session_index_for_child

Request SessionIndexForChild from the runtime

request_session_info

Request SessionInfo from the runtime

request_validation_code

Request ValidationCode from the runtime

request_validator_groups

Request ValidatorGroups from the runtime

request_validators

Request Validators from the runtime

signing_key

From the given set of validators, find the first key we can sign with, if any.

signing_key_and_index

From the given set of validators, find the first key we can sign with, if any, and return it along with the validator index.

Type Definitions

RuntimeApiReceiver

A type alias for Runtime API receivers.