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 rand;
• pub use metered;

Modules

• database
  Database trait for subsystem. Database trait for polkadot db.
• metrics
  This module reexports Prometheus types and defines the Metrics trait.
• nesting_sender
  Nested message sending
• 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

• 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
• 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

• Subsystem
  A trait that describes the Subsystems that can run on the Orchestra.
• 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.
• choose_random_subset_with_rng
  Choose a random subset of min elements using a specific Random Generator Rng 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.
• gen_ratio_rng
  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_on_chain_votes
  Request FetchOnChainVotes from the runtime
• 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_validation_code_by_hash
  Request ValidationCodeByHash from the runtime
• request_validation_code_hash
  Request ValidationCodeHash from the runtime
• request_validator_groups
  Request ValidatorGroups from the runtime
• request_validators
  Request Validators from the runtime
• sign
  Sign the given data with the given validator ID.
• 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.