• Peter Goodspeed-Niklaus's avatar
    mod subsystem-util (#1376) · d7684115
    Peter Goodspeed-Niklaus authored
    * Add subsystem-util crate.
    Start by moving the JobCanceler here.
    * copy utility functions for requesting runtime data; generalize
    * convert subsystem-util from crate to module in subsystem
    The point of making a sub-crate is to ensure that only the necessary
    parts of a program get compiled; if a dependent package needed only
    subsystem-util, and not subsystem, then subsystem wouldn't need to
    be compiled.
    However, that will never happen: subsystem-util depends on
    subsystem::messages, so subsystem will always be compiled.
    Therefore, it makes more sense to add it as a module in the existing
    crate than as a new and distinct crate.
    * make runtime request sender type generic
    * candidate backing subsystem uses util for api requests
    * add struct Validator representing the local validator
    This struct can be constructed when the local node is a validator;
    the constructor fails otherwise. It stores a bit of local data, and
    provides some utility methods.
    * add alternate constructor for better efficiency
    * refactor candidate backing to use utility methods
    * fix test breakage caused by reordering tests
    * restore test which accidentally got deleted during merge
    * start extracting jobs management into helper traits + structs
    * use util::{JobHandle, Jobs} in CandidateBackingSubsystem
    * implement generic job-manager subsystem impl
    This means that the work of implementing a subsystem boils down
    to implementing the job, and then writing an appropriate
    type definition, i.e.
    pub type CandidateBackingSubsystem<Spawner, Context> =
    	util::JobManager<Spawner, Context, CandidateBackingJob>;
    * add hash-extraction helper to messages
    * fix errors caused by improper rebase
    * doc improvement
    * simplify conversion from overseer communication to job message
    * document fn hash for all messages
    * rename fn hash() -> fn relay_parent
    * gracefully shut down running futures on Conclude
    * ensure we're validating with the proper validator index
    * rename: handle_unhashed_msg -> handle_orphan_msg
    * impl Stream for Jobs<Spawner, Job>
    This turns out to be relatively complicated and requires some
    unsafe code, so we'll want either detailed review, or to choose
    to revert this commit.
    * add missing documentation for public items
    * use pin-project to eliminate unsafe code from this codebase
    * rename SenderMessage -> FromJob
    * reenvision the subsystem requests as an extension trait
    This works within `util.rs`, but fails in `core/backing/src/lib.rs`,
    because we don't actually create the struct soon enough. Continuing
    down this path would imply substantial rewriting.
    * Revert "reenvision the subsystem requests as an extension trait"
    This reverts commit a5639e36.
    The fact is, the new API is more complicated to no real benefit.
    * apply suggested futuresunordered join_all impl
    * CandidateValidationMessage variants have no top-level relay parents
    * rename handle_orphan_msg -> handle_unanchored_msg
    * make most node-core-backing types private
    Now the only public types exposed in that module are
    CandidateBackingSubsystem and ToJob. While ideally we could reduce
    the public interface to only the former type, that doesn't work
    because ToJob appears in the public interface of CandidateBackingSubsystem.
    This also involves changing the definition of CandidateBackingSubsystem;
    it is no longer a typedef, but a struct wrapping the job manager.