Module storage 

The storage seam: the only thing workers coordinate through.

There is no coordinator process in atune. Every worker — a thread, a process running atune run, a SLURM array task — talks to one Storage and to nothing else. Everything that makes that safe is a property of this trait — the guide’s Storage is the prose version:

• trial numbers are contiguous and race-safe, so seeds derived from them are too;
• state changes go through Storage::try_transition, which reports a lost race as Ok(false) rather than an error;
• finished trials are immutable — which is why a failing worker records its error text with Storage::set_error before it transitions the trial to TrialState::Failed, and why that text then survives;
• reads are incremental: Storage::sync returns only what happened after a Cursor, which is what keeps the study loop from re-reading the whole study on every decision;
• side-channel state is typed and versioned (StateBlob), not a pickled-object junk drawer.

Every backend passes one shared conformance suite: the conformance module, exported by the crate feature of the same name, generates one test per invariant for any backend that hands it a factory. MemStorage is the reference implementation and the oracle the suite is calibrated against.

Re-exports

pub use failover::FailedOver;

pub use failover::FailoverPolicy;

pub use failover::fail_over_stale;

pub use finalization::FinalizationAcquireRequest;

pub use finalization::FinalizationObservation;

pub use finalization::FinalizationToken;

pub use lifecycle::AbandonRequest;

pub use lifecycle::ClaimRequest;

pub use lifecycle::ClaimTarget;

pub use lifecycle::FailStaleRequest;

pub use lifecycle::FencedMutation;

pub use lifecycle::FencedMutationRequest;

pub use lifecycle::FinalizedStateRequest;

pub use lifecycle::LeaseObservation;

pub use lifecycle::ParamWrite;

pub use lifecycle::RenewRequest;

pub use lifecycle::ReservationOutcome;

pub use lifecycle::ReserveAndCreateRequest;

pub use lifecycle::ReserveOutcome;

pub use lifecycle::TerminalOutcome;

pub use lifecycle::TerminalRequest;

pub use lifecycle::TrialLifecycleStorage;

pub use lifecycle::TrialOwnerToken;

pub use lifecycle::TrialReservation;

pub use outbox::EffectIntent;

pub use outbox::FinalizationAdvanceRequest;

pub use outbox::FinalizationIntent;

pub use outbox::FinalizationPhase;

pub use outbox::OutboxAdvanceRequest;

pub use outbox::OutboxEffect;

pub use outbox::OutboxEffectCompletion;

pub use outbox::OutboxEffectIntent;

pub use outbox::OutboxEffectKey;

pub use outbox::OutboxKey;

pub use outbox::OutboxPhase;

pub use outbox::OutboxRecord;

pub use outbox::REPLACEMENT_BLOB_KIND;

pub use outbox::REPLACEMENT_BLOB_VERSION;

pub use outbox::ReplacementOutcome;

pub use outbox::ReplacementSpec;

pub use outbox::replacement_scope;

pub use outbox_page::DEFAULT_OUTBOX_PAGE_MAX_BYTES;

pub use outbox_page::DEFAULT_OUTBOX_PAGE_MAX_RECORDS;

pub use outbox_page::OutboxCursor;

pub use outbox_page::OutboxPage;

pub use outbox_page::OutboxPageItem;

pub use outbox_page::OutboxPageRequest;

Modules

conformance

The shared Storage conformance suite — “write your own backend”.

failover

Backend-independent stale-worker fail-over.

finalization

Durable, study-wide ownership for terminal finalization.

lifecycle

Atomic trial ownership and lifecycle capability.

lifecycle_conformance

Backend-independent conformance checks for super::TrialLifecycleStorage.

outbox

Durable terminal-finalization intent types.

outbox_page

Bounded, stateless traversal of durable finalization outboxes.

Structs

Cursor

A position in a study’s change log.

ImportBatch

One serializable, fully staged import.

ImportBatchResult

Result of one atomic import publication.

ImportStudy

One study staged for import.

ImportTrial

One trial staged for import.

JournalOptions

Everything a JournalStorage can be tuned with.

JournalStorage

A study in one append-only file: grep-able, resumable, and shared between processes with no server.

MemStorage

The reference in-memory Storage backend: RwLock-guarded, copy-on-write reads.

SnapshotRequest

A request for one hydrated storage read.

StateBlob

A typed, versioned piece of state persisted through storage.

StorageSnapshot

Trial deltas and side state read for one study observation.

StudySummary

The stable identity data exposed by the optional study catalog.

SyncPage

One bounded page of Storage::sync_limited.

Enums

Durability

When the log asks the filesystem to make a publication durable.

ImportOutcome

Terminal state represented by a staged import trial.

ImportTrialOutcome

Outcome for one staged trial in an ImportBatchResult.

Scope

What a StateBlob belongs to.

SnapshotConsistency

The consistency guarantee attached to a StorageSnapshot.

StudyCreateOutcome

The result of an atomic StudyCatalog::create_if_empty operation.

StudyLoadOutcome

The result of resolving a study name through StudyCatalog::find_by_name.

Traits

AtomicImportStorage

Optional storage capability for all-or-none import publication.

Storage

The persistence seam.

StudyCatalog

Optional storage capability for stable study identity queries.