Module location

Abstractions over files, cloud storage, etc used in persistence.

Structs

BlobMetadata

Metadata about a particular blob stored by persist

Determinate

An error coming from an underlying durability system (e.g. s3) indicating that the operation definitely did NOT succeed (e.g. permission denied).

Indeterminate

An error coming from an underlying durability system (e.g. s3) indicating that the operation might have succeeded (e.g. timeout).

SeqNo

The “sequence number” of a persist state change.

Tasked

Wraps all calls to a backing store in a new tokio task. This adds extra overhead, but insulates the system from callers who fail to drive futures promptly to completion, which can cause timeouts or resource exhaustion in a store.

VersionedData

An abstraction for a single arbitrarily-sized binary blob and an associated version number (sequence number).

Enums

CaSResult

Return type to indicate whether Consensus::compare_and_set succeeded or failed.

ExternalError

An error coming from an underlying durability system (e.g. s3) or from invalid data received from one.

Constants

BLOB_GET_LIVENESS_KEY

A key usable for liveness checks via Blob::get.

CONSENSUS_HEAD_LIVENESS_KEY

A key usable for liveness checks via Consensus::head.

SCAN_ALL

Helper constant to scan all states in Consensus::scan. The maximum possible SeqNo is i64::MAX.

Traits

Blob

An abstraction over read-write access to a bytes key->bytes value store.

Consensus

An abstraction for VersionedData held in a location in persistent storage where the data are conditionally updated by version.

Type Aliases

ResultStream

A boxed stream, similar to what async_trait desugars async functions to, but hardcoded to our standard result type.