Overview

sessionstore.Store is the storage-backed facade for one session’s ledger, lease backend, catalog KV, and offload blob store. It is constructed once from a validated storage.Composite; per-session lease and journal objects are opened from it.

Backend contract

The store requires all four composite primitives. A nil composite or nil Ledger, Leaser, KV, or Blobs returns *sessionstore.InvalidBackendError with the missing field instead of deferring a panic.

type Store struct { /* backend and options are package-private */ }

func Open(*storage.Composite, ...Option) (*Store, error)

The store does not own a session lease merely because it exists. A caller must call AcquireLease for a session before opening a writer journal or object GC.

Open and options

The exact configuration surface is:

type Options struct {
	OffloadThreshold int
}

type Option func(*Options)

func WithOffloadThreshold(n int) Option

The default threshold is 512 KiB. A non-positive override is ignored. Frames above the threshold are uploaded to the session blob prefix before their ledger pointer is appended.

store, err := sessionstore.Open(memstore.New(),
	sessionstore.WithOffloadThreshold(256*1024),
)
if err != nil {
	return err
}

Persistence roots

func (s *Store) PersistencePaths() ([]string, error)

This reports canonical local roots from primitives implementing storage.PathReporter. Providers without that optional capability contribute no path. Ambiguous or unresolvable reports return a typed *sessionstore.PersistencePathError; remote providers can legitimately return an empty list.

The canonical logical names are:

Journal entry points

The store’s per-session methods are:

func (s *Store) AcquireLease(context.Context, uuid.UUID) (journal.Lease, error)
func (s *Store) OpenJournal(context.Context, uuid.UUID, journal.Lease) (journal.SessionJournal, error)
func (s *Store) OpenEventReplayer(uuid.UUID, ReplayRequest) (journal.EventReplayer, error)
func (s *Store) OpenInternalEventReplayer(uuid.UUID, ReplayRequest) (journal.EventReplayer, error)
func (s *Store) OpenInternalRecordReplayer(uuid.UUID, ReplayRequest) (journal.RecordReplayer, error)
func (s *Store) OpenCatalog(...CatalogOption) *Catalog
func (s *Store) OpenObjectGC(uuid.UUID, journal.Lease) (*ObjectGC, error)

Construction of a replayer is cheap and performs no read. The context is used when its Open method binds a ledger cursor. The internal methods are for restore and maintenance; product readers should use the public event replayer.

Source and proof

• Store.Open, options, and paths
• storage.Composite
• sessionstore construction tests