cache

type Accessor interface {
	Get(id string) (ImmutableRef, error)
	New(s ImmutableRef) (MutableRef, error)
	GetMutable(id string) (MutableRef, error) // Rebase?
}

type Controller interface {
	DiskUsage(ctx context.Context) ([]*client.UsageInfo, error)
	Prune(ctx context.Context) (map[string]int64, error)
	GC(ctx context.Context) error
}

type GCPolicy struct {
	MaxSize         uint64
	MaxKeepDuration time.Duration
}

type ImmutableRef interface {
	Mountable
	ID() string
	Release() error
	Size(ctx context.Context) (int64, error)
}

type Manager interface {
	Accessor
	Controller
	Close() error
}

type ManagerOpt struct {
	Snapshotter snapshot.Snapshotter
	Root        string
	GCPolicy    GCPolicy
}

type Mountable interface {
	Mount() ([]mount.Mount, error)
}

type MutableRef interface {
	Mountable
	ID() string
	Freeze() (ImmutableRef, error)
	ReleaseAndCommit(ctx context.Context) (ImmutableRef, error)
	Size(ctx context.Context) (int64, error)
}