snapshoter

type Metrics struct {
	Scope                      promutils.Scope
	SnapshotSaveErrCounter     prometheus.Counter
	SnapshotCreationErrCounter prometheus.Counter
}

type Persistence interface {
	// Save Run(ctx context.Context)
	// Save saves the snapshot to the storage in a serialized form.
	Save(ctx context.Context, writer Writer, snapshot Snapshot)
	// Read reads the serialized snapshot from the storage and deserializes to its in memory format.
	Read(ctx context.Context, reader Reader) (Snapshot, error)
}

type Reader interface {
	// ReadSnapshot reads the snapshot from the reader
	ReadSnapshot(reader io.Reader) (Snapshot, error)
}

type Snapshot interface {
	// GetLastExecutionTime of the schedule given by the key
	GetLastExecutionTime(key string) *time.Time
	// UpdateLastExecutionTime of the schedule given by key to the lastExecTime
	UpdateLastExecutionTime(key string, lastExecTime *time.Time)
	// CreateSnapshot creates the snapshot of all the schedules and there execution times.
	Serialize() ([]byte, error)
	// BootstrapFrom bootstraps the snapshot from a byte array
	Deserialize(snapshot []byte) error
	// GetVersion gets the version number of snapshot written
	GetVersion() int
	// IsEmpty returns true if the snapshot contains no schedules
	IsEmpty() bool
	// Create an empty snapshot
	Create() Snapshot
}

type SnapshotV1 struct {
	// LastTimes map of the schedule name to last execution timestamp
	LastTimes map[string]*time.Time
}

type VersionedSnapshot struct {
	Version int
	Ser     []byte
}

type Writer interface {
	// WriteSnapshot writes the serialized form of the snapshot to the writer
	WriteSnapshot(writer io.Writer, snapshot Snapshot) error
}