rrd

type Printer interface {
	Print(w io.Writer) error
}

type RRD interface {
	// Slot returns the current window (slot) to store values.
	Slot() (Slot, error)
	// Counters, return all stored counters since the given time (since) until now.
	Counters(since time.Time) (map[string]float64, error)
	// Last returns the last reported value for a metric given the metric
	// name
	Last(key string) (value float64, ok bool, err error)

	// Close the db
	Close() error
}

type Slot interface {
	// Counter sets (or overrides) the current stored value for this key,
	// with value
	Counter(key string, value float64) error
	// Key return the key of the slot which is the window timestamp
	Key() uint64
}