// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package vclock

import (
	"time"
)

// VClockData is the persistent state of the Syncbase virtual clock.
// All times are UTC.
type VClockData struct {
	// System time at boot.
	SystemTimeAtBoot time.Time

	// Current estimate of NTP time minus system clock time.
	Skew time.Duration

	// Elapsed time since boot, as seen by VClockD. Used for detecting reboots.
	ElapsedTimeSinceBoot time.Duration

	// NTP server timestamp from the most recent NTP sync, or zero value if none.
	// Note, the NTP sync may have been performed by some peer device.
	LastNtpTs time.Time

	// Number of reboots since last NTP sync, accumulated across all hops of p2p
	// clock sync. E.g. if LastNtpTs came from some peer device, NumReboots will
	// equal that device's NumReboots at the time of sync plus the number of
	// reboots on this device since then.
	NumReboots uint16

	// Number of sync hops between this device and the source of LastNtpTs.
	NumHops uint16
}