// 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 clock

import (
	"time"
)

// ClockData is the persistent state of syncbase clock used to estimate current
// NTP time and catch any unexpected changes to system clock.
type ClockData struct {
	// UTC time in unix nano seconds obtained from system clock at boot.
	SystemTimeAtBoot int64

	// Skew in nanoseconds between the system clock and NTP time.
	Skew int64

	// The elapsed time in nanoseconds since boot as last seen during a run of
	// clockservice. This is used to determine if the device rebooted since the
	// last run of clockservice.
	ElapsedTimeSinceBoot int64

	// Timestamp received from NTP during last NTP sync. The last NTP sync could
	// be done either by this device or some other device that this device
	// synced its clock with.
	LastNtpTs ?time.Time

	// Number of cumulative reboots since last NTP sync. If the LastNtpTs was
	// received from a peer device then this field represents the number
	// of reboots on that device since it did NTP and the number of reboots
	// on this device since syncing with the peer device.
	NumReboots uint16

	// Number of hops between this device and the device that did the last
	// NTP sync.
	NumHops uint16
}