nimbus-eth2/beacon_chain/time.nim

50 lines
1.6 KiB
Nim

import
random,
asyncdispatch2,
spec/datatypes
type
Timestamp* = uint64 # Unix epoch timestamp in millisecond resolution
var
detectedClockDrift: int64
template now*: auto = fastEpochTime()
# TODO underflow when genesis has not yet happened!
proc timeSinceGenesis*(s: BeaconState): Timestamp =
Timestamp(int64(fastEpochTime() - s.genesis_time * 1000) -
detectedClockDrift)
template toSlot*(t: Timestamp): uint64 =
t div (SLOT_DURATION * 1000)
template slotStart*(s: BeaconState, slot: uint64): Timestamp =
(s.genesis_time + (slot * SLOT_DURATION)) * 1000
template slotMiddle*(s: BeaconState, slot: uint64): Timestamp =
s.slotStart(slot) + SLOT_DURATION * 500
template slotEnd*(s: BeaconState, slot: uint64): Timestamp =
s.slotStart(slot + 1)
proc randomTimeInSlot*(s: BeaconState,
slot: uint64,
interval: HSlice[float, float]): Timestamp =
## Returns a random moment within the slot.
## The interval must be a sub-interval of [0..1].
## Zero marks the begginning of the slot and One marks the end.
s.slotStart(slot) + Timestamp(rand(interval) * float(SLOT_DURATION * 1000))
proc slotDistanceFromNow*(s: BeaconState): int64 =
## Returns how many slots have passed since a particular BeaconState was finalized
int64(s.timeSinceGenesis() div (SLOT_DURATION * EPOCH_LENGTH * 1000)) - int64(s.finalized_epoch)
proc synchronizeClock*() {.async.} =
## This should determine the offset of the local clock against a global
## trusted time (e.g. it can be obtained from multiple time servers).
# TODO: implement this properly
detectedClockDrift = 0