nimbus-eth2/beacon_chain/time.nim

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import
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random,
chronos,
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spec/datatypes
type
Timestamp* = uint64 # Unix epoch timestamp in millisecond resolution
var
detectedClockDrift: int64
template now*: auto = fastEpochTime()
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# TODO underflow when genesis has not yet happened!
proc timeSinceGenesis*(s: BeaconState): Timestamp =
Timestamp(int64(fastEpochTime() - s.genesis_time * 1000) -
detectedClockDrift)
proc getSlotFromTime*(s: BeaconState, t = now()): SlotNumber =
GENESIS_SLOT + uint64((int64(t - s.genesis_time * 1000) - detectedClockDrift) div
int64(SLOT_DURATION * 1000))
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template slotStart*(s: BeaconState, slot: uint64): Timestamp =
(s.genesis_time + (slot * SLOT_DURATION)) * 1000
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template slotMiddle*(s: BeaconState, slot: uint64): Timestamp =
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s.slotStart(slot) + SLOT_DURATION * 500
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template slotEnd*(s: BeaconState, slot: uint64): Timestamp =
s.slotStart(slot + 1)
proc randomTimeInSlot*(s: BeaconState,
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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)
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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