prysm-pulse/beacon-chain/core/helpers/slot_epoch.go
Nishant Das 9ecef934d8 Update Beacon State to Match the Spec (#1489)
* first line of changes

* fix all tests in core package

* Finished fixing up all tests

* docs

* more docs
2019-02-06 10:44:27 -06:00

62 lines
1.8 KiB
Go

package helpers
import (
pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
"github.com/prysmaticlabs/prysm/shared/params"
)
// SlotToEpoch returns the epoch number of the input slot.
//
// Spec pseudocode definition:
// def slot_to_epoch(slot: SlotNumber) -> EpochNumber:
// return slot // EPOCH_LENGTH
func SlotToEpoch(slot uint64) uint64 {
return slot / params.BeaconConfig().EpochLength
}
// CurrentEpoch returns the current epoch number calculated from
// the slot number stored in beacon state.
//
// Spec pseudocode definition:
// def get_current_epoch(state: BeaconState) -> EpochNumber:
// return slot_to_epoch(state.slot)
func CurrentEpoch(state *pb.BeaconState) uint64 {
return SlotToEpoch(state.Slot)
}
// PrevEpoch returns the previous epoch number calculated from
// the slot number stored in beacon state. It also checks for
// underflow condition.
func PrevEpoch(state *pb.BeaconState) uint64 {
if SlotToEpoch(state.Slot) == 0 {
return 0
}
return SlotToEpoch(state.Slot) - 1
}
// NextEpoch returns the next epoch number calculated form
// the slot number stored in beacon state.
func NextEpoch(state *pb.BeaconState) uint64 {
return SlotToEpoch(state.Slot) + 1
}
// StartSlot returns the first slot number of the
// current epoch.
//
// Spec pseudocode definition:
// def get_epoch_start_slot(epoch: EpochNumber) -> SlotNumber:
// return epoch * EPOCH_LENGTH
func StartSlot(epoch uint64) uint64 {
return epoch * params.BeaconConfig().EpochLength
}
// AttestationCurrentEpoch returns the current epoch referenced by the attestation.
func AttestationCurrentEpoch(att *pb.AttestationData) uint64 {
return SlotToEpoch(att.Slot)
}
// AttestationJustifiedEpoch returns the justified epoch referenced by the attestation.
func AttestationJustifiedEpoch(att *pb.AttestationData) uint64 {
return SlotToEpoch(att.JustifiedSlot)
}