/// <summary>
/// Run ``on_attestation`` upon receiving a new ``attestation`` from either within a block or directly on the wire.
/// An ``attestation`` that is asserted as invalid may be valid at a later time,
/// consider scheduling it for later processing in such case.
/// </summary>
public async Task OnAttestationAsync(IStore store, Attestation attestation)
{
if (_logger.IsInfo())
{
Log.OnAttestation(_logger, attestation, null);
}
TimeParameters timeParameters = _timeParameterOptions.CurrentValue;
Checkpoint target = attestation.Data.Target;
// Attestations must be from the current or previous epoch
Slot currentSlot = GetCurrentSlot(store);
Epoch currentEpoch = _beaconChainUtility.ComputeEpochAtSlot(currentSlot);
// Use GENESIS_EPOCH for previous when genesis to avoid underflow
Epoch previousEpoch = currentEpoch > _chainConstants.GenesisEpoch
? currentEpoch - new Epoch(1)
: _chainConstants.GenesisEpoch;
if (target.Epoch != currentEpoch && target.Epoch != previousEpoch)
{
throw new ArgumentOutOfRangeException("attestation.Target.Epoch", target.Epoch,
$"Attestation target epoch must be either the current epoch {currentEpoch} or previous epoch {previousEpoch}.");
}
Epoch dataSlotEpoch = _beaconChainUtility.ComputeEpochAtSlot(attestation.Data.Slot);
if (attestation.Data.Target.Epoch != dataSlotEpoch)
{
throw new ArgumentOutOfRangeException("attestation.Data.Target.Epoch", attestation.Data.Target.Epoch,
$"Attestation data target epoch must match the attestation data slot {attestation.Data.Slot} (epoch {dataSlotEpoch}).");
}
// Attestations target be for a known block. If target block is unknown, delay consideration until the block is found
BeaconBlock targetBlock = (await store.GetSignedBlockAsync(target.Root).ConfigureAwait(false)).Message;
// Attestations cannot be from future epochs. If they are, delay consideration until the epoch arrives
BeaconState targetStoredState = await store.GetBlockStateAsync(target.Root).ConfigureAwait(false);
BeaconState baseState = BeaconState.Clone(targetStoredState);
Slot targetEpochStartSlot = _beaconChainUtility.ComputeStartSlotOfEpoch(target.Epoch);
if (currentSlot < targetEpochStartSlot)
{
throw new Exception(
$"Ättestation target epoch start slot {targetEpochStartSlot} should not be larger than the store current slot {currentSlot}).");
}
// Attestations must be for a known block. If block is unknown, delay consideration until the block is found
BeaconBlock attestationBlock =
(await store.GetSignedBlockAsync(attestation.Data.BeaconBlockRoot).ConfigureAwait(false)).Message;
// Attestations must not be for blocks in the future. If not, the attestation should not be considered
if (attestationBlock.Slot > attestation.Data.Slot)
{
throw new Exception(
$"Attestation data root slot {attestationBlock.Slot} should not be larger than the attestation data slot {attestation.Data.Slot}).");
}
// Store target checkpoint state if not yet seen
BeaconState?targetState = await store.GetCheckpointStateAsync(target, false).ConfigureAwait(false);
if (targetState == null)
{
_beaconStateTransition.ProcessSlots(baseState, targetEpochStartSlot);
await store.SetCheckpointStateAsync(target, baseState).ConfigureAwait(false);
targetState = baseState;
}
// Attestations can only affect the fork choice of subsequent slots.
// Delay consideration in the fork choice until their slot is in the past.
Slot newCurrentSlot = GetCurrentSlot(store);
if (newCurrentSlot < attestation.Data.Slot + 1)
{
throw new Exception(
$"Attestation data slot {attestation.Data.Slot} should not be larger than the store current slot {newCurrentSlot}).");
}
// Get state at the `target` to validate attestation and calculate the committees
IndexedAttestation indexedAttestation =
_beaconStateAccessor.GetIndexedAttestation(targetState, attestation);
Domain domain = _beaconStateAccessor.GetDomain(targetState,
_signatureDomainOptions.CurrentValue.BeaconAttester, indexedAttestation.Data.Target.Epoch);
bool isValid = _beaconChainUtility.IsValidIndexedAttestation(targetState, indexedAttestation, domain);
if (!isValid)
{
throw new Exception($"Indexed attestation {indexedAttestation} is not valid.");
}
// Update latest messages
IEnumerable <ValidatorIndex> attestingIndices =
_beaconStateAccessor.GetAttestingIndices(targetState, attestation.Data, attestation.AggregationBits);
foreach (ValidatorIndex index in attestingIndices)
{
LatestMessage?latestMessage = await store.GetLatestMessageAsync(index, false).ConfigureAwait(false);
if (latestMessage == null || target.Epoch > latestMessage !.Epoch)
{
latestMessage = new LatestMessage(target.Epoch, attestation.Data.BeaconBlockRoot);
await store.SetLatestMessageAsync(index, latestMessage).ConfigureAwait(false);
}
}
}
/// <summary>
/// Run ``on_attestation`` upon receiving a new ``attestation`` from either within a block or directly on the wire.
/// An ``attestation`` that is asserted as invalid may be valid at a later time,
/// consider scheduling it for later processing in such case.
/// </summary>
public void OnAttestation(IStore store, Attestation attestation)
{
var initialValues = _initialValueOptions.CurrentValue;
var timeParameters = _timeParameterOptions.CurrentValue;
var target = attestation.Data.Target;
// Attestations must be from the current or previous epoch
var currentSlot = GetCurrentSlot(store);
var currentEpoch = _beaconChainUtility.ComputeEpochAtSlot(currentSlot);
// Use GENESIS_EPOCH for previous when genesis to avoid underflow
var previousEpoch = currentEpoch > initialValues.GenesisEpoch
? currentEpoch - new Epoch(1)
: initialValues.GenesisEpoch;
if (target.Epoch != currentEpoch && target.Epoch != previousEpoch)
{
throw new ArgumentOutOfRangeException("attestation.Target.Epoch", target.Epoch, $"Attestation target epoch must be either the current epoch {currentEpoch} or previous epoch {previousEpoch}.");
}
// Cannot calculate the current shuffling if have not seen the target
if (!store.TryGetBlock(target.Root, out var targetBlock))
{
throw new ArgumentOutOfRangeException("attestation.Target.Root", target.Root, "Attestation target root not found in the block history.");
}
// Attestations target be for a known block. If target block is unknown, delay consideration until the block is found
if (!store.TryGetBlockState(target.Root, out var targetStoredState))
{
throw new ArgumentOutOfRangeException("attestation.Target.Root", target.Root, "Attestation target root not found in the block stores history.");
}
// Attestations cannot be from future epochs. If they are, delay consideration until the epoch arrives
var baseState = BeaconState.Clone(targetStoredState !);
var targetEpochStartSlot = _beaconChainUtility.ComputeStartSlotOfEpoch(target.Epoch);
var targetEpochStartSlotTime = baseState.GenesisTime + (ulong)targetEpochStartSlot * timeParameters.SecondsPerSlot;
if (store.Time < targetEpochStartSlotTime)
{
throw new Exception($"Ättestation target state time {targetEpochStartSlotTime} should not be larger than the store time {store.Time}).");
}
// Attestations must be for a known block. If block is unknown, delay consideration until the block is found
if (!store.TryGetBlock(attestation.Data.BeaconBlockRoot, out var storedAttestationBlock))
{
throw new ArgumentOutOfRangeException("attestation.Data.BeaconBlockRoot", attestation.Data.BeaconBlockRoot, "Attestation data root not found in the block history.");
}
var attestationBlock = storedAttestationBlock !;
// Attestations must not be for blocks in the future. If not, the attestation should not be considered
if (attestationBlock.Slot > attestation.Data.Slot)
{
throw new Exception($"Attestation data root slot {attestationBlock.Slot} should not be larger than the attestation data slot {attestation.Data.Slot}).");
}
// Store target checkpoint state if not yet seen
if (!store.TryGetCheckpointState(target, out var targetState))
{
_beaconStateTransition.ProcessSlots(baseState, targetEpochStartSlot);
store.SetCheckpointState(target, baseState);
targetState = baseState;
}
// Attestations can only affect the fork choice of subsequent slots.
// Delay consideration in the fork choice until their slot is in the past.
//var attestationDataSlotTime = ((ulong)attestation.Data.Slot + 1) * timeParameters.SecondsPerSlot;
ulong attestationDataSlotTime = targetState !.GenesisTime + ((ulong)attestation.Data.Slot + 1) * timeParameters.SecondsPerSlot;
if (store.Time < attestationDataSlotTime)
{
throw new Exception($"Ättestation data time {attestationDataSlotTime} should not be larger than the store time {store.Time}).");
}
// Get state at the `target` to validate attestation and calculate the committees
var indexedAttestation = _beaconStateAccessor.GetIndexedAttestation(targetState, attestation);
var domain = _beaconStateAccessor.GetDomain(targetState, _signatureDomainOptions.CurrentValue.BeaconAttester, indexedAttestation.Data.Target.Epoch);
var isValid = _beaconChainUtility.IsValidIndexedAttestation(targetState, indexedAttestation, domain);
if (!isValid)
{
throw new Exception($"Indexed attestation {indexedAttestation} is not valid.");
}
// Update latest messages
var attestingIndices = _beaconStateAccessor.GetAttestingIndices(targetState, attestation.Data, attestation.AggregationBits);
foreach (var index in attestingIndices)
{
if (!store.TryGetLatestMessage(index, out var latestMessage) || target.Epoch > latestMessage !.Epoch)
{
latestMessage = new LatestMessage(target.Epoch, attestation.Data.BeaconBlockRoot);
store.SetLatestMessage(index, latestMessage);
}
}
}