attestationutil

Documentation

Index

• func AttestingIndices(bf bitfield.Bitfield, committee []uint64) ([]uint64, error)
• func ConvertToIndexed(ctx context.Context, attestation *ethpb.Attestation, committee []uint64) (*ethpb.IndexedAttestation, error)

Functions

func AttestingIndices

func AttestingIndices(bf bitfield.Bitfield, committee []uint64) ([]uint64, error)

AttestingIndices returns the attesting participants indices from the attestation data. The committee is provided as an argument rather than a direct implementation from the spec definition. Having the committee as an argument allows for re-use of beacon committees when possible.

Spec pseudocode definition:

def get_attesting_indices(state: BeaconState,
                       data: AttestationData,
                       bits: Bitlist[MAX_VALIDATORS_PER_COMMITTEE]) -> Set[ValidatorIndex]:
 """
 Return the set of attesting indices corresponding to ``data`` and ``bits``.
 """
 committee = get_beacon_committee(state, data.slot, data.index)
 return set(index for i, index in enumerate(committee) if bits[i])

func ConvertToIndexed

func ConvertToIndexed(ctx context.Context, attestation *ethpb.Attestation, committee []uint64) (*ethpb.IndexedAttestation, error)

ConvertToIndexed converts attestation to (almost) indexed-verifiable form.

Note about spec pseudocode definition. The state was used by get_attesting_indices to determine the attestation committee. Now that we provide this as an argument, we no longer need to provide a state.

Spec pseudocode definition:

def get_indexed_attestation(state: BeaconState, attestation: Attestation) -> IndexedAttestation:
 """
 Return the indexed attestation corresponding to ``attestation``.
 """
 attesting_indices = get_attesting_indices(state, attestation.data, attestation.aggregation_bits)

 return IndexedAttestation(
     attesting_indices=sorted(attesting_indices),
     data=attestation.data,
     signature=attestation.signature,
 )