def validate_voting_beacon_block(chain: BaseBeaconChain,
attestation: Attestation) -> None:
# Check that beacon blocks attested to by the attestation are validated
try:
chain.get_block_by_root(attestation.data.beacon_block_root)
except BlockNotFound:
raise InvalidGossipMessage(
f"Failed to validate attestation={attestation},"
f" attested block={encode_hex(attestation.data.beacon_block_root)}"
" has not been not validated yet")
def get_blocks_from_fork_chain_by_root(
chain: BaseBeaconChain,
start_slot: Slot,
peer_head_block: BaseBeaconBlock,
slot_of_requested_blocks: Sequence[Slot],
) -> Iterable[BaseBeaconBlock]:
# Peer's head block is on a fork chain,
# start getting the requested blocks by
# traversing the history from the head.
# `slot_of_requested_blocks` starts with earliest slot
# and end with most recent slot, so we start traversing
# from the most recent slot.
cur_index = len(slot_of_requested_blocks) - 1
block = peer_head_block
if block.slot == slot_of_requested_blocks[cur_index]:
yield block
cur_index -= 1
while block.slot > start_slot and cur_index >= 0:
try:
block = chain.get_block_by_root(block.parent_root)
except (BlockNotFound, ValidationError):
# This should not happen as we only persist block if its
# ancestors are also in the database.
break
else:
while block.slot < slot_of_requested_blocks[cur_index]:
if cur_index > 0:
cur_index -= 1
else:
break
if block.slot == slot_of_requested_blocks[cur_index]:
yield block
def get_requested_beacon_blocks(
chain: BaseBeaconChain,
request: BeaconBlocksByRangeRequest
) -> Tuple[BaseBeaconBlock, ...]:
try:
requested_head = chain.get_block_by_root(
request.head_block_root
)
except (BlockNotFound, ValidationError) as error:
logger.info("Sending empty blocks, reason: %s", error)
return tuple()
# Check if slot of specified head block is greater than specified start slot
if requested_head.slot < request.start_slot:
raise InvalidRequest(
f"head block slot({requested_head.slot}) lower than `start_slot`({request.start_slot})"
)
try:
requested_beacon_blocks = _get_requested_beacon_blocks(
chain, request, requested_head
)
return requested_beacon_blocks
except ValidationError as val_error:
raise InvalidRequest(str(val_error))
def get_beacon_blocks_by_root(
chain: BaseBeaconChain,
request: BeaconBlocksByRootRequest,
) -> Iterable[BaseBeaconBlock]:
for block_root in request.block_roots:
try:
block = chain.get_block_by_root(block_root)
except (BlockNotFound, ValidationError):
pass
else:
yield block