def get_blocks_from_canonical_chain_by_slot(
chain: BaseBeaconChain,
slot_of_requested_blocks: Sequence[Slot],
) -> Iterable[BaseBeaconBlock]:
# If peer's head block is on our canonical chain,
# start getting the requested blocks by slots.
for slot in slot_of_requested_blocks:
try:
block = chain.get_canonical_block_by_slot(slot)
except BlockNotFound:
pass
else:
yield block
def _get_requested_beacon_blocks(
chain: BaseBeaconChain,
beacon_blocks_request: BeaconBlocksByRangeRequest,
requested_head_block: BaseBeaconBlock,
) -> Tuple[BaseBeaconBlock, ...]:
slot_of_requested_blocks = tuple(
beacon_blocks_request.start_slot + i * beacon_blocks_request.step
for i in range(beacon_blocks_request.count)
)
logger.info("slot_of_requested_blocks: %s", slot_of_requested_blocks)
slot_of_requested_blocks = tuple(
filter(lambda slot: slot <= requested_head_block.slot, slot_of_requested_blocks)
)
if len(slot_of_requested_blocks) == 0:
return tuple()
# We have the peer's head block in our database,
# next check if the head block is on our canonical chain.
try:
canonical_block_at_slot = chain.get_canonical_block_by_slot(
requested_head_block.slot
)
block_match = canonical_block_at_slot == requested_head_block
except BlockNotFound:
logger.debug(
(
"The requested head block is not on our canonical chain "
"requested_head_block: %s"
),
requested_head_block,
)
block_match = False
finally:
if block_match:
# Peer's head block is on our canonical chain
return get_blocks_from_canonical_chain_by_slot(
chain,
slot_of_requested_blocks,
)
else:
# Peer's head block is not on our canonical chain
# Validate `start_slot` is greater than our latest finalized slot
validate_start_slot(chain, beacon_blocks_request.start_slot)
return get_blocks_from_fork_chain_by_root(
chain,
beacon_blocks_request.start_slot,
requested_head_block,
slot_of_requested_blocks,
)