def _get_header_chain_gaps(cls, db: DatabaseAPI) -> ChainGaps:
try:
encoded_gaps = db[SchemaV1.make_header_chain_gaps_lookup_key()]
except KeyError:
return GENESIS_CHAIN_GAPS
else:
return rlp.decode(encoded_gaps, sedes=chain_gaps)
def _decanonicalize_descendant_orphans(
cls,
db: DatabaseAPI,
header: BlockHeaderAPI,
checkpoints: Tuple[Hash32, ...]) -> None:
# Determine if any children need to be de-canonicalized because they are not children of
# the new chain head
new_gaps = starting_gaps = cls._get_header_chain_gaps(db)
child_number = BlockNumber(header.block_number + 1)
try:
child = cls._get_canonical_block_header_by_number(db, child_number)
except HeaderNotFound:
# There is no canonical block here
next_invalid_child = None
else:
if child.parent_hash != header.hash:
if child.hash in checkpoints:
raise CheckpointsMustBeCanonical(
f"Trying to decanonicalize {child} while making {header} the chain tip"
)
else:
next_invalid_child = child
else:
next_invalid_child = None
while next_invalid_child:
# decanonicalize, and add gap for tracking
db.delete(SchemaV1.make_block_number_to_hash_lookup_key(child_number))
new_gaps = reopen_gap(child_number, new_gaps)
# find next child
child_number = BlockNumber(child_number + 1)
try:
# All contiguous children must now be made invalid
next_invalid_child = cls._get_canonical_block_header_by_number(db, child_number)
except HeaderNotFound:
# Found the end of this streak of canonical blocks
break
else:
if next_invalid_child.hash in checkpoints:
raise CheckpointsMustBeCanonical(
f"Trying to decanonicalize {next_invalid_child} while making {header} the"
" chain tip"
)
if new_gaps != starting_gaps:
db.set(
SchemaV1.make_header_chain_gaps_lookup_key(),
rlp.encode(new_gaps, sedes=chain_gaps)
)
def _decanonicalize_single(cls, db: DatabaseAPI, block_num: BlockNumber,
base_gaps: ChainGaps) -> ChainGaps:
"""
A single block number was found to no longer be canonical. At doc-time,
this only happens because it does not link up with a checkpoint header.
So de-canonicalize this block number and insert a gap in the tracked
chain gaps.
"""
db.delete(SchemaV1.make_block_number_to_hash_lookup_key(block_num))
new_gaps = reopen_gap(block_num, base_gaps)
if new_gaps != base_gaps:
db.set(SchemaV1.make_header_chain_gaps_lookup_key(),
rlp.encode(new_gaps, sedes=chain_gaps))
return new_gaps
def _update_header_chain_gaps(cls,
db: DatabaseAPI,
persisted_header: BlockHeaderAPI,
base_gaps: ChainGaps = None) -> GapInfo:
# If we make many updates in a row, we can avoid reloading the integrity info by
# continuously caching it and providing it as a parameter to this API
if base_gaps is None:
base_gaps = cls._get_header_chain_gaps(db)
gap_change, gaps = fill_gap(persisted_header.block_number, base_gaps)
if gap_change is not GapChange.NoChange:
db.set(SchemaV1.make_header_chain_gaps_lookup_key(),
rlp.encode(gaps, sedes=chain_gaps))
return gap_change, gaps
