def get_canonical_block_by_slot(self, slot: SlotNumber) -> BaseBeaconBlock:
"""
Return the block with the given number in the canonical chain.
Raise ``BlockNotFound`` if there's no block with the given number in the
canonical chain.
"""
validate_slot(slot)
return self.get_block_by_root(self.chaindb.get_canonical_block_root(slot))
def _get_canonical_block_root(db: BaseDB, slot: int) -> Hash32:
validate_slot(slot)
slot_to_root_key = SchemaV1.make_block_slot_to_root_lookup_key(slot)
try:
encoded_key = db[slot_to_root_key]
except KeyError:
raise BlockNotFound(
"No canonical block for block slot #{0}".format(slot))
else:
return ssz.decode(encoded_key, sedes=ssz.sedes.bytes_sedes)
def get_state_by_slot(self, slot: Slot) -> BeaconState:
"""
Return the requested state as specified by slot number.
Raise ``StateSlotNotFound`` if there's no state with the given slot in the db.
"""
validate_slot(slot)
sm_class = self.get_state_machine_class_for_block_slot(slot)
state_class = sm_class.get_state_class()
return self.chaindb.get_state_by_slot(slot, state_class)
def get_state_machine_class_for_block_slot(
cls,
slot: SlotNumber) -> Type['BaseBeaconStateMachine']:
"""
Return the ``StateMachine`` class for the given block slot number.
"""
if cls.sm_configuration is None:
raise AttributeError("Chain classes must define the StateMachines in sm_configuration")
validate_slot(slot)
for start_slot, sm_class in reversed(cls.sm_configuration):
if slot >= start_slot:
return sm_class
raise StateMachineNotFound("No StateMachine available for block slot: #{0}".format(slot))
def test_validate_slot(slot, is_valid):
if is_valid:
validate_slot(slot)
else:
with pytest.raises(ValidationError):
validate_slot(slot)
def _get_canonical_block_root_by_slot(cls, db: BaseDB,
slot: int) -> Hash32:
validate_slot(slot)
return cls._get_canonical_block_root(db, slot)
