def create_header_from_parent(difficulty_fn: Callable[[BlockHeaderAPI, int],
int],
parent_header: Optional[BlockHeaderAPI],
**header_params: Any) -> BlockHeaderAPI:
if 'gas_limit' not in header_params:
if parent_header is not None and not hasattr(parent_header,
'base_fee_per_gas'):
# If the previous block was not a London block,
# double the gas limit, so the new target is the old gas limit
header_params[
'gas_limit'] = parent_header.gas_limit * ELASTICITY_MULTIPLIER
else:
# frontier rules
header_params['gas_limit'] = compute_gas_limit(
parent_header,
genesis_gas_limit=GENESIS_GAS_LIMIT,
)
# byzantium
if 'timestamp' not in header_params:
header_params['timestamp'] = new_timestamp_from_parent(parent_header)
if 'difficulty' not in header_params:
if parent_header is None:
raise ValueError(
"Must set difficulty when creating a new genesis header (no parent)."
" Consider 1 for easy mining or eth.constants.GENESIS_DIFFICULTY for consistency."
)
else:
header_params['difficulty'] = difficulty_fn(
parent_header,
header_params['timestamp'],
)
# The general fill function doesn't recognize this custom field, so remove it
configured_fee_per_gas = header_params.pop('base_fee_per_gas', None)
all_fields = fill_header_params_from_parent(parent_header, **header_params)
calculated_fee_per_gas = calculate_expected_base_fee_per_gas(parent_header)
if configured_fee_per_gas is None:
all_fields['base_fee_per_gas'] = calculated_fee_per_gas
else:
# Must not configure an invalid base fee. So verify that either:
# 1. This is the genesis header, or
# 2. The configured value matches the calculated value from the parent
if parent_header is None or configured_fee_per_gas == calculated_fee_per_gas:
all_fields['base_fee_per_gas'] = configured_fee_per_gas
else:
raise ValidationError(
f"Cannot select an invalid base_fee_per_gas of:"
f" {configured_fee_per_gas}, expected: {calculated_fee_per_gas}"
)
new_header = LondonBlockHeader(**all_fields) # type:ignore
return new_header
def create_frontier_header_from_parent(parent_header: BlockHeader,
**header_params: Any) -> BlockHeader:
if 'difficulty' not in header_params:
# Use setdefault to ensure the new header has the same timestamp we use to calculate its
# difficulty.
header_params.setdefault('timestamp', parent_header.timestamp + 1)
header_params['difficulty'] = compute_frontier_difficulty(
parent_header,
header_params['timestamp'],
)
if 'gas_limit' not in header_params:
header_params['gas_limit'] = compute_gas_limit(
parent_header,
gas_limit_floor=GENESIS_GAS_LIMIT,
)
header = BlockHeader.from_parent(parent=parent_header, **header_params)
return header
def create_frontier_header_from_parent(parent_header: BlockHeaderAPI,
**header_params: Any) -> BlockHeader:
if 'timestamp' not in header_params:
header_params['timestamp'] = new_timestamp_from_parent(parent_header)
if 'difficulty' not in header_params:
# Use setdefault to ensure the new header has the same timestamp we use to calculate its
# difficulty.
header_params['difficulty'] = compute_frontier_difficulty(
parent_header,
header_params['timestamp'],
)
if 'gas_limit' not in header_params:
header_params['gas_limit'] = compute_gas_limit(
parent_header,
genesis_gas_limit=GENESIS_GAS_LIMIT,
)
all_fields = fill_header_params_from_parent(parent_header, **header_params)
return BlockHeader(**all_fields)