chia-blockchain/chia/consensus/find_fork_point.py

34 lines
1.2 KiB
Python

from typing import Union
from chia.consensus.block_record import BlockRecord
from chia.consensus.blockchain_interface import BlockchainInterface
from chia.types.header_block import HeaderBlock
def find_fork_point_in_chain(
blocks: BlockchainInterface,
block_1: Union[BlockRecord, HeaderBlock],
block_2: Union[BlockRecord, HeaderBlock],
) -> int:
"""Tries to find height where new chain (block_2) diverged from block_1 (assuming prev blocks
are all included in chain)
Returns -1 if chains have no common ancestor
* assumes the fork point is loaded in blocks
"""
while block_2.height > 0 or block_1.height > 0:
if block_2.height > block_1.height:
block_2 = blocks.block_record(block_2.prev_hash)
elif block_1.height > block_2.height:
block_1 = blocks.block_record(block_1.prev_hash)
else:
if block_2.header_hash == block_1.header_hash:
return block_2.height
block_2 = blocks.block_record(block_2.prev_hash)
block_1 = blocks.block_record(block_1.prev_hash)
if block_2 != block_1:
# All blocks are different
return -1
# First block is the same
return 0