import hashlib
from typing import Union, Iterable
from loopchain.blockchain.types import Hash32
from loopchain.blockchain.merkle import MerkleTree
from loopchain.blockchain.blocks import BlockProver as BaseBlockProver, BlockProverType
from loopchain.blockchain.blocks.v0_3 import receipts_hash_generator
class BlockProver(BaseBlockProver):
def __init__(self, values: Iterable, type_: 'BlockProverType'):
self.type = type_
self.hashes = [self.to_hash32(value) for value in values] if values else []
self._merkle_tree = MerkleTree()
def get_proof(self, hash_or_index: Union[Hash32, int]) -> list:
if isinstance(hash_or_index, Hash32):
index = self.hashes.index(hash_or_index)
else:
index = hash_or_index
if not self._merkle_tree.is_ready:
self.make_tree()
return self._merkle_tree.get_proof(index)
def get_proof_root(self) -> Hash32:
if not self._merkle_tree.is_ready:
self.make_tree()
root = self._merkle_tree.get_merkle_root()
return Hash32(root) if root is not None else Hash32.empty()
def prove(self, hash_: Hash32, root_hash: Hash32, proof: list) -> bool:
return MerkleTree.validate_proof(proof, hash_, root_hash)
def make_tree(self):
self._merkle_tree.reset_tree()
self._merkle_tree.add_leaf(self.hashes)
self._merkle_tree.make_tree()
def get_hash_generator(self):
if self.type == BlockProverType.Block:
return None # Do not need
if self.type == BlockProverType.Transaction:
return None # Do not need
if self.type == BlockProverType.Receipt:
return receipts_hash_generator
if self.type == BlockProverType.Rep:
return None
if self.type == BlockProverType.Vote:
return None
def to_hash32(self, value: Union[Hash32, bytes, bytearray, int, bool, dict]):
if value is None:
return Hash32.empty()
elif isinstance(value, Hash32):
return value
elif isinstance(value, (bytes, bytearray)) and len(value) == 32:
return Hash32(value)
if isinstance(value, bool):
value = b'\x01' if value else b'\x00'
elif isinstance(value, int):
if value < 0:
raise RuntimeError(f"value : {value} is negative.")
value = value.to_bytes((value.bit_length() + 7) // 8, "big")
elif isinstance(value, dict):
if self.type == BlockProverType.Receipt:
value = dict(value)
value.pop("failure", None)
value.pop("blockHash", None)
hash_generator = self.get_hash_generator()
value = hash_generator.generate_salted_origin(value)
value = value.encode()
return Hash32(hashlib.sha3_256(value).digest())
