def check_pow(
block_number, header_hash, mixhash, nonce, difficulty, is_test=False
) -> bool:
"""Check if the proof-of-work of the block is valid."""
if len(mixhash) != 32 or len(header_hash) != 32 or len(nonce) != 8:
return False
cache_gen, mining_gen = get_cache, hashimoto
if is_test:
cache_size, full_size = 1024, 32 * 1024
# use python implementation to allow overriding cache & dataset size
cache_gen = get_cache_slow
mining_gen = hashimoto_slow
else:
cache_size, full_size = (
get_cache_size(block_number),
get_full_size(block_number),
)
cache = cache_gen(cache_size, block_number)
mining_output = mining_gen(block_number, full_size, cache, header_hash, nonce)
if mining_output[b"mix digest"] != mixhash:
return False
result = int.from_bytes(mining_output[b"result"], byteorder="big")
return result <= 2 ** 256 // (difficulty or 1)
def mine(
block_number,
difficulty,
mining_hash,
start_nonce: int = 0,
rounds: int = 1000,
is_test: bool = False,
) -> Tuple[Optional[bytes], Optional[bytes]]:
cache_gen, mining_gen = get_cache, hashimoto
if is_test:
cache_size, full_size = 1024, 32 * 1024
# use python implementation to allow overriding cache & dataset size
cache_gen = get_cache_slow
mining_gen = hashimoto_slow
else:
cache_size, full_size = (
get_cache_size(block_number),
get_full_size(block_number),
)
cache = cache_gen(cache_size, block_number)
nonce = start_nonce
target = (2 ** 256 // (difficulty or 1) - 1).to_bytes(32, byteorder="big")
for i in range(1, rounds + 1):
# hashimoto expected big-indian byte representation
bin_nonce = (nonce + i).to_bytes(8, byteorder="big")
o = mining_gen(block_number, full_size, cache, mining_hash, bin_nonce)
if o[b"result"] <= target:
assert len(bin_nonce) == 8
assert len(o[b"mix digest"]) == 32
return bin_nonce, o[b"mix digest"]
return None, None