def random_header(prev_hash=None, height=-1, good_bits=None):
good_bits = good_bits or some_good_bits
raw_header = bytearray(urandom(80))
raw_header[72:76] = pack_le_uint32(random.choice(good_bits))
if prev_hash:
raw_header[4:36] = prev_hash
return Bitcoin.deserialized_header(bytes(raw_header), height)
def test_from_checkpoint(self):
header = Bitcoin.deserialized_header(bsv_checkpoint.raw_header, bsv_checkpoint.height)
chain = Chain.from_checkpoint(Bitcoin, bsv_checkpoint)
assert chain.height == bsv_checkpoint.height
assert chain.tip == header
assert chain.work == bsv_checkpoint.prev_work + header.work() == 0xd54c9a84f54e93d3d87015
assert chain.parent is None
assert chain._header_indices[-1] == bsv_checkpoint.height
def test_mainnet_2016_headers(tmpdir):
# Mainnet headers 0, 2015, 2016, 4031, 4032, ... 4249808
headers = setup_headers(tmpdir, 'mainnet-headers-2016')
chain = headers.chains()[0]
for height in range(0, len(headers), 2016):
header = headers.header_at_height(chain, height)
assert headers.required_bits(chain, height, None) == header.bits
assert headers.required_bits(chain, height + 1, None) == header.bits
assert header.difficulty() == 860_221_984_436.2223
bounded_bits = 403011440
# Test // 4 is lower bound for the last one
raw_header = bytearray(headers.raw_header_at_height(chain, height - 2016))
timestamp = Bitcoin.header_timestamp(raw_header)
# Add 8 weeks and a 14 seconds; the minimum to trigger it
raw_header[68:72] = pack_le_uint32(timestamp + 4 * 2016 * 600 + 14)
headers.set_one(height - 1, raw_header)
assert headers.required_bits(chain, height, ) == bounded_bits