def test_workflow():
f = tempfile.NamedTemporaryFile()
p = Storage(f)
a1 = p.write(b'one')
a2 = p.write(b'two')
p.commit_root_address(a2)
a3 = p.write(b'three')
assert p.get_root_address() == a2
a4 = p.write(b'four')
p.commit_root_address(a4)
assert p.read(a1) == b'one'
assert p.read(a2) == b'two'
assert p.read(a3) == b'three'
assert p.read(a4) == b'four'
assert p.get_root_address() == a4
def test_read():
f = tempfile.NamedTemporaryFile()
p = Storage(f)
f.seek(Storage.SUPERBLOCK_SIZE)
f.write(b'\x00\x00\x00\x00\x00\x00\x00\x0801234567')
value = p.read(Storage.SUPERBLOCK_SIZE)
assert value == b'01234567'