def test_read_write_i64():
stream = BytesIO()
write_i64(stream, 10)
assert stream.tell() == 8
stream.seek(0)
assert read_i64(stream) == 10
write_i64(stream, 11, 12, 13)
assert stream.tell() == 32
stream.seek(8)
assert read_i64(stream, 2) == (11, 12)
assert read_i64(stream, 1) == (13,)
assert read_i64(stream, 0) == ()
def _read_index(self):
try:
self._handle.seek(-8, os.SEEK_END)
self._handle.seek(read_i64(self._handle))
self._index = read_json(self._handle)
except:
raise IOError('unable to read index')
def _try_read_and_verify_version(cls, byte_stream):
if byte_stream.read(8) != FORMAT_STRING:
raise IOError('unrecognized file format')
try:
version = read_i64(byte_stream)
except:
raise IOError('unable to read file version')
if version != FORMAT_VERSION: # this could be later relaxed to a range of versions
raise IOError('incompatible version: {} (expected {})'.format(version, FORMAT_VERSION))
return version
def test_read_write_json(data):
stream = BytesIO()
total = write_json(stream, data)
assert stream.tell() == total
stream.seek(0)
length = read_i64(stream)
assert stream.tell() == total - length
assert json.loads(stream.read(length).decode('utf-8')) == data
stream.seek(0)
assert read_json(stream) == data