def _float_adjust(v, encode):
if encode and six.indexbytes(v, 0) & 0x80 != 0x00:
return b''.join(map(lambda x: six.int2byte(x ^ 0xff), six.iterbytes(v)))
elif not encode and six.indexbytes(v, 0) & 0x80 != 0x80:
return b''.join(map(lambda x: six.int2byte(x ^ 0xff), six.iterbytes(v)))
else:
return six.int2byte(six.indexbytes(v, 0) ^ 0x80) + v[1:]
def from_bytes(cls, v, start=0):
if not isinstance(v, bytes):
raise TypeError("Cannot parse versionstamp from non-byte string")
elif len(v) - start < cls.LENGTH:
raise ValueError("Versionstamp byte string is too short (only " +
str(len(v) - start) + " bytes to read from")
else:
tr_version = v[start:start + cls._TR_VERSION_LEN]
if tr_version == cls._UNSET_TR_VERSION:
tr_version = None
user_version = six.indexbytes(v, start + cls._TR_VERSION_LEN) * (
1 << 8) + six.indexbytes(v, start + cls._TR_VERSION_LEN + 1)
return Versionstamp(tr_version, user_version)
def _decode(v, pos):
code = six.indexbytes(v, pos)
if code == NULL_CODE:
return None, pos + 1
elif code == BYTES_CODE:
end = _find_terminator(v, pos + 1)
return v[pos + 1:end].replace(b"\x00\xFF", b"\x00"), end + 1
elif code == STRING_CODE:
end = _find_terminator(v, pos + 1)
return v[pos + 1:end].replace(b"\x00\xFF",
b"\x00").decode("utf-8"), end + 1
elif code >= INT_ZERO_CODE and code < POS_INT_END:
n = code - 20
end = pos + 1 + n
return struct.unpack(">Q", b'\x00' * (8 - n) + v[pos + 1:end])[0], end
elif code > NEG_INT_START and code < INT_ZERO_CODE:
n = 20 - code
end = pos + 1 + n
return struct.unpack(
">Q", b'\x00' * (8 - n) + v[pos + 1:end])[0] - _size_limits[n], end
elif code == POS_INT_END: # 0x1d; Positive 9-255 byte integer
length = six.indexbytes(v, pos + 1)
val = 0
for i in _range(length):
val = val << 8
val += six.indexbytes(v, pos + 2 + i)
return val, pos + 2 + length
elif code == NEG_INT_START: # 0x0b; Negative 9-255 byte integer
length = six.indexbytes(v, pos + 1) ^ 0xff
val = 0
for i in _range(length):
val = val << 8
val += six.indexbytes(v, pos + 2 + i)
return val - (1 << (length * 8)) + 1, pos + 2 + length
elif code == FLOAT_CODE:
return SingleFloat(
struct.unpack(">f", _float_adjust(v[pos + 1:pos + 5],
False))[0]), pos + 5
elif code == DOUBLE_CODE:
return struct.unpack(">d", _float_adjust(v[pos + 1:pos + 9],
False))[0], pos + 9
elif code == UUID_CODE:
return uuid.UUID(bytes=v[pos + 1:pos + 17]), pos + 17
elif code == FALSE_CODE:
if fdb.is_api_version_selected() and fdb.get_api_version() < 500:
raise ValueError("Invalid API version " + str(fdb._version) +
" for boolean types")
return False, pos + 1
elif code == TRUE_CODE:
if fdb.is_api_version_selected() and fdb.get_api_version() < 500:
raise ValueError("Invalid API version " + str(fdb._version) +
" for boolean types")
return True, pos + 1
elif code == VERSIONSTAMP_CODE:
return Versionstamp.from_bytes(v,
pos + 1), pos + 1 + Versionstamp.LENGTH
elif code == NESTED_CODE:
ret = []
end_pos = pos + 1
while end_pos < len(v):
if six.indexbytes(v, end_pos) == 0x00:
if end_pos + 1 < len(v) and six.indexbytes(
v, end_pos + 1) == 0xff:
ret.append(None)
end_pos += 2
else:
break
else:
val, end_pos = _decode(v, end_pos)
ret.append(val)
return tuple(ret), end_pos + 1
else:
raise ValueError("Unknown data type in DB: " + repr(v))
