Python wire_format.WIRETYPE_FIXED32属性代码示例

# 需要导入模块: from google.protobuf.internal import wire_format [as 别名]
# 或者: from google.protobuf.internal.wire_format import WIRETYPE_FIXED32 [as 别名]
def _DecodeUnknownField(buffer, pos, wire_type):
  """Decode a unknown field.  Returns the UnknownField and new position."""

  if wire_type == wire_format.WIRETYPE_VARINT:
    (data, pos) = _DecodeVarint(buffer, pos)
  elif wire_type == wire_format.WIRETYPE_FIXED64:
    (data, pos) = _DecodeFixed64(buffer, pos)
  elif wire_type == wire_format.WIRETYPE_FIXED32:
    (data, pos) = _DecodeFixed32(buffer, pos)
  elif wire_type == wire_format.WIRETYPE_LENGTH_DELIMITED:
    (size, pos) = _DecodeVarint(buffer, pos)
    data = buffer[pos:pos+size].tobytes()
    pos += size
  elif wire_type == wire_format.WIRETYPE_START_GROUP:
    (data, pos) = _DecodeUnknownFieldSet(buffer, pos)
  elif wire_type == wire_format.WIRETYPE_END_GROUP:
    return (0, -1)
  else:
    raise _DecodeError('Wrong wire type in tag.')

  return (data, pos) 

# 需要导入模块: from google.protobuf.internal import wire_format [as 别名]
# 或者: from google.protobuf.internal.wire_format import WIRETYPE_FIXED32 [as 别名]
def _FloatDecoder():
  """Returns a decoder for a float field.

  This code works around a bug in struct.unpack for non-finite 32-bit
  floating-point values.
  """

  local_unpack = struct.unpack

  def InnerDecode(buffer, pos):
    # We expect a 32-bit value in little-endian byte order.  Bit 1 is the sign
    # bit, bits 2-9 represent the exponent, and bits 10-32 are the significand.
    new_pos = pos + 4
    float_bytes = buffer[pos:new_pos]

    # If this value has all its exponent bits set, then it's non-finite.
    # In Python 2.4, struct.unpack will convert it to a finite 64-bit value.
    # To avoid that, we parse it specially.
    if (float_bytes[3:4] in b'\x7F\xFF' and float_bytes[2:3] >= b'\x80'):
      # If at least one significand bit is set...
      if float_bytes[0:3] != b'\x00\x00\x80':
        return (_NAN, new_pos)
      # If sign bit is set...
      if float_bytes[3:4] == b'\xFF':
        return (_NEG_INF, new_pos)
      return (_POS_INF, new_pos)

    # Note that we expect someone up-stack to catch struct.error and convert
    # it to _DecodeError -- this way we don't have to set up exception-
    # handling blocks every time we parse one value.
    result = local_unpack('<f', float_bytes)[0]
    return (result, new_pos)
  return _SimpleDecoder(wire_format.WIRETYPE_FIXED32, InnerDecode) 

# 需要导入模块: from google.protobuf.internal import wire_format [as 别名]
# 或者: from google.protobuf.internal.wire_format import WIRETYPE_FIXED32 [as 别名]
def _FloatDecoder():
  """Returns a decoder for a float field.

  This code works around a bug in struct.unpack for non-finite 32-bit
  floating-point values.
  """

  local_unpack = struct.unpack
  b = (lambda x:x) if _PY2 else lambda x:x.encode('latin1')  ##PY25

  def InnerDecode(buffer, pos):
    # We expect a 32-bit value in little-endian byte order.  Bit 1 is the sign
    # bit, bits 2-9 represent the exponent, and bits 10-32 are the significand.
    new_pos = pos + 4
    float_bytes = buffer[pos:new_pos]

    # If this value has all its exponent bits set, then it's non-finite.
    # In Python 2.4, struct.unpack will convert it to a finite 64-bit value.
    # To avoid that, we parse it specially.
    if ((float_bytes[3:4] in b('\x7F\xFF'))  ##PY25
##!PY25    if ((float_bytes[3:4] in b'\x7F\xFF')
        and (float_bytes[2:3] >= b('\x80'))):  ##PY25
##!PY25        and (float_bytes[2:3] >= b'\x80')):
      # If at least one significand bit is set...
      if float_bytes[0:3] != b('\x00\x00\x80'):  ##PY25
##!PY25      if float_bytes[0:3] != b'\x00\x00\x80':
        return (_NAN, new_pos)
      # If sign bit is set...
      if float_bytes[3:4] == b('\xFF'):  ##PY25
##!PY25      if float_bytes[3:4] == b'\xFF':
        return (_NEG_INF, new_pos)
      return (_POS_INF, new_pos)

    # Note that we expect someone up-stack to catch struct.error and convert
    # it to _DecodeError -- this way we don't have to set up exception-
    # handling blocks every time we parse one value.
    result = local_unpack('<f', float_bytes)[0]
    return (result, new_pos)
  return _SimpleDecoder(wire_format.WIRETYPE_FIXED32, InnerDecode) 

# 需要导入模块: from google.protobuf.internal import wire_format [as 别名]
# 或者: from google.protobuf.internal.wire_format import WIRETYPE_FIXED32 [as 别名]
def _FloatDecoder():
  """Returns a decoder for a float field.

  This code works around a bug in struct.unpack for non-finite 32-bit
  floating-point values.
  """

  local_unpack = struct.unpack

  def InnerDecode(buffer, pos):
    """Decode serialized float to a float and new position.

    Args:
      buffer: memoryview of the serialized bytes
      pos: int, position in the memory view to start at.

    Returns:
      Tuple[float, int] of the deserialized float value and new position
      in the serialized data.
    """
    # We expect a 32-bit value in little-endian byte order.  Bit 1 is the sign
    # bit, bits 2-9 represent the exponent, and bits 10-32 are the significand.
    new_pos = pos + 4
    float_bytes = buffer[pos:new_pos].tobytes()

    # If this value has all its exponent bits set, then it's non-finite.
    # In Python 2.4, struct.unpack will convert it to a finite 64-bit value.
    # To avoid that, we parse it specially.
    if (float_bytes[3:4] in b'\x7F\xFF' and float_bytes[2:3] >= b'\x80'):
      # If at least one significand bit is set...
      if float_bytes[0:3] != b'\x00\x00\x80':
        return (_NAN, new_pos)
      # If sign bit is set...
      if float_bytes[3:4] == b'\xFF':
        return (_NEG_INF, new_pos)
      return (_POS_INF, new_pos)

    # Note that we expect someone up-stack to catch struct.error and convert
    # it to _DecodeError -- this way we don't have to set up exception-
    # handling blocks every time we parse one value.
    result = local_unpack('<f', float_bytes)[0]
    return (result, new_pos)
  return _SimpleDecoder(wire_format.WIRETYPE_FIXED32, InnerDecode)