message_test.py 文件源码

def testExtremeDoubleValues(self, message_module):
    message = message_module.TestAllTypes()

    # Most positive exponent, no significand bits set.
    kMostPosExponentNoSigBits = math.pow(2, 1023)
    message.optional_double = kMostPosExponentNoSigBits
    message.ParseFromString(message.SerializeToString())
    self.assertTrue(message.optional_double == kMostPosExponentNoSigBits)

    # Most positive exponent, one significand bit set.
    kMostPosExponentOneSigBit = 1.5 * math.pow(2, 1023)
    message.optional_double = kMostPosExponentOneSigBit
    message.ParseFromString(message.SerializeToString())
    self.assertTrue(message.optional_double == kMostPosExponentOneSigBit)

    # Repeat last two cases with values of same magnitude, but negative.
    message.optional_double = -kMostPosExponentNoSigBits
    message.ParseFromString(message.SerializeToString())
    self.assertTrue(message.optional_double == -kMostPosExponentNoSigBits)

    message.optional_double = -kMostPosExponentOneSigBit
    message.ParseFromString(message.SerializeToString())
    self.assertTrue(message.optional_double == -kMostPosExponentOneSigBit)

    # Most negative exponent, no significand bits set.
    kMostNegExponentNoSigBits = math.pow(2, -1023)
    message.optional_double = kMostNegExponentNoSigBits
    message.ParseFromString(message.SerializeToString())
    self.assertTrue(message.optional_double == kMostNegExponentNoSigBits)

    # Most negative exponent, one significand bit set.
    kMostNegExponentOneSigBit = 1.5 * math.pow(2, -1023)
    message.optional_double = kMostNegExponentOneSigBit
    message.ParseFromString(message.SerializeToString())
    self.assertTrue(message.optional_double == kMostNegExponentOneSigBit)

    # Repeat last two cases with values of the same magnitude, but negative.
    message.optional_double = -kMostNegExponentNoSigBits
    message.ParseFromString(message.SerializeToString())
    self.assertTrue(message.optional_double == -kMostNegExponentNoSigBits)

    message.optional_double = -kMostNegExponentOneSigBit
    message.ParseFromString(message.SerializeToString())
    self.assertTrue(message.optional_double == -kMostNegExponentOneSigBit)