def testReadBytes(self):
s = 'abcd'
# Also test going past the total stream length.
for i in range(len(s) + 10):
stream = input_stream.InputStream(s)
self.assertEqual(s[:i], stream.ReadBytes(i))
self.assertEqual(min(i, len(s)), stream.Position())
stream = input_stream.InputStream(s)
self.assertRaises(message.DecodeError, stream.ReadBytes, -1)
def testReadVarUInt64Failure(self):
self.EnsureFailureOnEmptyStream(input_stream.InputStream.ReadVarUInt64)
# Try and fail to read something with the mythical 64th bit set.
s = '\x80\x80\x80\x80\x80\x80\x80\x80\x80\x02'
stream = input_stream.InputStream(s)
self.assertRaises(message.DecodeError, stream.ReadVarUInt64)
# Try and fail to read something that looks like
# a varint with more than 10 bytes.
s = '\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00'
stream = input_stream.InputStream(s)
self.assertRaises(message.DecodeError, stream.ReadVarUInt64)
def testReadVarUInt32Failure(self):
self.EnsureFailureOnEmptyStream(input_stream.InputStream.ReadVarUInt32)
# Try and fail to read UINT32_MAX + 1
s = '\x80\x80\x80\x80\x10'
stream = input_stream.InputStream(s)
self.assertRaises(message.DecodeError, stream.ReadVarUInt32)
# Try and fail to read something that looks like
# a varint with more than 10 bytes.
s = '\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00'
stream = input_stream.InputStream(s)
self.assertRaises(message.DecodeError, stream.ReadVarUInt32)
def EnsureFailureOnEmptyStream(self, input_stream_method):
"""Helper for integer-parsing tests below.
Ensures that the given InputStream method raises a DecodeError
if called on a stream with no bytes remaining.
"""
stream = input_stream.InputStream('')
self.assertRaises(message.DecodeError, input_stream_method, stream)
def __init__(self, s):
"""Initializes the decoder to read from s.
Args:
s: An immutable sequence of bytes, which must be accessible
via the Python buffer() primitive (i.e., buffer(s)).
"""
self._stream = input_stream.InputStream(s)
def testPosition(self):
stream = input_stream.InputStream('abcd')
self.assertEqual(0, stream.Position())
self.assertEqual(0, stream.Position()) # No side-effects.
stream.ReadBytes(1)
self.assertEqual(1, stream.Position())
stream.ReadBytes(1)
self.assertEqual(2, stream.Position())
stream.ReadBytes(10)
self.assertEqual(4, stream.Position()) # Can't go past end of stream.
def testSkipBytes(self):
stream = input_stream.InputStream('')
# Skipping bytes when at the end of stream
# should have no effect.
stream.SkipBytes(0)
stream.SkipBytes(1)
stream.SkipBytes(2)
self.assertTrue(stream.EndOfStream())
self.assertEqual(0, stream.Position())
# Try skipping within a stream.
stream = input_stream.InputStream('abcd')
self.assertEqual(0, stream.Position())
stream.SkipBytes(1)
self.assertEqual(1, stream.Position())
stream.SkipBytes(10) # Can't skip past the end.
self.assertEqual(4, stream.Position())
# Ensure that a negative skip raises an exception.
stream = input_stream.InputStream('abcd')
stream.SkipBytes(1)
self.assertRaises(message.DecodeError, stream.SkipBytes, -1)
def testGetSubBuffer(self):
stream = input_stream.InputStream('abcd')
# Try leaving out the size.
self.assertEqual('abcd', str(stream.GetSubBuffer()))
stream.SkipBytes(1)
# GetSubBuffer() always starts at current size.
self.assertEqual('bcd', str(stream.GetSubBuffer()))
# Try 0-size.
self.assertEqual('', str(stream.GetSubBuffer(0)))
# Negative sizes should raise an error.
self.assertRaises(message.DecodeError, stream.GetSubBuffer, -1)
# Positive sizes should work as expected.
self.assertEqual('b', str(stream.GetSubBuffer(1)))
self.assertEqual('bc', str(stream.GetSubBuffer(2)))
# Sizes longer than remaining bytes in the buffer should
# return the whole remaining buffer.
self.assertEqual('bcd', str(stream.GetSubBuffer(1000)))
def ReadVarintSuccessTestHelper(self, varints_and_ints, read_method):
"""Helper for tests below that test successful reads of various varints.
Args:
varints_and_ints: Iterable of (str, integer) pairs, where the string
gives the wire encoding and the integer gives the value we expect
to be returned by the read_method upon encountering this string.
read_method: Unbound InputStream method that is capable of reading
the encoded strings provided in the first elements of varints_and_ints.
"""
s = ''.join(s for s, i in varints_and_ints)
stream = input_stream.InputStream(s)
expected_pos = 0
self.assertEqual(expected_pos, stream.Position())
for s, expected_int in varints_and_ints:
self.assertEqual(expected_int, read_method(stream))
expected_pos += len(s)
self.assertEqual(expected_pos, stream.Position())
def testReadLittleEndian64(self): self.EnsureFailureOnEmptyStream(input_stream.InputStream.ReadLittleEndian64) s = '' # Read 0. s += '\x00\x00\x00\x00\x00\x00\x00\x00' # Read 1. s += '\x01\x00\x00\x00\x00\x00\x00\x00' # Read a bunch of different bytes. s += '\x01\x02\x03\x04\x05\x06\x07\x08' # Read max unsigned 64-bit int. s += '\xff\xff\xff\xff\xff\xff\xff\xff' # Try a read with fewer than 8 bytes left in the stream. s += '\x00\x00\x00' stream = input_stream.InputStream(s) self.assertEqual(0, stream.ReadLittleEndian64()) self.assertEqual(8, stream.Position()) self.assertEqual(1, stream.ReadLittleEndian64()) self.assertEqual(16, stream.Position()) self.assertEqual(0x0807060504030201, stream.ReadLittleEndian64()) self.assertEqual(24, stream.Position()) self.assertEqual(wire_format.UINT64_MAX, stream.ReadLittleEndian64()) self.assertEqual(32, stream.Position()) self.assertRaises(message.DecodeError, stream.ReadLittleEndian64)
def testEndOfStream(self):
stream = input_stream.InputStream('abcd')
self.assertFalse(stream.EndOfStream())
self.assertEqual('abcd', stream.ReadBytes(10))
self.assertTrue(stream.EndOfStream())
