def test_write_and_read(self):
buff = SlidingBuffer()
# Write and verify tell() still reports 0 and len is correct.
buff.write(TEST_BINARY_DATA)
self.assertEqual(buff.tell(), 0)
self.assertEqual(len(buff), len(TEST_BINARY_DATA))
# Read and verify tell() reports end.
self.assertEqual(buff.read(), TEST_BINARY_DATA)
self.assertEqual(buff.tell(), len(TEST_BINARY_DATA))
self.assertEqual(len(buff), len(TEST_BINARY_DATA))
def test_seek(self):
buff = SlidingBuffer()
buff.write(TEST_BINARY_DATA)
# Try to seek forward. Verify the tell() doesn't change.
with self.assertRaises(ValueError):
pos = buff.tell()
buff.seek(len(TEST_BINARY_DATA) + 1)
self.assertEqual(pos, buff.tell())
# Read 8 bytes, test seek backwards, read again, and flush.
self.assertEqual(buff.read(8), TEST_BINARY_DATA[:8])
buff.seek(0)
self.assertEqual(buff.read(8), TEST_BINARY_DATA[:8])
buff.flush()
self.assertEqual(buff.tell(), 8)
# Try to seek to a byte that has already been flushed.
with self.assertRaises(ValueError):
pos = buff.tell()
buff.seek(0)
self.assertEqual(pos, buff.tell())
def test_flush(self):
buff = SlidingBuffer()
# Write and verify tell() still reports 0 and len is correct.
buff.write(TEST_BINARY_DATA)
self.assertEqual(buff.tell(), 0)
self.assertEqual(len(buff), len(TEST_BINARY_DATA))
# Read 8 bytes and verify tell reports correctly.
self.assertEqual(buff.read(8), TEST_BINARY_DATA[:8])
self.assertEqual(buff.tell(), 8)
self.assertEqual(len(buff), len(TEST_BINARY_DATA))
# Flush buffer and verify tell doesn't change but len does.
buff.flush()
self.assertEqual(buff.tell(), 8)
self.assertEqual(len(buff), len(TEST_BINARY_DATA) - 8)
# Read remainder.
self.assertEqual(buff.read(), TEST_BINARY_DATA[8:])
self.assertEqual(buff.tell(), len(TEST_BINARY_DATA))
self.assertEqual(len(buff), len(TEST_BINARY_DATA[8:]))