1import unittest 2from test import support 3from test.support import os_helper 4 5import io # C implementation. 6import _pyio as pyio # Python implementation. 7 8# Simple test to ensure that optimizations in the IO library deliver the 9# expected results. For best testing, run this under a debug-build Python too 10# (to exercise asserts in the C code). 11 12lengths = list(range(1, 257)) + [512, 1000, 1024, 2048, 4096, 8192, 10000, 13 16384, 32768, 65536, 1000000] 14 15class BufferSizeTest: 16 def try_one(self, s): 17 # Write s + "\n" + s to file, then open it and ensure that successive 18 # .readline()s deliver what we wrote. 19 20 # Ensure we can open TESTFN for writing. 21 os_helper.unlink(os_helper.TESTFN) 22 23 # Since C doesn't guarantee we can write/read arbitrary bytes in text 24 # files, use binary mode. 25 f = self.open(os_helper.TESTFN, "wb") 26 try: 27 # write once with \n and once without 28 f.write(s) 29 f.write(b"\n") 30 f.write(s) 31 f.close() 32 f = open(os_helper.TESTFN, "rb") 33 line = f.readline() 34 self.assertEqual(line, s + b"\n") 35 line = f.readline() 36 self.assertEqual(line, s) 37 line = f.readline() 38 self.assertFalse(line) # Must be at EOF 39 f.close() 40 finally: 41 os_helper.unlink(os_helper.TESTFN) 42 43 def drive_one(self, pattern): 44 for length in lengths: 45 # Repeat string 'pattern' as often as needed to reach total length 46 # 'length'. Then call try_one with that string, a string one larger 47 # than that, and a string one smaller than that. Try this with all 48 # small sizes and various powers of 2, so we exercise all likely 49 # stdio buffer sizes, and "off by one" errors on both sides. 50 q, r = divmod(length, len(pattern)) 51 teststring = pattern * q + pattern[:r] 52 self.assertEqual(len(teststring), length) 53 self.try_one(teststring) 54 self.try_one(teststring + b"x") 55 self.try_one(teststring[:-1]) 56 57 def test_primepat(self): 58 # A pattern with prime length, to avoid simple relationships with 59 # stdio buffer sizes. 60 self.drive_one(b"1234567890\00\01\02\03\04\05\06") 61 62 def test_nullpat(self): 63 self.drive_one(b'\0' * 1000) 64 65 66class CBufferSizeTest(BufferSizeTest, unittest.TestCase): 67 open = io.open 68 69class PyBufferSizeTest(BufferSizeTest, unittest.TestCase): 70 open = staticmethod(pyio.open) 71 72 73if __name__ == "__main__": 74 unittest.main() 75