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cpython/Lib/test/test_io/test_general.py
Cody Maloney f752fde452
gh-138013: Split TextIO tests from test_io.test_general (#139173) 
gh-138013: Split TextIO tests from test_general

These tests take 1.3 seconds on my dev machine, match fairly closely
with testing `textio.c` implementation only.
2025-09-30 17:37:15 +02:00

2838 lines
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Python
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"""General tests for the io module.
New tests should go in more specific modules; see test_io/__init__.py
"""
import abc
import array
import errno
import os
import pickle
import random
import sys
import textwrap
import threading
import time
import unittest
import warnings
import weakref
from collections import deque, UserList
from itertools import cycle, count
from test import support
from test.support.script_helper import (
assert_python_ok, assert_python_failure, run_python_until_end)
from test.support import (
import_helper, is_apple, os_helper, threading_helper, warnings_helper,
)
from test.support.os_helper import FakePath
from .utils import byteslike, CTestCase, PyTestCase
import io # C implementation of io
import _pyio as pyio # Python implementation of io
class IOTest:
def setUp(self):
os_helper.unlink(os_helper.TESTFN)
def tearDown(self):
os_helper.unlink(os_helper.TESTFN)
def write_ops(self, f):
self.assertEqual(f.write(b"blah."), 5)
f.truncate(0)
self.assertEqual(f.tell(), 5)
f.seek(0)
self.assertEqual(f.write(b"blah."), 5)
self.assertEqual(f.seek(0), 0)
self.assertEqual(f.write(b"Hello."), 6)
self.assertEqual(f.tell(), 6)
self.assertEqual(f.seek(-1, 1), 5)
self.assertEqual(f.tell(), 5)
buffer = bytearray(b" world\n\n\n")
self.assertEqual(f.write(buffer), 9)
buffer[:] = b"*" * 9 # Overwrite our copy of the data
self.assertEqual(f.seek(0), 0)
self.assertEqual(f.write(b"h"), 1)
self.assertEqual(f.seek(-1, 2), 13)
self.assertEqual(f.tell(), 13)
self.assertEqual(f.truncate(12), 12)
self.assertEqual(f.tell(), 13)
self.assertRaises(TypeError, f.seek, 0.0)
def read_ops(self, f, buffered=False):
data = f.read(5)
self.assertEqual(data, b"hello")
data = byteslike(data)
self.assertEqual(f.readinto(data), 5)
self.assertEqual(bytes(data), b" worl")
data = bytearray(5)
self.assertEqual(f.readinto(data), 2)
self.assertEqual(len(data), 5)
self.assertEqual(data[:2], b"d\n")
self.assertEqual(f.seek(0), 0)
self.assertEqual(f.read(20), b"hello world\n")
self.assertEqual(f.read(1), b"")
self.assertEqual(f.readinto(byteslike(b"x")), 0)
self.assertEqual(f.seek(-6, 2), 6)
self.assertEqual(f.read(5), b"world")
self.assertEqual(f.read(0), b"")
self.assertEqual(f.readinto(byteslike()), 0)
self.assertEqual(f.seek(-6, 1), 5)
self.assertEqual(f.read(5), b" worl")
self.assertEqual(f.tell(), 10)
self.assertRaises(TypeError, f.seek, 0.0)
if buffered:
f.seek(0)
self.assertEqual(f.read(), b"hello world\n")
f.seek(6)
self.assertEqual(f.read(), b"world\n")
self.assertEqual(f.read(), b"")
f.seek(0)
data = byteslike(5)
self.assertEqual(f.readinto1(data), 5)
self.assertEqual(bytes(data), b"hello")
LARGE = 2**31
def large_file_ops(self, f):
assert f.readable()
assert f.writable()
try:
self.assertEqual(f.seek(self.LARGE), self.LARGE)
except (OverflowError, ValueError):
self.skipTest("no largefile support")
self.assertEqual(f.tell(), self.LARGE)
self.assertEqual(f.write(b"xxx"), 3)
self.assertEqual(f.tell(), self.LARGE + 3)
self.assertEqual(f.seek(-1, 1), self.LARGE + 2)
self.assertEqual(f.truncate(), self.LARGE + 2)
self.assertEqual(f.tell(), self.LARGE + 2)
self.assertEqual(f.seek(0, 2), self.LARGE + 2)
self.assertEqual(f.truncate(self.LARGE + 1), self.LARGE + 1)
self.assertEqual(f.tell(), self.LARGE + 2)
self.assertEqual(f.seek(0, 2), self.LARGE + 1)
self.assertEqual(f.seek(-1, 2), self.LARGE)
self.assertEqual(f.read(2), b"x")
def test_invalid_operations(self):
# Try writing on a file opened in read mode and vice-versa.
exc = self.UnsupportedOperation
with self.open(os_helper.TESTFN, "w", encoding="utf-8") as fp:
self.assertRaises(exc, fp.read)
self.assertRaises(exc, fp.readline)
with self.open(os_helper.TESTFN, "wb") as fp:
self.assertRaises(exc, fp.read)
self.assertRaises(exc, fp.readline)
with self.open(os_helper.TESTFN, "wb", buffering=0) as fp:
self.assertRaises(exc, fp.read)
self.assertRaises(exc, fp.readline)
with self.open(os_helper.TESTFN, "rb", buffering=0) as fp:
self.assertRaises(exc, fp.write, b"blah")
self.assertRaises(exc, fp.writelines, [b"blah\n"])
with self.open(os_helper.TESTFN, "rb") as fp:
self.assertRaises(exc, fp.write, b"blah")
self.assertRaises(exc, fp.writelines, [b"blah\n"])
with self.open(os_helper.TESTFN, "r", encoding="utf-8") as fp:
self.assertRaises(exc, fp.write, "blah")
self.assertRaises(exc, fp.writelines, ["blah\n"])
# Non-zero seeking from current or end pos
self.assertRaises(exc, fp.seek, 1, self.SEEK_CUR)
self.assertRaises(exc, fp.seek, -1, self.SEEK_END)
@support.cpython_only
def test_startup_optimization(self):
# gh-132952: Test that `io` is not imported at startup and that the
# __module__ of UnsupportedOperation is set to "io".
assert_python_ok("-S", "-c", textwrap.dedent(
"""
import sys
assert "io" not in sys.modules
try:
sys.stdin.truncate()
except Exception as e:
typ = type(e)
assert typ.__module__ == "io", (typ, typ.__module__)
assert typ.__name__ == "UnsupportedOperation", (typ, typ.__name__)
else:
raise AssertionError("Expected UnsupportedOperation")
"""
))
@unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()")
def test_optional_abilities(self):
# Test for OSError when optional APIs are not supported
# The purpose of this test is to try fileno(), reading, writing and
# seeking operations with various objects that indicate they do not
# support these operations.
def pipe_reader():
[r, w] = os.pipe()
os.close(w) # So that read() is harmless
return self.FileIO(r, "r")
def pipe_writer():
[r, w] = os.pipe()
self.addCleanup(os.close, r)
# Guarantee that we can write into the pipe without blocking
thread = threading.Thread(target=os.read, args=(r, 100))
thread.start()
self.addCleanup(thread.join)
return self.FileIO(w, "w")
def buffered_reader():
return self.BufferedReader(self.MockUnseekableIO())
def buffered_writer():
return self.BufferedWriter(self.MockUnseekableIO())
def buffered_random():
return self.BufferedRandom(self.BytesIO())
def buffered_rw_pair():
return self.BufferedRWPair(self.MockUnseekableIO(),
self.MockUnseekableIO())
def text_reader():
class UnseekableReader(self.MockUnseekableIO):
writable = self.BufferedIOBase.writable
write = self.BufferedIOBase.write
return self.TextIOWrapper(UnseekableReader(), "ascii")
def text_writer():
class UnseekableWriter(self.MockUnseekableIO):
readable = self.BufferedIOBase.readable
read = self.BufferedIOBase.read
return self.TextIOWrapper(UnseekableWriter(), "ascii")
tests = (
(pipe_reader, "fr"), (pipe_writer, "fw"),
(buffered_reader, "r"), (buffered_writer, "w"),
(buffered_random, "rws"), (buffered_rw_pair, "rw"),
(text_reader, "r"), (text_writer, "w"),
(self.BytesIO, "rws"), (self.StringIO, "rws"),
)
def do_test(test, obj, abilities):
readable = "r" in abilities
self.assertEqual(obj.readable(), readable)
writable = "w" in abilities
self.assertEqual(obj.writable(), writable)
if isinstance(obj, self.TextIOBase):
data = "3"
elif isinstance(obj, (self.BufferedIOBase, self.RawIOBase)):
data = b"3"
else:
self.fail("Unknown base class")
if "f" in abilities:
obj.fileno()
else:
self.assertRaises(OSError, obj.fileno)
if readable:
obj.read(1)
obj.read()
else:
self.assertRaises(OSError, obj.read, 1)
self.assertRaises(OSError, obj.read)
if writable:
obj.write(data)
else:
self.assertRaises(OSError, obj.write, data)
if sys.platform.startswith("win") and test in (
pipe_reader, pipe_writer):
# Pipes seem to appear as seekable on Windows
return
seekable = "s" in abilities
self.assertEqual(obj.seekable(), seekable)
if seekable:
obj.tell()
obj.seek(0)
else:
self.assertRaises(OSError, obj.tell)
self.assertRaises(OSError, obj.seek, 0)
if writable and seekable:
obj.truncate()
obj.truncate(0)
else:
self.assertRaises(OSError, obj.truncate)
self.assertRaises(OSError, obj.truncate, 0)
for [test, abilities] in tests:
with self.subTest(test):
if test == pipe_writer and not threading_helper.can_start_thread:
self.skipTest("Need threads")
with test() as obj:
do_test(test, obj, abilities)
def test_open_handles_NUL_chars(self):
fn_with_NUL = 'foo\0bar'
self.assertRaises(ValueError, self.open, fn_with_NUL, 'w', encoding="utf-8")
bytes_fn = bytes(fn_with_NUL, 'ascii')
with warnings.catch_warnings():
warnings.simplefilter("ignore", DeprecationWarning)
self.assertRaises(ValueError, self.open, bytes_fn, 'w', encoding="utf-8")
def test_raw_file_io(self):
with self.open(os_helper.TESTFN, "wb", buffering=0) as f:
self.assertEqual(f.readable(), False)
self.assertEqual(f.writable(), True)
self.assertEqual(f.seekable(), True)
self.write_ops(f)
with self.open(os_helper.TESTFN, "rb", buffering=0) as f:
self.assertEqual(f.readable(), True)
self.assertEqual(f.writable(), False)
self.assertEqual(f.seekable(), True)
self.read_ops(f)
def test_buffered_file_io(self):
with self.open(os_helper.TESTFN, "wb") as f:
self.assertEqual(f.readable(), False)
self.assertEqual(f.writable(), True)
self.assertEqual(f.seekable(), True)
self.write_ops(f)
with self.open(os_helper.TESTFN, "rb") as f:
self.assertEqual(f.readable(), True)
self.assertEqual(f.writable(), False)
self.assertEqual(f.seekable(), True)
self.read_ops(f, True)
def test_readline(self):
with self.open(os_helper.TESTFN, "wb") as f:
f.write(b"abc\ndef\nxyzzy\nfoo\x00bar\nanother line")
with self.open(os_helper.TESTFN, "rb") as f:
self.assertEqual(f.readline(), b"abc\n")
self.assertEqual(f.readline(10), b"def\n")
self.assertEqual(f.readline(2), b"xy")
self.assertEqual(f.readline(4), b"zzy\n")
self.assertEqual(f.readline(), b"foo\x00bar\n")
self.assertEqual(f.readline(None), b"another line")
self.assertRaises(TypeError, f.readline, 5.3)
with self.open(os_helper.TESTFN, "r", encoding="utf-8") as f:
self.assertRaises(TypeError, f.readline, 5.3)
def test_readline_nonsizeable(self):
# Issue #30061
# Crash when readline() returns an object without __len__
class R(self.IOBase):
def readline(self):
return None
self.assertRaises((TypeError, StopIteration), next, R())
def test_next_nonsizeable(self):
# Issue #30061
# Crash when __next__() returns an object without __len__
class R(self.IOBase):
def __next__(self):
return None
self.assertRaises(TypeError, R().readlines, 1)
def test_raw_bytes_io(self):
f = self.BytesIO()
self.write_ops(f)
data = f.getvalue()
self.assertEqual(data, b"hello world\n")
f = self.BytesIO(data)
self.read_ops(f, True)
def test_large_file_ops(self):
# On Windows and Apple platforms this test consumes large resources; It
# takes a long time to build the >2 GiB file and takes >2 GiB of disk
# space therefore the resource must be enabled to run this test.
if sys.platform[:3] == 'win' or is_apple:
support.requires(
'largefile',
'test requires %s bytes and a long time to run' % self.LARGE)
with self.open(os_helper.TESTFN, "w+b", 0) as f:
self.large_file_ops(f)
with self.open(os_helper.TESTFN, "w+b") as f:
self.large_file_ops(f)
def test_with_open(self):
for bufsize in (0, 100):
with self.open(os_helper.TESTFN, "wb", bufsize) as f:
f.write(b"xxx")
self.assertEqual(f.closed, True)
try:
with self.open(os_helper.TESTFN, "wb", bufsize) as f:
1/0
except ZeroDivisionError:
self.assertEqual(f.closed, True)
else:
self.fail("1/0 didn't raise an exception")
# issue 5008
def test_append_mode_tell(self):
with self.open(os_helper.TESTFN, "wb") as f:
f.write(b"xxx")
with self.open(os_helper.TESTFN, "ab", buffering=0) as f:
self.assertEqual(f.tell(), 3)
with self.open(os_helper.TESTFN, "ab") as f:
self.assertEqual(f.tell(), 3)
with self.open(os_helper.TESTFN, "a", encoding="utf-8") as f:
self.assertGreater(f.tell(), 0)
def test_destructor(self):
record = []
class MyFileIO(self.FileIO):
def __del__(self):
record.append(1)
try:
f = super().__del__
except AttributeError:
pass
else:
f()
def close(self):
record.append(2)
super().close()
def flush(self):
record.append(3)
super().flush()
with warnings_helper.check_warnings(('', ResourceWarning)):
f = MyFileIO(os_helper.TESTFN, "wb")
f.write(b"xxx")
del f
support.gc_collect()
self.assertEqual(record, [1, 2, 3])
with self.open(os_helper.TESTFN, "rb") as f:
self.assertEqual(f.read(), b"xxx")
def _check_base_destructor(self, base):
record = []
class MyIO(base):
def __init__(self):
# This exercises the availability of attributes on object
# destruction.
# (in the C version, close() is called by the tp_dealloc
# function, not by __del__)
self.on_del = 1
self.on_close = 2
self.on_flush = 3
def __del__(self):
record.append(self.on_del)
try:
f = super().__del__
except AttributeError:
pass
else:
f()
def close(self):
record.append(self.on_close)
super().close()
def flush(self):
record.append(self.on_flush)
super().flush()
f = MyIO()
del f
support.gc_collect()
self.assertEqual(record, [1, 2, 3])
def test_IOBase_destructor(self):
self._check_base_destructor(self.IOBase)
def test_RawIOBase_destructor(self):
self._check_base_destructor(self.RawIOBase)
def test_BufferedIOBase_destructor(self):
self._check_base_destructor(self.BufferedIOBase)
def test_TextIOBase_destructor(self):
self._check_base_destructor(self.TextIOBase)
def test_close_flushes(self):
with self.open(os_helper.TESTFN, "wb") as f:
f.write(b"xxx")
with self.open(os_helper.TESTFN, "rb") as f:
self.assertEqual(f.read(), b"xxx")
def test_array_writes(self):
a = array.array('i', range(10))
n = len(a.tobytes())
def check(f):
with f:
self.assertEqual(f.write(a), n)
f.writelines((a,))
check(self.BytesIO())
check(self.FileIO(os_helper.TESTFN, "w"))
check(self.BufferedWriter(self.MockRawIO()))
check(self.BufferedRandom(self.MockRawIO()))
check(self.BufferedRWPair(self.MockRawIO(), self.MockRawIO()))
def test_closefd(self):
self.assertRaises(ValueError, self.open, os_helper.TESTFN, 'w',
encoding="utf-8", closefd=False)
def test_read_closed(self):
with self.open(os_helper.TESTFN, "w", encoding="utf-8") as f:
f.write("egg\n")
with self.open(os_helper.TESTFN, "r", encoding="utf-8") as f:
file = self.open(f.fileno(), "r", encoding="utf-8", closefd=False)
self.assertEqual(file.read(), "egg\n")
file.seek(0)
file.close()
self.assertRaises(ValueError, file.read)
with self.open(os_helper.TESTFN, "rb") as f:
file = self.open(f.fileno(), "rb", closefd=False)
self.assertEqual(file.read()[:3], b"egg")
file.close()
self.assertRaises(ValueError, file.readinto, bytearray(1))
def test_no_closefd_with_filename(self):
# can't use closefd in combination with a file name
self.assertRaises(ValueError, self.open, os_helper.TESTFN, "r",
encoding="utf-8", closefd=False)
def test_closefd_attr(self):
with self.open(os_helper.TESTFN, "wb") as f:
f.write(b"egg\n")
with self.open(os_helper.TESTFN, "r", encoding="utf-8") as f:
self.assertEqual(f.buffer.raw.closefd, True)
file = self.open(f.fileno(), "r", encoding="utf-8", closefd=False)
self.assertEqual(file.buffer.raw.closefd, False)
def test_garbage_collection(self):
# FileIO objects are collected, and collecting them flushes
# all data to disk.
#
# Note that using warnings_helper.check_warnings() will keep the
# file alive due to the `source` argument to warn(). So, use
# catch_warnings() instead.
with warnings.catch_warnings():
warnings.simplefilter("ignore", ResourceWarning)
f = self.FileIO(os_helper.TESTFN, "wb")
f.write(b"abcxxx")
f.f = f
wr = weakref.ref(f)
del f
support.gc_collect()
self.assertIsNone(wr(), wr)
with self.open(os_helper.TESTFN, "rb") as f:
self.assertEqual(f.read(), b"abcxxx")
def test_unbounded_file(self):
# Issue #1174606: reading from an unbounded stream such as /dev/zero.
zero = "/dev/zero"
if not os.path.exists(zero):
self.skipTest("{0} does not exist".format(zero))
if sys.maxsize > 0x7FFFFFFF:
self.skipTest("test can only run in a 32-bit address space")
if support.real_max_memuse < support._2G:
self.skipTest("test requires at least 2 GiB of memory")
with self.open(zero, "rb", buffering=0) as f:
self.assertRaises(OverflowError, f.read)
with self.open(zero, "rb") as f:
self.assertRaises(OverflowError, f.read)
with self.open(zero, "r") as f:
self.assertRaises(OverflowError, f.read)
def check_flush_error_on_close(self, *args, **kwargs):
# Test that the file is closed despite failed flush
# and that flush() is called before file closed.
f = self.open(*args, **kwargs)
closed = []
def bad_flush():
closed[:] = [f.closed]
raise OSError()
f.flush = bad_flush
self.assertRaises(OSError, f.close) # exception not swallowed
self.assertTrue(f.closed)
self.assertTrue(closed) # flush() called
self.assertFalse(closed[0]) # flush() called before file closed
f.flush = lambda: None # break reference loop
def test_flush_error_on_close(self):
# raw file
# Issue #5700: io.FileIO calls flush() after file closed
self.check_flush_error_on_close(os_helper.TESTFN, 'wb', buffering=0)
fd = os.open(os_helper.TESTFN, os.O_WRONLY|os.O_CREAT)
self.check_flush_error_on_close(fd, 'wb', buffering=0)
fd = os.open(os_helper.TESTFN, os.O_WRONLY|os.O_CREAT)
self.check_flush_error_on_close(fd, 'wb', buffering=0, closefd=False)
os.close(fd)
# buffered io
self.check_flush_error_on_close(os_helper.TESTFN, 'wb')
fd = os.open(os_helper.TESTFN, os.O_WRONLY|os.O_CREAT)
self.check_flush_error_on_close(fd, 'wb')
fd = os.open(os_helper.TESTFN, os.O_WRONLY|os.O_CREAT)
self.check_flush_error_on_close(fd, 'wb', closefd=False)
os.close(fd)
# text io
self.check_flush_error_on_close(os_helper.TESTFN, 'w', encoding="utf-8")
fd = os.open(os_helper.TESTFN, os.O_WRONLY|os.O_CREAT)
self.check_flush_error_on_close(fd, 'w', encoding="utf-8")
fd = os.open(os_helper.TESTFN, os.O_WRONLY|os.O_CREAT)
self.check_flush_error_on_close(fd, 'w', encoding="utf-8", closefd=False)
os.close(fd)
def test_multi_close(self):
f = self.open(os_helper.TESTFN, "wb", buffering=0)
f.close()
f.close()
f.close()
self.assertRaises(ValueError, f.flush)
def test_RawIOBase_read(self):
# Exercise the default limited RawIOBase.read(n) implementation (which
# calls readinto() internally).
rawio = self.MockRawIOWithoutRead((b"abc", b"d", None, b"efg", None))
self.assertEqual(rawio.read(2), b"ab")
self.assertEqual(rawio.read(2), b"c")
self.assertEqual(rawio.read(2), b"d")
self.assertEqual(rawio.read(2), None)
self.assertEqual(rawio.read(2), b"ef")
self.assertEqual(rawio.read(2), b"g")
self.assertEqual(rawio.read(2), None)
self.assertEqual(rawio.read(2), b"")
def test_types_have_dict(self):
test = (
self.IOBase(),
self.RawIOBase(),
self.TextIOBase(),
self.StringIO(),
self.BytesIO()
)
for obj in test:
self.assertHasAttr(obj, "__dict__")
def test_opener(self):
with self.open(os_helper.TESTFN, "w", encoding="utf-8") as f:
f.write("egg\n")
fd = os.open(os_helper.TESTFN, os.O_RDONLY)
def opener(path, flags):
return fd
with self.open("non-existent", "r", encoding="utf-8", opener=opener) as f:
self.assertEqual(f.read(), "egg\n")
def test_bad_opener_negative_1(self):
# Issue #27066.
def badopener(fname, flags):
return -1
with self.assertRaises(ValueError) as cm:
self.open('non-existent', 'r', opener=badopener)
self.assertEqual(str(cm.exception), 'opener returned -1')
def test_bad_opener_other_negative(self):
# Issue #27066.
def badopener(fname, flags):
return -2
with self.assertRaises(ValueError) as cm:
self.open('non-existent', 'r', opener=badopener)
self.assertEqual(str(cm.exception), 'opener returned -2')
def test_opener_invalid_fd(self):
# Check that OSError is raised with error code EBADF if the
# opener returns an invalid file descriptor (see gh-82212).
fd = os_helper.make_bad_fd()
with self.assertRaises(OSError) as cm:
self.open('foo', opener=lambda name, flags: fd)
self.assertEqual(cm.exception.errno, errno.EBADF)
def test_fileio_closefd(self):
# Issue #4841
with self.open(__file__, 'rb') as f1, \
self.open(__file__, 'rb') as f2:
fileio = self.FileIO(f1.fileno(), closefd=False)
# .__init__() must not close f1
fileio.__init__(f2.fileno(), closefd=False)
f1.readline()
# .close() must not close f2
fileio.close()
f2.readline()
def test_nonbuffered_textio(self):
with warnings_helper.check_no_resource_warning(self):
with self.assertRaises(ValueError):
self.open(os_helper.TESTFN, 'w', encoding="utf-8", buffering=0)
def test_invalid_newline(self):
with warnings_helper.check_no_resource_warning(self):
with self.assertRaises(ValueError):
self.open(os_helper.TESTFN, 'w', encoding="utf-8", newline='invalid')
def test_buffered_readinto_mixin(self):
# Test the implementation provided by BufferedIOBase
class Stream(self.BufferedIOBase):
def read(self, size):
return b"12345"
read1 = read
stream = Stream()
for method in ("readinto", "readinto1"):
with self.subTest(method):
buffer = byteslike(5)
self.assertEqual(getattr(stream, method)(buffer), 5)
self.assertEqual(bytes(buffer), b"12345")
def test_fspath_support(self):
def check_path_succeeds(path):
with self.open(path, "w", encoding="utf-8") as f:
f.write("egg\n")
with self.open(path, "r", encoding="utf-8") as f:
self.assertEqual(f.read(), "egg\n")
check_path_succeeds(FakePath(os_helper.TESTFN))
check_path_succeeds(FakePath(os.fsencode(os_helper.TESTFN)))
with self.open(os_helper.TESTFN, "w", encoding="utf-8") as f:
bad_path = FakePath(f.fileno())
with self.assertRaises(TypeError):
self.open(bad_path, 'w', encoding="utf-8")
bad_path = FakePath(None)
with self.assertRaises(TypeError):
self.open(bad_path, 'w', encoding="utf-8")
bad_path = FakePath(FloatingPointError)
with self.assertRaises(FloatingPointError):
self.open(bad_path, 'w', encoding="utf-8")
# ensure that refcounting is correct with some error conditions
with self.assertRaisesRegex(ValueError, 'read/write/append mode'):
self.open(FakePath(os_helper.TESTFN), 'rwxa', encoding="utf-8")
def test_RawIOBase_readall(self):
# Exercise the default unlimited RawIOBase.read() and readall()
# implementations.
rawio = self.MockRawIOWithoutRead((b"abc", b"d", b"efg"))
self.assertEqual(rawio.read(), b"abcdefg")
rawio = self.MockRawIOWithoutRead((b"abc", b"d", b"efg"))
self.assertEqual(rawio.readall(), b"abcdefg")
def test_BufferedIOBase_readinto(self):
# Exercise the default BufferedIOBase.readinto() and readinto1()
# implementations (which call read() or read1() internally).
class Reader(self.BufferedIOBase):
def __init__(self, avail):
self.avail = avail
def read(self, size):
result = self.avail[:size]
self.avail = self.avail[size:]
return result
def read1(self, size):
"""Returns no more than 5 bytes at once"""
return self.read(min(size, 5))
tests = (
# (test method, total data available, read buffer size, expected
# read size)
("readinto", 10, 5, 5),
("readinto", 10, 6, 6), # More than read1() can return
("readinto", 5, 6, 5), # Buffer larger than total available
("readinto", 6, 7, 6),
("readinto", 10, 0, 0), # Empty buffer
("readinto1", 10, 5, 5), # Result limited to single read1() call
("readinto1", 10, 6, 5), # Buffer larger than read1() can return
("readinto1", 5, 6, 5), # Buffer larger than total available
("readinto1", 6, 7, 5),
("readinto1", 10, 0, 0), # Empty buffer
)
UNUSED_BYTE = 0x81
for test in tests:
with self.subTest(test):
method, avail, request, result = test
reader = Reader(bytes(range(avail)))
buffer = bytearray((UNUSED_BYTE,) * request)
method = getattr(reader, method)
self.assertEqual(method(buffer), result)
self.assertEqual(len(buffer), request)
self.assertSequenceEqual(buffer[:result], range(result))
unused = (UNUSED_BYTE,) * (request - result)
self.assertSequenceEqual(buffer[result:], unused)
self.assertEqual(len(reader.avail), avail - result)
def test_close_assert(self):
class R(self.IOBase):
def __setattr__(self, name, value):
pass
def flush(self):
raise OSError()
f = R()
# This would cause an assertion failure.
self.assertRaises(OSError, f.close)
# Silence destructor error
R.flush = lambda self: None
@threading_helper.requires_working_threading()
def test_write_readline_races(self):
# gh-134908: Concurrent iteration over a file caused races
thread_count = 2
write_count = 100
read_count = 100
def writer(file, barrier):
barrier.wait()
for _ in range(write_count):
file.write("x")
def reader(file, barrier):
barrier.wait()
for _ in range(read_count):
for line in file:
self.assertEqual(line, "")
with self.open(os_helper.TESTFN, "w+") as f:
barrier = threading.Barrier(thread_count + 1)
reader = threading.Thread(target=reader, args=(f, barrier))
writers = [threading.Thread(target=writer, args=(f, barrier))
for _ in range(thread_count)]
with threading_helper.catch_threading_exception() as cm:
with threading_helper.start_threads(writers + [reader]):
pass
self.assertIsNone(cm.exc_type)
self.assertEqual(os.stat(os_helper.TESTFN).st_size,
write_count * thread_count)
class CIOTest(IOTest, CTestCase):
def test_IOBase_finalize(self):
# Issue #12149: segmentation fault on _PyIOBase_finalize when both a
# class which inherits IOBase and an object of this class are caught
# in a reference cycle and close() is already in the method cache.
class MyIO(self.IOBase):
def close(self):
pass
# create an instance to populate the method cache
MyIO()
obj = MyIO()
obj.obj = obj
wr = weakref.ref(obj)
del MyIO
del obj
support.gc_collect()
self.assertIsNone(wr(), wr)
@support.cpython_only
class TestIOCTypes(unittest.TestCase):
def setUp(self):
_io = import_helper.import_module("_io")
self.types = [
_io.BufferedRWPair,
_io.BufferedRandom,
_io.BufferedReader,
_io.BufferedWriter,
_io.BytesIO,
_io.FileIO,
_io.IncrementalNewlineDecoder,
_io.StringIO,
_io.TextIOWrapper,
_io._BufferedIOBase,
_io._BytesIOBuffer,
_io._IOBase,
_io._RawIOBase,
_io._TextIOBase,
]
if sys.platform == "win32":
self.types.append(_io._WindowsConsoleIO)
self._io = _io
def test_immutable_types(self):
for tp in self.types:
with self.subTest(tp=tp):
with self.assertRaisesRegex(TypeError, "immutable"):
tp.foo = "bar"
def test_class_hierarchy(self):
def check_subs(types, base):
for tp in types:
with self.subTest(tp=tp, base=base):
self.assertIsSubclass(tp, base)
def recursive_check(d):
for k, v in d.items():
if isinstance(v, dict):
recursive_check(v)
elif isinstance(v, set):
check_subs(v, k)
else:
self.fail("corrupt test dataset")
_io = self._io
hierarchy = {
_io._IOBase: {
_io._BufferedIOBase: {
_io.BufferedRWPair,
_io.BufferedRandom,
_io.BufferedReader,
_io.BufferedWriter,
_io.BytesIO,
},
_io._RawIOBase: {
_io.FileIO,
},
_io._TextIOBase: {
_io.StringIO,
_io.TextIOWrapper,
},
},
}
if sys.platform == "win32":
hierarchy[_io._IOBase][_io._RawIOBase].add(_io._WindowsConsoleIO)
recursive_check(hierarchy)
def test_subclassing(self):
_io = self._io
dataset = {k: True for k in self.types}
dataset[_io._BytesIOBuffer] = False
for tp, is_basetype in dataset.items():
with self.subTest(tp=tp, is_basetype=is_basetype):
name = f"{tp.__name__}_subclass"
bases = (tp,)
if is_basetype:
_ = type(name, bases, {})
else:
msg = "not an acceptable base type"
with self.assertRaisesRegex(TypeError, msg):
_ = type(name, bases, {})
def test_disallow_instantiation(self):
_io = self._io
support.check_disallow_instantiation(self, _io._BytesIOBuffer)
def test_stringio_setstate(self):
# gh-127182: Calling __setstate__() with invalid arguments must not crash
obj = self._io.StringIO()
with self.assertRaisesRegex(
TypeError,
'initial_value must be str or None, not int',
):
obj.__setstate__((1, '', 0, {}))
obj.__setstate__((None, '', 0, {})) # should not crash
self.assertEqual(obj.getvalue(), '')
obj.__setstate__(('', '', 0, {}))
self.assertEqual(obj.getvalue(), '')
class PyIOTest(IOTest, PyTestCase):
pass
@support.cpython_only
class APIMismatchTest(unittest.TestCase):
def test_RawIOBase_io_in_pyio_match(self):
"""Test that pyio RawIOBase class has all c RawIOBase methods"""
mismatch = support.detect_api_mismatch(pyio.RawIOBase, io.RawIOBase,
ignore=('__weakref__', '__static_attributes__'))
self.assertEqual(mismatch, set(), msg='Python RawIOBase does not have all C RawIOBase methods')
def test_RawIOBase_pyio_in_io_match(self):
"""Test that c RawIOBase class has all pyio RawIOBase methods"""
mismatch = support.detect_api_mismatch(io.RawIOBase, pyio.RawIOBase)
self.assertEqual(mismatch, set(), msg='C RawIOBase does not have all Python RawIOBase methods')
class CommonBufferedTests:
# Tests common to BufferedReader, BufferedWriter and BufferedRandom
def test_detach(self):
raw = self.MockRawIO()
buf = self.tp(raw)
self.assertIs(buf.detach(), raw)
self.assertRaises(ValueError, buf.detach)
repr(buf) # Should still work
def test_fileno(self):
rawio = self.MockRawIO()
bufio = self.tp(rawio)
self.assertEqual(42, bufio.fileno())
def test_invalid_args(self):
rawio = self.MockRawIO()
bufio = self.tp(rawio)
# Invalid whence
self.assertRaises(ValueError, bufio.seek, 0, -1)
self.assertRaises(ValueError, bufio.seek, 0, 9)
def test_override_destructor(self):
tp = self.tp
record = []
class MyBufferedIO(tp):
def __del__(self):
record.append(1)
try:
f = super().__del__
except AttributeError:
pass
else:
f()
def close(self):
record.append(2)
super().close()
def flush(self):
record.append(3)
super().flush()
rawio = self.MockRawIO()
bufio = MyBufferedIO(rawio)
del bufio
support.gc_collect()
self.assertEqual(record, [1, 2, 3])
def test_context_manager(self):
# Test usability as a context manager
rawio = self.MockRawIO()
bufio = self.tp(rawio)
def _with():
with bufio:
pass
_with()
# bufio should now be closed, and using it a second time should raise
# a ValueError.
self.assertRaises(ValueError, _with)
def test_error_through_destructor(self):
# Test that the exception state is not modified by a destructor,
# even if close() fails.
rawio = self.CloseFailureIO()
with support.catch_unraisable_exception() as cm:
with self.assertRaises(AttributeError):
self.tp(rawio).xyzzy
self.assertEqual(cm.unraisable.exc_type, OSError)
def test_repr(self):
raw = self.MockRawIO()
b = self.tp(raw)
clsname = r"(%s\.)?%s" % (self.tp.__module__, self.tp.__qualname__)
self.assertRegex(repr(b), "<%s>" % clsname)
raw.name = "dummy"
self.assertRegex(repr(b), "<%s name='dummy'>" % clsname)
raw.name = b"dummy"
self.assertRegex(repr(b), "<%s name=b'dummy'>" % clsname)
def test_recursive_repr(self):
# Issue #25455
raw = self.MockRawIO()
b = self.tp(raw)
with support.swap_attr(raw, 'name', b), support.infinite_recursion(25):
with self.assertRaises(RuntimeError):
repr(b) # Should not crash
def test_flush_error_on_close(self):
# Test that buffered file is closed despite failed flush
# and that flush() is called before file closed.
raw = self.MockRawIO()
closed = []
def bad_flush():
closed[:] = [b.closed, raw.closed]
raise OSError()
raw.flush = bad_flush
b = self.tp(raw)
self.assertRaises(OSError, b.close) # exception not swallowed
self.assertTrue(b.closed)
self.assertTrue(raw.closed)
self.assertTrue(closed) # flush() called
self.assertFalse(closed[0]) # flush() called before file closed
self.assertFalse(closed[1])
raw.flush = lambda: None # break reference loop
def test_close_error_on_close(self):
raw = self.MockRawIO()
def bad_flush():
raise OSError('flush')
def bad_close():
raise OSError('close')
raw.close = bad_close
b = self.tp(raw)
b.flush = bad_flush
with self.assertRaises(OSError) as err: # exception not swallowed
b.close()
self.assertEqual(err.exception.args, ('close',))
self.assertIsInstance(err.exception.__context__, OSError)
self.assertEqual(err.exception.__context__.args, ('flush',))
self.assertFalse(b.closed)
# Silence destructor error
raw.close = lambda: None
b.flush = lambda: None
def test_nonnormalized_close_error_on_close(self):
# Issue #21677
raw = self.MockRawIO()
def bad_flush():
raise non_existing_flush
def bad_close():
raise non_existing_close
raw.close = bad_close
b = self.tp(raw)
b.flush = bad_flush
with self.assertRaises(NameError) as err: # exception not swallowed
b.close()
self.assertIn('non_existing_close', str(err.exception))
self.assertIsInstance(err.exception.__context__, NameError)
self.assertIn('non_existing_flush', str(err.exception.__context__))
self.assertFalse(b.closed)
# Silence destructor error
b.flush = lambda: None
raw.close = lambda: None
def test_multi_close(self):
raw = self.MockRawIO()
b = self.tp(raw)
b.close()
b.close()
b.close()
self.assertRaises(ValueError, b.flush)
def test_unseekable(self):
bufio = self.tp(self.MockUnseekableIO(b"A" * 10))
self.assertRaises(self.UnsupportedOperation, bufio.tell)
self.assertRaises(self.UnsupportedOperation, bufio.seek, 0)
def test_readonly_attributes(self):
raw = self.MockRawIO()
buf = self.tp(raw)
x = self.MockRawIO()
with self.assertRaises(AttributeError):
buf.raw = x
def test_pickling_subclass(self):
global MyBufferedIO
class MyBufferedIO(self.tp):
def __init__(self, raw, tag):
super().__init__(raw)
self.tag = tag
def __getstate__(self):
return self.tag, self.raw.getvalue()
def __setstate__(slf, state):
tag, value = state
slf.__init__(self.BytesIO(value), tag)
raw = self.BytesIO(b'data')
buf = MyBufferedIO(raw, tag='ham')
for proto in range(pickle.HIGHEST_PROTOCOL + 1):
with self.subTest(protocol=proto):
pickled = pickle.dumps(buf, proto)
newbuf = pickle.loads(pickled)
self.assertEqual(newbuf.raw.getvalue(), b'data')
self.assertEqual(newbuf.tag, 'ham')
del MyBufferedIO
class SizeofTest:
@support.cpython_only
def test_sizeof(self):
bufsize1 = 4096
bufsize2 = 8192
rawio = self.MockRawIO()
bufio = self.tp(rawio, buffer_size=bufsize1)
size = sys.getsizeof(bufio) - bufsize1
rawio = self.MockRawIO()
bufio = self.tp(rawio, buffer_size=bufsize2)
self.assertEqual(sys.getsizeof(bufio), size + bufsize2)
@support.cpython_only
def test_buffer_freeing(self) :
bufsize = 4096
rawio = self.MockRawIO()
bufio = self.tp(rawio, buffer_size=bufsize)
size = sys.getsizeof(bufio) - bufsize
bufio.close()
self.assertEqual(sys.getsizeof(bufio), size)
class BufferedReaderTest(CommonBufferedTests):
read_mode = "rb"
def test_constructor(self):
rawio = self.MockRawIO([b"abc"])
bufio = self.tp(rawio)
bufio.__init__(rawio)
bufio.__init__(rawio, buffer_size=1024)
bufio.__init__(rawio, buffer_size=16)
self.assertEqual(b"abc", bufio.read())
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=0)
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=-16)
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=-1)
rawio = self.MockRawIO([b"abc"])
bufio.__init__(rawio)
self.assertEqual(b"abc", bufio.read())
def test_uninitialized(self):
bufio = self.tp.__new__(self.tp)
del bufio
bufio = self.tp.__new__(self.tp)
self.assertRaisesRegex((ValueError, AttributeError),
'uninitialized|has no attribute',
bufio.read, 0)
bufio.__init__(self.MockRawIO())
self.assertEqual(bufio.read(0), b'')
def test_read(self):
for arg in (None, 7):
rawio = self.MockRawIO((b"abc", b"d", b"efg"))
bufio = self.tp(rawio)
self.assertEqual(b"abcdefg", bufio.read(arg))
# Invalid args
self.assertRaises(ValueError, bufio.read, -2)
def test_read1(self):
rawio = self.MockRawIO((b"abc", b"d", b"efg"))
bufio = self.tp(rawio)
self.assertEqual(b"a", bufio.read(1))
self.assertEqual(b"b", bufio.read1(1))
self.assertEqual(rawio._reads, 1)
self.assertEqual(b"", bufio.read1(0))
self.assertEqual(b"c", bufio.read1(100))
self.assertEqual(rawio._reads, 1)
self.assertEqual(b"d", bufio.read1(100))
self.assertEqual(rawio._reads, 2)
self.assertEqual(b"efg", bufio.read1(100))
self.assertEqual(rawio._reads, 3)
self.assertEqual(b"", bufio.read1(100))
self.assertEqual(rawio._reads, 4)
def test_read1_arbitrary(self):
rawio = self.MockRawIO((b"abc", b"d", b"efg"))
bufio = self.tp(rawio)
self.assertEqual(b"a", bufio.read(1))
self.assertEqual(b"bc", bufio.read1())
self.assertEqual(b"d", bufio.read1())
self.assertEqual(b"efg", bufio.read1(-1))
self.assertEqual(rawio._reads, 3)
self.assertEqual(b"", bufio.read1())
self.assertEqual(rawio._reads, 4)
def test_readinto(self):
rawio = self.MockRawIO((b"abc", b"d", b"efg"))
bufio = self.tp(rawio)
b = bytearray(2)
self.assertEqual(bufio.readinto(b), 2)
self.assertEqual(b, b"ab")
self.assertEqual(bufio.readinto(b), 2)
self.assertEqual(b, b"cd")
self.assertEqual(bufio.readinto(b), 2)
self.assertEqual(b, b"ef")
self.assertEqual(bufio.readinto(b), 1)
self.assertEqual(b, b"gf")
self.assertEqual(bufio.readinto(b), 0)
self.assertEqual(b, b"gf")
rawio = self.MockRawIO((b"abc", None))
bufio = self.tp(rawio)
self.assertEqual(bufio.readinto(b), 2)
self.assertEqual(b, b"ab")
self.assertEqual(bufio.readinto(b), 1)
self.assertEqual(b, b"cb")
def test_readinto1(self):
buffer_size = 10
rawio = self.MockRawIO((b"abc", b"de", b"fgh", b"jkl"))
bufio = self.tp(rawio, buffer_size=buffer_size)
b = bytearray(2)
self.assertEqual(bufio.peek(3), b'abc')
self.assertEqual(rawio._reads, 1)
self.assertEqual(bufio.readinto1(b), 2)
self.assertEqual(b, b"ab")
self.assertEqual(rawio._reads, 1)
self.assertEqual(bufio.readinto1(b), 1)
self.assertEqual(b[:1], b"c")
self.assertEqual(rawio._reads, 1)
self.assertEqual(bufio.readinto1(b), 2)
self.assertEqual(b, b"de")
self.assertEqual(rawio._reads, 2)
b = bytearray(2*buffer_size)
self.assertEqual(bufio.peek(3), b'fgh')
self.assertEqual(rawio._reads, 3)
self.assertEqual(bufio.readinto1(b), 6)
self.assertEqual(b[:6], b"fghjkl")
self.assertEqual(rawio._reads, 4)
def test_readinto_array(self):
buffer_size = 60
data = b"a" * 26
rawio = self.MockRawIO((data,))
bufio = self.tp(rawio, buffer_size=buffer_size)
# Create an array with element size > 1 byte
b = array.array('i', b'x' * 32)
assert len(b) != 16
# Read into it. We should get as many *bytes* as we can fit into b
# (which is more than the number of elements)
n = bufio.readinto(b)
self.assertGreater(n, len(b))
# Check that old contents of b are preserved
bm = memoryview(b).cast('B')
self.assertLess(n, len(bm))
self.assertEqual(bm[:n], data[:n])
self.assertEqual(bm[n:], b'x' * (len(bm[n:])))
def test_readinto1_array(self):
buffer_size = 60
data = b"a" * 26
rawio = self.MockRawIO((data,))
bufio = self.tp(rawio, buffer_size=buffer_size)
# Create an array with element size > 1 byte
b = array.array('i', b'x' * 32)
assert len(b) != 16
# Read into it. We should get as many *bytes* as we can fit into b
# (which is more than the number of elements)
n = bufio.readinto1(b)
self.assertGreater(n, len(b))
# Check that old contents of b are preserved
bm = memoryview(b).cast('B')
self.assertLess(n, len(bm))
self.assertEqual(bm[:n], data[:n])
self.assertEqual(bm[n:], b'x' * (len(bm[n:])))
def test_readlines(self):
def bufio():
rawio = self.MockRawIO((b"abc\n", b"d\n", b"ef"))
return self.tp(rawio)
self.assertEqual(bufio().readlines(), [b"abc\n", b"d\n", b"ef"])
self.assertEqual(bufio().readlines(5), [b"abc\n", b"d\n"])
self.assertEqual(bufio().readlines(None), [b"abc\n", b"d\n", b"ef"])
def test_buffering(self):
data = b"abcdefghi"
dlen = len(data)
tests = [
[ 100, [ 3, 1, 4, 8 ], [ dlen, 0 ] ],
[ 100, [ 3, 3, 3], [ dlen ] ],
[ 4, [ 1, 2, 4, 2 ], [ 4, 4, 1 ] ],
]
for bufsize, buf_read_sizes, raw_read_sizes in tests:
rawio = self.MockFileIO(data)
bufio = self.tp(rawio, buffer_size=bufsize)
pos = 0
for nbytes in buf_read_sizes:
self.assertEqual(bufio.read(nbytes), data[pos:pos+nbytes])
pos += nbytes
# this is mildly implementation-dependent
self.assertEqual(rawio.read_history, raw_read_sizes)
def test_read_non_blocking(self):
# Inject some None's in there to simulate EWOULDBLOCK
rawio = self.MockRawIO((b"abc", b"d", None, b"efg", None, None, None))
bufio = self.tp(rawio)
self.assertEqual(b"abcd", bufio.read(6))
self.assertEqual(b"e", bufio.read(1))
self.assertEqual(b"fg", bufio.read())
self.assertEqual(b"", bufio.peek(1))
self.assertIsNone(bufio.read())
self.assertEqual(b"", bufio.read())
rawio = self.MockRawIO((b"a", None, None))
self.assertEqual(b"a", rawio.readall())
self.assertIsNone(rawio.readall())
def test_read_past_eof(self):
rawio = self.MockRawIO((b"abc", b"d", b"efg"))
bufio = self.tp(rawio)
self.assertEqual(b"abcdefg", bufio.read(9000))
def test_read_all(self):
rawio = self.MockRawIO((b"abc", b"d", b"efg"))
bufio = self.tp(rawio)
self.assertEqual(b"abcdefg", bufio.read())
@threading_helper.requires_working_threading()
@support.requires_resource('cpu')
def test_threads(self):
try:
# Write out many bytes with exactly the same number of 0's,
# 1's... 255's. This will help us check that concurrent reading
# doesn't duplicate or forget contents.
N = 1000
l = list(range(256)) * N
random.shuffle(l)
s = bytes(bytearray(l))
with self.open(os_helper.TESTFN, "wb") as f:
f.write(s)
with self.open(os_helper.TESTFN, self.read_mode, buffering=0) as raw:
bufio = self.tp(raw, 8)
errors = []
results = []
def f():
try:
# Intra-buffer read then buffer-flushing read
for n in cycle([1, 19]):
s = bufio.read(n)
if not s:
break
# list.append() is atomic
results.append(s)
except Exception as e:
errors.append(e)
raise
threads = [threading.Thread(target=f) for x in range(20)]
with threading_helper.start_threads(threads):
time.sleep(0.02) # yield
self.assertFalse(errors,
"the following exceptions were caught: %r" % errors)
s = b''.join(results)
for i in range(256):
c = bytes(bytearray([i]))
self.assertEqual(s.count(c), N)
finally:
os_helper.unlink(os_helper.TESTFN)
def test_unseekable(self):
bufio = self.tp(self.MockUnseekableIO(b"A" * 10))
self.assertRaises(self.UnsupportedOperation, bufio.tell)
self.assertRaises(self.UnsupportedOperation, bufio.seek, 0)
bufio.read(1)
self.assertRaises(self.UnsupportedOperation, bufio.seek, 0)
self.assertRaises(self.UnsupportedOperation, bufio.tell)
def test_misbehaved_io(self):
rawio = self.MisbehavedRawIO((b"abc", b"d", b"efg"))
bufio = self.tp(rawio)
self.assertRaises(OSError, bufio.seek, 0)
self.assertRaises(OSError, bufio.tell)
# Silence destructor error
bufio.close = lambda: None
def test_no_extraneous_read(self):
# Issue #9550; when the raw IO object has satisfied the read request,
# we should not issue any additional reads, otherwise it may block
# (e.g. socket).
bufsize = 16
for n in (2, bufsize - 1, bufsize, bufsize + 1, bufsize * 2):
rawio = self.MockRawIO([b"x" * n])
bufio = self.tp(rawio, bufsize)
self.assertEqual(bufio.read(n), b"x" * n)
# Simple case: one raw read is enough to satisfy the request.
self.assertEqual(rawio._extraneous_reads, 0,
"failed for {}: {} != 0".format(n, rawio._extraneous_reads))
# A more complex case where two raw reads are needed to satisfy
# the request.
rawio = self.MockRawIO([b"x" * (n - 1), b"x"])
bufio = self.tp(rawio, bufsize)
self.assertEqual(bufio.read(n), b"x" * n)
self.assertEqual(rawio._extraneous_reads, 0,
"failed for {}: {} != 0".format(n, rawio._extraneous_reads))
def test_read_on_closed(self):
# Issue #23796
b = self.BufferedReader(self.BytesIO(b"12"))
b.read(1)
b.close()
with self.subTest('peek'):
self.assertRaises(ValueError, b.peek)
with self.subTest('read1'):
self.assertRaises(ValueError, b.read1, 1)
with self.subTest('read'):
self.assertRaises(ValueError, b.read)
with self.subTest('readinto'):
self.assertRaises(ValueError, b.readinto, bytearray())
with self.subTest('readinto1'):
self.assertRaises(ValueError, b.readinto1, bytearray())
with self.subTest('flush'):
self.assertRaises(ValueError, b.flush)
with self.subTest('truncate'):
self.assertRaises(ValueError, b.truncate)
with self.subTest('seek'):
self.assertRaises(ValueError, b.seek, 0)
def test_truncate_on_read_only(self):
rawio = self.MockFileIO(b"abc")
bufio = self.tp(rawio)
self.assertFalse(bufio.writable())
self.assertRaises(self.UnsupportedOperation, bufio.truncate)
self.assertRaises(self.UnsupportedOperation, bufio.truncate, 0)
def test_tell_character_device_file(self):
# GH-95782
# For the (former) bug in BufferedIO to manifest, the wrapped IO obj
# must be able to produce at least 2 bytes.
raw = self.MockCharPseudoDevFileIO(b"12")
buf = self.tp(raw)
self.assertEqual(buf.tell(), 0)
self.assertEqual(buf.read(1), b"1")
self.assertEqual(buf.tell(), 0)
def test_seek_character_device_file(self):
raw = self.MockCharPseudoDevFileIO(b"12")
buf = self.tp(raw)
self.assertEqual(buf.seek(0, io.SEEK_CUR), 0)
self.assertEqual(buf.seek(1, io.SEEK_SET), 0)
self.assertEqual(buf.seek(0, io.SEEK_CUR), 0)
self.assertEqual(buf.read(1), b"1")
# In the C implementation, tell() sets the BufferedIO's abs_pos to 0,
# which means that the next seek() could return a negative offset if it
# does not sanity-check:
self.assertEqual(buf.tell(), 0)
self.assertEqual(buf.seek(0, io.SEEK_CUR), 0)
class CBufferedReaderTest(BufferedReaderTest, SizeofTest, CTestCase):
tp = io.BufferedReader
def test_initialization(self):
rawio = self.MockRawIO([b"abc"])
bufio = self.tp(rawio)
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=0)
self.assertRaises(ValueError, bufio.read)
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=-16)
self.assertRaises(ValueError, bufio.read)
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=-1)
self.assertRaises(ValueError, bufio.read)
def test_misbehaved_io_read(self):
rawio = self.MisbehavedRawIO((b"abc", b"d", b"efg"))
bufio = self.tp(rawio)
# _pyio.BufferedReader seems to implement reading different, so that
# checking this is not so easy.
self.assertRaises(OSError, bufio.read, 10)
def test_garbage_collection(self):
# C BufferedReader objects are collected.
# The Python version has __del__, so it ends into gc.garbage instead
self.addCleanup(os_helper.unlink, os_helper.TESTFN)
# Note that using warnings_helper.check_warnings() will keep the
# file alive due to the `source` argument to warn(). So, use
# catch_warnings() instead.
with warnings.catch_warnings():
warnings.simplefilter("ignore", ResourceWarning)
rawio = self.FileIO(os_helper.TESTFN, "w+b")
f = self.tp(rawio)
f.f = f
wr = weakref.ref(f)
del f
support.gc_collect()
self.assertIsNone(wr(), wr)
def test_args_error(self):
# Issue #17275
with self.assertRaisesRegex(TypeError, "BufferedReader"):
self.tp(self.BytesIO(), 1024, 1024, 1024)
def test_bad_readinto_value(self):
rawio = self.tp(self.BytesIO(b"12"))
rawio.readinto = lambda buf: -1
bufio = self.tp(rawio)
with self.assertRaises(OSError) as cm:
bufio.readline()
self.assertIsNone(cm.exception.__cause__)
def test_bad_readinto_type(self):
rawio = self.tp(self.BytesIO(b"12"))
rawio.readinto = lambda buf: b''
bufio = self.tp(rawio)
with self.assertRaises(OSError) as cm:
bufio.readline()
self.assertIsInstance(cm.exception.__cause__, TypeError)
class PyBufferedReaderTest(BufferedReaderTest, PyTestCase):
tp = pyio.BufferedReader
class BufferedWriterTest(CommonBufferedTests):
write_mode = "wb"
def test_constructor(self):
rawio = self.MockRawIO()
bufio = self.tp(rawio)
bufio.__init__(rawio)
bufio.__init__(rawio, buffer_size=1024)
bufio.__init__(rawio, buffer_size=16)
self.assertEqual(3, bufio.write(b"abc"))
bufio.flush()
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=0)
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=-16)
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=-1)
bufio.__init__(rawio)
self.assertEqual(3, bufio.write(b"ghi"))
bufio.flush()
self.assertEqual(b"".join(rawio._write_stack), b"abcghi")
def test_uninitialized(self):
bufio = self.tp.__new__(self.tp)
del bufio
bufio = self.tp.__new__(self.tp)
self.assertRaisesRegex((ValueError, AttributeError),
'uninitialized|has no attribute',
bufio.write, b'')
bufio.__init__(self.MockRawIO())
self.assertEqual(bufio.write(b''), 0)
def test_detach_flush(self):
raw = self.MockRawIO()
buf = self.tp(raw)
buf.write(b"howdy!")
self.assertFalse(raw._write_stack)
buf.detach()
self.assertEqual(raw._write_stack, [b"howdy!"])
def test_write(self):
# Write to the buffered IO but don't overflow the buffer.
writer = self.MockRawIO()
bufio = self.tp(writer, 8)
bufio.write(b"abc")
self.assertFalse(writer._write_stack)
buffer = bytearray(b"def")
bufio.write(buffer)
buffer[:] = b"***" # Overwrite our copy of the data
bufio.flush()
self.assertEqual(b"".join(writer._write_stack), b"abcdef")
def test_write_overflow(self):
writer = self.MockRawIO()
bufio = self.tp(writer, 8)
contents = b"abcdefghijklmnop"
for n in range(0, len(contents), 3):
bufio.write(contents[n:n+3])
flushed = b"".join(writer._write_stack)
# At least (total - 8) bytes were implicitly flushed, perhaps more
# depending on the implementation.
self.assertStartsWith(flushed, contents[:-8])
def check_writes(self, intermediate_func):
# Lots of writes, test the flushed output is as expected.
contents = bytes(range(256)) * 1000
n = 0
writer = self.MockRawIO()
bufio = self.tp(writer, 13)
# Generator of write sizes: repeat each N 15 times then proceed to N+1
def gen_sizes():
for size in count(1):
for i in range(15):
yield size
sizes = gen_sizes()
while n < len(contents):
size = min(next(sizes), len(contents) - n)
self.assertEqual(bufio.write(contents[n:n+size]), size)
intermediate_func(bufio)
n += size
bufio.flush()
self.assertEqual(contents, b"".join(writer._write_stack))
def test_writes(self):
self.check_writes(lambda bufio: None)
def test_writes_and_flushes(self):
self.check_writes(lambda bufio: bufio.flush())
def test_writes_and_seeks(self):
def _seekabs(bufio):
pos = bufio.tell()
bufio.seek(pos + 1, 0)
bufio.seek(pos - 1, 0)
bufio.seek(pos, 0)
self.check_writes(_seekabs)
def _seekrel(bufio):
pos = bufio.seek(0, 1)
bufio.seek(+1, 1)
bufio.seek(-1, 1)
bufio.seek(pos, 0)
self.check_writes(_seekrel)
def test_writes_and_truncates(self):
self.check_writes(lambda bufio: bufio.truncate(bufio.tell()))
def test_write_non_blocking(self):
raw = self.MockNonBlockWriterIO()
bufio = self.tp(raw, 8)
self.assertEqual(bufio.write(b"abcd"), 4)
self.assertEqual(bufio.write(b"efghi"), 5)
# 1 byte will be written, the rest will be buffered
raw.block_on(b"k")
self.assertEqual(bufio.write(b"jklmn"), 5)
# 8 bytes will be written, 8 will be buffered and the rest will be lost
raw.block_on(b"0")
try:
bufio.write(b"opqrwxyz0123456789")
except self.BlockingIOError as e:
written = e.characters_written
else:
self.fail("BlockingIOError should have been raised")
self.assertEqual(written, 16)
self.assertEqual(raw.pop_written(),
b"abcdefghijklmnopqrwxyz")
self.assertEqual(bufio.write(b"ABCDEFGHI"), 9)
s = raw.pop_written()
# Previously buffered bytes were flushed
self.assertStartsWith(s, b"01234567A")
def test_write_and_rewind(self):
raw = self.BytesIO()
bufio = self.tp(raw, 4)
self.assertEqual(bufio.write(b"abcdef"), 6)
self.assertEqual(bufio.tell(), 6)
bufio.seek(0, 0)
self.assertEqual(bufio.write(b"XY"), 2)
bufio.seek(6, 0)
self.assertEqual(raw.getvalue(), b"XYcdef")
self.assertEqual(bufio.write(b"123456"), 6)
bufio.flush()
self.assertEqual(raw.getvalue(), b"XYcdef123456")
def test_flush(self):
writer = self.MockRawIO()
bufio = self.tp(writer, 8)
bufio.write(b"abc")
bufio.flush()
self.assertEqual(b"abc", writer._write_stack[0])
def test_writelines(self):
l = [b'ab', b'cd', b'ef']
writer = self.MockRawIO()
bufio = self.tp(writer, 8)
bufio.writelines(l)
bufio.flush()
self.assertEqual(b''.join(writer._write_stack), b'abcdef')
def test_writelines_userlist(self):
l = UserList([b'ab', b'cd', b'ef'])
writer = self.MockRawIO()
bufio = self.tp(writer, 8)
bufio.writelines(l)
bufio.flush()
self.assertEqual(b''.join(writer._write_stack), b'abcdef')
def test_writelines_error(self):
writer = self.MockRawIO()
bufio = self.tp(writer, 8)
self.assertRaises(TypeError, bufio.writelines, [1, 2, 3])
self.assertRaises(TypeError, bufio.writelines, None)
self.assertRaises(TypeError, bufio.writelines, 'abc')
def test_destructor(self):
writer = self.MockRawIO()
bufio = self.tp(writer, 8)
bufio.write(b"abc")
del bufio
support.gc_collect()
self.assertEqual(b"abc", writer._write_stack[0])
def test_truncate(self):
# Truncate implicitly flushes the buffer.
self.addCleanup(os_helper.unlink, os_helper.TESTFN)
with self.open(os_helper.TESTFN, self.write_mode, buffering=0) as raw:
bufio = self.tp(raw, 8)
bufio.write(b"abcdef")
self.assertEqual(bufio.truncate(3), 3)
self.assertEqual(bufio.tell(), 6)
with self.open(os_helper.TESTFN, "rb", buffering=0) as f:
self.assertEqual(f.read(), b"abc")
def test_truncate_after_write(self):
# Ensure that truncate preserves the file position after
# writes longer than the buffer size.
# Issue: https://bugs.python.org/issue32228
self.addCleanup(os_helper.unlink, os_helper.TESTFN)
with self.open(os_helper.TESTFN, "wb") as f:
# Fill with some buffer
f.write(b'\x00' * 10000)
buffer_sizes = [8192, 4096, 200]
for buffer_size in buffer_sizes:
with self.open(os_helper.TESTFN, "r+b", buffering=buffer_size) as f:
f.write(b'\x00' * (buffer_size + 1))
# After write write_pos and write_end are set to 0
f.read(1)
# read operation makes sure that pos != raw_pos
f.truncate()
self.assertEqual(f.tell(), buffer_size + 2)
@threading_helper.requires_working_threading()
@support.requires_resource('cpu')
def test_threads(self):
try:
# Write out many bytes from many threads and test they were
# all flushed.
N = 1000
contents = bytes(range(256)) * N
sizes = cycle([1, 19])
n = 0
queue = deque()
while n < len(contents):
size = next(sizes)
queue.append(contents[n:n+size])
n += size
del contents
# We use a real file object because it allows us to
# exercise situations where the GIL is released before
# writing the buffer to the raw streams. This is in addition
# to concurrency issues due to switching threads in the middle
# of Python code.
with self.open(os_helper.TESTFN, self.write_mode, buffering=0) as raw:
bufio = self.tp(raw, 8)
errors = []
def f():
try:
while True:
try:
s = queue.popleft()
except IndexError:
return
bufio.write(s)
except Exception as e:
errors.append(e)
raise
threads = [threading.Thread(target=f) for x in range(20)]
with threading_helper.start_threads(threads):
time.sleep(0.02) # yield
self.assertFalse(errors,
"the following exceptions were caught: %r" % errors)
bufio.close()
with self.open(os_helper.TESTFN, "rb") as f:
s = f.read()
for i in range(256):
self.assertEqual(s.count(bytes([i])), N)
finally:
os_helper.unlink(os_helper.TESTFN)
def test_misbehaved_io(self):
rawio = self.MisbehavedRawIO()
bufio = self.tp(rawio, 5)
self.assertRaises(OSError, bufio.seek, 0)
self.assertRaises(OSError, bufio.tell)
self.assertRaises(OSError, bufio.write, b"abcdef")
# Silence destructor error
bufio.close = lambda: None
def test_max_buffer_size_removal(self):
with self.assertRaises(TypeError):
self.tp(self.MockRawIO(), 8, 12)
def test_write_error_on_close(self):
raw = self.MockRawIO()
def bad_write(b):
raise OSError()
raw.write = bad_write
b = self.tp(raw)
b.write(b'spam')
self.assertRaises(OSError, b.close) # exception not swallowed
self.assertTrue(b.closed)
@threading_helper.requires_working_threading()
def test_slow_close_from_thread(self):
# Issue #31976
rawio = self.SlowFlushRawIO()
bufio = self.tp(rawio, 8)
t = threading.Thread(target=bufio.close)
t.start()
rawio.in_flush.wait()
self.assertRaises(ValueError, bufio.write, b'spam')
self.assertTrue(bufio.closed)
t.join()
class CBufferedWriterTest(BufferedWriterTest, SizeofTest, CTestCase):
tp = io.BufferedWriter
def test_initialization(self):
rawio = self.MockRawIO()
bufio = self.tp(rawio)
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=0)
self.assertRaises(ValueError, bufio.write, b"def")
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=-16)
self.assertRaises(ValueError, bufio.write, b"def")
self.assertRaises(ValueError, bufio.__init__, rawio, buffer_size=-1)
self.assertRaises(ValueError, bufio.write, b"def")
def test_garbage_collection(self):
# C BufferedWriter objects are collected, and collecting them flushes
# all data to disk.
# The Python version has __del__, so it ends into gc.garbage instead
self.addCleanup(os_helper.unlink, os_helper.TESTFN)
# Note that using warnings_helper.check_warnings() will keep the
# file alive due to the `source` argument to warn(). So, use
# catch_warnings() instead.
with warnings.catch_warnings():
warnings.simplefilter("ignore", ResourceWarning)
rawio = self.FileIO(os_helper.TESTFN, "w+b")
f = self.tp(rawio)
f.write(b"123xxx")
f.x = f
wr = weakref.ref(f)
del f
support.gc_collect()
self.assertIsNone(wr(), wr)
with self.open(os_helper.TESTFN, "rb") as f:
self.assertEqual(f.read(), b"123xxx")
def test_args_error(self):
# Issue #17275
with self.assertRaisesRegex(TypeError, "BufferedWriter"):
self.tp(self.BytesIO(), 1024, 1024, 1024)
class PyBufferedWriterTest(BufferedWriterTest, PyTestCase):
tp = pyio.BufferedWriter
class BufferedRWPairTest:
def test_constructor(self):
pair = self.tp(self.MockRawIO(), self.MockRawIO())
self.assertFalse(pair.closed)
def test_uninitialized(self):
pair = self.tp.__new__(self.tp)
del pair
pair = self.tp.__new__(self.tp)
self.assertRaisesRegex((ValueError, AttributeError),
'uninitialized|has no attribute',
pair.read, 0)
self.assertRaisesRegex((ValueError, AttributeError),
'uninitialized|has no attribute',
pair.write, b'')
pair.__init__(self.MockRawIO(), self.MockRawIO())
self.assertEqual(pair.read(0), b'')
self.assertEqual(pair.write(b''), 0)
def test_detach(self):
pair = self.tp(self.MockRawIO(), self.MockRawIO())
self.assertRaises(self.UnsupportedOperation, pair.detach)
def test_constructor_max_buffer_size_removal(self):
with self.assertRaises(TypeError):
self.tp(self.MockRawIO(), self.MockRawIO(), 8, 12)
def test_constructor_with_not_readable(self):
class NotReadable(self.MockRawIO):
def readable(self):
return False
self.assertRaises(OSError, self.tp, NotReadable(), self.MockRawIO())
def test_constructor_with_not_writeable(self):
class NotWriteable(self.MockRawIO):
def writable(self):
return False
self.assertRaises(OSError, self.tp, self.MockRawIO(), NotWriteable())
def test_read(self):
pair = self.tp(self.BytesIO(b"abcdef"), self.MockRawIO())
self.assertEqual(pair.read(3), b"abc")
self.assertEqual(pair.read(1), b"d")
self.assertEqual(pair.read(), b"ef")
pair = self.tp(self.BytesIO(b"abc"), self.MockRawIO())
self.assertEqual(pair.read(None), b"abc")
def test_readlines(self):
pair = lambda: self.tp(self.BytesIO(b"abc\ndef\nh"), self.MockRawIO())
self.assertEqual(pair().readlines(), [b"abc\n", b"def\n", b"h"])
self.assertEqual(pair().readlines(), [b"abc\n", b"def\n", b"h"])
self.assertEqual(pair().readlines(5), [b"abc\n", b"def\n"])
def test_read1(self):
# .read1() is delegated to the underlying reader object, so this test
# can be shallow.
pair = self.tp(self.BytesIO(b"abcdef"), self.MockRawIO())
self.assertEqual(pair.read1(3), b"abc")
self.assertEqual(pair.read1(), b"def")
def test_readinto(self):
for method in ("readinto", "readinto1"):
with self.subTest(method):
pair = self.tp(self.BytesIO(b"abcdef"), self.MockRawIO())
data = byteslike(b'\0' * 5)
self.assertEqual(getattr(pair, method)(data), 5)
self.assertEqual(bytes(data), b"abcde")
# gh-138720: C BufferedRWPair would destruct in a bad order resulting in
# an unraisable exception.
support.gc_collect()
def test_write(self):
w = self.MockRawIO()
pair = self.tp(self.MockRawIO(), w)
pair.write(b"abc")
pair.flush()
buffer = bytearray(b"def")
pair.write(buffer)
buffer[:] = b"***" # Overwrite our copy of the data
pair.flush()
self.assertEqual(w._write_stack, [b"abc", b"def"])
def test_peek(self):
pair = self.tp(self.BytesIO(b"abcdef"), self.MockRawIO())
self.assertStartsWith(pair.peek(3), b"abc")
self.assertEqual(pair.read(3), b"abc")
def test_readable(self):
pair = self.tp(self.MockRawIO(), self.MockRawIO())
self.assertTrue(pair.readable())
def test_writeable(self):
pair = self.tp(self.MockRawIO(), self.MockRawIO())
self.assertTrue(pair.writable())
def test_seekable(self):
# BufferedRWPairs are never seekable, even if their readers and writers
# are.
pair = self.tp(self.MockRawIO(), self.MockRawIO())
self.assertFalse(pair.seekable())
# .flush() is delegated to the underlying writer object and has been
# tested in the test_write method.
def test_close_and_closed(self):
pair = self.tp(self.MockRawIO(), self.MockRawIO())
self.assertFalse(pair.closed)
pair.close()
self.assertTrue(pair.closed)
def test_reader_close_error_on_close(self):
def reader_close():
reader_non_existing
reader = self.MockRawIO()
reader.close = reader_close
writer = self.MockRawIO()
pair = self.tp(reader, writer)
with self.assertRaises(NameError) as err:
pair.close()
self.assertIn('reader_non_existing', str(err.exception))
self.assertTrue(pair.closed)
self.assertFalse(reader.closed)
self.assertTrue(writer.closed)
# Silence destructor error
reader.close = lambda: None
def test_writer_close_error_on_close(self):
def writer_close():
writer_non_existing
reader = self.MockRawIO()
writer = self.MockRawIO()
writer.close = writer_close
pair = self.tp(reader, writer)
with self.assertRaises(NameError) as err:
pair.close()
self.assertIn('writer_non_existing', str(err.exception))
self.assertFalse(pair.closed)
self.assertTrue(reader.closed)
self.assertFalse(writer.closed)
# Silence destructor error
writer.close = lambda: None
writer = None
# Ignore BufferedWriter (of the BufferedRWPair) unraisable exception
with support.catch_unraisable_exception():
# Ignore BufferedRWPair unraisable exception
with support.catch_unraisable_exception():
pair = None
support.gc_collect()
support.gc_collect()
def test_reader_writer_close_error_on_close(self):
def reader_close():
reader_non_existing
def writer_close():
writer_non_existing
reader = self.MockRawIO()
reader.close = reader_close
writer = self.MockRawIO()
writer.close = writer_close
pair = self.tp(reader, writer)
with self.assertRaises(NameError) as err:
pair.close()
self.assertIn('reader_non_existing', str(err.exception))
self.assertIsInstance(err.exception.__context__, NameError)
self.assertIn('writer_non_existing', str(err.exception.__context__))
self.assertFalse(pair.closed)
self.assertFalse(reader.closed)
self.assertFalse(writer.closed)
# Silence destructor error
reader.close = lambda: None
writer.close = lambda: None
def test_isatty(self):
class SelectableIsAtty(self.MockRawIO):
def __init__(self, isatty):
super().__init__()
self._isatty = isatty
def isatty(self):
return self._isatty
pair = self.tp(SelectableIsAtty(False), SelectableIsAtty(False))
self.assertFalse(pair.isatty())
pair = self.tp(SelectableIsAtty(True), SelectableIsAtty(False))
self.assertTrue(pair.isatty())
pair = self.tp(SelectableIsAtty(False), SelectableIsAtty(True))
self.assertTrue(pair.isatty())
pair = self.tp(SelectableIsAtty(True), SelectableIsAtty(True))
self.assertTrue(pair.isatty())
def test_weakref_clearing(self):
brw = self.tp(self.MockRawIO(), self.MockRawIO())
ref = weakref.ref(brw)
brw = None
ref = None # Shouldn't segfault.
class CBufferedRWPairTest(BufferedRWPairTest, CTestCase):
tp = io.BufferedRWPair
class PyBufferedRWPairTest(BufferedRWPairTest, PyTestCase):
tp = pyio.BufferedRWPair
class BufferedRandomTest(BufferedReaderTest, BufferedWriterTest):
read_mode = "rb+"
write_mode = "wb+"
def test_constructor(self):
BufferedReaderTest.test_constructor(self)
BufferedWriterTest.test_constructor(self)
def test_uninitialized(self):
BufferedReaderTest.test_uninitialized(self)
BufferedWriterTest.test_uninitialized(self)
def test_read_and_write(self):
raw = self.MockRawIO((b"asdf", b"ghjk"))
rw = self.tp(raw, 8)
self.assertEqual(b"as", rw.read(2))
rw.write(b"ddd")
rw.write(b"eee")
self.assertFalse(raw._write_stack) # Buffer writes
self.assertEqual(b"ghjk", rw.read())
self.assertEqual(b"dddeee", raw._write_stack[0])
def test_seek_and_tell(self):
raw = self.BytesIO(b"asdfghjkl")
rw = self.tp(raw)
self.assertEqual(b"as", rw.read(2))
self.assertEqual(2, rw.tell())
rw.seek(0, 0)
self.assertEqual(b"asdf", rw.read(4))
rw.write(b"123f")
rw.seek(0, 0)
self.assertEqual(b"asdf123fl", rw.read())
self.assertEqual(9, rw.tell())
rw.seek(-4, 2)
self.assertEqual(5, rw.tell())
rw.seek(2, 1)
self.assertEqual(7, rw.tell())
self.assertEqual(b"fl", rw.read(11))
rw.flush()
self.assertEqual(b"asdf123fl", raw.getvalue())
self.assertRaises(TypeError, rw.seek, 0.0)
def check_flush_and_read(self, read_func):
raw = self.BytesIO(b"abcdefghi")
bufio = self.tp(raw)
self.assertEqual(b"ab", read_func(bufio, 2))
bufio.write(b"12")
self.assertEqual(b"ef", read_func(bufio, 2))
self.assertEqual(6, bufio.tell())
bufio.flush()
self.assertEqual(6, bufio.tell())
self.assertEqual(b"ghi", read_func(bufio))
raw.seek(0, 0)
raw.write(b"XYZ")
# flush() resets the read buffer
bufio.flush()
bufio.seek(0, 0)
self.assertEqual(b"XYZ", read_func(bufio, 3))
def test_flush_and_read(self):
self.check_flush_and_read(lambda bufio, *args: bufio.read(*args))
def test_flush_and_readinto(self):
def _readinto(bufio, n=-1):
b = bytearray(n if n >= 0 else 9999)
n = bufio.readinto(b)
return bytes(b[:n])
self.check_flush_and_read(_readinto)
def test_flush_and_peek(self):
def _peek(bufio, n=-1):
# This relies on the fact that the buffer can contain the whole
# raw stream, otherwise peek() can return less.
b = bufio.peek(n)
if n != -1:
b = b[:n]
bufio.seek(len(b), 1)
return b
self.check_flush_and_read(_peek)
def test_flush_and_write(self):
raw = self.BytesIO(b"abcdefghi")
bufio = self.tp(raw)
bufio.write(b"123")
bufio.flush()
bufio.write(b"45")
bufio.flush()
bufio.seek(0, 0)
self.assertEqual(b"12345fghi", raw.getvalue())
self.assertEqual(b"12345fghi", bufio.read())
def test_threads(self):
BufferedReaderTest.test_threads(self)
BufferedWriterTest.test_threads(self)
def test_writes_and_peek(self):
def _peek(bufio):
bufio.peek(1)
self.check_writes(_peek)
def _peek(bufio):
pos = bufio.tell()
bufio.seek(-1, 1)
bufio.peek(1)
bufio.seek(pos, 0)
self.check_writes(_peek)
def test_writes_and_reads(self):
def _read(bufio):
bufio.seek(-1, 1)
bufio.read(1)
self.check_writes(_read)
def test_writes_and_read1s(self):
def _read1(bufio):
bufio.seek(-1, 1)
bufio.read1(1)
self.check_writes(_read1)
def test_writes_and_readintos(self):
def _read(bufio):
bufio.seek(-1, 1)
bufio.readinto(bytearray(1))
self.check_writes(_read)
def test_write_after_readahead(self):
# Issue #6629: writing after the buffer was filled by readahead should
# first rewind the raw stream.
for overwrite_size in [1, 5]:
raw = self.BytesIO(b"A" * 10)
bufio = self.tp(raw, 4)
# Trigger readahead
self.assertEqual(bufio.read(1), b"A")
self.assertEqual(bufio.tell(), 1)
# Overwriting should rewind the raw stream if it needs so
bufio.write(b"B" * overwrite_size)
self.assertEqual(bufio.tell(), overwrite_size + 1)
# If the write size was smaller than the buffer size, flush() and
# check that rewind happens.
bufio.flush()
self.assertEqual(bufio.tell(), overwrite_size + 1)
s = raw.getvalue()
self.assertEqual(s,
b"A" + b"B" * overwrite_size + b"A" * (9 - overwrite_size))
def test_write_rewind_write(self):
# Various combinations of reading / writing / seeking backwards / writing again
def mutate(bufio, pos1, pos2):
assert pos2 >= pos1
# Fill the buffer
bufio.seek(pos1)
bufio.read(pos2 - pos1)
bufio.write(b'\x02')
# This writes earlier than the previous write, but still inside
# the buffer.
bufio.seek(pos1)
bufio.write(b'\x01')
b = b"\x80\x81\x82\x83\x84"
for i in range(0, len(b)):
for j in range(i, len(b)):
raw = self.BytesIO(b)
bufio = self.tp(raw, 100)
mutate(bufio, i, j)
bufio.flush()
expected = bytearray(b)
expected[j] = 2
expected[i] = 1
self.assertEqual(raw.getvalue(), expected,
"failed result for i=%d, j=%d" % (i, j))
def test_truncate_after_read_or_write(self):
raw = self.BytesIO(b"A" * 10)
bufio = self.tp(raw, 100)
self.assertEqual(bufio.read(2), b"AA") # the read buffer gets filled
self.assertEqual(bufio.truncate(), 2)
self.assertEqual(bufio.write(b"BB"), 2) # the write buffer increases
self.assertEqual(bufio.truncate(), 4)
def test_misbehaved_io(self):
BufferedReaderTest.test_misbehaved_io(self)
BufferedWriterTest.test_misbehaved_io(self)
def test_interleaved_read_write(self):
# Test for issue #12213
with self.BytesIO(b'abcdefgh') as raw:
with self.tp(raw, 100) as f:
f.write(b"1")
self.assertEqual(f.read(1), b'b')
f.write(b'2')
self.assertEqual(f.read1(1), b'd')
f.write(b'3')
buf = bytearray(1)
f.readinto(buf)
self.assertEqual(buf, b'f')
f.write(b'4')
self.assertEqual(f.peek(1), b'h')
f.flush()
self.assertEqual(raw.getvalue(), b'1b2d3f4h')
with self.BytesIO(b'abc') as raw:
with self.tp(raw, 100) as f:
self.assertEqual(f.read(1), b'a')
f.write(b"2")
self.assertEqual(f.read(1), b'c')
f.flush()
self.assertEqual(raw.getvalue(), b'a2c')
def test_read1_after_write(self):
with self.BytesIO(b'abcdef') as raw:
with self.tp(raw, 3) as f:
f.write(b"1")
self.assertEqual(f.read1(1), b'b')
f.flush()
self.assertEqual(raw.getvalue(), b'1bcdef')
with self.BytesIO(b'abcdef') as raw:
with self.tp(raw, 3) as f:
f.write(b"1")
self.assertEqual(f.read1(), b'bcd')
f.flush()
self.assertEqual(raw.getvalue(), b'1bcdef')
with self.BytesIO(b'abcdef') as raw:
with self.tp(raw, 3) as f:
f.write(b"1")
# XXX: read(100) returns different numbers of bytes
# in Python and C implementations.
self.assertEqual(f.read1(100)[:3], b'bcd')
f.flush()
self.assertEqual(raw.getvalue(), b'1bcdef')
def test_interleaved_readline_write(self):
with self.BytesIO(b'ab\ncdef\ng\n') as raw:
with self.tp(raw) as f:
f.write(b'1')
self.assertEqual(f.readline(), b'b\n')
f.write(b'2')
self.assertEqual(f.readline(), b'def\n')
f.write(b'3')
self.assertEqual(f.readline(), b'\n')
f.flush()
self.assertEqual(raw.getvalue(), b'1b\n2def\n3\n')
# You can't construct a BufferedRandom over a non-seekable stream.
test_unseekable = None
# writable() returns True, so there's no point to test it over
# a writable stream.
test_truncate_on_read_only = None
class CBufferedRandomTest(BufferedRandomTest, SizeofTest, CTestCase):
tp = io.BufferedRandom
def test_garbage_collection(self):
CBufferedReaderTest.test_garbage_collection(self)
CBufferedWriterTest.test_garbage_collection(self)
def test_args_error(self):
# Issue #17275
with self.assertRaisesRegex(TypeError, "BufferedRandom"):
self.tp(self.BytesIO(), 1024, 1024, 1024)
class PyBufferedRandomTest(BufferedRandomTest, PyTestCase):
tp = pyio.BufferedRandom
# XXX Tests for open()
class MiscIOTest:
# for test__all__, actual values are set in subclasses
name_of_module = None
extra_exported = ()
not_exported = ()
def tearDown(self):
os_helper.unlink(os_helper.TESTFN)
def test___all__(self):
support.check__all__(self, self.io, self.name_of_module,
extra=self.extra_exported,
not_exported=self.not_exported)
def test_attributes(self):
f = self.open(os_helper.TESTFN, "wb", buffering=0)
self.assertEqual(f.mode, "wb")
f.close()
f = self.open(os_helper.TESTFN, "w+", encoding="utf-8")
self.assertEqual(f.mode, "w+")
self.assertEqual(f.buffer.mode, "rb+") # Does it really matter?
self.assertEqual(f.buffer.raw.mode, "rb+")
g = self.open(f.fileno(), "wb", closefd=False)
self.assertEqual(g.mode, "wb")
self.assertEqual(g.raw.mode, "wb")
self.assertEqual(g.name, f.fileno())
self.assertEqual(g.raw.name, f.fileno())
f.close()
g.close()
def test_removed_u_mode(self):
# bpo-37330: The "U" mode has been removed in Python 3.11
for mode in ("U", "rU", "r+U"):
with self.assertRaises(ValueError) as cm:
self.open(os_helper.TESTFN, mode)
self.assertIn('invalid mode', str(cm.exception))
@unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()")
def test_open_pipe_with_append(self):
# bpo-27805: Ignore ESPIPE from lseek() in open().
r, w = os.pipe()
self.addCleanup(os.close, r)
f = self.open(w, 'a', encoding="utf-8")
self.addCleanup(f.close)
# Check that the file is marked non-seekable. On Windows, however, lseek
# somehow succeeds on pipes.
if sys.platform != 'win32':
self.assertFalse(f.seekable())
def test_io_after_close(self):
for kwargs in [
{"mode": "w"},
{"mode": "wb"},
{"mode": "w", "buffering": 1},
{"mode": "w", "buffering": 2},
{"mode": "wb", "buffering": 0},
{"mode": "r"},
{"mode": "rb"},
{"mode": "r", "buffering": 1},
{"mode": "r", "buffering": 2},
{"mode": "rb", "buffering": 0},
{"mode": "w+"},
{"mode": "w+b"},
{"mode": "w+", "buffering": 1},
{"mode": "w+", "buffering": 2},
{"mode": "w+b", "buffering": 0},
]:
if "b" not in kwargs["mode"]:
kwargs["encoding"] = "utf-8"
f = self.open(os_helper.TESTFN, **kwargs)
f.close()
self.assertRaises(ValueError, f.flush)
self.assertRaises(ValueError, f.fileno)
self.assertRaises(ValueError, f.isatty)
self.assertRaises(ValueError, f.__iter__)
if hasattr(f, "peek"):
self.assertRaises(ValueError, f.peek, 1)
self.assertRaises(ValueError, f.read)
if hasattr(f, "read1"):
self.assertRaises(ValueError, f.read1, 1024)
self.assertRaises(ValueError, f.read1)
if hasattr(f, "readall"):
self.assertRaises(ValueError, f.readall)
if hasattr(f, "readinto"):
self.assertRaises(ValueError, f.readinto, bytearray(1024))
if hasattr(f, "readinto1"):
self.assertRaises(ValueError, f.readinto1, bytearray(1024))
self.assertRaises(ValueError, f.readline)
self.assertRaises(ValueError, f.readlines)
self.assertRaises(ValueError, f.readlines, 1)
self.assertRaises(ValueError, f.seek, 0)
self.assertRaises(ValueError, f.tell)
self.assertRaises(ValueError, f.truncate)
self.assertRaises(ValueError, f.write,
b"" if "b" in kwargs['mode'] else "")
self.assertRaises(ValueError, f.writelines, [])
self.assertRaises(ValueError, next, f)
def test_blockingioerror(self):
# Various BlockingIOError issues
class C(str):
pass
c = C("")
b = self.BlockingIOError(1, c)
c.b = b
b.c = c
wr = weakref.ref(c)
del c, b
support.gc_collect()
self.assertIsNone(wr(), wr)
def test_abcs(self):
# Test the visible base classes are ABCs.
self.assertIsInstance(self.IOBase, abc.ABCMeta)
self.assertIsInstance(self.RawIOBase, abc.ABCMeta)
self.assertIsInstance(self.BufferedIOBase, abc.ABCMeta)
self.assertIsInstance(self.TextIOBase, abc.ABCMeta)
def _check_abc_inheritance(self, abcmodule):
with self.open(os_helper.TESTFN, "wb", buffering=0) as f:
self.assertIsInstance(f, abcmodule.IOBase)
self.assertIsInstance(f, abcmodule.RawIOBase)
self.assertNotIsInstance(f, abcmodule.BufferedIOBase)
self.assertNotIsInstance(f, abcmodule.TextIOBase)
with self.open(os_helper.TESTFN, "wb") as f:
self.assertIsInstance(f, abcmodule.IOBase)
self.assertNotIsInstance(f, abcmodule.RawIOBase)
self.assertIsInstance(f, abcmodule.BufferedIOBase)
self.assertNotIsInstance(f, abcmodule.TextIOBase)
with self.open(os_helper.TESTFN, "w", encoding="utf-8") as f:
self.assertIsInstance(f, abcmodule.IOBase)
self.assertNotIsInstance(f, abcmodule.RawIOBase)
self.assertNotIsInstance(f, abcmodule.BufferedIOBase)
self.assertIsInstance(f, abcmodule.TextIOBase)
def test_abc_inheritance(self):
# Test implementations inherit from their respective ABCs
self._check_abc_inheritance(self)
def test_abc_inheritance_official(self):
# Test implementations inherit from the official ABCs of the
# baseline "io" module.
self._check_abc_inheritance(io)
def _check_warn_on_dealloc(self, *args, **kwargs):
f = self.open(*args, **kwargs)
r = repr(f)
with self.assertWarns(ResourceWarning) as cm:
f = None
support.gc_collect()
self.assertIn(r, str(cm.warning.args[0]))
def test_warn_on_dealloc(self):
self._check_warn_on_dealloc(os_helper.TESTFN, "wb", buffering=0)
self._check_warn_on_dealloc(os_helper.TESTFN, "wb")
self._check_warn_on_dealloc(os_helper.TESTFN, "w", encoding="utf-8")
def _check_warn_on_dealloc_fd(self, *args, **kwargs):
fds = []
def cleanup_fds():
for fd in fds:
try:
os.close(fd)
except OSError as e:
if e.errno != errno.EBADF:
raise
self.addCleanup(cleanup_fds)
r, w = os.pipe()
fds += r, w
self._check_warn_on_dealloc(r, *args, **kwargs)
# When using closefd=False, there's no warning
r, w = os.pipe()
fds += r, w
with warnings_helper.check_no_resource_warning(self):
self.open(r, *args, closefd=False, **kwargs)
@unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()")
def test_warn_on_dealloc_fd(self):
self._check_warn_on_dealloc_fd("rb", buffering=0)
self._check_warn_on_dealloc_fd("rb")
self._check_warn_on_dealloc_fd("r", encoding="utf-8")
def test_pickling(self):
# Pickling file objects is forbidden
msg = "cannot pickle"
for kwargs in [
{"mode": "w"},
{"mode": "wb"},
{"mode": "wb", "buffering": 0},
{"mode": "r"},
{"mode": "rb"},
{"mode": "rb", "buffering": 0},
{"mode": "w+"},
{"mode": "w+b"},
{"mode": "w+b", "buffering": 0},
]:
if "b" not in kwargs["mode"]:
kwargs["encoding"] = "utf-8"
for protocol in range(pickle.HIGHEST_PROTOCOL + 1):
with self.subTest(protocol=protocol, kwargs=kwargs):
with self.open(os_helper.TESTFN, **kwargs) as f:
with self.assertRaisesRegex(TypeError, msg):
pickle.dumps(f, protocol)
@unittest.skipIf(support.is_emscripten, "Emscripten corrupts memory when writing to nonblocking fd")
def test_nonblock_pipe_write_bigbuf(self):
self._test_nonblock_pipe_write(16*1024)
@unittest.skipIf(support.is_emscripten, "Emscripten corrupts memory when writing to nonblocking fd")
def test_nonblock_pipe_write_smallbuf(self):
self._test_nonblock_pipe_write(1024)
@unittest.skipUnless(hasattr(os, 'set_blocking'),
'os.set_blocking() required for this test')
@unittest.skipUnless(hasattr(os, "pipe"), "requires os.pipe()")
def _test_nonblock_pipe_write(self, bufsize):
sent = []
received = []
r, w = os.pipe()
os.set_blocking(r, False)
os.set_blocking(w, False)
# To exercise all code paths in the C implementation we need
# to play with buffer sizes. For instance, if we choose a
# buffer size less than or equal to _PIPE_BUF (4096 on Linux)
# then we will never get a partial write of the buffer.
rf = self.open(r, mode='rb', closefd=True, buffering=bufsize)
wf = self.open(w, mode='wb', closefd=True, buffering=bufsize)
with rf, wf:
for N in 9999, 73, 7574:
try:
i = 0
while True:
msg = bytes([i % 26 + 97]) * N
sent.append(msg)
wf.write(msg)
i += 1
except self.BlockingIOError as e:
self.assertEqual(e.args[0], errno.EAGAIN)
self.assertEqual(e.args[2], e.characters_written)
sent[-1] = sent[-1][:e.characters_written]
received.append(rf.read())
msg = b'BLOCKED'
wf.write(msg)
sent.append(msg)
while True:
try:
wf.flush()
break
except self.BlockingIOError as e:
self.assertEqual(e.args[0], errno.EAGAIN)
self.assertEqual(e.args[2], e.characters_written)
self.assertEqual(e.characters_written, 0)
received.append(rf.read())
received += iter(rf.read, None)
sent, received = b''.join(sent), b''.join(received)
self.assertEqual(sent, received)
self.assertTrue(wf.closed)
self.assertTrue(rf.closed)
def test_create_fail(self):
# 'x' mode fails if file is existing
with self.open(os_helper.TESTFN, 'w', encoding="utf-8"):
pass
self.assertRaises(FileExistsError, self.open, os_helper.TESTFN, 'x', encoding="utf-8")
def test_create_writes(self):
# 'x' mode opens for writing
with self.open(os_helper.TESTFN, 'xb') as f:
f.write(b"spam")
with self.open(os_helper.TESTFN, 'rb') as f:
self.assertEqual(b"spam", f.read())
def test_open_allargs(self):
# there used to be a buffer overflow in the parser for rawmode
self.assertRaises(ValueError, self.open, os_helper.TESTFN, 'rwax+', encoding="utf-8")
def test_check_encoding_errors(self):
# bpo-37388: open() and TextIOWrapper must check encoding and errors
# arguments in dev mode
mod = self.io.__name__
filename = __file__
invalid = 'Boom, Shaka Laka, Boom!'
code = textwrap.dedent(f'''
import sys
from {mod} import open, TextIOWrapper
try:
open({filename!r}, encoding={invalid!r})
except LookupError:
pass
else:
sys.exit(21)
try:
open({filename!r}, errors={invalid!r})
except LookupError:
pass
else:
sys.exit(22)
fp = open({filename!r}, "rb")
with fp:
try:
TextIOWrapper(fp, encoding={invalid!r})
except LookupError:
pass
else:
sys.exit(23)
try:
TextIOWrapper(fp, errors={invalid!r})
except LookupError:
pass
else:
sys.exit(24)
sys.exit(10)
''')
proc = assert_python_failure('-X', 'dev', '-c', code)
self.assertEqual(proc.rc, 10, proc)
def test_check_encoding_warning(self):
# PEP 597: Raise warning when encoding is not specified
# and sys.flags.warn_default_encoding is set.
mod = self.io.__name__
filename = __file__
code = textwrap.dedent(f'''\
import sys
from {mod} import open, TextIOWrapper
import pathlib
with open({filename!r}) as f: # line 5
pass
pathlib.Path({filename!r}).read_text() # line 8
''')
proc = assert_python_ok('-X', 'warn_default_encoding', '-c', code)
warnings = proc.err.splitlines()
self.assertEqual(len(warnings), 2)
self.assertStartsWith(warnings[0], b"<string>:5: EncodingWarning: ")
self.assertStartsWith(warnings[1], b"<string>:8: EncodingWarning: ")
def test_text_encoding(self):
# PEP 597, bpo-47000. io.text_encoding() returns "locale" or "utf-8"
# based on sys.flags.utf8_mode
code = "import io; print(io.text_encoding(None))"
proc = assert_python_ok('-X', 'utf8=0', '-c', code)
self.assertEqual(b"locale", proc.out.strip())
proc = assert_python_ok('-X', 'utf8=1', '-c', code)
self.assertEqual(b"utf-8", proc.out.strip())
class CMiscIOTest(MiscIOTest, CTestCase):
name_of_module = "io", "_io"
extra_exported = "BlockingIOError",
def test_readinto_buffer_overflow(self):
# Issue #18025
class BadReader(self.io.BufferedIOBase):
def read(self, n=-1):
return b'x' * 10**6
bufio = BadReader()
b = bytearray(2)
self.assertRaises(ValueError, bufio.readinto, b)
def check_daemon_threads_shutdown_deadlock(self, stream_name):
# Issue #23309: deadlocks at shutdown should be avoided when a
# daemon thread and the main thread both write to a file.
code = """if 1:
import sys
import time
import threading
from test.support import SuppressCrashReport
file = sys.{stream_name}
def run():
while True:
file.write('.')
file.flush()
crash = SuppressCrashReport()
crash.__enter__()
# don't call __exit__(): the crash occurs at Python shutdown
thread = threading.Thread(target=run)
thread.daemon = True
thread.start()
time.sleep(0.5)
file.write('!')
file.flush()
""".format_map(locals())
res, _ = run_python_until_end("-c", code)
err = res.err.decode()
if res.rc != 0:
# Failure: should be a fatal error
pattern = (r"Fatal Python error: _enter_buffered_busy: "
r"could not acquire lock "
r"for <(_io\.)?BufferedWriter name='<{stream_name}>'> "
r"at interpreter shutdown, possibly due to "
r"daemon threads".format_map(locals()))
self.assertRegex(err, pattern)
else:
self.assertFalse(err.strip('.!'))
@threading_helper.requires_working_threading()
@support.requires_resource('walltime')
def test_daemon_threads_shutdown_stdout_deadlock(self):
self.check_daemon_threads_shutdown_deadlock('stdout')
@threading_helper.requires_working_threading()
@support.requires_resource('walltime')
def test_daemon_threads_shutdown_stderr_deadlock(self):
self.check_daemon_threads_shutdown_deadlock('stderr')
class PyMiscIOTest(MiscIOTest, PyTestCase):
name_of_module = "_pyio", "io"
extra_exported = "BlockingIOError", "open_code",
not_exported = "valid_seek_flags",
class ProtocolsTest(unittest.TestCase):
class MyReader:
def read(self, sz=-1):
return b""
class MyWriter:
def write(self, b: bytes):
pass
def test_reader_subclass(self):
self.assertIsSubclass(self.MyReader, io.Reader)
self.assertNotIsSubclass(str, io.Reader)
def test_writer_subclass(self):
self.assertIsSubclass(self.MyWriter, io.Writer)
self.assertNotIsSubclass(str, io.Writer)
if __name__ == "__main__":
unittest.main()
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