_compat.py 23.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786
# flake8: noqa
import codecs
import io
import os
import re
import sys
from weakref import WeakKeyDictionary

PY2 = sys.version_info[0] == 2
CYGWIN = sys.platform.startswith("cygwin")
MSYS2 = sys.platform.startswith("win") and ("GCC" in sys.version)
# Determine local App Engine environment, per Google's own suggestion
APP_ENGINE = "APPENGINE_RUNTIME" in os.environ and "Development/" in os.environ.get(
    "SERVER_SOFTWARE", ""
)
WIN = sys.platform.startswith("win") and not APP_ENGINE and not MSYS2
DEFAULT_COLUMNS = 80


_ansi_re = re.compile(r"\033\[[;?0-9]*[a-zA-Z]")


def get_filesystem_encoding():
    return sys.getfilesystemencoding() or sys.getdefaultencoding()


def _make_text_stream(
    stream, encoding, errors, force_readable=False, force_writable=False
):
    if encoding is None:
        encoding = get_best_encoding(stream)
    if errors is None:
        errors = "replace"
    return _NonClosingTextIOWrapper(
        stream,
        encoding,
        errors,
        line_buffering=True,
        force_readable=force_readable,
        force_writable=force_writable,
    )


def is_ascii_encoding(encoding):
    """Checks if a given encoding is ascii."""
    try:
        return codecs.lookup(encoding).name == "ascii"
    except LookupError:
        return False


def get_best_encoding(stream):
    """Returns the default stream encoding if not found."""
    rv = getattr(stream, "encoding", None) or sys.getdefaultencoding()
    if is_ascii_encoding(rv):
        return "utf-8"
    return rv


class _NonClosingTextIOWrapper(io.TextIOWrapper):
    def __init__(
        self,
        stream,
        encoding,
        errors,
        force_readable=False,
        force_writable=False,
        **extra
    ):
        self._stream = stream = _FixupStream(stream, force_readable, force_writable)
        io.TextIOWrapper.__init__(self, stream, encoding, errors, **extra)

    # The io module is a place where the Python 3 text behavior
    # was forced upon Python 2, so we need to unbreak
    # it to look like Python 2.
    if PY2:

        def write(self, x):
            if isinstance(x, str) or is_bytes(x):
                try:
                    self.flush()
                except Exception:
                    pass
                return self.buffer.write(str(x))
            return io.TextIOWrapper.write(self, x)

        def writelines(self, lines):
            for line in lines:
                self.write(line)

    def __del__(self):
        try:
            self.detach()
        except Exception:
            pass

    def isatty(self):
        # https://bitbucket.org/pypy/pypy/issue/1803
        return self._stream.isatty()


class _FixupStream(object):
    """The new io interface needs more from streams than streams
    traditionally implement.  As such, this fix-up code is necessary in
    some circumstances.

    The forcing of readable and writable flags are there because some tools
    put badly patched objects on sys (one such offender are certain version
    of jupyter notebook).
    """

    def __init__(self, stream, force_readable=False, force_writable=False):
        self._stream = stream
        self._force_readable = force_readable
        self._force_writable = force_writable

    def __getattr__(self, name):
        return getattr(self._stream, name)

    def read1(self, size):
        f = getattr(self._stream, "read1", None)
        if f is not None:
            return f(size)
        # We only dispatch to readline instead of read in Python 2 as we
        # do not want cause problems with the different implementation
        # of line buffering.
        if PY2:
            return self._stream.readline(size)
        return self._stream.read(size)

    def readable(self):
        if self._force_readable:
            return True
        x = getattr(self._stream, "readable", None)
        if x is not None:
            return x()
        try:
            self._stream.read(0)
        except Exception:
            return False
        return True

    def writable(self):
        if self._force_writable:
            return True
        x = getattr(self._stream, "writable", None)
        if x is not None:
            return x()
        try:
            self._stream.write("")
        except Exception:
            try:
                self._stream.write(b"")
            except Exception:
                return False
        return True

    def seekable(self):
        x = getattr(self._stream, "seekable", None)
        if x is not None:
            return x()
        try:
            self._stream.seek(self._stream.tell())
        except Exception:
            return False
        return True


if PY2:
    text_type = unicode
    raw_input = raw_input
    string_types = (str, unicode)
    int_types = (int, long)
    iteritems = lambda x: x.iteritems()
    range_type = xrange

    def is_bytes(x):
        return isinstance(x, (buffer, bytearray))

    _identifier_re = re.compile(r"^[a-zA-Z_][a-zA-Z0-9_]*$")

    # For Windows, we need to force stdout/stdin/stderr to binary if it's
    # fetched for that.  This obviously is not the most correct way to do
    # it as it changes global state.  Unfortunately, there does not seem to
    # be a clear better way to do it as just reopening the file in binary
    # mode does not change anything.
    #
    # An option would be to do what Python 3 does and to open the file as
    # binary only, patch it back to the system, and then use a wrapper
    # stream that converts newlines.  It's not quite clear what's the
    # correct option here.
    #
    # This code also lives in _winconsole for the fallback to the console
    # emulation stream.
    #
    # There are also Windows environments where the `msvcrt` module is not
    # available (which is why we use try-catch instead of the WIN variable
    # here), such as the Google App Engine development server on Windows. In
    # those cases there is just nothing we can do.
    def set_binary_mode(f):
        return f

    try:
        import msvcrt
    except ImportError:
        pass
    else:

        def set_binary_mode(f):
            try:
                fileno = f.fileno()
            except Exception:
                pass
            else:
                msvcrt.setmode(fileno, os.O_BINARY)
            return f

    try:
        import fcntl
    except ImportError:
        pass
    else:

        def set_binary_mode(f):
            try:
                fileno = f.fileno()
            except Exception:
                pass
            else:
                flags = fcntl.fcntl(fileno, fcntl.F_GETFL)
                fcntl.fcntl(fileno, fcntl.F_SETFL, flags & ~os.O_NONBLOCK)
            return f

    def isidentifier(x):
        return _identifier_re.search(x) is not None

    def get_binary_stdin():
        return set_binary_mode(sys.stdin)

    def get_binary_stdout():
        _wrap_std_stream("stdout")
        return set_binary_mode(sys.stdout)

    def get_binary_stderr():
        _wrap_std_stream("stderr")
        return set_binary_mode(sys.stderr)

    def get_text_stdin(encoding=None, errors=None):
        rv = _get_windows_console_stream(sys.stdin, encoding, errors)
        if rv is not None:
            return rv
        return _make_text_stream(sys.stdin, encoding, errors, force_readable=True)

    def get_text_stdout(encoding=None, errors=None):
        _wrap_std_stream("stdout")
        rv = _get_windows_console_stream(sys.stdout, encoding, errors)
        if rv is not None:
            return rv
        return _make_text_stream(sys.stdout, encoding, errors, force_writable=True)

    def get_text_stderr(encoding=None, errors=None):
        _wrap_std_stream("stderr")
        rv = _get_windows_console_stream(sys.stderr, encoding, errors)
        if rv is not None:
            return rv
        return _make_text_stream(sys.stderr, encoding, errors, force_writable=True)

    def filename_to_ui(value):
        if isinstance(value, bytes):
            value = value.decode(get_filesystem_encoding(), "replace")
        return value


else:
    import io

    text_type = str
    raw_input = input
    string_types = (str,)
    int_types = (int,)
    range_type = range
    isidentifier = lambda x: x.isidentifier()
    iteritems = lambda x: iter(x.items())

    def is_bytes(x):
        return isinstance(x, (bytes, memoryview, bytearray))

    def _is_binary_reader(stream, default=False):
        try:
            return isinstance(stream.read(0), bytes)
        except Exception:
            return default
            # This happens in some cases where the stream was already
            # closed.  In this case, we assume the default.

    def _is_binary_writer(stream, default=False):
        try:
            stream.write(b"")
        except Exception:
            try:
                stream.write("")
                return False
            except Exception:
                pass
            return default
        return True

    def _find_binary_reader(stream):
        # We need to figure out if the given stream is already binary.
        # This can happen because the official docs recommend detaching
        # the streams to get binary streams.  Some code might do this, so
        # we need to deal with this case explicitly.
        if _is_binary_reader(stream, False):
            return stream

        buf = getattr(stream, "buffer", None)

        # Same situation here; this time we assume that the buffer is
        # actually binary in case it's closed.
        if buf is not None and _is_binary_reader(buf, True):
            return buf

    def _find_binary_writer(stream):
        # We need to figure out if the given stream is already binary.
        # This can happen because the official docs recommend detatching
        # the streams to get binary streams.  Some code might do this, so
        # we need to deal with this case explicitly.
        if _is_binary_writer(stream, False):
            return stream

        buf = getattr(stream, "buffer", None)

        # Same situation here; this time we assume that the buffer is
        # actually binary in case it's closed.
        if buf is not None and _is_binary_writer(buf, True):
            return buf

    def _stream_is_misconfigured(stream):
        """A stream is misconfigured if its encoding is ASCII."""
        # If the stream does not have an encoding set, we assume it's set
        # to ASCII.  This appears to happen in certain unittest
        # environments.  It's not quite clear what the correct behavior is
        # but this at least will force Click to recover somehow.
        return is_ascii_encoding(getattr(stream, "encoding", None) or "ascii")

    def _is_compat_stream_attr(stream, attr, value):
        """A stream attribute is compatible if it is equal to the
        desired value or the desired value is unset and the attribute
        has a value.
        """
        stream_value = getattr(stream, attr, None)
        return stream_value == value or (value is None and stream_value is not None)

    def _is_compatible_text_stream(stream, encoding, errors):
        """Check if a stream's encoding and errors attributes are
        compatible with the desired values.
        """
        return _is_compat_stream_attr(
            stream, "encoding", encoding
        ) and _is_compat_stream_attr(stream, "errors", errors)

    def _force_correct_text_stream(
        text_stream,
        encoding,
        errors,
        is_binary,
        find_binary,
        force_readable=False,
        force_writable=False,
    ):
        if is_binary(text_stream, False):
            binary_reader = text_stream
        else:
            # If the stream looks compatible, and won't default to a
            # misconfigured ascii encoding, return it as-is.
            if _is_compatible_text_stream(text_stream, encoding, errors) and not (
                encoding is None and _stream_is_misconfigured(text_stream)
            ):
                return text_stream

            # Otherwise, get the underlying binary reader.
            binary_reader = find_binary(text_stream)

            # If that's not possible, silently use the original reader
            # and get mojibake instead of exceptions.
            if binary_reader is None:
                return text_stream

        # Default errors to replace instead of strict in order to get
        # something that works.
        if errors is None:
            errors = "replace"

        # Wrap the binary stream in a text stream with the correct
        # encoding parameters.
        return _make_text_stream(
            binary_reader,
            encoding,
            errors,
            force_readable=force_readable,
            force_writable=force_writable,
        )

    def _force_correct_text_reader(text_reader, encoding, errors, force_readable=False):
        return _force_correct_text_stream(
            text_reader,
            encoding,
            errors,
            _is_binary_reader,
            _find_binary_reader,
            force_readable=force_readable,
        )

    def _force_correct_text_writer(text_writer, encoding, errors, force_writable=False):
        return _force_correct_text_stream(
            text_writer,
            encoding,
            errors,
            _is_binary_writer,
            _find_binary_writer,
            force_writable=force_writable,
        )

    def get_binary_stdin():
        reader = _find_binary_reader(sys.stdin)
        if reader is None:
            raise RuntimeError("Was not able to determine binary stream for sys.stdin.")
        return reader

    def get_binary_stdout():
        writer = _find_binary_writer(sys.stdout)
        if writer is None:
            raise RuntimeError(
                "Was not able to determine binary stream for sys.stdout."
            )
        return writer

    def get_binary_stderr():
        writer = _find_binary_writer(sys.stderr)
        if writer is None:
            raise RuntimeError(
                "Was not able to determine binary stream for sys.stderr."
            )
        return writer

    def get_text_stdin(encoding=None, errors=None):
        rv = _get_windows_console_stream(sys.stdin, encoding, errors)
        if rv is not None:
            return rv
        return _force_correct_text_reader(
            sys.stdin, encoding, errors, force_readable=True
        )

    def get_text_stdout(encoding=None, errors=None):
        rv = _get_windows_console_stream(sys.stdout, encoding, errors)
        if rv is not None:
            return rv
        return _force_correct_text_writer(
            sys.stdout, encoding, errors, force_writable=True
        )

    def get_text_stderr(encoding=None, errors=None):
        rv = _get_windows_console_stream(sys.stderr, encoding, errors)
        if rv is not None:
            return rv
        return _force_correct_text_writer(
            sys.stderr, encoding, errors, force_writable=True
        )

    def filename_to_ui(value):
        if isinstance(value, bytes):
            value = value.decode(get_filesystem_encoding(), "replace")
        else:
            value = value.encode("utf-8", "surrogateescape").decode("utf-8", "replace")
        return value


def get_streerror(e, default=None):
    if hasattr(e, "strerror"):
        msg = e.strerror
    else:
        if default is not None:
            msg = default
        else:
            msg = str(e)
    if isinstance(msg, bytes):
        msg = msg.decode("utf-8", "replace")
    return msg


def _wrap_io_open(file, mode, encoding, errors):
    """On Python 2, :func:`io.open` returns a text file wrapper that
    requires passing ``unicode`` to ``write``. Need to open the file in
    binary mode then wrap it in a subclass that can write ``str`` and
    ``unicode``.

    Also handles not passing ``encoding`` and ``errors`` in binary mode.
    """
    binary = "b" in mode

    if binary:
        kwargs = {}
    else:
        kwargs = {"encoding": encoding, "errors": errors}

    if not PY2 or binary:
        return io.open(file, mode, **kwargs)

    f = io.open(file, "{}b".format(mode.replace("t", "")))
    return _make_text_stream(f, **kwargs)


def open_stream(filename, mode="r", encoding=None, errors="strict", atomic=False):
    binary = "b" in mode

    # Standard streams first.  These are simple because they don't need
    # special handling for the atomic flag.  It's entirely ignored.
    if filename == "-":
        if any(m in mode for m in ["w", "a", "x"]):
            if binary:
                return get_binary_stdout(), False
            return get_text_stdout(encoding=encoding, errors=errors), False
        if binary:
            return get_binary_stdin(), False
        return get_text_stdin(encoding=encoding, errors=errors), False

    # Non-atomic writes directly go out through the regular open functions.
    if not atomic:
        return _wrap_io_open(filename, mode, encoding, errors), True

    # Some usability stuff for atomic writes
    if "a" in mode:
        raise ValueError(
            "Appending to an existing file is not supported, because that"
            " would involve an expensive `copy`-operation to a temporary"
            " file. Open the file in normal `w`-mode and copy explicitly"
            " if that's what you're after."
        )
    if "x" in mode:
        raise ValueError("Use the `overwrite`-parameter instead.")
    if "w" not in mode:
        raise ValueError("Atomic writes only make sense with `w`-mode.")

    # Atomic writes are more complicated.  They work by opening a file
    # as a proxy in the same folder and then using the fdopen
    # functionality to wrap it in a Python file.  Then we wrap it in an
    # atomic file that moves the file over on close.
    import errno
    import random

    try:
        perm = os.stat(filename).st_mode
    except OSError:
        perm = None

    flags = os.O_RDWR | os.O_CREAT | os.O_EXCL

    if binary:
        flags |= getattr(os, "O_BINARY", 0)

    while True:
        tmp_filename = os.path.join(
            os.path.dirname(filename),
            ".__atomic-write{:08x}".format(random.randrange(1 << 32)),
        )
        try:
            fd = os.open(tmp_filename, flags, 0o666 if perm is None else perm)
            break
        except OSError as e:
            if e.errno == errno.EEXIST or (
                os.name == "nt"
                and e.errno == errno.EACCES
                and os.path.isdir(e.filename)
                and os.access(e.filename, os.W_OK)
            ):
                continue
            raise

    if perm is not None:
        os.chmod(tmp_filename, perm)  # in case perm includes bits in umask

    f = _wrap_io_open(fd, mode, encoding, errors)
    return _AtomicFile(f, tmp_filename, os.path.realpath(filename)), True


# Used in a destructor call, needs extra protection from interpreter cleanup.
if hasattr(os, "replace"):
    _replace = os.replace
    _can_replace = True
else:
    _replace = os.rename
    _can_replace = not WIN


class _AtomicFile(object):
    def __init__(self, f, tmp_filename, real_filename):
        self._f = f
        self._tmp_filename = tmp_filename
        self._real_filename = real_filename
        self.closed = False

    @property
    def name(self):
        return self._real_filename

    def close(self, delete=False):
        if self.closed:
            return
        self._f.close()
        if not _can_replace:
            try:
                os.remove(self._real_filename)
            except OSError:
                pass
        _replace(self._tmp_filename, self._real_filename)
        self.closed = True

    def __getattr__(self, name):
        return getattr(self._f, name)

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_value, tb):
        self.close(delete=exc_type is not None)

    def __repr__(self):
        return repr(self._f)


auto_wrap_for_ansi = None
colorama = None
get_winterm_size = None


def strip_ansi(value):
    return _ansi_re.sub("", value)


def _is_jupyter_kernel_output(stream):
    if WIN:
        # TODO: Couldn't test on Windows, should't try to support until
        # someone tests the details wrt colorama.
        return

    while isinstance(stream, (_FixupStream, _NonClosingTextIOWrapper)):
        stream = stream._stream

    return stream.__class__.__module__.startswith("ipykernel.")


def should_strip_ansi(stream=None, color=None):
    if color is None:
        if stream is None:
            stream = sys.stdin
        return not isatty(stream) and not _is_jupyter_kernel_output(stream)
    return not color


# If we're on Windows, we provide transparent integration through
# colorama.  This will make ANSI colors through the echo function
# work automatically.
if WIN:
    # Windows has a smaller terminal
    DEFAULT_COLUMNS = 79

    from ._winconsole import _get_windows_console_stream, _wrap_std_stream

    def _get_argv_encoding():
        import locale

        return locale.getpreferredencoding()

    if PY2:

        def raw_input(prompt=""):
            sys.stderr.flush()
            if prompt:
                stdout = _default_text_stdout()
                stdout.write(prompt)
            stdin = _default_text_stdin()
            return stdin.readline().rstrip("\r\n")

    try:
        import colorama
    except ImportError:
        pass
    else:
        _ansi_stream_wrappers = WeakKeyDictionary()

        def auto_wrap_for_ansi(stream, color=None):
            """This function wraps a stream so that calls through colorama
            are issued to the win32 console API to recolor on demand.  It
            also ensures to reset the colors if a write call is interrupted
            to not destroy the console afterwards.
            """
            try:
                cached = _ansi_stream_wrappers.get(stream)
            except Exception:
                cached = None
            if cached is not None:
                return cached
            strip = should_strip_ansi(stream, color)
            ansi_wrapper = colorama.AnsiToWin32(stream, strip=strip)
            rv = ansi_wrapper.stream
            _write = rv.write

            def _safe_write(s):
                try:
                    return _write(s)
                except:
                    ansi_wrapper.reset_all()
                    raise

            rv.write = _safe_write
            try:
                _ansi_stream_wrappers[stream] = rv
            except Exception:
                pass
            return rv

        def get_winterm_size():
            win = colorama.win32.GetConsoleScreenBufferInfo(
                colorama.win32.STDOUT
            ).srWindow
            return win.Right - win.Left, win.Bottom - win.Top


else:

    def _get_argv_encoding():
        return getattr(sys.stdin, "encoding", None) or get_filesystem_encoding()

    _get_windows_console_stream = lambda *x: None
    _wrap_std_stream = lambda *x: None


def term_len(x):
    return len(strip_ansi(x))


def isatty(stream):
    try:
        return stream.isatty()
    except Exception:
        return False


def _make_cached_stream_func(src_func, wrapper_func):
    cache = WeakKeyDictionary()

    def func():
        stream = src_func()
        try:
            rv = cache.get(stream)
        except Exception:
            rv = None
        if rv is not None:
            return rv
        rv = wrapper_func()
        try:
            stream = src_func()  # In case wrapper_func() modified the stream
            cache[stream] = rv
        except Exception:
            pass
        return rv

    return func


_default_text_stdin = _make_cached_stream_func(lambda: sys.stdin, get_text_stdin)
_default_text_stdout = _make_cached_stream_func(lambda: sys.stdout, get_text_stdout)
_default_text_stderr = _make_cached_stream_func(lambda: sys.stderr, get_text_stderr)


binary_streams = {
    "stdin": get_binary_stdin,
    "stdout": get_binary_stdout,
    "stderr": get_binary_stderr,
}

text_streams = {
    "stdin": get_text_stdin,
    "stdout": get_text_stdout,
    "stderr": get_text_stderr,
}