JezK
Edit File: _compat.py
import codecs import io import os import re import sys import typing as t from weakref import WeakKeyDictionary 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 auto_wrap_for_ansi: t.Optional[t.Callable[[t.TextIO], t.TextIO]] = None _ansi_re = re.compile(r"\033\[[;?0-9]*[a-zA-Z]") def get_filesystem_encoding() -> str: return sys.getfilesystemencoding() or sys.getdefaultencoding() def _make_text_stream( stream: t.BinaryIO, encoding: t.Optional[str], errors: t.Optional[str], force_readable: bool = False, force_writable: bool = False, ) -> t.TextIO: 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: str) -> bool: """Checks if a given encoding is ascii.""" try: return codecs.lookup(encoding).name == "ascii" except LookupError: return False def get_best_encoding(stream: t.IO) -> str: """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: t.BinaryIO, encoding: t.Optional[str], errors: t.Optional[str], force_readable: bool = False, force_writable: bool = False, **extra: t.Any, ) -> None: self._stream = stream = t.cast( t.BinaryIO, _FixupStream(stream, force_readable, force_writable) ) super().__init__(stream, encoding, errors, **extra) def __del__(self) -> None: try: self.detach() except Exception: pass def isatty(self) -> bool: # https://bitbucket.org/pypy/pypy/issue/1803 return self._stream.isatty() class _FixupStream: """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: t.BinaryIO, force_readable: bool = False, force_writable: bool = False, ): self._stream = stream self._force_readable = force_readable self._force_writable = force_writable def __getattr__(self, name: str) -> t.Any: return getattr(self._stream, name) def read1(self, size: int) -> bytes: f = getattr(self._stream, "read1", None) if f is not None: return t.cast(bytes, f(size)) return self._stream.read(size) def readable(self) -> bool: if self._force_readable: return True x = getattr(self._stream, "readable", None) if x is not None: return t.cast(bool, x()) try: self._stream.read(0) except Exception: return False return True def writable(self) -> bool: if self._force_writable: return True x = getattr(self._stream, "writable", None) if x is not None: return t.cast(bool, x()) try: self._stream.write("") # type: ignore except Exception: try: self._stream.write(b"") except Exception: return False return True def seekable(self) -> bool: x = getattr(self._stream, "seekable", None) if x is not None: return t.cast(bool, x()) try: self._stream.seek(self._stream.tell()) except Exception: return False return True def _is_binary_reader(stream: t.IO, default: bool = False) -> bool: 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: t.IO, default: bool = False) -> bool: try: stream.write(b"") except Exception: try: stream.write("") return False except Exception: pass return default return True def _find_binary_reader(stream: t.IO) -> t.Optional[t.BinaryIO]: # 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 t.cast(t.BinaryIO, 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 t.cast(t.BinaryIO, buf) return None def _find_binary_writer(stream: t.IO) -> t.Optional[t.BinaryIO]: # 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_writer(stream, False): return t.cast(t.BinaryIO, 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 t.cast(t.BinaryIO, buf) return None def _stream_is_misconfigured(stream: t.TextIO) -> bool: """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: t.TextIO, attr: str, value: t.Optional[str]) -> bool: """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: t.TextIO, encoding: t.Optional[str], errors: t.Optional[str] ) -> bool: """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: t.IO, encoding: t.Optional[str], errors: t.Optional[str], is_binary: t.Callable[[t.IO, bool], bool], find_binary: t.Callable[[t.IO], t.Optional[t.BinaryIO]], force_readable: bool = False, force_writable: bool = False, ) -> t.TextIO: if is_binary(text_stream, False): binary_reader = t.cast(t.BinaryIO, text_stream) else: text_stream = t.cast(t.TextIO, text_stream) # 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. possible_binary_reader = find_binary(text_stream) # If that's not possible, silently use the original reader # and get mojibake instead of exceptions. if possible_binary_reader is None: return text_stream binary_reader = possible_binary_reader # 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: t.IO, encoding: t.Optional[str], errors: t.Optional[str], force_readable: bool = False, ) -> t.TextIO: 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: t.IO, encoding: t.Optional[str], errors: t.Optional[str], force_writable: bool = False, ) -> t.TextIO: return _force_correct_text_stream( text_writer, encoding, errors, _is_binary_writer, _find_binary_writer, force_writable=force_writable, ) def get_binary_stdin() -> t.BinaryIO: 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() -> t.BinaryIO: 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() -> t.BinaryIO: 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: t.Optional[str] = None, errors: t.Optional[str] = None ) -> t.TextIO: 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: t.Optional[str] = None, errors: t.Optional[str] = None ) -> t.TextIO: 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: t.Optional[str] = None, errors: t.Optional[str] = None ) -> t.TextIO: 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 _wrap_io_open( file: t.Union[str, os.PathLike, int], mode: str, encoding: t.Optional[str], errors: t.Optional[str], ) -> t.IO: """Handles not passing ``encoding`` and ``errors`` in binary mode.""" if "b" in mode: return open(file, mode) return open(file, mode, encoding=encoding, errors=errors) def open_stream( filename: str, mode: str = "r", encoding: t.Optional[str] = None, errors: t.Optional[str] = "strict", atomic: bool = False, ) -> t.Tuple[t.IO, bool]: binary = "b" in mode # Standard streams first. These are simple because they ignore the # atomic flag. Use fsdecode to handle Path("-"). if os.fsdecode(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: t.Optional[int] = 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), f".__atomic-write{random.randrange(1 << 32):08x}", ) 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) af = _AtomicFile(f, tmp_filename, os.path.realpath(filename)) return t.cast(t.IO, af), True class _AtomicFile: def __init__(self, f: t.IO, tmp_filename: str, real_filename: str) -> None: self._f = f self._tmp_filename = tmp_filename self._real_filename = real_filename self.closed = False @property def name(self) -> str: return self._real_filename def close(self, delete: bool = False) -> None: if self.closed: return self._f.close() os.replace(self._tmp_filename, self._real_filename) self.closed = True def __getattr__(self, name: str) -> t.Any: return getattr(self._f, name) def __enter__(self) -> "_AtomicFile": return self def __exit__(self, exc_type, exc_value, tb): # type: ignore self.close(delete=exc_type is not None) def __repr__(self) -> str: return repr(self._f) def strip_ansi(value: str) -> str: return _ansi_re.sub("", value) def _is_jupyter_kernel_output(stream: t.IO) -> bool: while isinstance(stream, (_FixupStream, _NonClosingTextIOWrapper)): stream = stream._stream return stream.__class__.__module__.startswith("ipykernel.") def should_strip_ansi( stream: t.Optional[t.IO] = None, color: t.Optional[bool] = None ) -> bool: 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 # On Windows, wrap the output streams with colorama to support ANSI # color codes. # NOTE: double check is needed so mypy does not analyze this on Linux if sys.platform.startswith("win") and WIN: from ._winconsole import _get_windows_console_stream def _get_argv_encoding() -> str: import locale return locale.getpreferredencoding() _ansi_stream_wrappers: t.MutableMapping[t.TextIO, t.TextIO] = WeakKeyDictionary() def auto_wrap_for_ansi( stream: t.TextIO, color: t.Optional[bool] = None ) -> t.TextIO: """Support ANSI color and style codes on Windows by wrapping a stream with colorama. """ try: cached = _ansi_stream_wrappers.get(stream) except Exception: cached = None if cached is not None: return cached import colorama strip = should_strip_ansi(stream, color) ansi_wrapper = colorama.AnsiToWin32(stream, strip=strip) rv = t.cast(t.TextIO, ansi_wrapper.stream) _write = rv.write def _safe_write(s): try: return _write(s) except BaseException: ansi_wrapper.reset_all() raise rv.write = _safe_write try: _ansi_stream_wrappers[stream] = rv except Exception: pass return rv else: def _get_argv_encoding() -> str: return getattr(sys.stdin, "encoding", None) or get_filesystem_encoding() def _get_windows_console_stream( f: t.TextIO, encoding: t.Optional[str], errors: t.Optional[str] ) -> t.Optional[t.TextIO]: return None def term_len(x: str) -> int: return len(strip_ansi(x)) def isatty(stream: t.IO) -> bool: try: return stream.isatty() except Exception: return False def _make_cached_stream_func( src_func: t.Callable[[], t.TextIO], wrapper_func: t.Callable[[], t.TextIO] ) -> t.Callable[[], t.TextIO]: cache: t.MutableMapping[t.TextIO, t.TextIO] = WeakKeyDictionary() def func() -> t.TextIO: stream = src_func() try: rv = cache.get(stream) except Exception: rv = None if rv is not None: return rv rv = wrapper_func() try: 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: t.Mapping[str, t.Callable[[], t.BinaryIO]] = { "stdin": get_binary_stdin, "stdout": get_binary_stdout, "stderr": get_binary_stderr, } text_streams: t.Mapping[ str, t.Callable[[t.Optional[str], t.Optional[str]], t.TextIO] ] = { "stdin": get_text_stdin, "stdout": get_text_stdout, "stderr": get_text_stderr, }