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view mercurial/pycompat.py @ 49263:63fd0282ad40
node: stop converting binascii.Error to TypeError in bin()
Changeset f574cc00831a introduced the wrapper, to make bin() behave like on
Python 2, where it raised TypeError in many cases. Another previous approach,
changing callers to catch binascii.Error in addition to TypeError, was backed
out after negative review feedback [1].
However, I think it?s worth reconsidering the approach. Now that we?re on
Python 3 only, callers have to catch only binascii.Error instead of both.
Catching binascii.Error instead of TypeError has the advantage that it?s less
likely to cover a programming error (e.g. passing an int to bin() raises
TypeError). Also, raising TypeError never made sense semantically when bin()
got an argument of valid type.
As a side-effect, this fixed an exception in test-http-bad-server.t. The TODO
was outdated: it was not an uncaught ValueError in batch.results() but uncaught
TypeError from the now removed wrapper. Now that bin() raises binascii.Error
instead of TypeError, it gets converted to a proper error in
wirepeer.heads.<locals>.decode() that catches ValueError (superclass of
binascii.Error). This is a good example of why this changeset is a good idea.
Catching TypeError instead of ValueError there would not make much sense.
[1] https://phab.mercurial-scm.org/D2244
author | Manuel Jacob <me@manueljacob.de> |
---|---|
date | Mon, 30 May 2022 16:18:12 +0200 |
parents | e45c39273395 |
children | 9cd327509cd4 |
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# pycompat.py - portability shim for python 3 # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Mercurial portability shim for python 3. This contains aliases to hide python version-specific details from the core. """ import builtins import codecs import concurrent.futures as futures import functools import getopt import http.client as httplib import http.cookiejar as cookielib import inspect import io import json import os import queue import shlex import socketserver import struct import sys import tempfile import xmlrpc.client as xmlrpclib ispy3 = sys.version_info[0] >= 3 ispypy = '__pypy__' in sys.builtin_module_names TYPE_CHECKING = False if not globals(): # hide this from non-pytype users import typing TYPE_CHECKING = typing.TYPE_CHECKING def future_set_exception_info(f, exc_info): f.set_exception(exc_info[0]) FileNotFoundError = builtins.FileNotFoundError def identity(a): return a def _rapply(f, xs): if xs is None: # assume None means non-value of optional data return xs if isinstance(xs, (list, set, tuple)): return type(xs)(_rapply(f, x) for x in xs) if isinstance(xs, dict): return type(xs)((_rapply(f, k), _rapply(f, v)) for k, v in xs.items()) return f(xs) def rapply(f, xs): """Apply function recursively to every item preserving the data structure >>> def f(x): ... return 'f(%s)' % x >>> rapply(f, None) is None True >>> rapply(f, 'a') 'f(a)' >>> rapply(f, {'a'}) == {'f(a)'} True >>> rapply(f, ['a', 'b', None, {'c': 'd'}, []]) ['f(a)', 'f(b)', None, {'f(c)': 'f(d)'}, []] >>> xs = [object()] >>> rapply(identity, xs) is xs True """ if f is identity: # fast path mainly for py2 return xs return _rapply(f, xs) if os.name == r'nt': # MBCS (or ANSI) filesystem encoding must be used as before. # Otherwise non-ASCII filenames in existing repositories would be # corrupted. # This must be set once prior to any fsencode/fsdecode calls. sys._enablelegacywindowsfsencoding() # pytype: disable=module-attr fsencode = os.fsencode fsdecode = os.fsdecode oscurdir = os.curdir.encode('ascii') oslinesep = os.linesep.encode('ascii') osname = os.name.encode('ascii') ospathsep = os.pathsep.encode('ascii') ospardir = os.pardir.encode('ascii') ossep = os.sep.encode('ascii') osaltsep = os.altsep if osaltsep: osaltsep = osaltsep.encode('ascii') osdevnull = os.devnull.encode('ascii') sysplatform = sys.platform.encode('ascii') sysexecutable = sys.executable if sysexecutable: sysexecutable = os.fsencode(sysexecutable) def maplist(*args): return list(map(*args)) def rangelist(*args): return list(range(*args)) def ziplist(*args): return list(zip(*args)) rawinput = input getargspec = inspect.getfullargspec long = int if getattr(sys, 'argv', None) is not None: # On POSIX, the char** argv array is converted to Python str using # Py_DecodeLocale(). The inverse of this is Py_EncodeLocale(), which # isn't directly callable from Python code. In practice, os.fsencode() # can be used instead (this is recommended by Python's documentation # for sys.argv). # # On Windows, the wchar_t **argv is passed into the interpreter as-is. # Like POSIX, we need to emulate what Py_EncodeLocale() would do. But # there's an additional wrinkle. What we really want to access is the # ANSI codepage representation of the arguments, as this is what # `int main()` would receive if Python 3 didn't define `int wmain()` # (this is how Python 2 worked). To get that, we encode with the mbcs # encoding, which will pass CP_ACP to the underlying Windows API to # produce bytes. if os.name == r'nt': sysargv = [a.encode("mbcs", "ignore") for a in sys.argv] else: sysargv = [fsencode(a) for a in sys.argv] bytechr = struct.Struct('>B').pack byterepr = b'%r'.__mod__ class bytestr(bytes): """A bytes which mostly acts as a Python 2 str >>> bytestr(), bytestr(bytearray(b'foo')), bytestr(u'ascii'), bytestr(1) ('', 'foo', 'ascii', '1') >>> s = bytestr(b'foo') >>> assert s is bytestr(s) __bytes__() should be called if provided: >>> class bytesable: ... def __bytes__(self): ... return b'bytes' >>> bytestr(bytesable()) 'bytes' There's no implicit conversion from non-ascii str as its encoding is unknown: >>> bytestr(chr(0x80)) # doctest: +ELLIPSIS Traceback (most recent call last): ... UnicodeEncodeError: ... Comparison between bytestr and bytes should work: >>> assert bytestr(b'foo') == b'foo' >>> assert b'foo' == bytestr(b'foo') >>> assert b'f' in bytestr(b'foo') >>> assert bytestr(b'f') in b'foo' Sliced elements should be bytes, not integer: >>> s[1], s[:2] (b'o', b'fo') >>> list(s), list(reversed(s)) ([b'f', b'o', b'o'], [b'o', b'o', b'f']) As bytestr type isn't propagated across operations, you need to cast bytes to bytestr explicitly: >>> s = bytestr(b'foo').upper() >>> t = bytestr(s) >>> s[0], t[0] (70, b'F') Be careful to not pass a bytestr object to a function which expects bytearray-like behavior. >>> t = bytes(t) # cast to bytes >>> assert type(t) is bytes """ # Trick pytype into not demanding Iterable[int] be passed to __new__(), # since the appropriate bytes format is done internally. # # https://github.com/google/pytype/issues/500 if TYPE_CHECKING: def __init__(self, s=b''): pass def __new__(cls, s=b''): if isinstance(s, bytestr): return s if not isinstance( s, (bytes, bytearray) ) and not hasattr( # hasattr-py3-only s, u'__bytes__' ): s = str(s).encode('ascii') return bytes.__new__(cls, s) def __getitem__(self, key): s = bytes.__getitem__(self, key) if not isinstance(s, bytes): s = bytechr(s) return s def __iter__(self): return iterbytestr(bytes.__iter__(self)) def __repr__(self): return bytes.__repr__(self)[1:] # drop b'' def iterbytestr(s): """Iterate bytes as if it were a str object of Python 2""" return map(bytechr, s) def maybebytestr(s): """Promote bytes to bytestr""" if isinstance(s, bytes): return bytestr(s) return s def sysbytes(s): """Convert an internal str (e.g. keyword, __doc__) back to bytes This never raises UnicodeEncodeError, but only ASCII characters can be round-trip by sysstr(sysbytes(s)). """ if isinstance(s, bytes): return s return s.encode('utf-8') def sysstr(s): """Return a keyword str to be passed to Python functions such as getattr() and str.encode() This never raises UnicodeDecodeError. Non-ascii characters are considered invalid and mapped to arbitrary but unique code points such that 'sysstr(a) != sysstr(b)' for all 'a != b'. """ if isinstance(s, builtins.str): return s return s.decode('latin-1') def strurl(url): """Converts a bytes url back to str""" if isinstance(url, bytes): return url.decode('ascii') return url def bytesurl(url): """Converts a str url to bytes by encoding in ascii""" if isinstance(url, str): return url.encode('ascii') return url def raisewithtb(exc, tb): """Raise exception with the given traceback""" raise exc.with_traceback(tb) def getdoc(obj): """Get docstring as bytes; may be None so gettext() won't confuse it with _('')""" doc = getattr(obj, '__doc__', None) if doc is None: return doc return sysbytes(doc) def _wrapattrfunc(f): @functools.wraps(f) def w(object, name, *args): return f(object, sysstr(name), *args) return w # these wrappers are automagically imported by hgloader delattr = _wrapattrfunc(builtins.delattr) getattr = _wrapattrfunc(builtins.getattr) hasattr = _wrapattrfunc(builtins.hasattr) setattr = _wrapattrfunc(builtins.setattr) xrange = builtins.range unicode = str def open(name, mode=b'r', buffering=-1, encoding=None): return builtins.open(name, sysstr(mode), buffering, encoding) safehasattr = _wrapattrfunc(builtins.hasattr) def _getoptbwrapper(orig, args, shortlist, namelist): """ Takes bytes arguments, converts them to unicode, pass them to getopt.getopt(), convert the returned values back to bytes and then return them for Python 3 compatibility as getopt.getopt() don't accepts bytes on Python 3. """ args = [a.decode('latin-1') for a in args] shortlist = shortlist.decode('latin-1') namelist = [a.decode('latin-1') for a in namelist] opts, args = orig(args, shortlist, namelist) opts = [(a[0].encode('latin-1'), a[1].encode('latin-1')) for a in opts] args = [a.encode('latin-1') for a in args] return opts, args def strkwargs(dic): """ Converts the keys of a python dictonary to str i.e. unicodes so that they can be passed as keyword arguments as dictionaries with bytes keys can't be passed as keyword arguments to functions on Python 3. """ dic = {k.decode('latin-1'): v for k, v in dic.items()} return dic def byteskwargs(dic): """ Converts keys of python dictionaries to bytes as they were converted to str to pass that dictonary as a keyword argument on Python 3. """ dic = {k.encode('latin-1'): v for k, v in dic.items()} return dic # TODO: handle shlex.shlex(). def shlexsplit(s, comments=False, posix=True): """ Takes bytes argument, convert it to str i.e. unicodes, pass that into shlex.split(), convert the returned value to bytes and return that for Python 3 compatibility as shelx.split() don't accept bytes on Python 3. """ ret = shlex.split(s.decode('latin-1'), comments, posix) return [a.encode('latin-1') for a in ret] iteritems = lambda x: x.items() itervalues = lambda x: x.values() json_loads = json.loads isjython = sysplatform.startswith(b'java') isdarwin = sysplatform.startswith(b'darwin') islinux = sysplatform.startswith(b'linux') isposix = osname == b'posix' iswindows = osname == b'nt' def getoptb(args, shortlist, namelist): return _getoptbwrapper(getopt.getopt, args, shortlist, namelist) def gnugetoptb(args, shortlist, namelist): return _getoptbwrapper(getopt.gnu_getopt, args, shortlist, namelist) def mkdtemp(suffix=b'', prefix=b'tmp', dir=None): return tempfile.mkdtemp(suffix, prefix, dir) # text=True is not supported; use util.from/tonativeeol() instead def mkstemp(suffix=b'', prefix=b'tmp', dir=None): return tempfile.mkstemp(suffix, prefix, dir) # TemporaryFile does not support an "encoding=" argument on python2. # This wrapper file are always open in byte mode. def unnamedtempfile(mode=None, *args, **kwargs): if mode is None: mode = 'w+b' else: mode = sysstr(mode) assert 'b' in mode return tempfile.TemporaryFile(mode, *args, **kwargs) # NamedTemporaryFile does not support an "encoding=" argument on python2. # This wrapper file are always open in byte mode. def namedtempfile( mode=b'w+b', bufsize=-1, suffix=b'', prefix=b'tmp', dir=None, delete=True ): mode = sysstr(mode) assert 'b' in mode return tempfile.NamedTemporaryFile( mode, bufsize, suffix=suffix, prefix=prefix, dir=dir, delete=delete )