pycompat: remove large Python 2 block

We no longer support Python 2. So we can delete its compatibility
code and remove the conditional and dedent the Python 3 code.

In order to make the linter happy, we had to inline imports in the
stanza at the top of the file.

Differential Revision: https://phab.mercurial-scm.org/D12250

mercurial/pycompat.py

@@ -1,527 +1,471 b''
 # 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.
 """
 
 from __future__ import absolute_import
 
 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 pickle
 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 ispy3:
-    import builtins
-    import codecs
-    import functools
-    import io
-    import struct
-
     if os.name == r'nt' and sys.version_info >= (3, 6):
         # 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)
     bytesio = io.BytesIO
     # TODO deprecate stringio name, as it is a lie on Python 3.
     stringio = bytesio
 
+
     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(object):
         ...     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()
 
     # Python 3.5's json.load and json.loads require str. We polyfill its
     # code for detecting encoding from bytes.
     if sys.version_info[0:2] < (3, 6):
 
         def _detect_encoding(b):
             bstartswith = b.startswith
             if bstartswith((codecs.BOM_UTF32_BE, codecs.BOM_UTF32_LE)):
                 return 'utf-32'
             if bstartswith((codecs.BOM_UTF16_BE, codecs.BOM_UTF16_LE)):
                 return 'utf-16'
             if bstartswith(codecs.BOM_UTF8):
                 return 'utf-8-sig'
 
             if len(b) >= 4:
                 if not b[0]:
                     # 00 00 -- -- - utf-32-be
                     # 00 XX -- -- - utf-16-be
                     return 'utf-16-be' if b[1] else 'utf-32-be'
                 if not b[1]:
                     # XX 00 00 00 - utf-32-le
                     # XX 00 00 XX - utf-16-le
                     # XX 00 XX -- - utf-16-le
                     return 'utf-16-le' if b[2] or b[3] else 'utf-32-le'
             elif len(b) == 2:
                 if not b[0]:
                     # 00 XX - utf-16-be
                     return 'utf-16-be'
                 if not b[1]:
                     # XX 00 - utf-16-le
                     return 'utf-16-le'
             # default
             return 'utf-8'
 
         def json_loads(s, *args, **kwargs):
             if isinstance(s, (bytes, bytearray)):
                 s = s.decode(_detect_encoding(s), 'surrogatepass')
 
             return json.loads(s, *args, **kwargs)
 
-    else:
-        json_loads = json.loads
 
 else:
-    import cStringIO
-
-    xrange = xrange
-    unicode = unicode
-    bytechr = chr
-    byterepr = repr
-    bytestr = str
-    iterbytestr = iter
-    maybebytestr = identity
-    sysbytes = identity
-    sysstr = identity
-    strurl = identity
-    bytesurl = identity
-    open = open
-    delattr = delattr
-    getattr = getattr
-    hasattr = hasattr
-    setattr = setattr
-
-    # this can't be parsed on Python 3
-    exec(b'def raisewithtb(exc, tb):\n    raise exc, None, tb\n')
-
-    def fsencode(filename):
-        """
-        Partial backport from os.py in Python 3, which only accepts bytes.
-        In Python 2, our paths should only ever be bytes, a unicode path
-        indicates a bug.
-        """
-        if isinstance(filename, str):
-            return filename
-        else:
-            raise TypeError("expect str, not %s" % type(filename).__name__)
-
-    # In Python 2, fsdecode() has a very chance to receive bytes. So it's
-    # better not to touch Python 2 part as it's already working fine.
-    fsdecode = identity
-
-    def getdoc(obj):
-        return getattr(obj, '__doc__', None)
-
-    _notset = object()
-
-    def safehasattr(thing, attr):
-        return getattr(thing, attr, _notset) is not _notset
-
-    def _getoptbwrapper(orig, args, shortlist, namelist):
-        return orig(args, shortlist, namelist)
-
-    strkwargs = identity
-    byteskwargs = identity
-
-    oscurdir = os.curdir
-    oslinesep = os.linesep
-    osname = os.name
-    ospathsep = os.pathsep
-    ospardir = os.pardir
-    ossep = os.sep
-    osaltsep = os.altsep
-    osdevnull = os.devnull
-    long = long
-    if getattr(sys, 'argv', None) is not None:
-        sysargv = sys.argv
-    sysplatform = sys.platform
-    sysexecutable = sys.executable
-    shlexsplit = shlex.split
-    bytesio = cStringIO.StringIO
-    stringio = bytesio
-    maplist = map
-    rangelist = range
-    ziplist = zip
-    rawinput = raw_input
-    getargspec = inspect.getargspec
-    iteritems = lambda x: x.iteritems()
-    itervalues = lambda x: x.itervalues()
     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
     )