view mercurial/urllibcompat.py @ 50662:12f13b13f414 stable

revlog: avoid possible collision between directory and temporary index

Since 6.4, we create a temporary index file to write the split data without
overwriting the inline version too early. However, the store encoding does not
prevent these new `.i.s` file to collide with a directory with the same name.
While the odds for such a collision to happens are fairly low, the collision
would prevent Mercurial from working.

The store encoding have a mitigation solution in place to prevent such
collisions from happening for `.i` and `.d` files, but not for other extensions.
We cannot update this encoding scheme to solve the issue since it would diverge
from older version of Mercurial.

Instead, we create an alternative directory tree dedicated to such files.
The use of the `.i` extension combined with store encoding will prevent
collisions there.

# urllibcompat.py - adapters to ease using urllib2 on Py2 and urllib on Py3
#
# Copyright 2017 Google, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import http.server
import urllib.error
import urllib.parse
import urllib.request
import urllib.response

from .pycompat import getattr
from . import pycompat

_sysstr = pycompat.sysstr


class _pycompatstub:
    def __init__(self):
        self._aliases = {}

    def _registeraliases(self, origin, items):
        """Add items that will be populated at the first access"""
        items = map(_sysstr, items)
        self._aliases.update(
            (item.replace('_', '').lower(), (origin, item)) for item in items
        )

    def _registeralias(self, origin, attr, name):
        """Alias ``origin``.``attr`` as ``name``"""
        self._aliases[_sysstr(name)] = (origin, _sysstr(attr))

    def __getattr__(self, name):
        try:
            origin, item = self._aliases[name]
        except KeyError:
            raise AttributeError(name)
        self.__dict__[name] = obj = getattr(origin, item)
        return obj


httpserver = _pycompatstub()
urlreq = _pycompatstub()
urlerr = _pycompatstub()

urlreq._registeraliases(
    urllib.parse,
    (
        b"splitattr",
        b"splitpasswd",
        b"splitport",
        b"splituser",
        b"urlparse",
        b"urlunparse",
    ),
)
urlreq._registeralias(urllib.parse, b"parse_qs", b"parseqs")
urlreq._registeralias(urllib.parse, b"parse_qsl", b"parseqsl")
urlreq._registeralias(urllib.parse, b"unquote_to_bytes", b"unquote")

urlreq._registeraliases(
    urllib.request,
    (
        b"AbstractHTTPHandler",
        b"BaseHandler",
        b"build_opener",
        b"FileHandler",
        b"FTPHandler",
        b"ftpwrapper",
        b"HTTPHandler",
        b"HTTPSHandler",
        b"install_opener",
        b"pathname2url",
        b"HTTPBasicAuthHandler",
        b"HTTPDigestAuthHandler",
        b"HTTPPasswordMgrWithDefaultRealm",
        b"ProxyHandler",
        b"Request",
        b"url2pathname",
        b"urlopen",
    ),
)


urlreq._registeraliases(
    urllib.response,
    (
        b"addclosehook",
        b"addinfourl",
    ),
)

urlerr._registeraliases(
    urllib.error,
    (
        b"HTTPError",
        b"URLError",
    ),
)

httpserver._registeraliases(
    http.server,
    (
        b"HTTPServer",
        b"BaseHTTPRequestHandler",
        b"SimpleHTTPRequestHandler",
        b"CGIHTTPRequestHandler",
    ),
)

# urllib.parse.quote() accepts both str and bytes, decodes bytes
# (if necessary), and returns str. This is wonky. We provide a custom
# implementation that only accepts bytes and emits bytes.
def quote(s, safe='/'):
    # bytestr has an __iter__ that emits characters. quote_from_bytes()
    # does an iteration and expects ints. We coerce to bytes to appease it.
    if isinstance(s, pycompat.bytestr):
        s = bytes(s)
    s = urllib.parse.quote_from_bytes(s, safe=safe)
    return s.encode('ascii', 'strict')


# urllib.parse.urlencode() returns str. We use this function to make
# sure we return bytes.
def urlencode(query, doseq=False):
    s = urllib.parse.urlencode(query, doseq=doseq)
    return s.encode('ascii')


urlreq.quote = quote
urlreq.urlencode = urlencode


def getfullurl(req):
    return req.full_url


def gethost(req):
    return req.host


def getselector(req):
    return req.selector


def getdata(req):
    return req.data


def hasdata(req):
    return req.data is not None