mercurial/urllibcompat.py

lock: pass "success" boolean to _afterlock callbacks

This lets the callback decide if it should actually run or not. I suspect that
most callbacks (and hooks) *should not* run in this scenario, but I'm trying
to not break any existing behavior. `persistmanifestcache`, however, seems
actively dangerous to run: we just encountered an exception and the repo is in
an unknown state (hopefully a consistent one due to transactions, but this is
not 100% guaranteed), and the data we cache may be based on this unknown
state.

This was observed by our users since we wrap some of the functions that
persistmanifestcache calls and it expects that the repo object is in a certain
state that we'd set up earlier. If the user hits ctrl-c before we establish
that state, we end up crashing there. I'm going to  make that extension
resilient to this issue, but figured it might be a common issue and should be
handled here as well instead of just working around the issue.

Differential Revision: https://phab.mercurial-scm.org/D7459

# 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.
from __future__ import absolute_import

from .pycompat import getattr
from . import pycompat

_sysstr = pycompat.sysstr


class _pycompatstub(object):
    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()

if pycompat.ispy3:
    import urllib.parse

    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")
    import urllib.request

    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",
        ),
    )
    import urllib.response

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

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

    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


else:
    import BaseHTTPServer
    import CGIHTTPServer
    import SimpleHTTPServer
    import urllib2
    import urllib
    import urlparse

    urlreq._registeraliases(
        urllib,
        (
            b"addclosehook",
            b"addinfourl",
            b"ftpwrapper",
            b"pathname2url",
            b"quote",
            b"splitattr",
            b"splitpasswd",
            b"splitport",
            b"splituser",
            b"unquote",
            b"url2pathname",
            b"urlencode",
        ),
    )
    urlreq._registeraliases(
        urllib2,
        (
            b"AbstractHTTPHandler",
            b"BaseHandler",
            b"build_opener",
            b"FileHandler",
            b"FTPHandler",
            b"HTTPBasicAuthHandler",
            b"HTTPDigestAuthHandler",
            b"HTTPHandler",
            b"HTTPPasswordMgrWithDefaultRealm",
            b"HTTPSHandler",
            b"install_opener",
            b"ProxyHandler",
            b"Request",
            b"urlopen",
        ),
    )
    urlreq._registeraliases(urlparse, (b"urlparse", b"urlunparse",))
    urlreq._registeralias(urlparse, b"parse_qs", b"parseqs")
    urlreq._registeralias(urlparse, b"parse_qsl", b"parseqsl")
    urlerr._registeraliases(urllib2, (b"HTTPError", b"URLError",))
    httpserver._registeraliases(
        BaseHTTPServer, (b"HTTPServer", b"BaseHTTPRequestHandler",)
    )
    httpserver._registeraliases(
        SimpleHTTPServer, (b"SimpleHTTPRequestHandler",)
    )
    httpserver._registeraliases(CGIHTTPServer, (b"CGIHTTPRequestHandler",))

    def gethost(req):
        return req.get_host()

    def getselector(req):
        return req.get_selector()

    def getfullurl(req):
        return req.get_full_url()

    def getdata(req):
        return req.get_data()

    def hasdata(req):
        return req.has_data()