view mercurial/url.py @ 43252:32187ae9eeb3

copies: simplify the handling of merges Instead of stacking copies for both parent on the head, we move copies outside of the heap into a dedicated dictionary. The two side of merge can we merged sooner, making the algorithm simpler. This simplicity reflect in the heap structure and speed up the execution for copies involving a large amount of merges. Here are timing for perfpathcopies of multiple revision pairs. - filelog: timing using filelog (with the introrev condition dropped) - base: this series base - before: the parent of this changeset - after: this changeset revision: large amount; added files: large amount; rename small amount; c3b14617fbd7 9ba6ab77fd29 filelog: ! wall 3.679613 comb 3.680000 user 3.580000 sys 0.100000 (median of 3) base: ! wall 8.884369 comb 8.880000 user 8.850000 sys 0.030000 (median of 3) before: ! wall 8.443747 comb 8.420000 user 8.410000 sys 0.010000 (median of 3) after: ! wall 4.697917 comb 4.690000 user 4.660000 sys 0.030000 (median of 3) revision: large amount; added files: small amount; rename small amount; c3b14617fbd7 f650a9b140d2 filelog: ! wall 0.003357 comb 0.010000 user 0.010000 sys 0.000000 (median of 781) base: ! wall 12.398524 comb 12.400000 user 12.330000 sys 0.070000 (median of 3) before: ! wall 10.852593 comb 10.850000 user 10.800000 sys 0.050000 (median of 3) after: ! wall 6.750832 comb 6.750000 user 6.640000 sys 0.110000 (median of 3) revision: large amount; added files: large amount; rename large amount; 08ea3258278e d9fa043f30c0 filelog: ! wall 2.754687 comb 2.760000 user 2.650000 sys 0.110000 (median of 4) base: ! wall 1.423166 comb 1.420000 user 1.400000 sys 0.020000 (median of 8) before: ! wall 1.068041 comb 1.060000 user 1.050000 sys 0.010000 (median of 10) after: ! wall 1.045916 comb 1.050000 user 1.040000 sys 0.010000 (median of 10) revision: small amount; added files: large amount; rename large amount; df6f7a526b60 a83dc6a2d56f filelog: ! wall 1.552293 comb 1.550000 user 1.510000 sys 0.040000 (median of 6 base: ! wall 0.022662 comb 0.020000 user 0.020000 sys 0.000000 (median of 128) before: ! wall 0.021111 comb 0.020000 user 0.020000 sys 0.000000 (median of 139) after: ! wall 0.021577 comb 0.020000 user 0.020000 sys 0.000000 (median of 138) revision: small amount; added files: large amount; rename small amount; 4aa4e1f8e19a 169138063d63 filelog: ! wall 1.500983 comb 1.500000 user 1.420000 sys 0.080000 (median of 7) base: ! wall 0.006956 comb 0.010000 user 0.010000 sys 0.000000 (median of 392) before: ! wall 0.004356 comb 0.010000 user 0.010000 sys 0.000000 (median of 675) after: ! wall 0.004329 comb 0.000000 user 0.000000 sys 0.000000 (median of 682) revision: small amount; added files: small amount; rename small amount; 4bc173b045a6 964879152e2e filelog: ! wall 0.011745 comb 0.020000 user 0.020000 sys 0.000000 (median of 250) base: ! wall 0.000156 comb 0.000000 user 0.000000 sys 0.000000 (median of 17180) before: ! wall 0.000100 comb 0.000000 user 0.000000 sys 0.000000 (median of 26912) after: ! wall 0.000105 comb 0.000000 user 0.000000 sys 0.000000 (median of 25689) revision: medium amount; added files: large amount; rename medium amount; c95f1ced15f2 2c68e87c3efe filelog: ! wall 3.228230 comb 3.230000 user 3.110000 sys 0.120000 (median of 4) base: ! wall 0.997640 comb 1.000000 user 0.980000 sys 0.020000 (median of 10) before: ! wall 0.778291 comb 0.780000 user 0.780000 sys 0.000000 (median of 13) after: ! wall 0.706594 comb 0.710000 user 0.710000 sys 0.000000 (median of 15) revision: medium amount; added files: medium amount; rename small amount; d343da0c55a8 d7746d32bf9d filelog: ! wall 1.052501 comb 1.060000 user 1.040000 sys 0.020000 (median of 10 base: ! wall 0.214519 comb 0.220000 user 0.220000 sys 0.000000 (median of 45) before: ! wall 0.160804 comb 0.160000 user 0.160000 sys 0.000000 (median of 62) after: ! wall 0.163736 comb 0.160000 user 0.160000 sys 0.000000 (median of 60) Differential Revision: https://phab.mercurial-scm.org/D7069
author Pierre-Yves David <pierre-yves.david@octobus.net>
date Wed, 02 Oct 2019 13:43:27 -0400
parents d783f945a701
children 9f70512ae2cf
line wrap: on
line source

# url.py - HTTP handling for mercurial
#
# Copyright 2005, 2006, 2007, 2008 Matt Mackall <mpm@selenic.com>
# Copyright 2006, 2007 Alexis S. L. Carvalho <alexis@cecm.usp.br>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
#
# 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

import base64
import os
import socket
import sys

from .i18n import _
from .pycompat import getattr
from . import (
    encoding,
    error,
    httpconnection as httpconnectionmod,
    keepalive,
    pycompat,
    sslutil,
    urllibcompat,
    util,
)
from .utils import stringutil

httplib = util.httplib
stringio = util.stringio
urlerr = util.urlerr
urlreq = util.urlreq


def escape(s, quote=None):
    '''Replace special characters "&", "<" and ">" to HTML-safe sequences.
    If the optional flag quote is true, the quotation mark character (")
    is also translated.

    This is the same as cgi.escape in Python, but always operates on
    bytes, whereas cgi.escape in Python 3 only works on unicodes.
    '''
    s = s.replace(b"&", b"&amp;")
    s = s.replace(b"<", b"&lt;")
    s = s.replace(b">", b"&gt;")
    if quote:
        s = s.replace(b'"', b"&quot;")
    return s


class passwordmgr(object):
    def __init__(self, ui, passwddb):
        self.ui = ui
        self.passwddb = passwddb

    def add_password(self, realm, uri, user, passwd):
        return self.passwddb.add_password(realm, uri, user, passwd)

    def find_user_password(self, realm, authuri):
        assert isinstance(realm, (type(None), str))
        assert isinstance(authuri, str)
        authinfo = self.passwddb.find_user_password(realm, authuri)
        user, passwd = authinfo
        user, passwd = pycompat.bytesurl(user), pycompat.bytesurl(passwd)
        if user and passwd:
            self._writedebug(user, passwd)
            return (pycompat.strurl(user), pycompat.strurl(passwd))

        if not user or not passwd:
            res = httpconnectionmod.readauthforuri(self.ui, authuri, user)
            if res:
                group, auth = res
                user, passwd = auth.get(b'username'), auth.get(b'password')
                self.ui.debug(b"using auth.%s.* for authentication\n" % group)
        if not user or not passwd:
            u = util.url(pycompat.bytesurl(authuri))
            u.query = None
            if not self.ui.interactive():
                raise error.Abort(
                    _(b'http authorization required for %s')
                    % util.hidepassword(bytes(u))
                )

            self.ui.write(
                _(b"http authorization required for %s\n")
                % util.hidepassword(bytes(u))
            )
            self.ui.write(_(b"realm: %s\n") % pycompat.bytesurl(realm))
            if user:
                self.ui.write(_(b"user: %s\n") % user)
            else:
                user = self.ui.prompt(_(b"user:"), default=None)

            if not passwd:
                passwd = self.ui.getpass()

        self.passwddb.add_password(realm, authuri, user, passwd)
        self._writedebug(user, passwd)
        return (pycompat.strurl(user), pycompat.strurl(passwd))

    def _writedebug(self, user, passwd):
        msg = _(b'http auth: user %s, password %s\n')
        self.ui.debug(msg % (user, passwd and b'*' * len(passwd) or b'not set'))

    def find_stored_password(self, authuri):
        return self.passwddb.find_user_password(None, authuri)


class proxyhandler(urlreq.proxyhandler):
    def __init__(self, ui):
        proxyurl = ui.config(b"http_proxy", b"host") or encoding.environ.get(
            b'http_proxy'
        )
        # XXX proxyauthinfo = None

        if proxyurl:
            # proxy can be proper url or host[:port]
            if not (
                proxyurl.startswith(b'http:') or proxyurl.startswith(b'https:')
            ):
                proxyurl = b'http://' + proxyurl + b'/'
            proxy = util.url(proxyurl)
            if not proxy.user:
                proxy.user = ui.config(b"http_proxy", b"user")
                proxy.passwd = ui.config(b"http_proxy", b"passwd")

            # see if we should use a proxy for this url
            no_list = [b"localhost", b"127.0.0.1"]
            no_list.extend(
                [p.lower() for p in ui.configlist(b"http_proxy", b"no")]
            )
            no_list.extend(
                [
                    p.strip().lower()
                    for p in encoding.environ.get(b"no_proxy", b'').split(b',')
                    if p.strip()
                ]
            )
            # "http_proxy.always" config is for running tests on localhost
            if ui.configbool(b"http_proxy", b"always"):
                self.no_list = []
            else:
                self.no_list = no_list

            # Keys and values need to be str because the standard library
            # expects them to be.
            proxyurl = str(proxy)
            proxies = {r'http': proxyurl, r'https': proxyurl}
            ui.debug(b'proxying through %s\n' % util.hidepassword(bytes(proxy)))
        else:
            proxies = {}

        urlreq.proxyhandler.__init__(self, proxies)
        self.ui = ui

    def proxy_open(self, req, proxy, type_):
        host = pycompat.bytesurl(urllibcompat.gethost(req)).split(b':')[0]
        for e in self.no_list:
            if host == e:
                return None
            if e.startswith(b'*.') and host.endswith(e[2:]):
                return None
            if e.startswith(b'.') and host.endswith(e[1:]):
                return None

        return urlreq.proxyhandler.proxy_open(self, req, proxy, type_)


def _gen_sendfile(orgsend):
    def _sendfile(self, data):
        # send a file
        if isinstance(data, httpconnectionmod.httpsendfile):
            # if auth required, some data sent twice, so rewind here
            data.seek(0)
            for chunk in util.filechunkiter(data):
                orgsend(self, chunk)
        else:
            orgsend(self, data)

    return _sendfile


has_https = util.safehasattr(urlreq, b'httpshandler')


class httpconnection(keepalive.HTTPConnection):
    # must be able to send big bundle as stream.
    send = _gen_sendfile(keepalive.HTTPConnection.send)

    def getresponse(self):
        proxyres = getattr(self, 'proxyres', None)
        if proxyres:
            if proxyres.will_close:
                self.close()
            self.proxyres = None
            return proxyres
        return keepalive.HTTPConnection.getresponse(self)


# Large parts of this function have their origin from before Python 2.6
# and could potentially be removed.
def _generic_start_transaction(handler, h, req):
    tunnel_host = req._tunnel_host
    if tunnel_host:
        if tunnel_host[:7] not in [r'http://', r'https:/']:
            tunnel_host = r'https://' + tunnel_host
        new_tunnel = True
    else:
        tunnel_host = urllibcompat.getselector(req)
        new_tunnel = False

    if new_tunnel or tunnel_host == urllibcompat.getfullurl(req):  # has proxy
        u = util.url(pycompat.bytesurl(tunnel_host))
        if new_tunnel or u.scheme == b'https':  # only use CONNECT for HTTPS
            h.realhostport = b':'.join([u.host, (u.port or b'443')])
            h.headers = req.headers.copy()
            h.headers.update(handler.parent.addheaders)
            return

    h.realhostport = None
    h.headers = None


def _generic_proxytunnel(self):
    proxyheaders = dict(
        [
            (x, self.headers[x])
            for x in self.headers
            if x.lower().startswith(r'proxy-')
        ]
    )
    self.send(b'CONNECT %s HTTP/1.0\r\n' % self.realhostport)
    for header in pycompat.iteritems(proxyheaders):
        self.send(b'%s: %s\r\n' % header)
    self.send(b'\r\n')

    # majority of the following code is duplicated from
    # httplib.HTTPConnection as there are no adequate places to
    # override functions to provide the needed functionality
    # strict was removed in Python 3.4.
    kwargs = {}
    if not pycompat.ispy3:
        kwargs[b'strict'] = self.strict

    res = self.response_class(self.sock, method=self._method, **kwargs)

    while True:
        version, status, reason = res._read_status()
        if status != httplib.CONTINUE:
            break
        # skip lines that are all whitespace
        list(iter(lambda: res.fp.readline().strip(), b''))
    res.status = status
    res.reason = reason.strip()

    if res.status == 200:
        # skip lines until we find a blank line
        list(iter(res.fp.readline, b'\r\n'))
        return True

    if version == b'HTTP/1.0':
        res.version = 10
    elif version.startswith(b'HTTP/1.'):
        res.version = 11
    elif version == b'HTTP/0.9':
        res.version = 9
    else:
        raise httplib.UnknownProtocol(version)

    if res.version == 9:
        res.length = None
        res.chunked = 0
        res.will_close = 1
        res.msg = httplib.HTTPMessage(stringio())
        return False

    res.msg = httplib.HTTPMessage(res.fp)
    res.msg.fp = None

    # are we using the chunked-style of transfer encoding?
    trenc = res.msg.getheader(b'transfer-encoding')
    if trenc and trenc.lower() == b"chunked":
        res.chunked = 1
        res.chunk_left = None
    else:
        res.chunked = 0

    # will the connection close at the end of the response?
    res.will_close = res._check_close()

    # do we have a Content-Length?
    # NOTE: RFC 2616, section 4.4, #3 says we ignore this if
    # transfer-encoding is "chunked"
    length = res.msg.getheader(b'content-length')
    if length and not res.chunked:
        try:
            res.length = int(length)
        except ValueError:
            res.length = None
        else:
            if res.length < 0:  # ignore nonsensical negative lengths
                res.length = None
    else:
        res.length = None

    # does the body have a fixed length? (of zero)
    if (
        status == httplib.NO_CONTENT
        or status == httplib.NOT_MODIFIED
        or 100 <= status < 200
        or res._method == b'HEAD'  # 1xx codes
    ):
        res.length = 0

    # if the connection remains open, and we aren't using chunked, and
    # a content-length was not provided, then assume that the connection
    # WILL close.
    if not res.will_close and not res.chunked and res.length is None:
        res.will_close = 1

    self.proxyres = res

    return False


class httphandler(keepalive.HTTPHandler):
    def http_open(self, req):
        return self.do_open(httpconnection, req)

    def _start_transaction(self, h, req):
        _generic_start_transaction(self, h, req)
        return keepalive.HTTPHandler._start_transaction(self, h, req)


class logginghttpconnection(keepalive.HTTPConnection):
    def __init__(self, createconn, *args, **kwargs):
        keepalive.HTTPConnection.__init__(self, *args, **kwargs)
        self._create_connection = createconn

    if sys.version_info < (2, 7, 7):
        # copied from 2.7.14, since old implementations directly call
        # socket.create_connection()
        def connect(self):
            self.sock = self._create_connection(
                (self.host, self.port), self.timeout, self.source_address
            )
            if self._tunnel_host:
                self._tunnel()


class logginghttphandler(httphandler):
    """HTTP handler that logs socket I/O."""

    def __init__(self, logfh, name, observeropts, timeout=None):
        super(logginghttphandler, self).__init__(timeout=timeout)

        self._logfh = logfh
        self._logname = name
        self._observeropts = observeropts

    # do_open() calls the passed class to instantiate an HTTPConnection. We
    # pass in a callable method that creates a custom HTTPConnection instance
    # whose callback to create the socket knows how to proxy the socket.
    def http_open(self, req):
        return self.do_open(self._makeconnection, req)

    def _makeconnection(self, *args, **kwargs):
        def createconnection(*args, **kwargs):
            sock = socket.create_connection(*args, **kwargs)
            return util.makeloggingsocket(
                self._logfh, sock, self._logname, **self._observeropts
            )

        return logginghttpconnection(createconnection, *args, **kwargs)


if has_https:

    class httpsconnection(keepalive.HTTPConnection):
        response_class = keepalive.HTTPResponse
        default_port = httplib.HTTPS_PORT
        # must be able to send big bundle as stream.
        send = _gen_sendfile(keepalive.safesend)
        getresponse = keepalive.wrapgetresponse(httplib.HTTPConnection)

        def __init__(
            self,
            host,
            port=None,
            key_file=None,
            cert_file=None,
            *args,
            **kwargs
        ):
            keepalive.HTTPConnection.__init__(self, host, port, *args, **kwargs)
            self.key_file = key_file
            self.cert_file = cert_file

        def connect(self):
            self.sock = socket.create_connection((self.host, self.port))

            host = self.host
            if self.realhostport:  # use CONNECT proxy
                _generic_proxytunnel(self)
                host = self.realhostport.rsplit(b':', 1)[0]
            self.sock = sslutil.wrapsocket(
                self.sock,
                self.key_file,
                self.cert_file,
                ui=self.ui,
                serverhostname=host,
            )
            sslutil.validatesocket(self.sock)

    class httpshandler(keepalive.KeepAliveHandler, urlreq.httpshandler):
        def __init__(self, ui, timeout=None):
            keepalive.KeepAliveHandler.__init__(self, timeout=timeout)
            urlreq.httpshandler.__init__(self)
            self.ui = ui
            self.pwmgr = passwordmgr(self.ui, self.ui.httppasswordmgrdb)

        def _start_transaction(self, h, req):
            _generic_start_transaction(self, h, req)
            return keepalive.KeepAliveHandler._start_transaction(self, h, req)

        def https_open(self, req):
            # urllibcompat.getfullurl() does not contain credentials
            # and we may need them to match the certificates.
            url = urllibcompat.getfullurl(req)
            user, password = self.pwmgr.find_stored_password(url)
            res = httpconnectionmod.readauthforuri(self.ui, url, user)
            if res:
                group, auth = res
                self.auth = auth
                self.ui.debug(b"using auth.%s.* for authentication\n" % group)
            else:
                self.auth = None
            return self.do_open(self._makeconnection, req)

        def _makeconnection(self, host, port=None, *args, **kwargs):
            keyfile = None
            certfile = None

            if len(args) >= 1:  # key_file
                keyfile = args[0]
            if len(args) >= 2:  # cert_file
                certfile = args[1]
            args = args[2:]

            # if the user has specified different key/cert files in
            # hgrc, we prefer these
            if self.auth and b'key' in self.auth and b'cert' in self.auth:
                keyfile = self.auth[b'key']
                certfile = self.auth[b'cert']

            conn = httpsconnection(
                host, port, keyfile, certfile, *args, **kwargs
            )
            conn.ui = self.ui
            return conn


class httpdigestauthhandler(urlreq.httpdigestauthhandler):
    def __init__(self, *args, **kwargs):
        urlreq.httpdigestauthhandler.__init__(self, *args, **kwargs)
        self.retried_req = None

    def reset_retry_count(self):
        # Python 2.6.5 will call this on 401 or 407 errors and thus loop
        # forever. We disable reset_retry_count completely and reset in
        # http_error_auth_reqed instead.
        pass

    def http_error_auth_reqed(self, auth_header, host, req, headers):
        # Reset the retry counter once for each request.
        if req is not self.retried_req:
            self.retried_req = req
            self.retried = 0
        return urlreq.httpdigestauthhandler.http_error_auth_reqed(
            self, auth_header, host, req, headers
        )


class httpbasicauthhandler(urlreq.httpbasicauthhandler):
    def __init__(self, *args, **kwargs):
        self.auth = None
        urlreq.httpbasicauthhandler.__init__(self, *args, **kwargs)
        self.retried_req = None

    def http_request(self, request):
        if self.auth:
            request.add_unredirected_header(self.auth_header, self.auth)

        return request

    def https_request(self, request):
        if self.auth:
            request.add_unredirected_header(self.auth_header, self.auth)

        return request

    def reset_retry_count(self):
        # Python 2.6.5 will call this on 401 or 407 errors and thus loop
        # forever. We disable reset_retry_count completely and reset in
        # http_error_auth_reqed instead.
        pass

    def http_error_auth_reqed(self, auth_header, host, req, headers):
        # Reset the retry counter once for each request.
        if req is not self.retried_req:
            self.retried_req = req
            self.retried = 0
        return urlreq.httpbasicauthhandler.http_error_auth_reqed(
            self, auth_header, host, req, headers
        )

    def retry_http_basic_auth(self, host, req, realm):
        user, pw = self.passwd.find_user_password(
            realm, urllibcompat.getfullurl(req)
        )
        if pw is not None:
            raw = b"%s:%s" % (pycompat.bytesurl(user), pycompat.bytesurl(pw))
            auth = r'Basic %s' % pycompat.strurl(base64.b64encode(raw).strip())
            if req.get_header(self.auth_header, None) == auth:
                return None
            self.auth = auth
            req.add_unredirected_header(self.auth_header, auth)
            return self.parent.open(req)
        else:
            return None


class cookiehandler(urlreq.basehandler):
    def __init__(self, ui):
        self.cookiejar = None

        cookiefile = ui.config(b'auth', b'cookiefile')
        if not cookiefile:
            return

        cookiefile = util.expandpath(cookiefile)
        try:
            cookiejar = util.cookielib.MozillaCookieJar(
                pycompat.fsdecode(cookiefile)
            )
            cookiejar.load()
            self.cookiejar = cookiejar
        except util.cookielib.LoadError as e:
            ui.warn(
                _(
                    b'(error loading cookie file %s: %s; continuing without '
                    b'cookies)\n'
                )
                % (cookiefile, stringutil.forcebytestr(e))
            )

    def http_request(self, request):
        if self.cookiejar:
            self.cookiejar.add_cookie_header(request)

        return request

    def https_request(self, request):
        if self.cookiejar:
            self.cookiejar.add_cookie_header(request)

        return request


handlerfuncs = []


def opener(
    ui,
    authinfo=None,
    useragent=None,
    loggingfh=None,
    loggingname=b's',
    loggingopts=None,
    sendaccept=True,
):
    '''
    construct an opener suitable for urllib2
    authinfo will be added to the password manager

    The opener can be configured to log socket events if the various
    ``logging*`` arguments are specified.

    ``loggingfh`` denotes a file object to log events to.
    ``loggingname`` denotes the name of the to print when logging.
    ``loggingopts`` is a dict of keyword arguments to pass to the constructed
    ``util.socketobserver`` instance.

    ``sendaccept`` allows controlling whether the ``Accept`` request header
    is sent. The header is sent by default.
    '''
    timeout = ui.configwith(float, b'http', b'timeout')
    handlers = []

    if loggingfh:
        handlers.append(
            logginghttphandler(
                loggingfh, loggingname, loggingopts or {}, timeout=timeout
            )
        )
        # We don't yet support HTTPS when logging I/O. If we attempt to open
        # an HTTPS URL, we'll likely fail due to unknown protocol.

    else:
        handlers.append(httphandler(timeout=timeout))
        if has_https:
            handlers.append(httpshandler(ui, timeout=timeout))

    handlers.append(proxyhandler(ui))

    passmgr = passwordmgr(ui, ui.httppasswordmgrdb)
    if authinfo is not None:
        realm, uris, user, passwd = authinfo
        saveduser, savedpass = passmgr.find_stored_password(uris[0])
        if user != saveduser or passwd:
            passmgr.add_password(realm, uris, user, passwd)
        ui.debug(
            b'http auth: user %s, password %s\n'
            % (user, passwd and b'*' * len(passwd) or b'not set')
        )

    handlers.extend(
        (httpbasicauthhandler(passmgr), httpdigestauthhandler(passmgr))
    )
    handlers.extend([h(ui, passmgr) for h in handlerfuncs])
    handlers.append(cookiehandler(ui))
    opener = urlreq.buildopener(*handlers)

    # keepalive.py's handlers will populate these attributes if they exist.
    opener.requestscount = 0
    opener.sentbytescount = 0
    opener.receivedbytescount = 0

    # The user agent should should *NOT* be used by servers for e.g.
    # protocol detection or feature negotiation: there are other
    # facilities for that.
    #
    # "mercurial/proto-1.0" was the original user agent string and
    # exists for backwards compatibility reasons.
    #
    # The "(Mercurial %s)" string contains the distribution
    # name and version. Other client implementations should choose their
    # own distribution name. Since servers should not be using the user
    # agent string for anything, clients should be able to define whatever
    # user agent they deem appropriate.
    #
    # The custom user agent is for lfs, because unfortunately some servers
    # do look at this value.
    if not useragent:
        agent = b'mercurial/proto-1.0 (Mercurial %s)' % util.version()
        opener.addheaders = [(r'User-agent', pycompat.sysstr(agent))]
    else:
        opener.addheaders = [(r'User-agent', pycompat.sysstr(useragent))]

    # This header should only be needed by wire protocol requests. But it has
    # been sent on all requests since forever. We keep sending it for backwards
    # compatibility reasons. Modern versions of the wire protocol use
    # X-HgProto-<N> for advertising client support.
    if sendaccept:
        opener.addheaders.append((r'Accept', r'application/mercurial-0.1'))

    return opener


def open(ui, url_, data=None, sendaccept=True):
    u = util.url(url_)
    if u.scheme:
        u.scheme = u.scheme.lower()
        url_, authinfo = u.authinfo()
    else:
        path = util.normpath(os.path.abspath(url_))
        url_ = b'file://' + pycompat.bytesurl(urlreq.pathname2url(path))
        authinfo = None
    return opener(ui, authinfo, sendaccept=sendaccept).open(
        pycompat.strurl(url_), data
    )


def wrapresponse(resp):
    """Wrap a response object with common error handlers.

    This ensures that any I/O from any consumer raises the appropriate
    error and messaging.
    """
    origread = resp.read

    class readerproxy(resp.__class__):
        def read(self, size=None):
            try:
                return origread(size)
            except httplib.IncompleteRead as e:
                # e.expected is an integer if length known or None otherwise.
                if e.expected:
                    got = len(e.partial)
                    total = e.expected + got
                    msg = _(
                        b'HTTP request error (incomplete response; '
                        b'expected %d bytes got %d)'
                    ) % (total, got)
                else:
                    msg = _(b'HTTP request error (incomplete response)')

                raise error.PeerTransportError(
                    msg,
                    hint=_(
                        b'this may be an intermittent network failure; '
                        b'if the error persists, consider contacting the '
                        b'network or server operator'
                    ),
                )
            except httplib.HTTPException as e:
                raise error.PeerTransportError(
                    _(b'HTTP request error (%s)') % e,
                    hint=_(
                        b'this may be an intermittent network failure; '
                        b'if the error persists, consider contacting the '
                        b'network or server operator'
                    ),
                )

    resp.__class__ = readerproxy