view mercurial/httpconnection.py @ 50316:87f0155d68aa stable

revlog: improve the robustness of the splitting process

The previous "in-place" splitting, preserving the splitting on transaction
failure had a couple of issue in case of transaction rollback:
- a race windows that could still lead to a crash and data loss
- it corrupted the `fncache`.

So instead, we use a new approach that we summarized as "we do a backup of the
inline revlog pre-split, and we restore this in case of failure".
To make readers live easier, we don't overwrite the inline index file until
transaction finalization. (once the transaction get into its finalization phase,
it is not expected to rollback, unless some crash happens).

To do so, we write the index of the split index in a temporary file that we use
until transaction finalization. We also keep a backup of the initial inline file
to be able to rollback the split if needed.

As a result, transaction rollback cancel the split and no longer corrupt
fncache. We also no longer have a small inconsistency windows where the
transaction could be unrecoverable.

# httpconnection.py - urllib2 handler for new http support
#
# Copyright 2005, 2006, 2007, 2008 Olivia Mackall <[e-mail]>
# Copyright 2006, 2007 Alexis S. L. Carvalho <[e-mail]>
# Copyright 2006 Vadim Gelfer <[e-mail]>
# Copyright 2011 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 os

from .i18n import _
from .pycompat import open
from . import (
    pycompat,
    util,
)
from .utils import (
    urlutil,
)


urlerr = util.urlerr
urlreq = util.urlreq

# moved here from url.py to avoid a cycle
class httpsendfile:
    """This is a wrapper around the objects returned by python's "open".

    Its purpose is to send file-like objects via HTTP.
    It do however not define a __len__ attribute because the length
    might be more than Py_ssize_t can handle.
    """

    def __init__(self, ui, *args, **kwargs):
        self.ui = ui
        self._data = open(*args, **kwargs)
        self.seek = self._data.seek
        self.close = self._data.close
        self.write = self._data.write
        self.length = os.fstat(self._data.fileno()).st_size
        self._pos = 0
        self._progress = self._makeprogress()

    def _makeprogress(self):
        # We pass double the max for total because we currently have
        # to send the bundle twice in the case of a server that
        # requires authentication. Since we can't know until we try
        # once whether authentication will be required, just lie to
        # the user and maybe the push succeeds suddenly at 50%.
        return self.ui.makeprogress(
            _(b'sending'), unit=_(b'kb'), total=(self.length // 1024 * 2)
        )

    def read(self, *args, **kwargs):
        ret = self._data.read(*args, **kwargs)
        if not ret:
            self._progress.complete()
            return ret
        self._pos += len(ret)
        self._progress.update(self._pos // 1024)
        return ret

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()


# moved here from url.py to avoid a cycle
def readauthforuri(ui, uri, user):
    uri = pycompat.bytesurl(uri)
    # Read configuration
    groups = {}
    for key, val in ui.configitems(b'auth'):
        if key in (b'cookiefile',):
            continue

        if b'.' not in key:
            ui.warn(_(b"ignoring invalid [auth] key '%s'\n") % key)
            continue
        group, setting = key.rsplit(b'.', 1)
        gdict = groups.setdefault(group, {})
        if setting in (b'username', b'cert', b'key'):
            val = util.expandpath(val)
        gdict[setting] = val

    # Find the best match
    scheme, hostpath = uri.split(b'://', 1)
    bestuser = None
    bestlen = 0
    bestauth = None
    for group, auth in groups.items():
        if user and user != auth.get(b'username', user):
            # If a username was set in the URI, the entry username
            # must either match it or be unset
            continue
        prefix = auth.get(b'prefix')
        if not prefix:
            continue

        prefixurl = urlutil.url(prefix)
        if prefixurl.user and prefixurl.user != user:
            # If a username was set in the prefix, it must match the username in
            # the URI.
            continue

        # The URI passed in has been stripped of credentials, so erase the user
        # here to allow simpler matching.
        prefixurl.user = None
        prefix = bytes(prefixurl)

        p = prefix.split(b'://', 1)
        if len(p) > 1:
            schemes, prefix = [p[0]], p[1]
        else:
            schemes = (auth.get(b'schemes') or b'https').split()
        if (
            (prefix == b'*' or hostpath.startswith(prefix))
            and (
                len(prefix) > bestlen
                or (
                    len(prefix) == bestlen
                    and not bestuser
                    and b'username' in auth
                )
            )
            and scheme in schemes
        ):
            bestlen = len(prefix)
            bestauth = group, auth
            bestuser = auth.get(b'username')
            if user and not bestuser:
                auth[b'username'] = user
    return bestauth