view hgext/factotum.py @ 18993:0fd0612dc855

annotate: increase refcount of each revisions correctly (issue3841)

Before this patch, refcount (managed in "needed") of parents of each
revisions in "visit" is increased, only when parent is not annotated
yet (examined by "p not in hist").

But this causes less refcount of the revision like "A" in the tree
below ("A" is assumed as the second parent of "C"):

    A --- B --- C
      \       /
       \-----/

Steps of annotation for "C" in this case are shown below:

  1. for "C"
    1.1 increase refcount of "B"
    1.2 increase refcount of "A" (=> 1)
    1.3 defer annotation for "C"

  2. for "A"
    2.1 annotate for "A" (=> put result into "hist[A]")
    2.2 clear "pcache[A]" ("pcache[A] = []")

  3. for "B"
    3.1 not increase refcount of "A", because "A not in hist" is False
    3.2 annotate for "B"
    3.3 decrease refcount of "A" (=> 0)
    3.4 delete "hist[A]", even though "A" is still needed by "C"
    3.5 clear "pcache[B]"

  4. for "C", again
    4.1 not increase refcount of "B", because "B not in hist" is False
    4.2 increase refcount of "A" (=> 1)
    4.3 defer annotation for "C"

  5. for "A", again
    5.1 annotate for "A" (=> put result into "hist[A]", again)
    5.2 clear "pcache[A]"

  6. for "C", once again
    6.1 not increase refcount of "B", because "B not in hist" is False
    6.2 not increase refcount of "A", because "A not in hist" is False
    6.3 annotate for "C"
    6.4 decrease refcount of "A", and delete "hist[A]"
    6.5 decrease refcount of "B", and delete "hist[B]"
    6.6 clear "pcache[C]"

At step (5.1), annotation for "A" mis-recognizes that all lines are
created at "A", because "pcache[A]" already cleared at step (2.2)
prevents from scanning ancestors of "A".

So, annotation for "C" or its descendants loses information about "A"
or its ancestors.

The root cause of this problem is that refcount of "A" is decreased at
step (3.3), even though it isn't increased at step (3.1).

To increase refcount correctly, this patch increases refcount of each
parents of each revisions:

  - regardless of "p not in hist" or not, and
  - only once for each revisions in "visit" (by "not pcached")

In fact, this problem should occur only on legacy repositories in
which a filelog includes the merging between the revision and its
ancestor (as the second parent), because:

  - tree is scanned in depth-first

    without such merging, revisions in "visit" refer different
    revisions as parent each other

  - recent Mercurial doesn't allow such merging

    changelog and manifest can include such merging someway, but
    filelogs can't, because "localrepository._filecommit()" converts
    such merging request to linear history.

This patch tests merging cases below: these cases are from filelog of
"mercurial/commands.py" in the repository of Mercurial itself.

  - both parents are same

        10 --- 11 --- 12
                  \_/

        filelogrev: changesetid:
          10          00ea3613f82c
          11          fc4a6e5b5812
          12          4f802588cdfb

  - the second parent is also ancestor of the first one

        37 --- 38 --- 39 --- 40
                  \________/

        filelogrev: changesetid:
          37          f8d56da6ac8f
          38          38919e1c254d
          39          d3400605d246
          40          f06a4a3b86a7

# factotum.py - Plan 9 factotum integration for Mercurial
#
# Copyright (C) 2012 Steven Stallion <[e-mail]>
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
# Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

'''http authentication with factotum

This extension allows the factotum(4) facility on Plan 9 from Bell Labs
platforms to provide authentication information for HTTP access. Configuration
entries specified in the auth section as well as authentication information
provided in the repository URL are fully supported. If no prefix is specified,
a value of "*" will be assumed.

By default, keys are specified as::

  proto=pass service=hg prefix=<prefix> user=<username> !password=<password>

If the factotum extension is unable to read the required key, one will be
requested interactively.

A configuration section is available to customize runtime behavior. By
default, these entries are::

  [factotum]
  executable = /bin/auth/factotum
  mountpoint = /mnt/factotum
  service = hg

The executable entry defines the full path to the factotum binary. The
mountpoint entry defines the path to the factotum file service. Lastly, the
service entry controls the service name used when reading keys.

'''

from mercurial.i18n import _
from mercurial.url import passwordmgr
from mercurial import httpconnection, util
import os, urllib2

ERRMAX = 128

def auth_getkey(self, params):
    if not self.ui.interactive():
        raise util.Abort(_('factotum not interactive'))
    if 'user=' not in params:
        params = '%s user?' % params
    params = '%s !password?' % params
    os.system("%s -g '%s'" % (_executable, params))

def auth_getuserpasswd(self, getkey, params):
    params = 'proto=pass %s' % params
    while True:
        fd = os.open('%s/rpc' % _mountpoint, os.O_RDWR)
        try:
            try:
                os.write(fd, 'start %s' % params)
                l = os.read(fd, ERRMAX).split()
                if l[0] == 'ok':
                    os.write(fd, 'read')
                    l = os.read(fd, ERRMAX).split()
                    if l[0] == 'ok':
                        return l[1:]
            except (OSError, IOError):
                raise util.Abort(_('factotum not responding'))
        finally:
            os.close(fd)
        getkey(self, params)

def monkeypatch_method(cls):
    def decorator(func):
        setattr(cls, func.__name__, func)
        return func
    return decorator

@monkeypatch_method(passwordmgr)
def find_user_password(self, realm, authuri):
    user, passwd = urllib2.HTTPPasswordMgrWithDefaultRealm.find_user_password(
        self, realm, authuri)
    if user and passwd:
        self._writedebug(user, passwd)
        return (user, passwd)

    prefix = ''
    res = httpconnection.readauthforuri(self.ui, authuri, user)
    if res:
        _, auth = res
        prefix = auth.get('prefix')
        user, passwd = auth.get('username'), auth.get('password')
    if not user or not passwd:
        if not prefix:
            prefix = '*'
        params = 'service=%s prefix=%s' % (_service, prefix)
        if user:
            params = '%s user=%s' % (params, user)
        user, passwd = auth_getuserpasswd(self, auth_getkey, params)

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

def uisetup(ui):
    global _executable
    _executable = ui.config('factotum', 'executable', '/bin/auth/factotum')
    global _mountpoint
    _mountpoint = ui.config('factotum', 'mountpoint', '/mnt/factotum')
    global _service
    _service = ui.config('factotum', 'service', 'hg')