view hgext/largefiles/remotestore.py @ 24158:d414c28db84d stable

largefiles: access to specific fields only if largefiles enabled (issue4547)

Even if largefiles extension is enabled in a repository, "repo"
object, which isn't "largefiles.reposetup()"-ed, is passed to
overridden functions in the cases below unexpectedly, because
extensions are enabled for each repositories strictly.

  (1) clone without -U:
  (2) pull with -U:
  (3) pull with --rebase:

    combination of "enabled@src", "disabled@dst" and
    "not-required@src" cause this situation.

       largefiles     requirement
    @src     @dst     @src            result
    -------- -------- --------------- --------------------
    enabled  disabled not-required    aborted unexpectedly
                      required        requirement error (intentional)
    -------- -------- --------------- --------------------
    enabled  enabled  *               success
    -------- -------- --------------- --------------------
    disabled enabled  *               success (only for "pull")
    -------- -------- --------------- --------------------
    disabled disabled not-required    success
                      required        requirement error (intentional)
    -------- -------- --------------- --------------------

  (4) update/revert with a subrepo disabling largefiles

In these cases, overridden functions cause accessing to largefiles
specific fields of not "largefiles.reposetup()"-ed "repo" object, and
execution is aborted.

  - (1), (2), (4) cause accessing to "_lfstatuswriters" in
    "getstatuswriter()" invoked via "updatelfiles()"

  - (3) causes accessing to "_lfcommithooks" in "overriderebase()"

For safe accessing to these fields, this patch examines whether passed
"repo" object is "largefiles.reposetup()"-ed or not before accessing
to them.

This patch chooses examining existence of newly introduced
"_largefilesenabled" instead of "_lfcommithooks" and
"_lfstatuswriters" directly, because the former is better name for the
generic "largefiles is enabled in this repo" mark than the latter.

In the future, all other overridden functions should avoid largefiles
specific processing for efficiency, and "_largefilesenabled" is better
also for such purpose.

BTW, "lfstatus" can't be used for such purpose, because some code
paths set it forcibly regardless of existence of it in specified
"repo" object.

# Copyright 2010-2011 Fog Creek Software
# Copyright 2010-2011 Unity Technologies
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''remote largefile store; the base class for wirestore'''

import urllib2

from mercurial import util, wireproto
from mercurial.i18n import _

import lfutil
import basestore

class remotestore(basestore.basestore):
    '''a largefile store accessed over a network'''
    def __init__(self, ui, repo, url):
        super(remotestore, self).__init__(ui, repo, url)

    def put(self, source, hash):
        if self.sendfile(source, hash):
            raise util.Abort(
                _('remotestore: could not put %s to remote store %s')
                % (source, util.hidepassword(self.url)))
        self.ui.debug(
            _('remotestore: put %s to remote store %s\n')
            % (source, util.hidepassword(self.url)))

    def exists(self, hashes):
        return dict((h, s == 0) for (h, s) in # dict-from-generator
                    self._stat(hashes).iteritems())

    def sendfile(self, filename, hash):
        self.ui.debug('remotestore: sendfile(%s, %s)\n' % (filename, hash))
        fd = None
        try:
            try:
                fd = lfutil.httpsendfile(self.ui, filename)
            except IOError, e:
                raise util.Abort(
                    _('remotestore: could not open file %s: %s')
                    % (filename, str(e)))
            return self._put(hash, fd)
        finally:
            if fd:
                fd.close()

    def _getfile(self, tmpfile, filename, hash):
        try:
            chunks = self._get(hash)
        except urllib2.HTTPError, e:
            # 401s get converted to util.Aborts; everything else is fine being
            # turned into a StoreError
            raise basestore.StoreError(filename, hash, self.url, str(e))
        except urllib2.URLError, e:
            # This usually indicates a connection problem, so don't
            # keep trying with the other files... they will probably
            # all fail too.
            raise util.Abort('%s: %s' %
                             (util.hidepassword(self.url), e.reason))
        except IOError, e:
            raise basestore.StoreError(filename, hash, self.url, str(e))

        return lfutil.copyandhash(chunks, tmpfile)

    def _verifyfile(self, cctx, cset, contents, standin, verified):
        filename = lfutil.splitstandin(standin)
        if not filename:
            return False
        fctx = cctx[standin]
        key = (filename, fctx.filenode())
        if key in verified:
            return False

        verified.add(key)

        expecthash = fctx.data()[0:40]
        stat = self._stat([expecthash])[expecthash]
        if not stat:
            return False
        elif stat == 1:
            self.ui.warn(
                _('changeset %s: %s: contents differ\n')
                % (cset, filename))
            return True # failed
        elif stat == 2:
            self.ui.warn(
                _('changeset %s: %s missing\n')
                % (cset, filename))
            return True # failed
        else:
            raise RuntimeError('verify failed: unexpected response from '
                               'statlfile (%r)' % stat)

    def batch(self):
        '''Support for remote batching.'''
        return wireproto.remotebatch(self)