view hgext/largefiles/localstore.py @ 35455:02ea370c2baa

split: new extension to split changesets

This diff introduces an experimental split extension to split changesets.

The implementation is largely inspired by Laurent Charignon's implementation
for mutable-history (changeset 9603aa1ecdfd54b0d86e262318a72e0a2ffeb6cc [1])

This version contains various improvements:

  - Rebase by default.
    This is more friendly for new users. Split won't lead to merge conflicts
    so a rebase won't give the user more trouble.
    This has been on by default at Facebook for months now and seems to be a
    good UX improvement.
    The rebase skips obsoleted or orphaned changesets, which can avoid
    issues like allowdivergence, merge conflicts, etc. This is more flexible
    because the user can decide what to do next (see the last test case in
    test-split.t)

  - Remove "Done split? [y/n]" prompt.
    That could be detected by checking `repo.status()` instead.

  - Works with obsstore disabled.
    Without obsstore, split uses strip to clean up old nodes, and it can
    even handle split a non-head changeset with "allowunstable" disabled,
    since it runs a rebase to solve the "unstable" issue in a same
    transaction.

  - More friendly editor text.
    Put what has been already split into the editor text so users won't lost
    track about where they are.

[1]: https://bitbucket.org/marmoute/mutable-history/commits/9603aa1ecdfd54b

Differential Revision: https://phab.mercurial-scm.org/D1082

# Copyright 2009-2010 Gregory P. Ward
# Copyright 2009-2010 Intelerad Medical Systems Incorporated
# 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.

'''store class for local filesystem'''
from __future__ import absolute_import

from mercurial.i18n import _
from mercurial import util

from . import (
    basestore,
    lfutil,
)

class localstore(basestore.basestore):
    '''localstore first attempts to grab files out of the store in the remote
    Mercurial repository.  Failing that, it attempts to grab the files from
    the user cache.'''

    def __init__(self, ui, repo, remote):
        self.remote = remote.local()
        super(localstore, self).__init__(ui, repo, self.remote.url())

    def put(self, source, hash):
        if lfutil.instore(self.remote, hash):
            return
        lfutil.link(source, lfutil.storepath(self.remote, hash))

    def exists(self, hashes):
        retval = {}
        for hash in hashes:
            retval[hash] = lfutil.instore(self.remote, hash)
        return retval

    def _getfile(self, tmpfile, filename, hash):
        path = lfutil.findfile(self.remote, hash)
        if not path:
            raise basestore.StoreError(filename, hash, self.url,
                _("can't get file locally"))
        with open(path, 'rb') as fd:
            return lfutil.copyandhash(
                util.filechunkiter(fd), tmpfile)

    def _verifyfiles(self, contents, filestocheck):
        failed = False
        for cset, filename, expectedhash in filestocheck:
            storepath, exists = lfutil.findstorepath(self.repo, expectedhash)
            if not exists:
                storepath, exists = lfutil.findstorepath(
                    self.remote, expectedhash)
            if not exists:
                self.ui.warn(
                    _('changeset %s: %s references missing %s\n')
                    % (cset, filename, storepath))
                failed = True
            elif contents:
                actualhash = lfutil.hashfile(storepath)
                if actualhash != expectedhash:
                    self.ui.warn(
                        _('changeset %s: %s references corrupted %s\n')
                        % (cset, filename, storepath))
                    failed = True
        return failed