view tests/bruterebase.py @ 35565:bdae51a83dfb

clonebundle: make it possible to retrieve the initial bundle through largefile

By setting the default path early enough, we make it possible to retrieve a
clone bundle as a largefile from the repository we are cloning.

But... why?

Clone bundle is a great feature to speeds up clone of large repository. However
one of the main obstacle for clone bundle deployment is the authentication
scheme. For non public project, just putting a static file on some random CDN is
not an option as we have to make sure people have the proper permission to
retrieves the bundle. On the other hand, 'largefiles' already have all the
necessary logic to serve arbitrary binary files -after- an authentication
checks. So reusing an existing large file infrastructure can be a significant
shortcut to clone bundle in this kind of closed environment.

The idea might seems strange, but the necessary update to the large file
extensions are quite small while the benefits are huge. In addition, since all
the extra logic live in the 'largefiles' extensions, core does not have to know
anything about it.

# bruterebase.py - brute force rebase testing
#
# Copyright 2017 Facebook, Inc.
#
# 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

from mercurial import (
    error,
    registrar,
    revsetlang,
)

from hgext import rebase

try:
    xrange
except NameError:
    xrange = range

cmdtable = {}
command = registrar.command(cmdtable)

@command(b'debugbruterebase')
def debugbruterebase(ui, repo, source, dest):
    """for every non-empty subset of source, run rebase -r subset -d dest

    Print one line summary for each subset. Assume obsstore is enabled.
    """
    srevs = list(repo.revs(source))

    with repo.wlock(), repo.lock():
        repolen = len(repo)
        cl = repo.changelog

        def getdesc(rev):
            result = cl.changelogrevision(rev).description
            if rev >= repolen:
                result += b"'"
            return result

        for i in xrange(1, 2 ** len(srevs)):
            subset = [rev for j, rev in enumerate(srevs) if i & (1 << j) != 0]
            spec = revsetlang.formatspec(b'%ld', subset)
            tr = repo.transaction(b'rebase')
            tr.report = lambda x: 0 # hide "transaction abort"

            ui.pushbuffer()
            try:
                rebase.rebase(ui, repo, dest=dest, rev=[spec])
            except error.Abort as ex:
                summary = b'ABORT: %s' % ex
            except Exception as ex:
                summary = b'CRASH: %s' % ex
            else:
                # short summary about new nodes
                cl = repo.changelog
                descs = []
                for rev in xrange(repolen, len(repo)):
                    desc = b'%s:' % getdesc(rev)
                    for prev in cl.parentrevs(rev):
                        if prev > -1:
                            desc += getdesc(prev)
                    descs.append(desc)
                descs.sort()
                summary = ' '.join(descs)
            ui.popbuffer()
            repo.vfs.tryunlink(b'rebasestate')

            subsetdesc = b''.join(getdesc(rev) for rev in subset)
            ui.write((b'%s: %s\n') % (subsetdesc.rjust(len(srevs)), summary))
            tr.abort()