view tests/bruterebase.py @ 39366:a41497b5117c

copies: improve logic of deciding copytracing on based of config options

Few months ago or maybe a year ago, I imported Fb's heuristics based copytracing
algorithms. While importing that, I renamed `experimental.disablecopytrace` with
`experimental.copytrace` and the behavior of the new config option was like
this:

  * "heuristics" : Fb's heuristic copytracing algorithm
  * "off" : copytracing is turned off
  * something else: copytracing is on

This is the behavior right now also and this is bad because it hardcodes the
string 'off' to turn off the copytracing. On big repositories, copytracing is
very slow and people wants to turn copytracing off. However if the user sets it
to 'False', 'Off', '0', none of them is going to disbale copytracing while they
should.
I lacked the understanding of why this can be bad when I coded it.

After this patch, the new behavior of the config option will be:

  * "heuristics": Fb's heuristic copytracing algorithm
  * '0', 'false', 'off', 'never', 'no', 'NO', all the values which
    repo.ui.configbool() evaluates to False: copytracing in turned off
  * something else: copytracing is on

Since 'off' still evaluates to copytracing being turned off, this is not BC.
Also the config option is experimental.

Differential Revision: https://phab.mercurial-scm.org/D4416

# 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 = b' '.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()