sidedatacopies: only store an entry if it has values
This will make for a shorter storage and help use to write faster code in simple
case. This change already provided a speed boost for copy tracing.
For example here is combined time of running copies tracing on a 6989 pairs of
revision on the pypy repos:
before: 771s
after: 631s - 18%
This also has a very positive impact on changelog size. For example here are the
number for the `00changelog.d` file of pypy.
before:
30449712 Bytes
after:
24973718 Bytes - 18%
This give an overall quite acceptable overhead for storing copies into the
changelog:
filelog-only:
23370586
sidedata:
24973718 Bytes + 7%
Differential Revision: https://phab.mercurial-scm.org/D7068
# rewriteutil.py - utility functions for rewriting changesets
#
# Copyright 2017 Octobus <contact@octobus.net>
#
# 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 .i18n import _
from . import (
error,
node,
obsolete,
revset,
)
def precheck(repo, revs, action=b'rewrite'):
"""check if revs can be rewritten
action is used to control the error message.
Make sure this function is called after taking the lock.
"""
if node.nullrev in revs:
msg = _(b"cannot %s null changeset") % action
hint = _(b"no changeset checked out")
raise error.Abort(msg, hint=hint)
if len(repo[None].parents()) > 1:
raise error.Abort(_(b"cannot %s while merging") % action)
publicrevs = repo.revs(b'%ld and public()', revs)
if publicrevs:
msg = _(b"cannot %s public changesets") % action
hint = _(b"see 'hg help phases' for details")
raise error.Abort(msg, hint=hint)
newunstable = disallowednewunstable(repo, revs)
if newunstable:
raise error.Abort(_(b"cannot %s changeset with children") % action)
def disallowednewunstable(repo, revs):
"""Checks whether editing the revs will create new unstable changesets and
are we allowed to create them.
To allow new unstable changesets, set the config:
`experimental.evolution.allowunstable=True`
"""
allowunstable = obsolete.isenabled(repo, obsolete.allowunstableopt)
if allowunstable:
return revset.baseset()
return repo.revs(b"(%ld::) - %ld", revs, revs)