bookflow: new extension for bookmark-based branching
This extension should be helpful for feature branches - based workflows.
At my company we first considered branches, but weren't sure about creating a lot of permanent objects.
We tried bookmarks, but found some scenarios to be difficult to control.
The main problem, was the active bookmark being moved on update.
Disabling that made everything a lot more predictable.
Bookmarks move on commit, and updating means switching between them.
The extension also implements a few minor features to better guide the workflow:
- hg bookmark NAME can be ambiguous (create or move), unlike hg branch. The extension requires -rev to move.
- require an active bookmark on commit.
- some bookmarks can be protected (like @), useful for teams, that require code reviews.
- block creation of new branches.
The initial implementation requires no changes in the core, but it does rely on some implementation details.
I thought it may be useful to discuss the functionality first, and then focus making the code more robust.
Differential Revision: https://phab.mercurial-scm.org/D4312
# unionrepo.py - repository class for viewing union of repository changesets
#
# Derived from bundlerepo.py
# Copyright 2006, 2007 Benoit Boissinot <bboissin@gmail.com>
# Copyright 2013 Unity Technologies, Mads Kiilerich <madski@unity3d.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Repository class for "in-memory pull" of one local repository to another,
allowing operations like diff and log with revsets.
"""
from __future__ import absolute_import
from .i18n import _
from .node import nullid
from . import (
changelog,
cmdutil,
encoding,
error,
filelog,
localrepo,
manifest,
mdiff,
pathutil,
revlog,
util,
vfs as vfsmod,
)
class unionrevlog(revlog.revlog):
def __init__(self, opener, indexfile, revlog2, linkmapper):
# How it works:
# To retrieve a revision, we just need to know the node id so we can
# look it up in revlog2.
#
# To differentiate a rev in the second revlog from a rev in the revlog,
# we check revision against repotiprev.
opener = vfsmod.readonlyvfs(opener)
revlog.revlog.__init__(self, opener, indexfile)
self.revlog2 = revlog2
n = len(self)
self.repotiprev = n - 1
self.bundlerevs = set() # used by 'bundle()' revset expression
for rev2 in self.revlog2:
rev = self.revlog2.index[rev2]
# rev numbers - in revlog2, very different from self.rev
_start, _csize, rsize, base, linkrev, p1rev, p2rev, node = rev
flags = _start & 0xFFFF
if linkmapper is None: # link is to same revlog
assert linkrev == rev2 # we never link back
link = n
else: # rev must be mapped from repo2 cl to unified cl by linkmapper
link = linkmapper(linkrev)
if linkmapper is not None: # link is to same revlog
base = linkmapper(base)
if node in self.nodemap:
# this happens for the common revlog revisions
self.bundlerevs.add(self.nodemap[node])
continue
p1node = self.revlog2.node(p1rev)
p2node = self.revlog2.node(p2rev)
# TODO: it's probably wrong to set compressed length to None, but
# I have no idea if csize is valid in the base revlog context.
e = (flags, None, rsize, base,
link, self.rev(p1node), self.rev(p2node), node)
self.index.append(e)
self.nodemap[node] = n
self.bundlerevs.add(n)
n += 1
def _chunk(self, rev):
if rev <= self.repotiprev:
return revlog.revlog._chunk(self, rev)
return self.revlog2._chunk(self.node(rev))
def revdiff(self, rev1, rev2):
"""return or calculate a delta between two revisions"""
if rev1 > self.repotiprev and rev2 > self.repotiprev:
return self.revlog2.revdiff(
self.revlog2.rev(self.node(rev1)),
self.revlog2.rev(self.node(rev2)))
elif rev1 <= self.repotiprev and rev2 <= self.repotiprev:
return self.baserevdiff(rev1, rev2)
return mdiff.textdiff(self.revision(rev1), self.revision(rev2))
def revision(self, nodeorrev, _df=None, raw=False):
"""return an uncompressed revision of a given node or revision
number.
"""
if isinstance(nodeorrev, int):
rev = nodeorrev
node = self.node(rev)
else:
node = nodeorrev
rev = self.rev(node)
if node == nullid:
return ""
if rev > self.repotiprev:
text = self.revlog2.revision(node)
self._revisioncache = (node, rev, text)
else:
text = self.baserevision(rev)
# already cached
return text
def baserevision(self, nodeorrev):
# Revlog subclasses may override 'revision' method to modify format of
# content retrieved from revlog. To use unionrevlog with such class one
# needs to override 'baserevision' and make more specific call here.
return revlog.revlog.revision(self, nodeorrev)
def baserevdiff(self, rev1, rev2):
# Exists for the same purpose as baserevision.
return revlog.revlog.revdiff(self, rev1, rev2)
def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
raise NotImplementedError
def addgroup(self, deltas, transaction, addrevisioncb=None):
raise NotImplementedError
def strip(self, rev, minlink):
raise NotImplementedError
def checksize(self):
raise NotImplementedError
class unionchangelog(unionrevlog, changelog.changelog):
def __init__(self, opener, opener2):
changelog.changelog.__init__(self, opener)
linkmapper = None
changelog2 = changelog.changelog(opener2)
unionrevlog.__init__(self, opener, self.indexfile, changelog2,
linkmapper)
def baserevision(self, nodeorrev):
# Although changelog doesn't override 'revision' method, some extensions
# may replace this class with another that does. Same story with
# manifest and filelog classes.
return changelog.changelog.revision(self, nodeorrev)
def baserevdiff(self, rev1, rev2):
return changelog.changelog.revdiff(self, rev1, rev2)
class unionmanifest(unionrevlog, manifest.manifestrevlog):
def __init__(self, opener, opener2, linkmapper):
manifest.manifestrevlog.__init__(self, opener)
manifest2 = manifest.manifestrevlog(opener2)
unionrevlog.__init__(self, opener, self.indexfile, manifest2,
linkmapper)
def baserevision(self, nodeorrev):
return manifest.manifestrevlog.revision(self, nodeorrev)
def baserevdiff(self, rev1, rev2):
return manifest.manifestrevlog.revdiff(self, rev1, rev2)
class unionfilelog(filelog.filelog):
def __init__(self, opener, path, opener2, linkmapper, repo):
filelog.filelog.__init__(self, opener, path)
filelog2 = filelog.filelog(opener2, path)
self._revlog = unionrevlog(opener, self.indexfile,
filelog2._revlog, linkmapper)
self._repo = repo
self.repotiprev = self._revlog.repotiprev
self.revlog2 = self._revlog.revlog2
def baserevision(self, nodeorrev):
return filelog.filelog.revision(self, nodeorrev)
def baserevdiff(self, rev1, rev2):
return filelog.filelog.revdiff(self, rev1, rev2)
def iscensored(self, rev):
"""Check if a revision is censored."""
if rev <= self.repotiprev:
return filelog.filelog.iscensored(self, rev)
node = self.node(rev)
return self.revlog2.iscensored(self.revlog2.rev(node))
class unionpeer(localrepo.localpeer):
def canpush(self):
return False
class unionrepository(object):
"""Represents the union of data in 2 repositories.
Instances are not usable if constructed directly. Use ``instance()``
or ``makeunionrepository()`` to create a usable instance.
"""
def __init__(self, repo2, url):
self.repo2 = repo2
self._url = url
self.ui.setconfig('phases', 'publish', False, 'unionrepo')
@localrepo.unfilteredpropertycache
def changelog(self):
return unionchangelog(self.svfs, self.repo2.svfs)
@localrepo.unfilteredpropertycache
def manifestlog(self):
rootstore = unionmanifest(self.svfs, self.repo2.svfs,
self.unfiltered()._clrev)
return manifest.manifestlog(self.svfs, self, rootstore)
def _clrev(self, rev2):
"""map from repo2 changelog rev to temporary rev in self.changelog"""
node = self.repo2.changelog.node(rev2)
return self.changelog.rev(node)
def url(self):
return self._url
def file(self, f):
return unionfilelog(self.svfs, f, self.repo2.svfs,
self.unfiltered()._clrev, self)
def close(self):
self.repo2.close()
def cancopy(self):
return False
def peer(self):
return unionpeer(self)
def getcwd(self):
return encoding.getcwd() # always outside the repo
def instance(ui, path, create, intents=None, createopts=None):
if create:
raise error.Abort(_('cannot create new union repository'))
parentpath = ui.config("bundle", "mainreporoot")
if not parentpath:
# try to find the correct path to the working directory repo
parentpath = cmdutil.findrepo(encoding.getcwd())
if parentpath is None:
parentpath = ''
if parentpath:
# Try to make the full path relative so we get a nice, short URL.
# In particular, we don't want temp dir names in test outputs.
cwd = encoding.getcwd()
if parentpath == cwd:
parentpath = ''
else:
cwd = pathutil.normasprefix(cwd)
if parentpath.startswith(cwd):
parentpath = parentpath[len(cwd):]
if path.startswith('union:'):
s = path.split(":", 1)[1].split("+", 1)
if len(s) == 1:
repopath, repopath2 = parentpath, s[0]
else:
repopath, repopath2 = s
else:
repopath, repopath2 = parentpath, path
return makeunionrepository(ui, repopath, repopath2)
def makeunionrepository(ui, repopath1, repopath2):
"""Make a union repository object from 2 local repo paths."""
repo1 = localrepo.instance(ui, repopath1, create=False)
repo2 = localrepo.instance(ui, repopath2, create=False)
url = 'union:%s+%s' % (util.expandpath(repopath1),
util.expandpath(repopath2))
class derivedunionrepository(unionrepository, repo1.__class__):
pass
repo = repo1
repo.__class__ = derivedunionrepository
unionrepository.__init__(repo1, repo2, url)
return repo