git: skeleton of a new extension to _directly_ operate on git repos
This is based in part of work I did years ago in hgit, but it's mostly
new code since I'm using pygit2 instead of dulwich and the hg storage
interfaces have improved. Some cleanup of old hgit code by Pulkit,
which I greatly appreciate.
test-git-interop.t does not cover a whole lot of cases, but it
passes. It includes status, diff, making a new commit, and `hg annotate`
working on the git repository.
This is _not_ (yet) production quality code: this is an
experiment. Known technical debt lurking in this implementation:
* Writing bookmarks just totally ignores transactions.
* The way progress is threaded down into the gitstore is awful.
* Ideally we'd find a way to incrementally reindex DAGs. I'm not sure
how to do that efficiently, so we might need a "known only fast-forwards"
mode on the DAG indexer for use on `hg commit` and friends.
* We don't even _try_ to do anything reasonable for `hg pull` or `hg push`.
* Mercurial need an interface for the changelog type.
Tests currently require git 2.24 as far as I'm aware: `git status` has
some changed output that I didn't try and handle in a compatible way.
This patch has produced some interesting cleanups, most recently on
the manifest type. I expect continuing down this road will produce
other meritorious cleanups throughout our code.
Differential Revision: https://phab.mercurial-scm.org/D6734
# git.py - git support for the convert extension
#
# Copyright 2005-2009 Matt Mackall <mpm@selenic.com> and others
#
# 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
import os
from mercurial.i18n import _
from mercurial import (
config,
error,
node as nodemod,
pycompat,
)
from . import common
class submodule(object):
def __init__(self, path, node, url):
self.path = path
self.node = node
self.url = url
def hgsub(self):
return b"%s = [git]%s" % (self.path, self.url)
def hgsubstate(self):
return b"%s %s" % (self.node, self.path)
# Keys in extra fields that should not be copied if the user requests.
bannedextrakeys = {
# Git commit object built-ins.
b'tree',
b'parent',
b'author',
b'committer',
# Mercurial built-ins.
b'branch',
b'close',
}
class convert_git(common.converter_source, common.commandline):
# Windows does not support GIT_DIR= construct while other systems
# cannot remove environment variable. Just assume none have
# both issues.
def _gitcmd(self, cmd, *args, **kwargs):
return cmd(b'--git-dir=%s' % self.path, *args, **kwargs)
def gitrun0(self, *args, **kwargs):
return self._gitcmd(self.run0, *args, **kwargs)
def gitrun(self, *args, **kwargs):
return self._gitcmd(self.run, *args, **kwargs)
def gitrunlines0(self, *args, **kwargs):
return self._gitcmd(self.runlines0, *args, **kwargs)
def gitrunlines(self, *args, **kwargs):
return self._gitcmd(self.runlines, *args, **kwargs)
def gitpipe(self, *args, **kwargs):
return self._gitcmd(self._run3, *args, **kwargs)
def __init__(self, ui, repotype, path, revs=None):
super(convert_git, self).__init__(ui, repotype, path, revs=revs)
common.commandline.__init__(self, ui, b'git')
# Pass an absolute path to git to prevent from ever being interpreted
# as a URL
path = os.path.abspath(path)
if os.path.isdir(path + b"/.git"):
path += b"/.git"
if not os.path.exists(path + b"/objects"):
raise common.NoRepo(
_(b"%s does not look like a Git repository") % path
)
# The default value (50) is based on the default for 'git diff'.
similarity = ui.configint(b'convert', b'git.similarity')
if similarity < 0 or similarity > 100:
raise error.Abort(_(b'similarity must be between 0 and 100'))
if similarity > 0:
self.simopt = [b'-C%d%%' % similarity]
findcopiesharder = ui.configbool(
b'convert', b'git.findcopiesharder'
)
if findcopiesharder:
self.simopt.append(b'--find-copies-harder')
renamelimit = ui.configint(b'convert', b'git.renamelimit')
self.simopt.append(b'-l%d' % renamelimit)
else:
self.simopt = []
common.checktool(b'git', b'git')
self.path = path
self.submodules = []
self.catfilepipe = self.gitpipe(b'cat-file', b'--batch')
self.copyextrakeys = self.ui.configlist(b'convert', b'git.extrakeys')
banned = set(self.copyextrakeys) & bannedextrakeys
if banned:
raise error.Abort(
_(b'copying of extra key is forbidden: %s')
% _(b', ').join(sorted(banned))
)
committeractions = self.ui.configlist(
b'convert', b'git.committeractions'
)
messagedifferent = None
messagealways = None
for a in committeractions:
if a.startswith((b'messagedifferent', b'messagealways')):
k = a
v = None
if b'=' in a:
k, v = a.split(b'=', 1)
if k == b'messagedifferent':
messagedifferent = v or b'committer:'
elif k == b'messagealways':
messagealways = v or b'committer:'
if messagedifferent and messagealways:
raise error.Abort(
_(
b'committeractions cannot define both '
b'messagedifferent and messagealways'
)
)
dropcommitter = b'dropcommitter' in committeractions
replaceauthor = b'replaceauthor' in committeractions
if dropcommitter and replaceauthor:
raise error.Abort(
_(
b'committeractions cannot define both '
b'dropcommitter and replaceauthor'
)
)
if dropcommitter and messagealways:
raise error.Abort(
_(
b'committeractions cannot define both '
b'dropcommitter and messagealways'
)
)
if not messagedifferent and not messagealways:
messagedifferent = b'committer:'
self.committeractions = {
b'dropcommitter': dropcommitter,
b'replaceauthor': replaceauthor,
b'messagedifferent': messagedifferent,
b'messagealways': messagealways,
}
def after(self):
for f in self.catfilepipe:
f.close()
def getheads(self):
if not self.revs:
output, status = self.gitrun(
b'rev-parse', b'--branches', b'--remotes'
)
heads = output.splitlines()
if status:
raise error.Abort(_(b'cannot retrieve git heads'))
else:
heads = []
for rev in self.revs:
rawhead, ret = self.gitrun(b'rev-parse', b'--verify', rev)
heads.append(rawhead[:-1])
if ret:
raise error.Abort(_(b'cannot retrieve git head "%s"') % rev)
return heads
def catfile(self, rev, ftype):
if rev == nodemod.nullhex:
raise IOError
self.catfilepipe[0].write(rev + b'\n')
self.catfilepipe[0].flush()
info = self.catfilepipe[1].readline().split()
if info[1] != ftype:
raise error.Abort(
_(b'cannot read %r object at %s')
% (pycompat.bytestr(ftype), rev)
)
size = int(info[2])
data = self.catfilepipe[1].read(size)
if len(data) < size:
raise error.Abort(
_(b'cannot read %r object at %s: unexpected size')
% (ftype, rev)
)
# read the trailing newline
self.catfilepipe[1].read(1)
return data
def getfile(self, name, rev):
if rev == nodemod.nullhex:
return None, None
if name == b'.hgsub':
data = b'\n'.join([m.hgsub() for m in self.submoditer()])
mode = b''
elif name == b'.hgsubstate':
data = b'\n'.join([m.hgsubstate() for m in self.submoditer()])
mode = b''
else:
data = self.catfile(rev, b"blob")
mode = self.modecache[(name, rev)]
return data, mode
def submoditer(self):
null = nodemod.nullhex
for m in sorted(self.submodules, key=lambda p: p.path):
if m.node != null:
yield m
def parsegitmodules(self, content):
"""Parse the formatted .gitmodules file, example file format:
[submodule "sub"]\n
\tpath = sub\n
\turl = git://giturl\n
"""
self.submodules = []
c = config.config()
# Each item in .gitmodules starts with whitespace that cant be parsed
c.parse(
b'.gitmodules',
b'\n'.join(line.strip() for line in content.split(b'\n')),
)
for sec in c.sections():
s = c[sec]
if b'url' in s and b'path' in s:
self.submodules.append(submodule(s[b'path'], b'', s[b'url']))
def retrievegitmodules(self, version):
modules, ret = self.gitrun(
b'show', b'%s:%s' % (version, b'.gitmodules')
)
if ret:
# This can happen if a file is in the repo that has permissions
# 160000, but there is no .gitmodules file.
self.ui.warn(
_(b"warning: cannot read submodules config file in %s\n")
% version
)
return
try:
self.parsegitmodules(modules)
except error.ParseError:
self.ui.warn(
_(b"warning: unable to parse .gitmodules in %s\n") % version
)
return
for m in self.submodules:
node, ret = self.gitrun(b'rev-parse', b'%s:%s' % (version, m.path))
if ret:
continue
m.node = node.strip()
def getchanges(self, version, full):
if full:
raise error.Abort(_(b"convert from git does not support --full"))
self.modecache = {}
cmd = (
[b'diff-tree', b'-z', b'--root', b'-m', b'-r']
+ self.simopt
+ [version]
)
output, status = self.gitrun(*cmd)
if status:
raise error.Abort(_(b'cannot read changes in %s') % version)
changes = []
copies = {}
seen = set()
entry = None
subexists = [False]
subdeleted = [False]
difftree = output.split(b'\x00')
lcount = len(difftree)
i = 0
skipsubmodules = self.ui.configbool(b'convert', b'git.skipsubmodules')
def add(entry, f, isdest):
seen.add(f)
h = entry[3]
p = entry[1] == b"100755"
s = entry[1] == b"120000"
renamesource = not isdest and entry[4][0] == b'R'
if f == b'.gitmodules':
if skipsubmodules:
return
subexists[0] = True
if entry[4] == b'D' or renamesource:
subdeleted[0] = True
changes.append((b'.hgsub', nodemod.nullhex))
else:
changes.append((b'.hgsub', b''))
elif entry[1] == b'160000' or entry[0] == b':160000':
if not skipsubmodules:
subexists[0] = True
else:
if renamesource:
h = nodemod.nullhex
self.modecache[(f, h)] = (p and b"x") or (s and b"l") or b""
changes.append((f, h))
while i < lcount:
l = difftree[i]
i += 1
if not entry:
if not l.startswith(b':'):
continue
entry = tuple(pycompat.bytestr(p) for p in l.split())
continue
f = l
if entry[4][0] == b'C':
copysrc = f
copydest = difftree[i]
i += 1
f = copydest
copies[copydest] = copysrc
if f not in seen:
add(entry, f, False)
# A file can be copied multiple times, or modified and copied
# simultaneously. So f can be repeated even if fdest isn't.
if entry[4][0] == b'R':
# rename: next line is the destination
fdest = difftree[i]
i += 1
if fdest not in seen:
add(entry, fdest, True)
# .gitmodules isn't imported at all, so it being copied to
# and fro doesn't really make sense
if f != b'.gitmodules' and fdest != b'.gitmodules':
copies[fdest] = f
entry = None
if subexists[0]:
if subdeleted[0]:
changes.append((b'.hgsubstate', nodemod.nullhex))
else:
self.retrievegitmodules(version)
changes.append((b'.hgsubstate', b''))
return (changes, copies, set())
def getcommit(self, version):
c = self.catfile(version, b"commit") # read the commit hash
end = c.find(b"\n\n")
message = c[end + 2 :]
message = self.recode(message)
l = c[:end].splitlines()
parents = []
author = committer = None
extra = {}
for e in l[1:]:
n, v = e.split(b" ", 1)
if n == b"author":
p = v.split()
tm, tz = p[-2:]
author = b" ".join(p[:-2])
if author[0] == b"<":
author = author[1:-1]
author = self.recode(author)
if n == b"committer":
p = v.split()
tm, tz = p[-2:]
committer = b" ".join(p[:-2])
if committer[0] == b"<":
committer = committer[1:-1]
committer = self.recode(committer)
if n == b"parent":
parents.append(v)
if n in self.copyextrakeys:
extra[n] = v
if self.committeractions[b'dropcommitter']:
committer = None
elif self.committeractions[b'replaceauthor']:
author = committer
if committer:
messagealways = self.committeractions[b'messagealways']
messagedifferent = self.committeractions[b'messagedifferent']
if messagealways:
message += b'\n%s %s\n' % (messagealways, committer)
elif messagedifferent and author != committer:
message += b'\n%s %s\n' % (messagedifferent, committer)
tzs, tzh, tzm = tz[-5:-4] + b"1", tz[-4:-2], tz[-2:]
tz = -int(tzs) * (int(tzh) * 3600 + int(tzm))
date = tm + b" " + (b"%d" % tz)
saverev = self.ui.configbool(b'convert', b'git.saverev')
c = common.commit(
parents=parents,
date=date,
author=author,
desc=message,
rev=version,
extra=extra,
saverev=saverev,
)
return c
def numcommits(self):
output, ret = self.gitrunlines(b'rev-list', b'--all')
if ret:
raise error.Abort(
_(b'cannot retrieve number of commits in %s') % self.path
)
return len(output)
def gettags(self):
tags = {}
alltags = {}
output, status = self.gitrunlines(b'ls-remote', b'--tags', self.path)
if status:
raise error.Abort(_(b'cannot read tags from %s') % self.path)
prefix = b'refs/tags/'
# Build complete list of tags, both annotated and bare ones
for line in output:
line = line.strip()
if line.startswith(b"error:") or line.startswith(b"fatal:"):
raise error.Abort(_(b'cannot read tags from %s') % self.path)
node, tag = line.split(None, 1)
if not tag.startswith(prefix):
continue
alltags[tag[len(prefix) :]] = node
# Filter out tag objects for annotated tag refs
for tag in alltags:
if tag.endswith(b'^{}'):
tags[tag[:-3]] = alltags[tag]
else:
if tag + b'^{}' in alltags:
continue
else:
tags[tag] = alltags[tag]
return tags
def getchangedfiles(self, version, i):
changes = []
if i is None:
output, status = self.gitrunlines(
b'diff-tree', b'--root', b'-m', b'-r', version
)
if status:
raise error.Abort(_(b'cannot read changes in %s') % version)
for l in output:
if b"\t" not in l:
continue
m, f = l[:-1].split(b"\t")
changes.append(f)
else:
output, status = self.gitrunlines(
b'diff-tree',
b'--name-only',
b'--root',
b'-r',
version,
b'%s^%d' % (version, i + 1),
b'--',
)
if status:
raise error.Abort(_(b'cannot read changes in %s') % version)
changes = [f.rstrip(b'\n') for f in output]
return changes
def getbookmarks(self):
bookmarks = {}
# Handle local and remote branches
remoteprefix = self.ui.config(b'convert', b'git.remoteprefix')
reftypes = [
# (git prefix, hg prefix)
(b'refs/remotes/origin/', remoteprefix + b'/'),
(b'refs/heads/', b''),
]
exclude = {
b'refs/remotes/origin/HEAD',
}
try:
output, status = self.gitrunlines(b'show-ref')
for line in output:
line = line.strip()
rev, name = line.split(None, 1)
# Process each type of branch
for gitprefix, hgprefix in reftypes:
if not name.startswith(gitprefix) or name in exclude:
continue
name = b'%s%s' % (hgprefix, name[len(gitprefix) :])
bookmarks[name] = rev
except Exception:
pass
return bookmarks
def checkrevformat(self, revstr, mapname=b'splicemap'):
""" git revision string is a 40 byte hex """
self.checkhexformat(revstr, mapname)