sapling/hgext/gitlookup.py
Kostia Balytskyi e75b9fc1b1 fb-hgext: move most of hgext3rd and related tests to core
Summary:
This commit moves most of the stuff in hgext3rd and related tests to
hg-crew/hgext and hg-crew/test respectively.

The things that are not moved are the ones which require some more complex
imports.


Depends on D6675309

Test Plan: - tests are failing at this commit, fixes are in the following commits

Reviewers: #sourcecontrol

Differential Revision: https://phabricator.intern.facebook.com/D6675329
2018-01-09 03:03:59 -08:00

342 lines
11 KiB
Python

# gitlookup.py - server-side support for hg->git and git->hg lookups
#
# Copyright 2014 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.
''' extension that will look up hashes from an hg-git map file over the wire.
This also provides client and server commands to download all the Git
metadata via bundle2. Example usage:
- get the git equivalent of hg 47d743e068523a9346a5ea4e429eeab185c886c6
hg identify --id -r\\
_gitlookup_hg_47d743e068523a9346a5ea4e429eeab185c886c6\\
ssh://server/repo
- get the hg equivalent of git 6916a3c30f53878032dea8d01074d8c2a03927bd
hg identify --id -r\\
_gitlookup_git_6916a3c30f53878032dea8d01074d8c2a03927bd\\
ssh://server/repo
::
[gitlookup]
# Define the location of the map file with the mapfile config option.
mapfile = <location of map file>
# The config option onlymapdelta controls how the server handles the hg-git
# map. A True value corresponds to serving only missing map data while False
# corresponds to serving the complete map.
onlymapdelta = False
'''
import errno
import json
from mercurial import (
bundle2,
encoding,
error,
exchange,
extensions,
hg,
localrepo,
registrar,
util,
wireproto,
)
from mercurial.node import (
bin,
hex,
nullid,
)
from mercurial.i18n import _
cmdtable = {}
command = registrar.command(cmdtable)
def wrapwireprotocommand(command, wrapper):
'''Wrap the wire proto command named `command' in table
Just like extensions.wrapcommand, except for wire protocol commands.
'''
assert util.safehasattr(wrapper, '__call__')
origfn, args = wireproto.commands[command]
def wrap(*args, **kwargs):
return util.checksignature(wrapper)(
util.checksignature(origfn), *args, **kwargs)
wireproto.commands[command] = wrap, args
return wrapper
def remotelookup(orig, repo, proto, key):
k = encoding.tolocal(key)
if k.startswith('_gitlookup_'):
ret = _dolookup(repo, k)
if ret is not None:
success = 1
return '%s %s\n' % (success, ret)
return orig(repo, proto, key)
def locallookup(orig, repo, key):
gitlookup = _dolookup(repo, key)
if gitlookup:
return bin(gitlookup)
else:
return orig(repo, key)
def _dolookup(repo, key):
mapfile = repo.ui.configpath('gitlookup', 'mapfile')
if mapfile is None:
return None
if not isinstance(key, str):
return None
# direction: git to hg = g, hg to git = h
if key.startswith('_gitlookup_git_'):
direction = 'tohg'
sha = key[15:]
elif key.startswith('_gitlookup_hg_'):
direction = 'togit'
sha = key[14:]
else:
return None
hggitmap = open(mapfile, 'rb')
for line in hggitmap:
gitsha, hgsha = line.strip().split(' ', 1)
if direction == 'tohg' and sha == gitsha:
return hgsha
if direction == 'togit' and sha == hgsha:
return gitsha
return None
@command('gitgetmeta', [], '[SOURCE]')
def gitgetmeta(ui, repo, source='default'):
'''get git metadata from a server that supports fb_gitmeta'''
source, branch = hg.parseurl(ui.expandpath(source))
other = hg.peer(repo, {}, source)
ui.status(_('getting git metadata from %s\n') %
util.hidepassword(source))
kwargs = {'bundlecaps': exchange.caps20to10(repo)}
capsblob = bundle2.encodecaps(bundle2.getrepocaps(repo))
kwargs['bundlecaps'].add('bundle2=' + util.urlreq.quote(capsblob))
# this would ideally not be in the bundlecaps at all, but adding new kwargs
# for wire transmissions is not possible as of Mercurial d19164a018a1
kwargs['bundlecaps'].add('fb_gitmeta')
kwargs['heads'] = [nullid]
kwargs['cg'] = False
kwargs['common'] = _getcommonheads(repo)
bundle = other.getbundle('pull', **kwargs)
try:
op = bundle2.processbundle(repo, bundle)
except error.BundleValueError as exc:
raise error.Abort('missing support for %s' % exc)
writebytes = op.records['fb:gitmeta:writebytes']
ui.status(_('wrote %d files (%d bytes)\n') %
(len(writebytes), sum(writebytes)))
hgheadsfile = 'git-synced-hgheads'
gitmapfile = 'git-mapfile'
gitmetafiles = set(
[gitmapfile, 'git-named-branches', 'git-tags', 'git-remote-refs'])
def _getfile(repo, filename):
try:
return repo.vfs(filename)
except (IOError, OSError) as e:
if e.errno != errno.ENOENT:
repo.ui.warn(_("warning: unable to read %s: %s\n") % (filename, e))
return None
def _getcommonheads(repo):
commonheads = []
f = _getfile(repo, hgheadsfile)
if f:
commonheads = f.readlines()
commonheads = [bin(x.strip()) for x in commonheads]
return commonheads
def _isheadmissing(repo, heads):
return not all(repo.known(heads))
def _getmissinglines(mapfile, missinghashes):
missinglines = set()
# Avoid expensive lookup through the map file if there is no missing hash.
if not missinghashes:
return missinglines
hashestofind = missinghashes.copy()
for line in mapfile:
gitsha, hgsha = line.strip().split(' ', 1)
if hgsha in hashestofind:
missinglines.add(line)
# Return the missing lines if we found all of them.
hashestofind.remove(hgsha)
if not hashestofind:
return missinglines
raise error.Abort(_('gitmeta: missing hashes in file %s') % mapfile.name)
class _githgmappayload(object):
def __init__(self, needfullsync, newheads, missinglines):
self.needfullsync = needfullsync
self.newheads = newheads
self.missinglines = missinglines
def _todict(self):
d = {}
d['needfullsync'] = self.needfullsync
d['newheads'] = list(self.newheads)
d['missinglines'] = list(self.missinglines)
return d
def tojson(self):
return json.dumps(self._todict())
@classmethod
def _fromdict(cls, d):
needfullsync = d['needfullsync']
newheads = set(d['newheads'])
missinglines = set(d['missinglines'])
return cls(needfullsync, newheads, missinglines)
@classmethod
def fromjson(cls, jsonstr):
d = json.loads(jsonstr)
return cls._fromdict(d)
@exchange.getbundle2partsgenerator('b2x:fb:gitmeta:githgmap')
def _getbundlegithgmappart(bundler, repo, source, bundlecaps=None, **kwargs):
'''send missing git to hg map data via bundle2'''
if 'fb_gitmeta' in bundlecaps:
# Do nothing if the config indicates serving the complete git-hg map
# file. _getbundlegitmetapart will handle serving the complete file in
# this case.
if not repo.ui.configbool('gitlookup', 'onlymapdelta', False):
return
mapfile = _getfile(repo, gitmapfile)
if not mapfile:
return
commonheads = kwargs['common']
# If there are missing heads, we will sync everything.
if _isheadmissing(repo, commonheads):
commonheads = []
needfullsync = (len(commonheads) == 0)
heads = repo.heads()
newheads = set(hex(head) for head in heads)
missingcommits = repo.changelog.findmissing(commonheads, heads)
missinghashes = set(hex(commit) for commit in missingcommits)
missinglines = _getmissinglines(mapfile, missinghashes)
payload = _githgmappayload(needfullsync, newheads, missinglines)
serializedpayload = payload.tojson()
part = bundle2.bundlepart(
'b2x:fb:gitmeta:githgmap',
[('filename', gitmapfile)],
data = serializedpayload
)
bundler.addpart(part)
@exchange.getbundle2partsgenerator('b2x:fb:gitmeta')
def _getbundlegitmetapart(bundler, repo, source, bundlecaps=None, **kwargs):
'''send git metadata via bundle2'''
if 'fb_gitmeta' in bundlecaps:
filestooverwrite = gitmetafiles
# Exclude the git-hg map file if the config indicates that the server
# should only be serving the missing map data. _getbundle2partsgenerator
# will serve the missing map data in this case.
if repo.ui.configbool('gitlookup', 'onlymapdelta', False):
filestooverwrite = filestooverwrite - set([gitmapfile])
for fname in sorted(filestooverwrite):
f = _getfile(repo, fname)
if not f:
continue
part = bundle2.bundlepart('b2x:fb:gitmeta',
[('filename', fname)],
data=f.read())
bundler.addpart(part)
def _writefile(op, filename, data):
with op.repo.vfs(filename, 'w+', atomictemp=True) as f:
op.repo.ui.note(_('writing .hg/%s\n') % filename)
f.write(data)
op.records.add('fb:gitmeta:writebytes', len(data))
def _validatepartparams(op, params):
if 'filename' not in params:
raise error.Abort(_("gitmeta: 'filename' missing"))
fname = params['filename']
if fname not in gitmetafiles:
op.repo.ui.warn(
_("warning: gitmeta: unknown file '%s' skipped\n") % fname)
return False
return True
@bundle2.parthandler('b2x:fb:gitmeta:githgmap', ('filename',))
@bundle2.parthandler('fb:gitmeta:githgmap', ('filename',))
def bundle2getgithgmap(op, part):
params = dict(part.mandatoryparams)
if _validatepartparams(op, params):
filename = params['filename']
with op.repo.wlock():
data = _githgmappayload.fromjson(part.read())
missinglines = data.missinglines
# No need to update anything if already in sync.
if not missinglines:
return
if data.needfullsync:
newlines = missinglines
else:
mapfile = _getfile(op.repo, filename)
if mapfile:
currentlines = set(mapfile.readlines())
if currentlines & missinglines:
msg = 'warning: gitmeta: unexpected lines in .hg/%s\n'
op.repo.ui.warn(_(msg) % filename)
currentlines.update(missinglines)
newlines = currentlines
else:
raise error.Abort(
_('gitmeta: could not read from .hg/%s') % filename)
_writefile(op, filename, ''.join(newlines))
_writefile(op, hgheadsfile, '\n'.join(data.newheads))
@bundle2.parthandler('b2x:fb:gitmeta', ('filename',))
@bundle2.parthandler('fb:gitmeta', ('filename',))
def bundle2getgitmeta(op, part):
'''unbundle a bundle2 containing git metadata on the client'''
params = dict(part.mandatoryparams)
if _validatepartparams(op, params):
filename = params['filename']
with op.repo.wlock():
data = part.read()
_writefile(op, filename, data)
def extsetup(ui):
wrapwireprotocommand('lookup', remotelookup)
extensions.wrapfunction(localrepo.localrepository, 'lookup', locallookup)