Mercurial > hg
view mercurial/archival.py @ 32697:19b9fc40cc51
revlog: skeleton support for version 2 revlogs
There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.
It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.
This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.
An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.
To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.
Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.
There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 19 May 2017 20:29:11 -0700 |
parents | 7feab0e7702d |
children | 3047167733dc |
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# archival.py - revision archival for mercurial # # Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com> # # 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 gzip import os import struct import tarfile import time import zipfile import zlib from .i18n import _ from . import ( cmdutil, encoding, error, match as matchmod, util, vfs as vfsmod, ) stringio = util.stringio # from unzip source code: _UNX_IFREG = 0x8000 _UNX_IFLNK = 0xa000 def tidyprefix(dest, kind, prefix): '''choose prefix to use for names in archive. make sure prefix is safe for consumers.''' if prefix: prefix = util.normpath(prefix) else: if not isinstance(dest, str): raise ValueError('dest must be string if no prefix') prefix = os.path.basename(dest) lower = prefix.lower() for sfx in exts.get(kind, []): if lower.endswith(sfx): prefix = prefix[:-len(sfx)] break lpfx = os.path.normpath(util.localpath(prefix)) prefix = util.pconvert(lpfx) if not prefix.endswith('/'): prefix += '/' # Drop the leading '.' path component if present, so Windows can read the # zip files (issue4634) if prefix.startswith('./'): prefix = prefix[2:] if prefix.startswith('../') or os.path.isabs(lpfx) or '/../' in prefix: raise error.Abort(_('archive prefix contains illegal components')) return prefix exts = { 'tar': ['.tar'], 'tbz2': ['.tbz2', '.tar.bz2'], 'tgz': ['.tgz', '.tar.gz'], 'zip': ['.zip'], } def guesskind(dest): for kind, extensions in exts.iteritems(): if any(dest.endswith(ext) for ext in extensions): return kind return None def _rootctx(repo): # repo[0] may be hidden for rev in repo: return repo[rev] return repo['null'] def buildmetadata(ctx): '''build content of .hg_archival.txt''' repo = ctx.repo() hex = ctx.hex() if ctx.rev() is None: hex = ctx.p1().hex() if ctx.dirty(): hex += '+' base = 'repo: %s\nnode: %s\nbranch: %s\n' % ( _rootctx(repo).hex(), hex, encoding.fromlocal(ctx.branch())) tags = ''.join('tag: %s\n' % t for t in ctx.tags() if repo.tagtype(t) == 'global') if not tags: repo.ui.pushbuffer() opts = {'template': '{latesttag}\n{latesttagdistance}\n' '{changessincelatesttag}', 'style': '', 'patch': None, 'git': None} cmdutil.show_changeset(repo.ui, repo, opts).show(ctx) ltags, dist, changessince = repo.ui.popbuffer().split('\n') ltags = ltags.split(':') tags = ''.join('latesttag: %s\n' % t for t in ltags) tags += 'latesttagdistance: %s\n' % dist tags += 'changessincelatesttag: %s\n' % changessince return base + tags class tarit(object): '''write archive to tar file or stream. can write uncompressed, or compress with gzip or bzip2.''' class GzipFileWithTime(gzip.GzipFile): def __init__(self, *args, **kw): timestamp = None if 'timestamp' in kw: timestamp = kw.pop('timestamp') if timestamp is None: self.timestamp = time.time() else: self.timestamp = timestamp gzip.GzipFile.__init__(self, *args, **kw) def _write_gzip_header(self): self.fileobj.write('\037\213') # magic header self.fileobj.write('\010') # compression method fname = self.name if fname and fname.endswith('.gz'): fname = fname[:-3] flags = 0 if fname: flags = gzip.FNAME self.fileobj.write(chr(flags)) gzip.write32u(self.fileobj, long(self.timestamp)) self.fileobj.write('\002') self.fileobj.write('\377') if fname: self.fileobj.write(fname + '\000') def __init__(self, dest, mtime, kind=''): self.mtime = mtime self.fileobj = None def taropen(mode, name='', fileobj=None): if kind == 'gz': mode = mode[0] if not fileobj: fileobj = open(name, mode + 'b') gzfileobj = self.GzipFileWithTime(name, mode + 'b', zlib.Z_BEST_COMPRESSION, fileobj, timestamp=mtime) self.fileobj = gzfileobj return tarfile.TarFile.taropen(name, mode, gzfileobj) else: return tarfile.open(name, mode + kind, fileobj) if isinstance(dest, str): self.z = taropen('w:', name=dest) else: self.z = taropen('w|', fileobj=dest) def addfile(self, name, mode, islink, data): i = tarfile.TarInfo(name) i.mtime = self.mtime i.size = len(data) if islink: i.type = tarfile.SYMTYPE i.mode = 0o777 i.linkname = data data = None i.size = 0 else: i.mode = mode data = stringio(data) self.z.addfile(i, data) def done(self): self.z.close() if self.fileobj: self.fileobj.close() class tellable(object): '''provide tell method for zipfile.ZipFile when writing to http response file object.''' def __init__(self, fp): self.fp = fp self.offset = 0 def __getattr__(self, key): return getattr(self.fp, key) def write(self, s): self.fp.write(s) self.offset += len(s) def tell(self): return self.offset class zipit(object): '''write archive to zip file or stream. can write uncompressed, or compressed with deflate.''' def __init__(self, dest, mtime, compress=True): if not isinstance(dest, str): try: dest.tell() except (AttributeError, IOError): dest = tellable(dest) self.z = zipfile.ZipFile(dest, 'w', compress and zipfile.ZIP_DEFLATED or zipfile.ZIP_STORED) # Python's zipfile module emits deprecation warnings if we try # to store files with a date before 1980. epoch = 315532800 # calendar.timegm((1980, 1, 1, 0, 0, 0, 1, 1, 0)) if mtime < epoch: mtime = epoch self.mtime = mtime self.date_time = time.gmtime(mtime)[:6] def addfile(self, name, mode, islink, data): i = zipfile.ZipInfo(name, self.date_time) i.compress_type = self.z.compression # unzip will not honor unix file modes unless file creator is # set to unix (id 3). i.create_system = 3 ftype = _UNX_IFREG if islink: mode = 0o777 ftype = _UNX_IFLNK i.external_attr = (mode | ftype) << 16 # add "extended-timestamp" extra block, because zip archives # without this will be extracted with unexpected timestamp, # if TZ is not configured as GMT i.extra += struct.pack('<hhBl', 0x5455, # block type: "extended-timestamp" 1 + 4, # size of this block 1, # "modification time is present" int(self.mtime)) # last modification (UTC) self.z.writestr(i, data) def done(self): self.z.close() class fileit(object): '''write archive as files in directory.''' def __init__(self, name, mtime): self.basedir = name self.opener = vfsmod.vfs(self.basedir) def addfile(self, name, mode, islink, data): if islink: self.opener.symlink(data, name) return f = self.opener(name, "w", atomictemp=True) f.write(data) f.close() destfile = os.path.join(self.basedir, name) os.chmod(destfile, mode) def done(self): pass archivers = { 'files': fileit, 'tar': tarit, 'tbz2': lambda name, mtime: tarit(name, mtime, 'bz2'), 'tgz': lambda name, mtime: tarit(name, mtime, 'gz'), 'uzip': lambda name, mtime: zipit(name, mtime, False), 'zip': zipit, } def archive(repo, dest, node, kind, decode=True, matchfn=None, prefix='', mtime=None, subrepos=False): '''create archive of repo as it was at node. dest can be name of directory, name of archive file, or file object to write archive to. kind is type of archive to create. decode tells whether to put files through decode filters from hgrc. matchfn is function to filter names of files to write to archive. prefix is name of path to put before every archive member.''' if kind == 'files': if prefix: raise error.Abort(_('cannot give prefix when archiving to files')) else: prefix = tidyprefix(dest, kind, prefix) def write(name, mode, islink, getdata): data = getdata() if decode: data = repo.wwritedata(name, data) archiver.addfile(prefix + name, mode, islink, data) if kind not in archivers: raise error.Abort(_("unknown archive type '%s'") % kind) ctx = repo[node] archiver = archivers[kind](dest, mtime or ctx.date()[0]) if repo.ui.configbool("ui", "archivemeta", True): name = '.hg_archival.txt' if not matchfn or matchfn(name): write(name, 0o644, False, lambda: buildmetadata(ctx)) if matchfn: files = [f for f in ctx.manifest().keys() if matchfn(f)] else: files = ctx.manifest().keys() total = len(files) if total: files.sort() repo.ui.progress(_('archiving'), 0, unit=_('files'), total=total) for i, f in enumerate(files): ff = ctx.flags(f) write(f, 'x' in ff and 0o755 or 0o644, 'l' in ff, ctx[f].data) repo.ui.progress(_('archiving'), i + 1, item=f, unit=_('files'), total=total) repo.ui.progress(_('archiving'), None) if subrepos: for subpath in sorted(ctx.substate): sub = ctx.workingsub(subpath) submatch = matchmod.subdirmatcher(subpath, matchfn) total += sub.archive(archiver, prefix, submatch, decode) if total == 0: raise error.Abort(_('no files match the archive pattern')) archiver.done() return total