Mercurial > hg
view hgext/relink.py @ 48693:de3ac3d2c60b
stream-clone: allow to change persistent-nodemap format during stream clone
Persistent nodemap affect the store format. However it is fairly isolated and
fast to generate locally. So not making it a fixed part of the stream clone is
useful.
This allow clients without persistent-nodemap support (default for client
without Rust enabled, or simply older client). So it make it possible to enable
persistent nodemap on client, where it can provide a massive boost. without too
much consequence.
To do so, we stop using it in the advertisement requirements for streaming and
let the client add/remove the necessary file depending of its configuration.
We still send the files as it seems like a small save to not regenerate them.
In addition, the way we match them will overlap with the changelog-v2/revlog-v2
so we can't simply skip the associated patterns.
Differential Revision: https://phab.mercurial-scm.org/D12096
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Thu, 27 Jan 2022 22:24:11 +0100 |
parents | b5e7cdb93abc |
children | 6000f5b25c9b |
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# Mercurial extension to provide 'hg relink' command # # Copyright (C) 2007 Brendan Cully <brendan@kublai.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """recreates hardlinks between repository clones""" from __future__ import absolute_import import os import stat from mercurial.i18n import _ from mercurial.pycompat import open from mercurial import ( error, hg, registrar, util, ) from mercurial.utils import ( stringutil, urlutil, ) cmdtable = {} command = registrar.command(cmdtable) # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should # be specifying the version(s) of Mercurial they are tested with, or # leave the attribute unspecified. testedwith = b'ships-with-hg-core' @command( b'relink', [], _(b'[ORIGIN]'), helpcategory=command.CATEGORY_MAINTENANCE ) def relink(ui, repo, origin=None, **opts): """recreate hardlinks between two repositories When repositories are cloned locally, their data files will be hardlinked so that they only use the space of a single repository. Unfortunately, subsequent pulls into either repository will break hardlinks for any files touched by the new changesets, even if both repositories end up pulling the same changes. Similarly, passing --rev to "hg clone" will fail to use any hardlinks, falling back to a complete copy of the source repository. This command lets you recreate those hardlinks and reclaim that wasted space. This repository will be relinked to share space with ORIGIN, which must be on the same local disk. If ORIGIN is omitted, looks for "default-relink", then "default", in [paths]. Do not attempt any read operations on this repository while the command is running. (Both repositories will be locked against writes.) """ if not util.safehasattr(util, b'samefile') or not util.safehasattr( util, b'samedevice' ): raise error.Abort(_(b'hardlinks are not supported on this system')) if origin is None and b'default-relink' in ui.paths: origin = b'default-relink' path, __ = urlutil.get_unique_pull_path(b'relink', repo, ui, origin) src = hg.repository(repo.baseui, path) ui.status(_(b'relinking %s to %s\n') % (src.store.path, repo.store.path)) if repo.root == src.root: ui.status(_(b'there is nothing to relink\n')) return if not util.samedevice(src.store.path, repo.store.path): # No point in continuing raise error.Abort(_(b'source and destination are on different devices')) with repo.lock(), src.lock(): candidates = sorted(collect(src, ui)) targets = prune(candidates, src.store.path, repo.store.path, ui) do_relink(src.store.path, repo.store.path, targets, ui) def collect(src, ui): seplen = len(os.path.sep) candidates = [] live = len(src[b'tip'].manifest()) # Your average repository has some files which were deleted before # the tip revision. We account for that by assuming that there are # 3 tracked files for every 2 live files as of the tip version of # the repository. # # mozilla-central as of 2010-06-10 had a ratio of just over 7:5. total = live * 3 // 2 src = src.store.path progress = ui.makeprogress(_(b'collecting'), unit=_(b'files'), total=total) pos = 0 ui.status( _(b"tip has %d files, estimated total number of files: %d\n") % (live, total) ) for dirpath, dirnames, filenames in os.walk(src): dirnames.sort() relpath = dirpath[len(src) + seplen :] for filename in sorted(filenames): if filename[-2:] not in (b'.d', b'.i'): continue st = os.stat(os.path.join(dirpath, filename)) if not stat.S_ISREG(st.st_mode): continue pos += 1 candidates.append((os.path.join(relpath, filename), st)) progress.update(pos, item=filename) progress.complete() ui.status(_(b'collected %d candidate storage files\n') % len(candidates)) return candidates def prune(candidates, src, dst, ui): def linkfilter(src, dst, st): try: ts = os.stat(dst) except OSError: # Destination doesn't have this file? return False if util.samefile(src, dst): return False if not util.samedevice(src, dst): # No point in continuing raise error.Abort( _(b'source and destination are on different devices') ) if st.st_size != ts.st_size: return False return st targets = [] progress = ui.makeprogress( _(b'pruning'), unit=_(b'files'), total=len(candidates) ) pos = 0 for fn, st in candidates: pos += 1 srcpath = os.path.join(src, fn) tgt = os.path.join(dst, fn) ts = linkfilter(srcpath, tgt, st) if not ts: ui.debug(b'not linkable: %s\n' % fn) continue targets.append((fn, ts.st_size)) progress.update(pos, item=fn) progress.complete() ui.status( _(b'pruned down to %d probably relinkable files\n') % len(targets) ) return targets def do_relink(src, dst, files, ui): def relinkfile(src, dst): bak = dst + b'.bak' os.rename(dst, bak) try: util.oslink(src, dst) except OSError: os.rename(bak, dst) raise os.remove(bak) CHUNKLEN = 65536 relinked = 0 savedbytes = 0 progress = ui.makeprogress( _(b'relinking'), unit=_(b'files'), total=len(files) ) pos = 0 for f, sz in files: pos += 1 source = os.path.join(src, f) tgt = os.path.join(dst, f) # Binary mode, so that read() works correctly, especially on Windows sfp = open(source, b'rb') dfp = open(tgt, b'rb') sin = sfp.read(CHUNKLEN) while sin: din = dfp.read(CHUNKLEN) if sin != din: break sin = sfp.read(CHUNKLEN) sfp.close() dfp.close() if sin: ui.debug(b'not linkable: %s\n' % f) continue try: relinkfile(source, tgt) progress.update(pos, item=f) relinked += 1 savedbytes += sz except OSError as inst: ui.warn(b'%s: %s\n' % (tgt, stringutil.forcebytestr(inst))) progress.complete() ui.status( _(b'relinked %d files (%s reclaimed)\n') % (relinked, util.bytecount(savedbytes)) )