Mercurial > hg
view hgext/relink.py @ 30661:ced0d686ecb3
convert: add config option to control storing original revision
common.commit.__init__ sets saverev=True by default. The side effect
of this is that the hg sink will always set the "convert_revision"
extras key to the commit being converted.
This patch adds a config option to disable this behavior.
While most consumers will want "convert_revision" to be a) written
b) with the exact Git commit that was converted, some have use cases
that prefer otherwise. In my case, I am performing significant
rewrites of a Git repository *before* it is fed into `hg convert`.
I have to do this because `hg convert` does not easily support the kind
of transform I desire, even with extensions. (For the curious, I am
"linearizing" the history of a GitHub repo by removing merge commits
which add little value to the final history. It isn't easy to do this
during `hg convert` because of Mercurial's file copy/rename metadata
requirements.)
In my scenario, my pre-convert transform stores a "convert_revision"
key in the Git commit object containing the original Git commit ID.
I want this original Git commit ID carried forward to Mercurial. By
disabling the setting of this extra during `hg convert` and copying
the value from the Git commit object, I can have the final
"convert_revision" extra key contain the original Git commit ID. An
added test verifies this exact scenario.
This feature could likely be implemented for other VCS sources. But
until someone needs the feature, I'm inclined to hold off implementing.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 22 Dec 2016 23:28:35 -0700 |
parents | d5883fd055c6 |
children | 46ba2cdda476 |
line wrap: on
line source
# 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 import ( cmdutil, error, hg, util, ) cmdtable = {} command = cmdutil.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 = 'ships-with-hg-core' @command('relink', [], _('[ORIGIN]')) 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, 'samefile') or not util.safehasattr(util, 'samedevice')): raise error.Abort(_('hardlinks are not supported on this system')) src = hg.repository(repo.baseui, ui.expandpath(origin or 'default-relink', origin or 'default')) ui.status(_('relinking %s to %s\n') % (src.store.path, repo.store.path)) if repo.root == src.root: ui.status(_('there is nothing to relink\n')) return if not util.samedevice(src.store.path, repo.store.path): # No point in continuing raise error.Abort(_('source and destination are on different devices')) locallock = repo.lock() try: remotelock = src.lock() try: 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) finally: remotelock.release() finally: locallock.release() def collect(src, ui): seplen = len(os.path.sep) candidates = [] live = len(src['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 pos = 0 ui.status(_("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 ('.d', '.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)) ui.progress(_('collecting'), pos, filename, _('files'), total) ui.progress(_('collecting'), None) ui.status(_('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( _('source and destination are on different devices')) if st.st_size != ts.st_size: return False return st targets = [] 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('not linkable: %s\n' % fn) continue targets.append((fn, ts.st_size)) ui.progress(_('pruning'), pos, fn, _('files'), total) ui.progress(_('pruning'), None) ui.status(_('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 + '.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 pos = 0 total = len(files) 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 = file(source, 'rb') dfp = file(tgt, '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('not linkable: %s\n' % f) continue try: relinkfile(source, tgt) ui.progress(_('relinking'), pos, f, _('files'), total) relinked += 1 savedbytes += sz except OSError as inst: ui.warn('%s: %s\n' % (tgt, str(inst))) ui.progress(_('relinking'), None) ui.status(_('relinked %d files (%s reclaimed)\n') % (relinked, util.bytecount(savedbytes)))