Mercurial > hg
view hgext/relink.py @ 10849:12ffc5ce1291
templater: cache self.defaults.get
author | Matt Mackall <mpm@selenic.com> |
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date | Mon, 05 Apr 2010 15:25:08 -0500 |
parents | cb0a7faa29ea |
children | 355a7535bcac |
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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 mercurial import cmdutil, hg, util from mercurial.i18n import _ import os, stat 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 hasattr(util, 'samefile') or not hasattr(util, 'samedevice'): raise util.Abort(_('hardlinks are not supported on this system')) src = hg.repository( cmdutil.remoteui(repo, opts), ui.expandpath(origin or 'default-relink', origin or 'default')) if not src.local(): raise util.Abort('must specify local origin repository') ui.status(_('relinking %s to %s\n') % (src.store.path, repo.store.path)) locallock = repo.lock() try: remotelock = src.lock() try: candidates = sorted(collect(src.store.path, 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 = [] for dirpath, dirnames, filenames in os.walk(src): relpath = dirpath[len(src) + seplen:] for filename in filenames: if not filename[-2:] in ('.d', '.i'): continue st = os.stat(os.path.join(dirpath, filename)) if not stat.S_ISREG(st.st_mode): continue candidates.append((os.path.join(relpath, filename), st)) 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 util.Abort( _('source and destination are on different devices')) if st.st_size != ts.st_size: return False return st targets = [] for fn, st in candidates: 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.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.os_link(src, dst) except OSError: os.rename(bak, dst) raise os.remove(bak) CHUNKLEN = 65536 relinked = 0 savedbytes = 0 f = '' 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, inst: ui.warn('%s: %s\n' % (tgt, str(inst))) ui.progress(_('relinking'), None) ui.status(_('relinked %d files (%d bytes reclaimed)\n') % (relinked, savedbytes)) cmdtable = { 'relink': ( relink, [], _('[ORIGIN]') ) }