relink.py
157 lines
| 5.0 KiB
| text/x-python
|
PythonLexer
/ hgext / relink.py
|
r9729 | # 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 | ||||
|
r10263 | # GNU General Public License version 2 or any later version. | ||
|
r9729 | |||
"""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 | ||||
|
r9886 | When repositories are cloned locally, their data files will be | ||
hardlinked so that they only use the space of a single repository. | ||||
|
r9729 | |||
|
r9886 | 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. | ||||
|
r9729 | |||
|
r9886 | Similarly, passing --rev to "hg clone" will fail to use any | ||
hardlinks, falling back to a complete copy of the source | ||||
repository. | ||||
|
r9729 | |||
|
r9886 | This command lets you recreate those hardlinks and reclaim that | ||
wasted space. | ||||
|
r9729 | |||
|
r9886 | 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]. | ||||
|
r9729 | |||
|
r9886 | Do not attempt any read operations on this repository while the | ||
command is running. (Both repositories will be locked against | ||||
writes.) | ||||
|
r9729 | """ | ||
|
r10218 | if not hasattr(util, 'samefile') or not hasattr(util, 'samedevice'): | ||
raise util.Abort(_('hardlinks are not supported on this system')) | ||||
|
r9729 | 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: | ||||
|
r10225 | candidates = sorted(collect(src.store.path, ui)) | ||
|
r10218 | targets = prune(candidates, src.store.path, repo.store.path, ui) | ||
|
r9729 | 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 | ||||
|
r10218 | def prune(candidates, src, dst, ui): | ||
def linkfilter(src, dst, st): | ||||
|
r9729 | try: | ||
ts = os.stat(dst) | ||||
except OSError: | ||||
# Destination doesn't have this file? | ||||
return False | ||||
|
r10218 | if util.samefile(src, dst): | ||
|
r9729 | return False | ||
|
r10218 | if not util.samedevice(src, dst): | ||
|
r9729 | # 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: | ||||
|
r10218 | srcpath = os.path.join(src, fn) | ||
|
r9729 | tgt = os.path.join(dst, fn) | ||
|
r10218 | ts = linkfilter(srcpath, tgt, st) | ||
|
r9729 | 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: | ||||
|
r10218 | util.os_link(src, dst) | ||
|
r9729 | 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) | ||||
|
r10218 | # Binary mode, so that read() works correctly, especially on Windows | ||
sfp = file(source, 'rb') | ||||
dfp = file(tgt, 'rb') | ||||
|
r9729 | sin = sfp.read(CHUNKLEN) | ||
while sin: | ||||
din = dfp.read(CHUNKLEN) | ||||
if sin != din: | ||||
break | ||||
sin = sfp.read(CHUNKLEN) | ||||
|
r10218 | sfp.close() | ||
dfp.close() | ||||
|
r9729 | if sin: | ||
ui.debug(_('not linkable: %s\n') % f) | ||||
continue | ||||
try: | ||||
relinkfile(source, tgt) | ||||
ui.progress(_('relink'), pos, f, _(' files'), total) | ||||
relinked += 1 | ||||
savedbytes += sz | ||||
except OSError, inst: | ||||
|
r9790 | ui.warn('%s: %s\n' % (tgt, str(inst))) | ||
|
r9729 | |||
ui.status(_('relinked %d files (%d bytes reclaimed)\n') % | ||||
(relinked, savedbytes)) | ||||
cmdtable = { | ||||
'relink': ( | ||||
relink, | ||||
[], | ||||
_('[ORIGIN]') | ||||
) | ||||
} | ||||