bundle2: support for bundling and unbundling payload
We add the ability to bundle and unbundle a payload in parts. The payload is the
actual binary data of the part. It is used to convey all the applicative data.
For now we stick to very simple implementation with all the data fit in single
chunk. This open the door to some bundle2 testing usage. This will be improved before
bundle2 get used for real. We need to be able to stream the payload in multiple
part to exchange any changegroup efficiently. This simple version will do for
now.
Bundling and unbundling are done in the same changeset because the test for
parts is less modular. However, the result is not too complex.
# repair.py - functions for repository repair for mercurial
#
# Copyright 2005, 2006 Chris Mason <mason@suse.com>
# Copyright 2007 Matt Mackall
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from mercurial import changegroup
from mercurial.node import short
from mercurial.i18n import _
import os
import errno
def _bundle(repo, bases, heads, node, suffix, compress=True):
"""create a bundle with the specified revisions as a backup"""
cg = repo.changegroupsubset(bases, heads, 'strip')
backupdir = repo.join("strip-backup")
if not os.path.isdir(backupdir):
os.mkdir(backupdir)
name = os.path.join(backupdir, "%s-%s.hg" % (short(node), suffix))
if compress:
bundletype = "HG10BZ"
else:
bundletype = "HG10UN"
return changegroup.writebundle(cg, name, bundletype)
def _collectfiles(repo, striprev):
"""find out the filelogs affected by the strip"""
files = set()
for x in xrange(striprev, len(repo)):
files.update(repo[x].files())
return sorted(files)
def _collectbrokencsets(repo, files, striprev):
"""return the changesets which will be broken by the truncation"""
s = set()
def collectone(revlog):
_, brokenset = revlog.getstrippoint(striprev)
s.update([revlog.linkrev(r) for r in brokenset])
collectone(repo.manifest)
for fname in files:
collectone(repo.file(fname))
return s
def strip(ui, repo, nodelist, backup="all", topic='backup'):
repo = repo.unfiltered()
repo.destroying()
cl = repo.changelog
# TODO handle undo of merge sets
if isinstance(nodelist, str):
nodelist = [nodelist]
striplist = [cl.rev(node) for node in nodelist]
striprev = min(striplist)
keeppartialbundle = backup == 'strip'
# Some revisions with rev > striprev may not be descendants of striprev.
# We have to find these revisions and put them in a bundle, so that
# we can restore them after the truncations.
# To create the bundle we use repo.changegroupsubset which requires
# the list of heads and bases of the set of interesting revisions.
# (head = revision in the set that has no descendant in the set;
# base = revision in the set that has no ancestor in the set)
tostrip = set(striplist)
for rev in striplist:
for desc in cl.descendants([rev]):
tostrip.add(desc)
files = _collectfiles(repo, striprev)
saverevs = _collectbrokencsets(repo, files, striprev)
# compute heads
saveheads = set(saverevs)
for r in xrange(striprev + 1, len(cl)):
if r not in tostrip:
saverevs.add(r)
saveheads.difference_update(cl.parentrevs(r))
saveheads.add(r)
saveheads = [cl.node(r) for r in saveheads]
# compute base nodes
if saverevs:
descendants = set(cl.descendants(saverevs))
saverevs.difference_update(descendants)
savebases = [cl.node(r) for r in saverevs]
stripbases = [cl.node(r) for r in tostrip]
# For a set s, max(parents(s) - s) is the same as max(heads(::s - s)), but
# is much faster
newbmtarget = repo.revs('max(parents(%ld) - (%ld))', tostrip, tostrip)
if newbmtarget:
newbmtarget = repo[newbmtarget[0]].node()
else:
newbmtarget = '.'
bm = repo._bookmarks
updatebm = []
for m in bm:
rev = repo[bm[m]].rev()
if rev in tostrip:
updatebm.append(m)
# create a changegroup for all the branches we need to keep
backupfile = None
if backup == "all":
backupfile = _bundle(repo, stripbases, cl.heads(), node, topic)
repo.ui.status(_("saved backup bundle to %s\n") % backupfile)
repo.ui.log("backupbundle", "saved backup bundle to %s\n", backupfile)
if saveheads or savebases:
# do not compress partial bundle if we remove it from disk later
chgrpfile = _bundle(repo, savebases, saveheads, node, 'temp',
compress=keeppartialbundle)
mfst = repo.manifest
tr = repo.transaction("strip")
offset = len(tr.entries)
try:
tr.startgroup()
cl.strip(striprev, tr)
mfst.strip(striprev, tr)
for fn in files:
repo.file(fn).strip(striprev, tr)
tr.endgroup()
try:
for i in xrange(offset, len(tr.entries)):
file, troffset, ignore = tr.entries[i]
repo.sopener(file, 'a').truncate(troffset)
tr.close()
except: # re-raises
tr.abort()
raise
if saveheads or savebases:
ui.note(_("adding branch\n"))
f = open(chgrpfile, "rb")
gen = changegroup.readbundle(f, chgrpfile)
if not repo.ui.verbose:
# silence internal shuffling chatter
repo.ui.pushbuffer()
repo.addchangegroup(gen, 'strip', 'bundle:' + chgrpfile, True)
if not repo.ui.verbose:
repo.ui.popbuffer()
f.close()
if not keeppartialbundle:
os.unlink(chgrpfile)
# remove undo files
for undofile in repo.undofiles():
try:
os.unlink(undofile)
except OSError, e:
if e.errno != errno.ENOENT:
ui.warn(_('error removing %s: %s\n') % (undofile, str(e)))
for m in updatebm:
bm[m] = repo[newbmtarget].node()
bm.write()
except: # re-raises
if backupfile:
ui.warn(_("strip failed, full bundle stored in '%s'\n")
% backupfile)
elif saveheads:
ui.warn(_("strip failed, partial bundle stored in '%s'\n")
% chgrpfile)
raise
repo.destroyed()