author | Pierre-Yves David <pierre-yves.david@fb.com> |
Mon, 24 Feb 2014 19:01:12 -0800 | |
changeset 811 | acfa2b67cff6 |
parent 800 | ad2060da7ffa |
permissions | -rw-r--r-- |
"""Extension to try and speed up transfer of obsolete markers. Mercurial 2.6 transfers obsolete markers in the dumbest way possible: it simply transfers all of them to the server on every operation. While this /works/, it's not ideal because it's a large amount of extra data for users to pull down (1.9M for the 17k obsolete markers in hg-crew as of this writing in late July 2013). It's also frustrating because this transfer takes a nontrivial amount of time. You can specify a strategy with the config knob obsolete.syncstrategy. Current strategies are "stock" and "boxfill". Default strategy is presently boxfill. :stock: use the default strategy of mercurial explaned above :boxfill: transmit obsolete markers which list any of transmitted changesets as a successor (transitively), as well as any kill markers for dead nodes descended from any of the precursors of outgoing.missing. TODO(durin42): consider better names for sync strategies. """ import sys from mercurial import base85 from mercurial import commands from mercurial import extensions from mercurial import node from mercurial import obsolete from mercurial import exchange from mercurial import revset from mercurial.i18n import _ _strategies = { 'stock': exchange._pushobsolete, } def _strategy(name, default=False): def inner(func): _strategies[name] = func if default: _strategies[None] = func return func return inner def _pushobsoletewrapper(orig, pushop): stratfn = _strategies[pushop.repo.ui.config('obsolete', 'syncstrategy')] return stratfn(pushop) extensions.wrapfunction(exchange, '_pushobsolete', _pushobsoletewrapper) def _precursors(repo, s): """Precursor of a changeset""" cs = set() nm = repo.changelog.nodemap markerbysubj = repo.obsstore.precursors for r in s: for p in markerbysubj.get(repo[r].node(), ()): pr = nm.get(p[0]) if pr is not None: cs.add(pr) return cs def _revsetprecursors(repo, subset, x): s = revset.getset(repo, revset.baseset(range(len(repo))), x) cs = _precursors(repo, s) return revset.baseset([r for r in subset if r in cs]) revset.symbols['_fastobs_precursors'] = _revsetprecursors @_strategy('boxfill', default=True) def boxfill(pushop): """The "fill in the box" strategy from the 2.6 sprint. See the notes[0] from the 2.6 sprint for what "fill in the box" means here. It's a fairly subtle algorithm, which may have surprising behavior at times, but was the least-bad option proposed at the sprint. [0]: https://bitbucket.org/durin42/2.6sprint-notes/src/tip/mercurial26-obsstore-rev.1398.txt """ repo = pushop.repo remote = pushop.remote outgoing = pushop.outgoing urepo = pushop.repo.unfiltered() # need to collect obsolete markers which list any of # outgoing.missing as a successor (transitively), as well as any # kill markers for dead nodes descended from any of the precursors # of outgoing.missing. boxedges = urepo.revs( '(descendants(_fastobs_precursors(%ln)) or ' ' descendants(%ln)) and hidden()', outgoing.missing, outgoing.missing) transmit = [] for node in outgoing.missing: transmit.extend(obsolete.precursormarkers(urepo[node])) for node in boxedges: transmit.extend(obsolete.successormarkers(urepo[node])) transmit = list(set(transmit)) xmit, total = len(transmit), len(repo.obsstore._all) repo.ui.status( 'boxpush: about to transmit %d obsolete markers (%d markers total)\n' % (xmit, total)) parts, size, chunk = [], 0, 0 def transmitmarks(): repo.ui.note( 'boxpush: sending a chunk of obsolete markers\n') data = ''.join([obsolete._pack('>B', obsolete._fmversion)] + parts) remote.pushkey('obsolete', 'dump-%d' % chunk, '', base85.b85encode(data)) for marker in transmit: enc = obsolete._encodeonemarker(_markertuple(marker)) parts.append(enc) size += len(enc) if size > obsolete._maxpayload: transmitmarks() parts, size = [], 0 chunk += 1 if parts: transmitmarks() def _markertuple(marker): return marker._data