Mercurial > hg
view mercurial/setdiscovery.py @ 14442:5b48ad1e7f1a
cmdutil: make private copies of option lists to avoid sharing monkeypatches
author | Matt Mackall <mpm@selenic.com> |
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date | Thu, 26 May 2011 17:15:35 -0500 |
parents | 2bf60f158ecb |
children | f03c82d1f50a |
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# setdiscovery.py - improved discovery of common nodeset for mercurial # # Copyright 2010 Benoit Boissinot <bboissin@gmail.com> # and Peter Arrenbrecht <peter@arrenbrecht.ch> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from node import nullid from i18n import _ import random, collections, util, dagutil def _updatesample(dag, nodes, sample, always, quicksamplesize=0): # if nodes is empty we scan the entire graph if nodes: heads = dag.headsetofconnecteds(nodes) else: heads = dag.heads() dist = {} visit = collections.deque(heads) seen = set() factor = 1 while visit: curr = visit.popleft() if curr in seen: continue d = dist.setdefault(curr, 1) if d > factor: factor *= 2 if d == factor: if curr not in always: # need this check for the early exit below sample.add(curr) if quicksamplesize and (len(sample) >= quicksamplesize): return seen.add(curr) for p in dag.parents(curr): if not nodes or p in nodes: dist.setdefault(p, d + 1) visit.append(p) def _setupsample(dag, nodes, size): if len(nodes) <= size: return set(nodes), None, 0 always = set(dag.heads()) desiredlen = size - len(always) if desiredlen <= 0: # This could be bad if there are very many heads, all unknown to the # server. We're counting on long request support here. return always, None, desiredlen return always, set(), desiredlen def _takequicksample(dag, nodes, size, initial): always, sample, desiredlen = _setupsample(dag, nodes, size) if sample is None: return always if initial: fromset = None else: fromset = nodes _updatesample(dag, fromset, sample, always, quicksamplesize=desiredlen) sample.update(always) return sample def _takefullsample(dag, nodes, size): always, sample, desiredlen = _setupsample(dag, nodes, size) if sample is None: return always # update from heads _updatesample(dag, nodes, sample, always) # update from roots _updatesample(dag.inverse(), nodes, sample, always) assert sample if len(sample) > desiredlen: sample = set(random.sample(sample, desiredlen)) elif len(sample) < desiredlen: more = desiredlen - len(sample) sample.update(random.sample(list(nodes - sample - always), more)) sample.update(always) return sample def findcommonheads(ui, local, remote, initialsamplesize=100, fullsamplesize=200, abortwhenunrelated=True): '''Return a tuple (common, anyincoming, remoteheads) used to identify missing nodes from or in remote. shortcutlocal determines whether we try use direct access to localrepo if remote is actually local. ''' roundtrips = 0 cl = local.changelog dag = dagutil.revlogdag(cl) nodes = dag.nodeset() # early exit if we know all the specified server heads already ui.debug("query 1; heads\n") roundtrips += 1 srvheadhashes = remote.heads() ## TODO We might want to request an additional random sample of the server's ## nodes batched with the heads query here. if cl.tip() == nullid: if srvheadhashes != [nullid]: return [nullid], True, srvheadhashes return [nullid], False, [] # start actual discovery (we note this before the next "if" for # compatibility reasons) ui.status(_("searching for changes\n")) srvheads = dag.internalizeall(srvheadhashes, filterunknown=True) if len(srvheads) == len(srvheadhashes): ui.note("all remote heads known locally\n") return (srvheadhashes, False, srvheadhashes,) # full blown discovery undecided = nodes # own nodes where I don't know if the server knows them common = set() # own nodes I know we both know missing = set() # own nodes I know the server lacks # treat remote heads as a first implicit sample response common.update(dag.ancestorset(srvheads)) undecided.difference_update(common) # use cheapish initial sample if common: ui.debug("taking initial sample\n") sample = _takefullsample(dag, undecided, size=fullsamplesize) else: ui.debug("taking quick initial sample\n") sample = _takequicksample(dag, nodes, size=initialsamplesize, initial=True) roundtrips += 1 ui.progress(_('searching'), roundtrips, unit=_('queries')) ui.debug("query %i; still undecided: %i, sample size is: %i\n" % (roundtrips, len(undecided), len(sample))) # indices between sample and externalized version must match sample = list(sample) yesno = remote.known(dag.externalizeall(sample)) while undecided: commoninsample = set(n for i, n in enumerate(sample) if yesno[i]) common.update(dag.ancestorset(commoninsample, common)) missinginsample = [n for i, n in enumerate(sample) if not yesno[i]] missing.update(dag.descendantset(missinginsample, missing)) undecided.difference_update(missing) undecided.difference_update(common) if not undecided: break ui.note("sampling from both directions\n") sample = _takefullsample(dag, undecided, size=fullsamplesize) roundtrips += 1 ui.progress(_('searching'), roundtrips, unit=_('queries')) ui.debug("query %i; still undecided: %i, sample size is: %i\n" % (roundtrips, len(undecided), len(sample))) # indices between sample and externalized version must match sample = list(sample) yesno = remote.known(dag.externalizeall(sample)) result = dag.headsetofconnecteds(common) ui.progress(_('searching'), None) ui.debug("%d total queries\n" % roundtrips) if not result and srvheadhashes != [nullid]: if abortwhenunrelated: raise util.Abort(_("repository is unrelated")) else: ui.warn(_("warning: repository is unrelated\n")) return (set([nullid]), True, srvheadhashes,) return (dag.externalizeall(result), True, srvheadhashes,)