Mercurial > hg
view mercurial/hbisect.py @ 40393:229d23cdb203
exchangev2: support fetching shallow files history
This commit teaches the exchangev2 client code to handle fetching shallow
files data.
Only shallow fetching of files data is supported: shallow fetching of
changeset and manifest data is explicitly not yet supported.
Previously, we would fetch file revisions for changesets that were received
by the current pull operation. In the new model, we calculate the set of
"relevant" changesets given the pull depth and only fetch files data for
those changesets.
We also teach the "filesdata" command invocation to vary parameters as needed.
The implementation here is far from complete or optimal. Subsequent pulls will
end up re-fetching a lot of files data. But the application of this data should
mostly be a no-op on the client, so it isn't a big deal.
Depending on the order file revisions are fetched in, revisions could get
inserted with the wrong revision number relationships. I think the best way
to deal with this is to remove revision numbers from storage and to either
dynamically derive them (by reconstructing a DAG from nodes/parents) or remove
revision numbers from the file storage interface completely.
A missing API that we'll likely want to write pretty soon is "ensure files
for revision(s) are present." We can kind of cajole exchangev2.pull() to do
this. But it isn't very efficient. For example, in simple cases like
widening the store to obtain data for a single revision, it is probably
more efficient to walk the manifest and find exactly which file revisions
are missing and to make explicit requests for just their data. In more
advanced cases, asking the server for all files data may be more efficient,
even though it requires sending data the client already has. There is tons
of room for future experimentation here. And TBH I'm not sure what the
final state will be.
Anyway, this commit gets us pretty close to being able to have shallow
and narrow checkouts with exchangev2/sqlite storage. Close enough that a
minimal extension should be able to provide fill in the gaps until the code
in core stabilizes and there is a user-facing way to trigger the
narrow/shallow bits from `hg clone` without also implying using of the
narrow extension...
Differential Revision: https://phab.mercurial-scm.org/D5169
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 19 Oct 2018 12:30:49 +0200 |
parents | 71f189941791 |
children | 566daffc607d |
line wrap: on
line source
# changelog bisection for mercurial # # Copyright 2007 Matt Mackall # Copyright 2005, 2006 Benoit Boissinot <benoit.boissinot@ens-lyon.org> # # Inspired by git bisect, extension skeleton taken from mq.py. # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import collections from .i18n import _ from .node import ( hex, short, ) from . import ( error, ) def bisect(repo, state): """find the next node (if any) for testing during a bisect search. returns a (nodes, number, good) tuple. 'nodes' is the final result of the bisect if 'number' is 0. Otherwise 'number' indicates the remaining possible candidates for the search and 'nodes' contains the next bisect target. 'good' is True if bisect is searching for a first good changeset, False if searching for a first bad one. """ changelog = repo.changelog clparents = changelog.parentrevs skip = set([changelog.rev(n) for n in state['skip']]) def buildancestors(bad, good): badrev = min([changelog.rev(n) for n in bad]) ancestors = collections.defaultdict(lambda: None) for rev in repo.revs("descendants(%ln) - ancestors(%ln)", good, good): ancestors[rev] = [] if ancestors[badrev] is None: return badrev, None return badrev, ancestors good = False badrev, ancestors = buildancestors(state['bad'], state['good']) if not ancestors: # looking for bad to good transition? good = True badrev, ancestors = buildancestors(state['good'], state['bad']) bad = changelog.node(badrev) if not ancestors: # now we're confused if (len(state['bad']) == 1 and len(state['good']) == 1 and state['bad'] != state['good']): raise error.Abort(_("starting revisions are not directly related")) raise error.Abort(_("inconsistent state, %d:%s is good and bad") % (badrev, short(bad))) # build children dict children = {} visit = collections.deque([badrev]) candidates = [] while visit: rev = visit.popleft() if ancestors[rev] == []: candidates.append(rev) for prev in clparents(rev): if prev != -1: if prev in children: children[prev].append(rev) else: children[prev] = [rev] visit.append(prev) candidates.sort() # have we narrowed it down to one entry? # or have all other possible candidates besides 'bad' have been skipped? tot = len(candidates) unskipped = [c for c in candidates if (c not in skip) and (c != badrev)] if tot == 1 or not unskipped: return ([changelog.node(c) for c in candidates], 0, good) perfect = tot // 2 # find the best node to test best_rev = None best_len = -1 poison = set() for rev in candidates: if rev in poison: # poison children poison.update(children.get(rev, [])) continue a = ancestors[rev] or [rev] ancestors[rev] = None x = len(a) # number of ancestors y = tot - x # number of non-ancestors value = min(x, y) # how good is this test? if value > best_len and rev not in skip: best_len = value best_rev = rev if value == perfect: # found a perfect candidate? quit early break if y < perfect and rev not in skip: # all downhill from here? # poison children poison.update(children.get(rev, [])) continue for c in children.get(rev, []): if ancestors[c]: ancestors[c] = list(set(ancestors[c] + a)) else: ancestors[c] = a + [c] assert best_rev is not None best_node = changelog.node(best_rev) return ([best_node], tot, good) def extendrange(repo, state, nodes, good): # bisect is incomplete when it ends on a merge node and # one of the parent was not checked. parents = repo[nodes[0]].parents() if len(parents) > 1: if good: side = state['bad'] else: side = state['good'] num = len(set(i.node() for i in parents) & set(side)) if num == 1: return parents[0].ancestor(parents[1]) return None def load_state(repo): state = {'current': [], 'good': [], 'bad': [], 'skip': []} for l in repo.vfs.tryreadlines("bisect.state"): kind, node = l[:-1].split() node = repo.lookup(node) if kind not in state: raise error.Abort(_("unknown bisect kind %s") % kind) state[kind].append(node) return state def save_state(repo, state): f = repo.vfs("bisect.state", "w", atomictemp=True) with repo.wlock(): for kind in sorted(state): for node in state[kind]: f.write("%s %s\n" % (kind, hex(node))) f.close() def resetstate(repo): """remove any bisect state from the repository""" if repo.vfs.exists("bisect.state"): repo.vfs.unlink("bisect.state") def checkstate(state): """check we have both 'good' and 'bad' to define a range Raise Abort exception otherwise.""" if state['good'] and state['bad']: return True if not state['good']: raise error.Abort(_('cannot bisect (no known good revisions)')) else: raise error.Abort(_('cannot bisect (no known bad revisions)')) def get(repo, status): """ Return a list of revision(s) that match the given status: - ``good``, ``bad``, ``skip``: csets explicitly marked as good/bad/skip - ``goods``, ``bads`` : csets topologically good/bad - ``range`` : csets taking part in the bisection - ``pruned`` : csets that are goods, bads or skipped - ``untested`` : csets whose fate is yet unknown - ``ignored`` : csets ignored due to DAG topology - ``current`` : the cset currently being bisected """ state = load_state(repo) if status in ('good', 'bad', 'skip', 'current'): return map(repo.changelog.rev, state[status]) else: # In the following sets, we do *not* call 'bisect()' with more # than one level of recursion, because that can be very, very # time consuming. Instead, we always develop the expression as # much as possible. # 'range' is all csets that make the bisection: # - have a good ancestor and a bad descendant, or conversely # that's because the bisection can go either way range = '( bisect(bad)::bisect(good) | bisect(good)::bisect(bad) )' _t = repo.revs('bisect(good)::bisect(bad)') # The sets of topologically good or bad csets if len(_t) == 0: # Goods are topologically after bads goods = 'bisect(good)::' # Pruned good csets bads = '::bisect(bad)' # Pruned bad csets else: # Goods are topologically before bads goods = '::bisect(good)' # Pruned good csets bads = 'bisect(bad)::' # Pruned bad csets # 'pruned' is all csets whose fate is already known: good, bad, skip skips = 'bisect(skip)' # Pruned skipped csets pruned = '( (%s) | (%s) | (%s) )' % (goods, bads, skips) # 'untested' is all cset that are- in 'range', but not in 'pruned' untested = '( (%s) - (%s) )' % (range, pruned) # 'ignored' is all csets that were not used during the bisection # due to DAG topology, but may however have had an impact. # E.g., a branch merged between bads and goods, but whose branch- # point is out-side of the range. iba = '::bisect(bad) - ::bisect(good)' # Ignored bads' ancestors iga = '::bisect(good) - ::bisect(bad)' # Ignored goods' ancestors ignored = '( ( (%s) | (%s) ) - (%s) )' % (iba, iga, range) if status == 'range': return repo.revs(range) elif status == 'pruned': return repo.revs(pruned) elif status == 'untested': return repo.revs(untested) elif status == 'ignored': return repo.revs(ignored) elif status == "goods": return repo.revs(goods) elif status == "bads": return repo.revs(bads) else: raise error.ParseError(_('invalid bisect state')) def label(repo, node): rev = repo.changelog.rev(node) # Try explicit sets if rev in get(repo, 'good'): # i18n: bisect changeset status return _('good') if rev in get(repo, 'bad'): # i18n: bisect changeset status return _('bad') if rev in get(repo, 'skip'): # i18n: bisect changeset status return _('skipped') if rev in get(repo, 'untested') or rev in get(repo, 'current'): # i18n: bisect changeset status return _('untested') if rev in get(repo, 'ignored'): # i18n: bisect changeset status return _('ignored') # Try implicit sets if rev in get(repo, 'goods'): # i18n: bisect changeset status return _('good (implicit)') if rev in get(repo, 'bads'): # i18n: bisect changeset status return _('bad (implicit)') return None def printresult(ui, repo, state, displayer, nodes, good): if len(nodes) == 1: # narrowed it down to a single revision if good: ui.write(_("The first good revision is:\n")) else: ui.write(_("The first bad revision is:\n")) displayer.show(repo[nodes[0]]) extendnode = extendrange(repo, state, nodes, good) if extendnode is not None: ui.write(_('Not all ancestors of this changeset have been' ' checked.\nUse bisect --extend to continue the ' 'bisection from\nthe common ancestor, %s.\n') % extendnode) else: # multiple possible revisions if good: ui.write(_("Due to skipped revisions, the first " "good revision could be any of:\n")) else: ui.write(_("Due to skipped revisions, the first " "bad revision could be any of:\n")) for n in nodes: displayer.show(repo[n]) displayer.close()