Mercurial > hg
view mercurial/treediscovery.py @ 37443:65250a66b55c
revlog: move censor logic into main revlog class
Previously, the revlog class implemented dummy methods for
various censor-related functionality. Revision censoring was
(and will continue to be) only possible on filelog instances.
So filelog implemented these methods to perform something
reasonable.
A problem with implementing censoring on filelog is that
it assumes filelog is a revlog. Upcoming work to formalize
the filelog interface will make this not true.
Furthermore, the censoring logic is security-sensitive. I
think action-at-a-distance with custom implementation of core
revlog APIs in derived classes is a bit dangerous. I think at
a minimum the censor logic should live in revlog.py.
I was tempted to created a "censored revlog" class that
basically pulled these methods out of filelog. But, I wasn't
a huge fan of overriding core methods in child classes. A
reason to do that would be performance. However, the censoring
code only comes into play when:
* hash verification fails
* delta generation
* applying deltas from changegroups
The new code is conditional on an instance attribute. So the
overhead for running the censored code when the revlog isn't
censorable is an attribute lookup. All of these operations are
at least a magnitude slower than a Python attribute lookup. So
there shouldn't be a performance concern.
Differential Revision: https://phab.mercurial-scm.org/D3151
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 05 Apr 2018 16:31:45 -0700 |
parents | 56b2bcea2529 |
children | 0ed11f9368fd |
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# discovery.py - protocol changeset discovery functions # # Copyright 2010 Matt Mackall <mpm@selenic.com> # # 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 ( nullid, short, ) from . import ( error, ) def findcommonincoming(repo, remote, heads=None, force=False): """Return a tuple (common, fetch, heads) used to identify the common subset of nodes between repo and remote. "common" is a list of (at least) the heads of the common subset. "fetch" is a list of roots of the nodes that would be incoming, to be supplied to changegroupsubset. "heads" is either the supplied heads, or else the remote's heads. """ knownnode = repo.changelog.hasnode search = [] fetch = set() seen = set() seenbranch = set() base = set() if not heads: heads = remote.heads() if repo.changelog.tip() == nullid: base.add(nullid) if heads != [nullid]: return [nullid], [nullid], list(heads) return [nullid], [], heads # assume we're closer to the tip than the root # and start by examining the heads repo.ui.status(_("searching for changes\n")) unknown = [] for h in heads: if not knownnode(h): unknown.append(h) else: base.add(h) if not unknown: return list(base), [], list(heads) req = set(unknown) reqcnt = 0 # search through remote branches # a 'branch' here is a linear segment of history, with four parts: # head, root, first parent, second parent # (a branch always has two parents (or none) by definition) unknown = collections.deque(remote.branches(unknown)) while unknown: r = [] while unknown: n = unknown.popleft() if n[0] in seen: continue repo.ui.debug("examining %s:%s\n" % (short(n[0]), short(n[1]))) if n[0] == nullid: # found the end of the branch pass elif n in seenbranch: repo.ui.debug("branch already found\n") continue elif n[1] and knownnode(n[1]): # do we know the base? repo.ui.debug("found incomplete branch %s:%s\n" % (short(n[0]), short(n[1]))) search.append(n[0:2]) # schedule branch range for scanning seenbranch.add(n) else: if n[1] not in seen and n[1] not in fetch: if knownnode(n[2]) and knownnode(n[3]): repo.ui.debug("found new changeset %s\n" % short(n[1])) fetch.add(n[1]) # earliest unknown for p in n[2:4]: if knownnode(p): base.add(p) # latest known for p in n[2:4]: if p not in req and not knownnode(p): r.append(p) req.add(p) seen.add(n[0]) if r: reqcnt += 1 repo.ui.progress(_('searching'), reqcnt, unit=_('queries')) repo.ui.debug("request %d: %s\n" % (reqcnt, " ".join(map(short, r)))) for p in xrange(0, len(r), 10): for b in remote.branches(r[p:p + 10]): repo.ui.debug("received %s:%s\n" % (short(b[0]), short(b[1]))) unknown.append(b) # do binary search on the branches we found while search: newsearch = [] reqcnt += 1 repo.ui.progress(_('searching'), reqcnt, unit=_('queries')) for n, l in zip(search, remote.between(search)): l.append(n[1]) p = n[0] f = 1 for i in l: repo.ui.debug("narrowing %d:%d %s\n" % (f, len(l), short(i))) if knownnode(i): if f <= 2: repo.ui.debug("found new branch changeset %s\n" % short(p)) fetch.add(p) base.add(i) else: repo.ui.debug("narrowed branch search to %s:%s\n" % (short(p), short(i))) newsearch.append((p, i)) break p, f = i, f * 2 search = newsearch # sanity check our fetch list for f in fetch: if knownnode(f): raise error.RepoError(_("already have changeset ") + short(f[:4])) base = list(base) if base == [nullid]: if force: repo.ui.warn(_("warning: repository is unrelated\n")) else: raise error.Abort(_("repository is unrelated")) repo.ui.debug("found new changesets starting at " + " ".join([short(f) for f in fetch]) + "\n") repo.ui.progress(_('searching'), None) repo.ui.debug("%d total queries\n" % reqcnt) return base, list(fetch), heads