Mercurial > hg
view mercurial/repoview.py @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | d345627d104b |
children | 2372284d9457 |
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# repoview.py - Filtered view of a localrepo object # # Copyright 2012 Pierre-Yves David <pierre-yves.david@ens-lyon.org> # Logilab SA <contact@logilab.fr> # # 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 copy import weakref from .node import nullrev from . import ( obsolete, phases, pycompat, tags as tagsmod, util, ) from .utils import ( repoviewutil, ) def hideablerevs(repo): """Revision candidates to be hidden This is a standalone function to allow extensions to wrap it. Because we use the set of immutable changesets as a fallback subset in branchmap (see mercurial.utils.repoviewutils.subsettable), you cannot set "public" changesets as "hideable". Doing so would break multiple code assertions and lead to crashes.""" obsoletes = obsolete.getrevs(repo, 'obsolete') internals = repo._phasecache.getrevset(repo, phases.localhiddenphases) internals = frozenset(internals) return obsoletes | internals def pinnedrevs(repo): """revisions blocking hidden changesets from being filtered """ cl = repo.changelog pinned = set() pinned.update([par.rev() for par in repo[None].parents()]) pinned.update([cl.rev(bm) for bm in repo._bookmarks.values()]) tags = {} tagsmod.readlocaltags(repo.ui, repo, tags, {}) if tags: rev, nodemap = cl.rev, cl.nodemap pinned.update(rev(t[0]) for t in tags.values() if t[0] in nodemap) return pinned def _revealancestors(pfunc, hidden, revs): """reveals contiguous chains of hidden ancestors of 'revs' by removing them from 'hidden' - pfunc(r): a funtion returning parent of 'r', - hidden: the (preliminary) hidden revisions, to be updated - revs: iterable of revnum, (Ancestors are revealed exclusively, i.e. the elements in 'revs' are *not* revealed) """ stack = list(revs) while stack: for p in pfunc(stack.pop()): if p != nullrev and p in hidden: hidden.remove(p) stack.append(p) def computehidden(repo, visibilityexceptions=None): """compute the set of hidden revision to filter During most operation hidden should be filtered.""" assert not repo.changelog.filteredrevs hidden = hideablerevs(repo) if hidden: hidden = set(hidden - pinnedrevs(repo)) if visibilityexceptions: hidden -= visibilityexceptions pfunc = repo.changelog.parentrevs mutable = repo._phasecache.getrevset(repo, phases.mutablephases) visible = mutable - hidden _revealancestors(pfunc, hidden, visible) return frozenset(hidden) def computesecret(repo, visibilityexceptions=None): """compute the set of revision that can never be exposed through hgweb Changeset in the secret phase (or above) should stay unaccessible.""" assert not repo.changelog.filteredrevs secrets = repo._phasecache.getrevset(repo, phases.remotehiddenphases) return frozenset(secrets) def computeunserved(repo, visibilityexceptions=None): """compute the set of revision that should be filtered when used a server Secret and hidden changeset should not pretend to be here.""" assert not repo.changelog.filteredrevs # fast path in simple case to avoid impact of non optimised code hiddens = filterrevs(repo, 'visible') secrets = filterrevs(repo, 'served.hidden') if secrets: return frozenset(hiddens | secrets) else: return hiddens def computemutable(repo, visibilityexceptions=None): assert not repo.changelog.filteredrevs # fast check to avoid revset call on huge repo if any(repo._phasecache.phaseroots[1:]): getphase = repo._phasecache.phase maymutable = filterrevs(repo, 'base') return frozenset(r for r in maymutable if getphase(repo, r)) return frozenset() def computeimpactable(repo, visibilityexceptions=None): """Everything impactable by mutable revision The immutable filter still have some chance to get invalidated. This will happen when: - you garbage collect hidden changeset, - public phase is moved backward, - something is changed in the filtering (this could be fixed) This filter out any mutable changeset and any public changeset that may be impacted by something happening to a mutable revision. This is achieved by filtered everything with a revision number egal or higher than the first mutable changeset is filtered.""" assert not repo.changelog.filteredrevs cl = repo.changelog firstmutable = len(cl) for roots in repo._phasecache.phaseroots[1:]: if roots: firstmutable = min(firstmutable, min(cl.rev(r) for r in roots)) # protect from nullrev root firstmutable = max(0, firstmutable) return frozenset(pycompat.xrange(firstmutable, len(cl))) # function to compute filtered set # # When adding a new filter you MUST update the table at: # mercurial.utils.repoviewutil.subsettable # Otherwise your filter will have to recompute all its branches cache # from scratch (very slow). filtertable = {'visible': computehidden, 'visible-hidden': computehidden, 'served.hidden': computesecret, 'served': computeunserved, 'immutable': computemutable, 'base': computeimpactable} _basefiltername = list(filtertable) def extrafilter(ui): """initialize extra filter and return its id If extra filtering is configured, we make sure the associated filtered view are declared and return the associated id. """ frevs = ui.config('experimental', 'extra-filter-revs') if frevs is None: return None fid = pycompat.sysbytes(util.DIGESTS['sha1'](frevs).hexdigest())[:12] combine = lambda fname: fname + '%' + fid subsettable = repoviewutil.subsettable if combine('base') not in filtertable: for name in _basefiltername: def extrafilteredrevs(repo, *args, **kwargs): baserevs = filtertable[name](repo, *args, **kwargs) extrarevs = frozenset(repo.revs(frevs)) return baserevs | extrarevs filtertable[combine(name)] = extrafilteredrevs if name in subsettable: subsettable[combine(name)] = combine(subsettable[name]) return fid def filterrevs(repo, filtername, visibilityexceptions=None): """returns set of filtered revision for this filter name visibilityexceptions is a set of revs which must are exceptions for hidden-state and must be visible. They are dynamic and hence we should not cache it's result""" if filtername not in repo.filteredrevcache: func = filtertable[filtername] if visibilityexceptions: return func(repo.unfiltered, visibilityexceptions) repo.filteredrevcache[filtername] = func(repo.unfiltered()) return repo.filteredrevcache[filtername] class repoview(object): """Provide a read/write view of a repo through a filtered changelog This object is used to access a filtered version of a repository without altering the original repository object itself. We can not alter the original object for two main reasons: - It prevents the use of a repo with multiple filters at the same time. In particular when multiple threads are involved. - It makes scope of the filtering harder to control. This object behaves very closely to the original repository. All attribute operations are done on the original repository: - An access to `repoview.someattr` actually returns `repo.someattr`, - A write to `repoview.someattr` actually sets value of `repo.someattr`, - A deletion of `repoview.someattr` actually drops `someattr` from `repo.__dict__`. The only exception is the `changelog` property. It is overridden to return a (surface) copy of `repo.changelog` with some revisions filtered. The `filtername` attribute of the view control the revisions that need to be filtered. (the fact the changelog is copied is an implementation detail). Unlike attributes, this object intercepts all method calls. This means that all methods are run on the `repoview` object with the filtered `changelog` property. For this purpose the simple `repoview` class must be mixed with the actual class of the repository. This ensures that the resulting `repoview` object have the very same methods than the repo object. This leads to the property below. repoview.method() --> repo.__class__.method(repoview) The inheritance has to be done dynamically because `repo` can be of any subclasses of `localrepo`. Eg: `bundlerepo` or `statichttprepo`. """ def __init__(self, repo, filtername, visibilityexceptions=None): object.__setattr__(self, r'_unfilteredrepo', repo) object.__setattr__(self, r'filtername', filtername) object.__setattr__(self, r'_clcachekey', None) object.__setattr__(self, r'_clcache', None) # revs which are exceptions and must not be hidden object.__setattr__(self, r'_visibilityexceptions', visibilityexceptions) # not a propertycache on purpose we shall implement a proper cache later @property def changelog(self): """return a filtered version of the changeset this changelog must not be used for writing""" # some cache may be implemented later unfi = self._unfilteredrepo unfichangelog = unfi.changelog # bypass call to changelog.method unfiindex = unfichangelog.index unfilen = len(unfiindex) unfinode = unfiindex[unfilen - 1][7] revs = filterrevs(unfi, self.filtername, self._visibilityexceptions) cl = self._clcache newkey = (unfilen, unfinode, hash(revs), unfichangelog._delayed) # if cl.index is not unfiindex, unfi.changelog would be # recreated, and our clcache refers to garbage object if (cl is not None and (cl.index is not unfiindex or newkey != self._clcachekey)): cl = None # could have been made None by the previous if if cl is None: cl = copy.copy(unfichangelog) cl.filteredrevs = revs object.__setattr__(self, r'_clcache', cl) object.__setattr__(self, r'_clcachekey', newkey) return cl def unfiltered(self): """Return an unfiltered version of a repo""" return self._unfilteredrepo def filtered(self, name, visibilityexceptions=None): """Return a filtered version of a repository""" if name == self.filtername and not visibilityexceptions: return self return self.unfiltered().filtered(name, visibilityexceptions) def __repr__(self): return r'<%s:%s %r>' % (self.__class__.__name__, pycompat.sysstr(self.filtername), self.unfiltered()) # everything access are forwarded to the proxied repo def __getattr__(self, attr): return getattr(self._unfilteredrepo, attr) def __setattr__(self, attr, value): return setattr(self._unfilteredrepo, attr, value) def __delattr__(self, attr): return delattr(self._unfilteredrepo, attr) # Python <3.4 easily leaks types via __mro__. See # https://bugs.python.org/issue17950. We cache dynamically created types # so they won't be leaked on every invocation of repo.filtered(). _filteredrepotypes = weakref.WeakKeyDictionary() def newtype(base): """Create a new type with the repoview mixin and the given base class""" if base not in _filteredrepotypes: class filteredrepo(repoview, base): pass _filteredrepotypes[base] = filteredrepo return _filteredrepotypes[base]