Mercurial > hg
view mercurial/repoview.py @ 42044:bb271ec2fbfb
compression: introduce a `storage.revlog.zstd.level` configuration
This option control the zstd compression level used when compressing revlog
chunk. The usage of zstd for revlog compression has not graduated from
experimental yet, but we intend to fix that soon.
The option name for the compression level is more straight forward to pick, so
this changesets comes first. Having a dedicated option for each compression
engine is useful because they don't support the same range of values.
I ran the same measurement as for the zlib compression level (in the parent
changesets). The variation in repository size is stay mostly in the same (small)
range. The "read/write" performance see smallish variation, but are overall much
better than zlib. Write performance show the same tend of having better write
performance for when reaching high-end compression.
Again, we don't intend to change the default zstd compression level (currently:
3) in this series. However this is worth investigating in the future.
The Performance comparison of zlib vs zstd is quite impressive. The repository
size stay in the same range, but the performance are much better in all
situations.
Comparison summary
==================
We are looking at:
- performance range for zlib
- performance range for zstd
- comparison of default zstd (level-3) to default zlib (level 6)
- comparison of the slowest zstd time to the fastest zlib time
Read performance:
-----------------
| zlib | zstd | cmp | f2s
mercurial | 0.170159 - 0.189219 | 0.144127 - 0.149624 | 80% | 88%
pypy | 2.679217 - 2.768691 | 1.532317 - 1.705044 | 60% | 63%
netbeans | 122.477027 - 141.620281 | 72.996346 - 89.731560 | 58% | 73%
mozilla | 147.867662 - 170.572118 | 91.700995 - 105.853099 | 56% | 71%
Write performance:
------------------
| zlib | zstd | cmp | f2s
mercurial | 53.250304 - 56.2936129 | 40.877025 - 45.677286 | 75% | 86%
pypy | 460.721984 - 476.589918 | 270.545409 - 301.002219 | 63% | 65%
netbeans | 520.560316 - 715.930400 | 370.356311 - 428.329652 | 55% | 82%
mozilla | 739.803002 - 987.056093 | 505.152906 - 591.930683 | 57% | 80%
Raw data
--------
repo alg lvl .hg/store size 00manifest.d read write
mercurial zlib 1 49,402,813 5,963,475 0.170159 53.250304
mercurial zlib 6 47,197,397 5,875,730 0.182820 56.264320
mercurial zlib 9 47,121,596 5,849,781 0.189219 56.293612
mercurial zstd 1 49,737,084 5,966,355 0.144127 40.877025
mercurial zstd 3 48,961,867 5,895,208 0.146376 42.268142
mercurial zstd 5 48,200,592 5,938,676 0.149624 43.162875
mercurial zstd 10 47,833,520 5,913,353 0.145185 44.012489
mercurial zstd 15 47,314,604 5,728,679 0.147686 45.677286
mercurial zstd 20 47,330,502 5,830,539 0.145789 45.025407
mercurial zstd 22 47,330,076 5,830,539 0.143996 44.690460
pypy zlib 1 370,830,572 28,462,425 2.679217 460.721984
pypy zlib 6 340,112,317 27,648,747 2.768691 467.537158
pypy zlib 9 338,360,736 27,639,003 2.763495 476.589918
pypy zstd 1 362,377,479 27,916,214 1.532317 270.545409
pypy zstd 3 354,137,693 27,905,988 1.686718 294.951509
pypy zstd 5 342,640,043 27,655,774 1.705044 301.002219
pypy zstd 10 334,224,327 27,164,493 1.567287 285.186239
pypy zstd 15 329,000,363 26,645,965 1.637729 299.561332
pypy zstd 20 324,534,039 26,199,547 1.526813 302.149827
pypy zstd 22 324,530,595 26,198,932 1.525718 307.821218
netbeans zlib 1 1,281,847,810 165,495,457 122.477027 520.560316
netbeans zlib 6 1,205,284,353 159,161,207 139.876147 715.930400
netbeans zlib 9 1,197,135,671 155,034,586 141.620281 678.297064
netbeans zstd 1 1,259,581,737 160,840,613 72.996346 370.356311
netbeans zstd 3 1,232,978,122 157,691,551 81.622317 396.733087
netbeans zstd 5 1,208,034,075 160,246,880 83.080549 364.342626
netbeans zstd 10 1,188,624,176 156,083,417 79.323935 403.594602
netbeans zstd 15 1,176,973,589 153,859,477 89.731560 428.329652
netbeans zstd 20 1,162,958,258 151,147,535 82.842667 392.335349
netbeans zstd 22 1,162,707,029 151,150,220 82.565695 402.840655
mozilla zlib 1 2,775,497,186 298,527,987 147.867662 751.263721
mozilla zlib 6 2,596,856,420 286,597,671 170.572118 987.056093
mozilla zlib 9 2,587,542,494 287,018,264 163.622338 739.803002
mozilla zstd 1 2,723,159,348 286,617,532 91.700995 570.042751
mozilla zstd 3 2,665,055,001 286,152,013 95.240155 561.412805
mozilla zstd 5 2,607,819,817 288,060,030 101.978048 505.152906
mozilla zstd 10 2,558,761,085 283,967,648 104.113481 497.771202
mozilla zstd 15 2,526,216,060 275,581,300 105.853099 591.930683
mozilla zstd 20 2,485,114,806 266,478,859 95.268795 576.515389
mozilla zstd 22 2,484,869,080 266,456,505 94.429282 572.785537
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Wed, 27 Mar 2019 18:35:59 +0100 |
parents | 06c976acc581 |
children | bc15e37ecc16 |
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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, ) 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.branchmap.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 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') if phases.hassecret(repo): secrets = repo._phasecache.getrevset(repo, phases.remotehiddenphases) return frozenset(hiddens | frozenset(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.branchmap.subsettable # Otherwise your filter will have to recompute all its branches cache # from scratch (very slow). filtertable = {'visible': computehidden, 'visible-hidden': computehidden, 'served': computeunserved, 'immutable': computemutable, 'base': computeimpactable} 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]