Mercurial > hg
view hgext/censor.py @ 49777:e1953a34c110
bundle: emit full snapshot as is, without doing a redelta
With the new `forced` delta-reused policy, it become important to be able to
send full snapshot where full snapshot are needed. Otherwise, the fallback delta
will simply be used on the client sideā¦ creating monstrous delta chain, since
revision that are meant as a reset of delta-chain chain becoming too complex are
simply adding a new full delta-tree on the leaf of another one.
In the `non-forced` cases, client process full snapshot from the bundle
differently from deltas, so client will still try to convert the full snapshot
into a delta if possible. So this will no lead to pathological storage
explosion.
I have considered making this configurable, but the impact seems limited enough
that it does not seems to be worth it. Especially with the current
sparse-revlog format that use "delta-tree" with multiple level snapshots, full
snapshot are much less frequent and not that different from other intermediate
snapshot that we are already sending over the wire anyway.
CPU wise, this will help the bundling side a little as it will not need to
reconstruct revisions and compute deltas. The unbundling side might save a tiny
amount of CPU as it won't need to reconstruct the delta-base to reconstruct the
revision full text. This only slightly visible in some of the benchmarks. And
have no real impact on most of them.
### data-env-vars.name = pypy-2018-08-01-zstd-sparse-revlog
# benchmark.name = perf-bundle
# benchmark.variants.revs = last-40000
before: 11.467186 seconds
just-emit-full: 11.190576 seconds (-2.41%)
with-pull-force: 11.041091 seconds (-3.72%)
# benchmark.name = perf-unbundle
# benchmark.variants.revs = last-40000
before: 16.744862
just-emit-full:: 16.561036 seconds (-1.10%)
with-pull-force: 16.389344 seconds (-2.12%)
# benchmark.name = pull
# benchmark.variants.revs = last-40000
before: 26.870569
just-emit-full: 26.391188 seconds (-1.78%)
with-pull-force: 25.633184 seconds (-4.60%)
Space wise (so network-wise) the impact is fairly small. When taking compression into
account.
Below are tests the size of `hg bundle --all` for a handful of benchmark repositories
(with bzip, zstd compression and without it)
This show a small increase in the bundle size, but nothing really significant
except maybe for mozilla-try (+12%) that nobody really pulls large chunk of anyway.
Mozilla-try is also the repository that benefit the most for not having to
recompute deltas client size.
### mercurial:
bzip-before: 26 406 342 bytes
bzip-after: 26 691 543 bytes +1.08%
zstd-before: 27 918 645 bytes
zstd-after: 28 075 896 bytes +0.56%
none-before: 98 675 601 bytes
none-after: 100 411 237 bytes +1.76%
### pypy
bzip-before: 201 295 752 bytes
bzip-after: 209 780 282 bytes +4.21%
zstd-before: 202 974 795 bytes
zstd-after: 205 165 780 bytes +1.08%
none-before: 871 070 261 bytes
none-after: 993 595 057 bytes +14.07%
### netbeans
bzip-before: 601 314 330 bytes
bzip-after: 614 246 241 bytes +2.15%
zstd-before: 604 745 136 bytes
zstd-after: 615 497 705 bytes +1.78%
none-before: 3 338 238 571 bytes
none-after: 3 439 422 535 bytes +3.03%
### mozilla-central
bzip-before: 1 493 006 921 bytes
bzip-after: 1 549 650 570 bytes +3.79%
zstd-before: 1 481 910 102 bytes
zstd-after: 1 513 052 415 bytes +2.10%
none-before: 6 535 929 910 bytes
none-after: 7 010 191 342 bytes +7.26%
### mozilla-try
bzip-before: 6 583 425 999 bytes
bzip-after: 7 423 536 928 bytes +12.76%
zstd-before: 6 021 009 212 bytes
zstd-after: 6 674 922 420 bytes +10.86%
none-before: 22 954 739 558 bytes
none-after: 26 013 854 771 bytes +13.32%
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
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date | Wed, 07 Dec 2022 20:12:23 +0100 |
parents | 6000f5b25c9b |
children | 51056bedbe0d |
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# Copyright (C) 2015 - Mike Edgar <adgar@google.com> # # This extension enables removal of file content at a given revision, # rewriting the data/metadata of successive revisions to preserve revision log # integrity. """erase file content at a given revision The censor command instructs Mercurial to erase all content of a file at a given revision *without updating the changeset hash.* This allows existing history to remain valid while preventing future clones/pulls from receiving the erased data. Typical uses for censor are due to security or legal requirements, including:: * Passwords, private keys, cryptographic material * Licensed data/code/libraries for which the license has expired * Personally Identifiable Information or other private data Censored nodes can interrupt mercurial's typical operation whenever the excised data needs to be materialized. Some commands, like ``hg cat``/``hg revert``, simply fail when asked to produce censored data. Others, like ``hg verify`` and ``hg update``, must be capable of tolerating censored data to continue to function in a meaningful way. Such commands only tolerate censored file revisions if they are allowed by the "censor.policy=ignore" config option. A few informative commands such as ``hg grep`` will unconditionally ignore censored data and merely report that it was encountered. """ from mercurial.i18n import _ from mercurial.node import short from mercurial import ( error, logcmdutil, registrar, scmutil, ) cmdtable = {} command = registrar.command(cmdtable) # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should # be specifying the version(s) of Mercurial they are tested with, or # leave the attribute unspecified. testedwith = b'ships-with-hg-core' @command( b'censor', [ ( b'r', b'rev', b'', _(b'censor file from specified revision'), _(b'REV'), ), (b't', b'tombstone', b'', _(b'replacement tombstone data'), _(b'TEXT')), ], _(b'-r REV [-t TEXT] [FILE]'), helpcategory=command.CATEGORY_MAINTENANCE, ) def censor(ui, repo, path, rev=b'', tombstone=b'', **opts): with repo.wlock(), repo.lock(): return _docensor(ui, repo, path, rev, tombstone, **opts) def _docensor(ui, repo, path, rev=b'', tombstone=b'', **opts): if not path: raise error.Abort(_(b'must specify file path to censor')) if not rev: raise error.Abort(_(b'must specify revision to censor')) wctx = repo[None] m = scmutil.match(wctx, (path,)) if m.anypats() or len(m.files()) != 1: raise error.Abort(_(b'can only specify an explicit filename')) path = m.files()[0] flog = repo.file(path) if not len(flog): raise error.Abort(_(b'cannot censor file with no history')) rev = logcmdutil.revsingle(repo, rev, rev).rev() try: ctx = repo[rev] except KeyError: raise error.Abort(_(b'invalid revision identifier %s') % rev) try: fctx = ctx.filectx(path) except error.LookupError: raise error.Abort(_(b'file does not exist at revision %s') % rev) fnode = fctx.filenode() heads = [] for headnode in repo.heads(): hc = repo[headnode] if path in hc and hc.filenode(path) == fnode: heads.append(hc) if heads: headlist = b', '.join([short(c.node()) for c in heads]) raise error.Abort( _(b'cannot censor file in heads (%s)') % headlist, hint=_(b'clean/delete and commit first'), ) wp = wctx.parents() if ctx.node() in [p.node() for p in wp]: raise error.Abort( _(b'cannot censor working directory'), hint=_(b'clean/delete/update first'), ) with repo.transaction(b'censor') as tr: flog.censorrevision(tr, fnode, tombstone=tombstone)