view hgext/censor.py @ 43254:181d28ba05da

copies: avoid instancing more changectx to access parent revisions We just need to know the revision numbers of the parents, creating full context is needlessly expensive. This provide a small, but noticeable performance boost. revision: large amount; added files: large amount; rename small amount; c3b14617fbd7 9ba6ab77fd29 before: ! wall 2.885636 comb 2.900000 user 2.870000 sys 0.030000 (median of 10) after: ! wall 2.702270 comb 2.710000 user 2.690000 sys 0.020000 (median of 10) revision: large amount; added files: small amount; rename small amount; c3b14617fbd7 f650a9b140d2 before: ! wall 4.298271 comb 4.290000 user 4.240000 sys 0.050000 (median of 10) after: ! wall 3.976610 comb 3.970000 user 3.920000 sys 0.050000 (median of 10) revision: large amount; added files: large amount; rename large amount; 08ea3258278e d9fa043f30c0 before: ! wall 0.773397 comb 0.770000 user 0.770000 sys 0.000000 (median of 11) after: ! wall 0.701634 comb 0.700000 user 0.700000 sys 0.000000 (median of 13) revision: small amount; added files: large amount; rename large amount; df6f7a526b60 a83dc6a2d56f before: ! wall 0.013585 comb 0.010000 user 0.010000 sys 0.000000 (median of 217) after: ! wall 0.013550 comb 0.010000 user 0.010000 sys 0.000000 (median of 218) revision: small amount; added files: large amount; rename small amount; 4aa4e1f8e19a 169138063d63 before: ! wall 0.003202 comb 0.000000 user 0.000000 sys 0.000000 (median of 929) after: ! wall 0.002993 comb 0.010000 user 0.010000 sys 0.000000 (median of 992) revision: small amount; added files: small amount; rename small amount; 4bc173b045a6 964879152e2e before: ! wall 0.000077 comb 0.000000 user 0.000000 sys 0.000000 (median of 12060) after: ! wall 0.000072 comb 0.000000 user 0.000000 sys 0.000000 (median of 12804) revision: medium amount; added files: large amount; rename medium amount; c95f1ced15f2 2c68e87c3efe before: ! wall 0.510614 comb 0.500000 user 0.500000 sys 0.000000 (median of 18) after: ! wall 0.473681 comb 0.470000 user 0.470000 sys 0.000000 (median of 20) revision: medium amount; added files: medium amount; rename small amount; d343da0c55a8 d7746d32bf9d before: ! wall 0.126552 comb 0.130000 user 0.130000 sys 0.000000 (median of 77) after: ! wall 0.115240 comb 0.110000 user 0.110000 sys 0.000000 (median of 85) Differential Revision: https://phab.mercurial-scm.org/D7122
author Pierre-Yves David <pierre-yves.david@octobus.net>
date Wed, 16 Oct 2019 17:49:30 +0200
parents 687b865b95ad
children bec734015b70
line wrap: on
line source

# 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.
"""

from __future__ import absolute_import

from mercurial.i18n import _
from mercurial.node import short

from mercurial import (
    error,
    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 = scmutil.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)