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Differential D10904

censor: split the core of the logic into its own function
ClosedPublic

Authored by marmoute on Jun 22 2021, 7:27 PM.

Details

Reviewers
Alphare
Group Reviewers
hg-reviewers
Commits
rHG5045ba2a3afd: censor: split the core of the logic into its own function
Summary

We now have a "generic" rewrite function (only able to do censoring for now)
and a thin wrapper that implement the censor API with it.

We are now ready to start incorporating strip specific changes.

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

marmoute created this revision.Jun 22 2021, 7:27 PM
Alphare accepted this revision.Jul 1 2021, 4:55 AM
This revision is now accepted and ready to land.Jul 1 2021, 4:55 AM

Revision Contents
Changeset List

PathPackages
Mmercurial/revlogutils/rewrite.py (35 lines)

Diff 28715

mercurial/revlogutils/rewrite.py

rl.opener.rename(newrl._datafile, rl._datafile) rl.opener.rename(newrl._datafile, rl._datafile)
rl.clearcaches() rl.clearcaches()
rl._loadindex() rl._loadindex()
def v2_censor(revlog, tr, censornode, tombstone=b''): def v2_censor(revlog, tr, censornode, tombstone=b''):
"""censors a revision in a "version 2" revlog""" """censors a revision in a "version 2" revlog"""
# General principle assert revlog._format_version != REVLOGV0, revlog._format_version
# assert revlog._format_version != REVLOGV1, revlog._format_version
# We create new revlog files (index/data/sidedata) to copy the content of
# the existing data without the censored data. censor_revs = {revlog.rev(censornode)}
# _rewrite_v2(revlog, tr, censor_revs, tombstone)
# We need to recompute new delta for any revision that used the censored
# revision as delta base. As the cumulative size of the new delta may be
# large, we store them in a temporary file until they are stored in their
# final destination.
#
# All data before the censored data can be blindly copied. The rest needs
# to be copied as we go and the associated index entry needs adjustement.
def _rewrite_v2(revlog, tr, censor_revs, tombstone=b''):
"""rewrite a revlog to censor some of its content
General principle
We create new revlog files (index/data/sidedata) to copy the content of
the existing data without the censored data.
We need to recompute new delta for any revision that used the censored
revision as delta base. As the cumulative size of the new delta may be
large, we store them in a temporary file until they are stored in their
final destination.
All data before the censored data can be blindly copied. The rest needs
to be copied as we go and the associated index entry needs adjustement.
"""
assert revlog._format_version != REVLOGV0, revlog._format_version assert revlog._format_version != REVLOGV0, revlog._format_version
assert revlog._format_version != REVLOGV1, revlog._format_version assert revlog._format_version != REVLOGV1, revlog._format_version
old_index = revlog.index old_index = revlog.index
docket = revlog._docket docket = revlog._docket
censor_revs = {revlog.rev(censornode)}
tombstone = storageutil.packmeta({b'censored': tombstone}, b'') tombstone = storageutil.packmeta({b'censored': tombstone}, b'')
first_excl_rev = min(censor_revs) first_excl_rev = min(censor_revs)
first_excl_entry = revlog.index[first_excl_rev] first_excl_entry = revlog.index[first_excl_rev]
index_cutoff = revlog.index.entry_size * first_excl_rev index_cutoff = revlog.index.entry_size * first_excl_rev
data_cutoff = first_excl_entry[ENTRY_DATA_OFFSET] >> 16 data_cutoff = first_excl_entry[ENTRY_DATA_OFFSET] >> 16
sidedata_cutoff = revlog.sidedata_cut_off(first_excl_rev) sidedata_cutoff = revlog.sidedata_cut_off(first_excl_rev)