revlog: move censor logic into main revlog class
Previously, the revlog class implemented dummy methods for
various censor-related functionality. Revision censoring was
(and will continue to be) only possible on filelog instances.
So filelog implemented these methods to perform something
reasonable.
A problem with implementing censoring on filelog is that
it assumes filelog is a revlog. Upcoming work to formalize
the filelog interface will make this not true.
Furthermore, the censoring logic is security-sensitive. I
think action-at-a-distance with custom implementation of core
revlog APIs in derived classes is a bit dangerous. I think at
a minimum the censor logic should live in revlog.py.
I was tempted to created a "censored revlog" class that
basically pulled these methods out of filelog. But, I wasn't
a huge fan of overriding core methods in child classes. A
reason to do that would be performance. However, the censoring
code only comes into play when:
* hash verification fails
* delta generation
* applying deltas from changegroups
The new code is conditional on an instance attribute. So the
overhead for running the censored code when the revlog isn't
censorable is an attribute lookup. All of these operations are
at least a magnitude slower than a Python attribute lookup. So
there shouldn't be a performance concern.
Differential Revision: https://phab.mercurial-scm.org/D3151
$ hg init test
$ cd test
$ echo foo>foo
$ hg addremove
adding foo
$ hg commit -m "1"
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ hg clone . ../branch
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ../branch
$ hg co
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo bar>>foo
$ hg commit -m "2"
$ cd ../test
$ hg pull ../branch
pulling from ../branch
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 30aff43faee1
(run 'hg update' to get a working copy)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
$ hg co
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat foo
foo
bar
$ hg manifest --debug
6f4310b00b9a147241b071a60c28a650827fb03d 644 foo
update to rev 0 with a date
$ hg upd -d foo 0
abort: you can't specify a revision and a date
[255]
$ cd ..
update with worker processes
#if no-windows
$ cat <<EOF > forceworker.py
> from mercurial import extensions, worker
> def nocost(orig, ui, costperop, nops):
> return worker._numworkers(ui) > 1
> def uisetup(ui):
> extensions.wrapfunction(worker, 'worthwhile', nocost)
> EOF
$ hg init worker
$ cd worker
$ cat <<EOF >> .hg/hgrc
> [extensions]
> forceworker = $TESTTMP/forceworker.py
> [worker]
> numcpus = 4
> EOF
$ for i in `$PYTHON $TESTDIR/seq.py 1 100`; do
> echo $i > $i
> done
$ hg ci -qAm 'add 100 files'
$ hg update null
0 files updated, 0 files merged, 100 files removed, 0 files unresolved
$ hg update -v | grep 100
getting 100
100 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ..
#endif