tests/test-repair-strip.t

match: convert O(n) to O(log n) in exactmatcher.visitchildrenset

When using narrow, during rebase this is called (at least) once per directory in
the set of files in the commit being rebased. Every time it's called, we did the
set arithmetic (now extracted and cached), which was probably pretty cheap but
not necessary to repeat each time, looped over every item in the matcher and
kept things that started with the directory we were querying.

With very large narrowspecs, and a commit that touched a file in a large number
of directories, this was slow. In a pathological repo, the rebase of a single
commit (that touched over 17k files, I believe in approximately as many
directories) with a narrowspec that had >32k entries took 8,246s of profiled
time, with 5,007s of that spent in visitchildrenset (transitively). With this
change, the time spent in visitchildrenset is less than 34s (which is where my
profile cut off). Most of the remaining time was network access due to our
custom remotefilelog-based setup not properly prefetching.

Differential Revision: https://phab.mercurial-scm.org/D10294

#require unix-permissions no-root reporevlogstore

  $ cat > $TESTTMP/dumpjournal.py <<EOF
  > import sys
  > for entry in sys.stdin.read().split('\n'):
  >     if entry:
  >         print(entry.split('\x00')[0])
  > EOF

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=">> $HGRCPATH

  $ teststrip() {
  >   hg -q up -C $1
  >   echo % before update $1, strip $2
  >   hg parents
  >   chmod -$3 $4
  >   hg strip $2 2>&1 | sed 's/\(bundle\).*/\1/' | sed 's/Permission denied.*\.hg\/store\/\(.*\)/Permission denied \.hg\/store\/\1/'
  >   echo % after update $1, strip $2
  >   chmod +$3 $4
  >   hg verify
  >   echo % journal contents
  >   if [ -f .hg/store/journal ]; then
  >       cat .hg/store/journal | "$PYTHON" $TESTTMP/dumpjournal.py
  >   else
  >       echo "(no journal)"
  >   fi
  >   if ls .hg/store/journal >/dev/null 2>&1; then
  >     hg recover --verify
  >   fi
  >   ls .hg/strip-backup/* >/dev/null 2>&1 && hg unbundle -q .hg/strip-backup/*
  >   rm -rf .hg/strip-backup
  > }

  $ hg init test
  $ cd test
  $ echo a > a
  $ hg -q ci -m "a" -A
  $ echo b > b
  $ hg -q ci -m "b" -A
  $ echo b2 >> b
  $ hg -q ci -m "b2" -A
  $ echo c > c
  $ hg -q ci -m "c" -A
  $ teststrip 0 2 w .hg/store/data/b.i
  % before update 0, strip 2
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
  saved backup bundle
  transaction abort!
  failed to truncate data/b.i
  rollback failed - please run hg recover
  (failure reason: [Errno *] Permission denied .hg/store/data/b.i') (glob)
  strip failed, backup bundle
  abort: Permission denied .hg/store/data/b.i'
  % after update 0, strip 2
  abandoned transaction found - run hg recover
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   b@?: rev 1 points to nonexistent changeset 2
   (expected 1)
   b@?: 736c29771fba not in manifests
  warning: orphan data file 'data/c.i'
  checked 2 changesets with 3 changes to 2 files
  2 warnings encountered!
  2 integrity errors encountered!
  % journal contents
  00changelog.i
  00manifest.i
  data/b.i
  data/c.i
  rolling back interrupted transaction
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 2 changes to 2 files
  $ teststrip 0 2 r .hg/store/data/b.i
  % before update 0, strip 2
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
  abort: Permission denied .hg/store/data/b.i'
  % after update 0, strip 2
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 4 changesets with 4 changes to 3 files
  % journal contents
  (no journal)
  $ teststrip 0 2 w .hg/store/00manifest.i
  % before update 0, strip 2
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
  saved backup bundle
  transaction abort!
  failed to truncate 00manifest.i
  rollback failed - please run hg recover
  (failure reason: [Errno *] Permission denied .hg/store/00manifest.i') (glob)
  strip failed, backup bundle
  abort: Permission denied .hg/store/00manifest.i'
  % after update 0, strip 2
  abandoned transaction found - run hg recover
  checking changesets
  checking manifests
   manifest@?: rev 2 points to nonexistent changeset 2
   manifest@?: 3362547cdf64 not in changesets
   manifest@?: rev 3 points to nonexistent changeset 3
   manifest@?: 265a85892ecb not in changesets
  crosschecking files in changesets and manifests
   c@3: in manifest but not in changeset
  checking files
   b@?: rev 1 points to nonexistent changeset 2
   (expected 1)
   c@?: rev 0 points to nonexistent changeset 3
  checked 2 changesets with 4 changes to 3 files
  1 warnings encountered!
  7 integrity errors encountered!
  (first damaged changeset appears to be 3)
  % journal contents
  00changelog.i
  00manifest.i
  data/b.i
  data/c.i
  rolling back interrupted transaction
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 2 changes to 2 files

  $ cd ..