tests/test-convert-hg-svn.t
author Arun Kulshreshtha <akulshreshtha@janestreet.com>
Tue, 30 Aug 2022 15:29:55 -0400
changeset 49491 c6a1beba27e9
parent 41496 e095a9688a31
child 50725 7e5be4a7cda7
permissions -rw-r--r--
bisect: avoid copying ancestor list for non-merge commits During a bisection, hg needs to compute a list of all ancestors for every candidate commit. This is accomplished via a bottom-up traversal of the set of candidates, during which each revision's ancestor list is populated using the ancestor list of its parent(s). Previously, this involved copying the entire list, which could be very long in if the bisection range was large. To help improve this, we can observe that each candidate commit is visited exactly once, at which point its ancestor list is copied into its children's lists and then dropped. In the case of non-merge commits, a commit's ancestor list consists exactly of its parent's list plus itself. This means that we can trivially reuse the parent's existing list for one of its non-merge children, which avoids copying entirely if that commit is the parent's only child. This makes bisections over linear ranges of commits much faster. During some informal testing in the large publicly-available `mozilla-central` repository, this noticeably sped up bisections over large ranges of history: Setup: $ cd mozilla-central $ hg bisect --reset $ hg bisect --good 0 $ hg log -r tip -T '{rev}\n' 628417 Test: $ time hg bisect --bad tip --noupdate Before: real 3m35.927s user 3m35.553s sys 0m0.319s After: real 1m41.142s user 1m40.810s sys 0m0.285s

#require svn svn-bindings

  $ filter_svn_output () {
  >     egrep -v 'Committing|Updating|(^$)' | sed -e 's/done$//' || true
  > }

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > convert =
  > mq =
  > EOF

  $ SVNREPOPATH=`pwd`/svn-repo
  $ SVNREPOURL="`"$PYTHON" $TESTDIR/svnurlof.py \"$SVNREPOPATH\"`"

  $ svnadmin create "$SVNREPOPATH"
  $ cat > "$SVNREPOPATH"/hooks/pre-revprop-change <<EOF
  > #!/bin/sh
  > 
  > REPOS="$1"
  > REV="$2"
  > USER="$3"
  > PROPNAME="$4"
  > ACTION="$5"
  > 
  > if [ "$ACTION" = "M" -a "$PROPNAME" = "svn:log" ]; then exit 0; fi
  > if [ "$ACTION" = "A" -a "$PROPNAME" = "hg:convert-branch" ]; then exit 0; fi
  > if [ "$ACTION" = "A" -a "$PROPNAME" = "hg:convert-rev" ]; then exit 0; fi
  > 
  > echo "Changing prohibited revision property" >&2
  > exit 1
  > EOF
  $ chmod +x "$SVNREPOPATH"/hooks/pre-revprop-change
  $ svn co "$SVNREPOURL" "$SVNREPOPATH"-wc
  Checked out revision 0.
  $ cd "$SVNREPOPATH"-wc
  $ echo a > a
  $ svn add a
  A         a
  $ svn ci -m'added a' a | filter_svn_output
  Adding         a
  Transmitting file data .
  Committed revision 1.
  $ cd ..

initial roundtrip

  $ hg convert -s svn -d hg "$SVNREPOPATH"-wc "$SVNREPOPATH"-hg | grep -v initializing
  scanning source...
  sorting...
  converting...
  0 added a
  $ hg convert -s hg -d svn "$SVNREPOPATH"-hg "$SVNREPOPATH"-wc
  scanning source...
  sorting...
  converting...

second roundtrip should do nothing

  $ hg convert -s svn -d hg "$SVNREPOPATH"-wc "$SVNREPOPATH"-hg
  scanning source...
  sorting...
  converting...
  $ hg convert -s hg -d svn "$SVNREPOPATH"-hg "$SVNREPOPATH"-wc
  scanning source...
  sorting...
  converting...

new hg rev

  $ hg clone "$SVNREPOPATH"-hg "$SVNREPOPATH"-work
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd "$SVNREPOPATH"-work
  $ echo b > b
  $ hg add b
  $ hg ci -mb

adding an empty revision

  $ hg qnew -m emtpy empty
  $ hg qfinish -a
  $ cd ..

echo hg to svn

  $ hg --cwd "$SVNREPOPATH"-hg pull -q "$SVNREPOPATH"-work
  $ hg convert -s hg -d svn "$SVNREPOPATH"-hg "$SVNREPOPATH"-wc
  scanning source...
  sorting...
  converting...
  1 b
  0 emtpy

svn back to hg should do nothing

  $ hg convert -s svn -d hg "$SVNREPOPATH"-wc "$SVNREPOPATH"-hg
  scanning source...
  sorting...
  converting...

hg back to svn should do nothing

  $ hg convert -s hg -d svn "$SVNREPOPATH"-hg "$SVNREPOPATH"-wc
  scanning source...
  sorting...
  converting...

verify which shamap format we are storing and must be able to handle

  $ cat svn-repo-hg/.hg/shamap
  svn:????????-????-????-????-????????????@1 ???????????????????????????????????????? (glob)
  svn:????????-????-????-????-????????????@2 ???????????????????????????????????????? (glob)
  svn:????????-????-????-????-????????????@2 ???????????????????????????????????????? (glob)
  $ cat svn-repo-wc/.svn/hg-shamap
  ???????????????????????????????????????? 1 (glob)
  ???????????????????????????????????????? svn:????????-????-????-????-????????????@2 (glob)
  ???????????????????????????????????????? svn:????????-????-????-????-????????????@2 (glob)