branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
#require git
$ echo "[core]" >> $HOME/.gitconfig
$ echo "autocrlf = false" >> $HOME/.gitconfig
$ echo "[core]" >> $HOME/.gitconfig
$ echo "autocrlf = false" >> $HOME/.gitconfig
$ cat <<EOF >> $HGRCPATH
> [extensions]
> convert =
> [convert]
> hg.usebranchnames = True
> hg.tagsbranch = tags-update
> EOF
$ GIT_AUTHOR_NAME='test'; export GIT_AUTHOR_NAME
$ GIT_AUTHOR_EMAIL='test@example.org'; export GIT_AUTHOR_EMAIL
$ GIT_AUTHOR_DATE="2007-01-01 00:00:00 +0000"; export GIT_AUTHOR_DATE
$ GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"; export GIT_COMMITTER_NAME
$ GIT_COMMITTER_EMAIL="$GIT_AUTHOR_EMAIL"; export GIT_COMMITTER_EMAIL
$ GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"; export GIT_COMMITTER_DATE
$ count=10
$ action()
> {
> GIT_AUTHOR_DATE="2007-01-01 00:00:$count +0000"
> GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"
> git "$@" >/dev/null 2>/dev/null || echo "git command error"
> count=`expr $count + 1`
> }
$ glog()
> {
> hg log -G --template '{rev} "{desc|firstline}" files: {files}\n' "$@"
> }
$ convertrepo()
> {
> hg convert --datesort git-repo hg-repo
> }
Build a GIT repo with at least 1 tag
$ mkdir git-repo
$ cd git-repo
$ git init >/dev/null 2>&1
$ echo a > a
$ git add a
$ action commit -m "rev1"
$ action tag -m "tag1" tag1
$ cd ..
Convert without tags
$ hg convert git-repo hg-repo --config convert.skiptags=True
initializing destination hg-repo repository
scanning source...
sorting...
converting...
0 rev1
updating bookmarks
$ hg -R hg-repo tags
tip 0:d98c8ad3a4cf
$ rm -rf hg-repo
Do a first conversion
$ convertrepo
initializing destination hg-repo repository
scanning source...
sorting...
converting...
0 rev1
updating tags
updating bookmarks
Simulate upstream updates after first conversion
$ cd git-repo
$ echo b > a
$ git add a
$ action commit -m "rev2"
$ action tag -m "tag2" tag2
$ cd ..
Perform an incremental conversion
$ convertrepo
scanning source...
sorting...
converting...
0 rev2
updating tags
updating bookmarks
Print the log
$ cd hg-repo
$ glog
o 3 "update tags" files: .hgtags
|
| o 2 "rev2" files: a
| |
o | 1 "update tags" files: .hgtags
/
o 0 "rev1" files: a
$ cd ..