Mercurial > hg
view tests/test-convert-clonebranches.t @ 26945:8a256cee72c8 stable
tags: create new sortdict for performance reasons
sortdict internally maintains a list of keys in insertion order. When a
key is replaced via __setitem__, we .remove() from this list. This
involves a linear scan and array adjustment. This is an expensive
operation.
The tags reading code was calling into sortdict.__setitem__ for each tag
in a read .hgtags revision. For repositories with thousands of tags or
thousands of .hgtags revisions, the overhead from list.remove()
noticeable.
This patch creates a new sortdict() so __setitem__ calls don't incur a
list.remove.
This doesn't appear to have any performance impact on my Firefox
repository. But that's only because tags reading doesn't show up in
profiles to begin with. I'm still waiting to hear from a user with over
10,000 tags and hundreds of heads on the impact of this patch.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 12 Nov 2015 13:16:04 -0800 |
parents | 701df761aa94 |
children | 75be14993fda |
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$ cat <<EOF >> $HGRCPATH > [extensions] > convert = > [convert] > hg.tagsbranch = 0 > EOF $ hg init source $ cd source $ echo a > a $ hg ci -qAm adda Add a merge with one parent in the same branch $ echo a >> a $ hg ci -qAm changea $ hg up -qC 0 $ hg branch branch0 marked working directory as branch branch0 (branches are permanent and global, did you want a bookmark?) $ echo b > b $ hg ci -qAm addb $ hg up -qC $ hg merge default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -qm mergeab $ hg tag -ql mergeab $ cd .. Miss perl... sometimes $ cat > filter.py <<EOF > import sys, re > > r = re.compile(r'^(?:\d+|pulling from)') > sys.stdout.writelines([l for l in sys.stdin if r.search(l)]) > EOF convert $ hg convert -v --config convert.hg.clonebranches=1 source dest | > python filter.py 3 adda 2 changea 1 addb pulling from default into branch0 1 changesets found 0 mergeab pulling from default into branch0 1 changesets found Add a merge with both parents and child in different branches $ cd source $ hg branch branch1 marked working directory as branch branch1 $ echo a > file1 $ hg ci -qAm c1 $ hg up -qC mergeab $ hg branch branch2 marked working directory as branch branch2 $ echo a > file2 $ hg ci -qAm c2 $ hg merge branch1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg branch branch3 marked working directory as branch branch3 $ hg ci -qAm c3 $ cd .. incremental conversion $ hg convert -v --config convert.hg.clonebranches=1 source dest | > python filter.py 2 c1 pulling from branch0 into branch1 4 changesets found 1 c2 pulling from branch0 into branch2 4 changesets found 0 c3 pulling from branch1 into branch3 5 changesets found pulling from branch2 into branch3 1 changesets found