Mercurial > hg
view tests/test-import-merge.t @ 17970:0b03454abae7
ancestor: faster algorithm for difference of ancestor sets
One of the major reasons rebase is slow in large repositories is
the computation of the detach set: the set of ancestors of the
changesets to rebase not in the destination parent. This is currently
done via a revset that does two walks all the way to the root of
the DAG. Instead of doing that, to find ancestors of a set <revs>
not in another set <common> we walk up the tree in reverse revision
number order, maintaining sets of nodes visited from <revs>, <common>
or both.
For the common case where the sets are close both topologically and
in revision number (relative to repository size), this has been
found to speed up rebase by around 15-20%. When the nodes are farther
apart and the DAG is highly branching, it is harder to say which
would win.
Here's how long computing the detach set takes in a linear repository
with over 400000 changesets, rebasing near tip:
Rebasing across 4 changesets
Revset method: 2.2s
New algorithm: 0.00015s
Rebasing across 250 changesets
Revset method: 2.2s
New algorithm: 0.00069s
Rebasing across 10000 changesets
Revset method: 2.4s
New algorithm: 0.019s
author | Siddharth Agarwal <sid0@fb.com> |
---|---|
date | Mon, 26 Nov 2012 11:46:51 -0800 |
parents | f2719b387380 |
children | 8eb3408bf005 |
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$ echo "[extensions]" >> $HGRCPATH $ echo "mq=" >> $HGRCPATH $ tipparents() { > hg parents --template "{rev}:{node|short} {desc|firstline}\n" -r tip > } Test import and merge diffs $ hg init repo $ cd repo $ echo a > a $ hg ci -Am adda adding a $ echo a >> a $ hg ci -m changea $ echo c > c $ hg ci -Am addc adding c $ hg up 0 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo b > b $ hg ci -Am addb adding b created new head $ hg up 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg merge 3 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m merge $ hg export . > ../merge.diff $ cd .. $ hg clone -r2 repo repo2 adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 2 files updating to branch default 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd repo2 $ hg pull -r3 ../repo pulling from ../repo searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) Test without --exact and diff.p1 == workingdir.p1 $ hg up 1 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg import ../merge.diff applying ../merge.diff $ tipparents 1:540395c44225 changea 3:102a90ea7b4a addb $ hg strip --no-backup tip 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test without --exact and diff.p1 != workingdir.p1 $ hg up 2 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg import ../merge.diff applying ../merge.diff $ tipparents 2:890ecaa90481 addc $ hg strip --no-backup tip 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test with --exact $ hg import --exact ../merge.diff applying ../merge.diff 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ tipparents 1:540395c44225 changea 3:102a90ea7b4a addb $ hg strip --no-backup tip 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test with --bypass and diff.p1 == workingdir.p1 $ hg up 1 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg import --bypass ../merge.diff applying ../merge.diff $ tipparents 1:540395c44225 changea 3:102a90ea7b4a addb $ hg strip --no-backup tip Test with --bypass and diff.p1 != workingdir.p1 $ hg up 2 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg import --bypass ../merge.diff applying ../merge.diff $ tipparents 2:890ecaa90481 addc $ hg strip --no-backup tip Test with --bypass and --exact $ hg import --bypass --exact ../merge.diff applying ../merge.diff $ tipparents 1:540395c44225 changea 3:102a90ea7b4a addb $ hg strip --no-backup tip $ cd ..