Mercurial > hg
view tests/test-addremove.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 | 6ef3107c661e |
children | 9f4778027bc2 |
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$ hg init rep $ cd rep $ mkdir dir $ touch foo dir/bar $ hg -v addremove adding dir/bar adding foo $ hg -v commit -m "add 1" dir/bar foo committed changeset 0:6f7f953567a2 $ cd dir/ $ touch ../foo_2 bar_2 $ hg -v addremove adding dir/bar_2 adding foo_2 $ hg -v commit -m "add 2" dir/bar_2 foo_2 committed changeset 1:e65414bf35c5 $ cd ../.. $ hg init sim $ cd sim $ echo a > a $ echo a >> a $ echo a >> a $ echo c > c $ hg commit -Ama adding a adding c $ mv a b $ rm c $ echo d > d $ hg addremove -n -s 50 # issue 1696 removing a adding b removing c adding d recording removal of a as rename to b (100% similar) $ hg addremove -s 50 removing a adding b removing c adding d recording removal of a as rename to b (100% similar) $ hg commit -mb $ cd ..