Mercurial > hg
view tests/test-mq-qgoto.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 | de99de39ba28 |
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$ echo "[extensions]" >> $HGRCPATH $ echo "mq=" >> $HGRCPATH $ hg init a $ cd a $ echo a > a $ hg ci -Ama adding a $ hg qnew a.patch $ echo a >> a $ hg qrefresh $ hg qnew b.patch $ echo b > b $ hg add b $ hg qrefresh $ hg qnew c.patch $ echo c > c $ hg add c $ hg qrefresh $ hg qgoto a.patch popping c.patch popping b.patch now at: a.patch $ hg qgoto c.patch applying b.patch applying c.patch now at: c.patch $ hg qgoto b.patch popping c.patch now at: b.patch Using index: $ hg qgoto 0 popping b.patch now at: a.patch $ hg qgoto 2 applying b.patch applying c.patch now at: c.patch No warnings when using index: $ hg qnew bug314159 $ echo d >> c $ hg qrefresh $ hg qnew bug141421 $ echo e >> c $ hg qrefresh $ hg qgoto 1 popping bug141421 popping bug314159 popping c.patch now at: b.patch $ hg qgoto 3 applying c.patch applying bug314159 now at: bug314159 Detect ambiguous non-index: $ hg qgoto 14 patch name "14" is ambiguous: bug314159 bug141421 abort: patch 14 not in series [255] $ cd ..