Mercurial > hg
view tests/test-pull-r.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 | 9263f86b9681 |
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$ hg init repo $ cd repo $ echo foo > foo $ hg ci -qAm 'add foo' $ echo >> foo $ hg ci -m 'change foo' $ hg up -qC 0 $ echo bar > bar $ hg ci -qAm 'add bar' $ hg log changeset: 2:effea6de0384 tag: tip parent: 0:bbd179dfa0a7 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: add bar changeset: 1:ed1b79f46b9a user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: change foo changeset: 0:bbd179dfa0a7 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: add foo $ cd .. don't show "(+1 heads)" message when pulling closed head $ hg clone -q repo repo2 $ hg clone -q repo2 repo3 $ cd repo2 $ hg up -q 0 $ echo hello >> foo $ hg ci -mx1 created new head $ hg ci -mx2 --close-branch $ cd ../repo3 $ hg heads -q --closed 2:effea6de0384 1:ed1b79f46b9a $ hg pull pulling from $TESTTMP/repo2 (glob) searching for changes adding changesets adding manifests adding file changes added 2 changesets with 1 changes to 1 files (run 'hg update' to get a working copy) $ hg heads -q --closed 4:00cfe9073916 2:effea6de0384 1:ed1b79f46b9a $ cd .. $ hg init copy $ cd copy Pull a missing revision: $ hg pull -qr missing ../repo abort: unknown revision 'missing'! [255] Pull multiple revisions with update: $ hg pull -qu -r 0 -r 1 ../repo $ hg -q parents 0:bbd179dfa0a7 $ hg rollback repository tip rolled back to revision -1 (undo pull) working directory now based on revision -1 $ hg pull -qr 0 ../repo $ hg log changeset: 0:bbd179dfa0a7 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: add foo $ hg pull -qr 1 ../repo $ hg log changeset: 1:ed1b79f46b9a tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: change foo changeset: 0:bbd179dfa0a7 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: add foo This used to abort: received changelog group is empty: $ hg pull -qr 1 ../repo $ cd ..