Mercurial > hg
view tests/test-archive-symlinks.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 | 6d632cf8a811 |
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$ "$TESTDIR/hghave" symlink || exit 80 $ origdir=`pwd` $ hg init repo $ cd repo $ ln -s nothing dangling avoid tar warnings about old timestamp $ hg ci -d '2000-01-01 00:00:00 +0000' -qAm 'add symlink' $ hg archive -t files ../archive $ hg archive -t tar -p tar ../archive.tar $ hg archive -t zip -p zip ../archive.zip files $ cd "$origdir" $ cd archive $ "$TESTDIR/readlink.py" dangling dangling -> nothing tar $ cd "$origdir" $ tar xf archive.tar $ cd tar $ "$TESTDIR/readlink.py" dangling dangling -> nothing zip $ cd "$origdir" $ unzip archive.zip > /dev/null $ cd zip $ "$TESTDIR/readlink.py" dangling dangling -> nothing $ cd ..