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view tests/test-convert-bzr-114.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 | d1f88ae495b4 |
children | 7a9cbb315d84 |
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$ "$TESTDIR/hghave" bzr114 || exit 80 $ . "$TESTDIR/bzr-definitions" The file/directory replacement can only be reproduced on bzr >= 1.4. Merge it back in test-convert-bzr-directories once this version becomes mainstream. replace file with dir $ mkdir test-replace-file-with-dir $ cd test-replace-file-with-dir $ bzr init -q source $ cd source $ echo d > d $ bzr add -q d $ bzr commit -q -m 'add d file' $ rm d $ mkdir d $ bzr add -q d $ bzr commit -q -m 'replace with d dir' $ echo a > d/a $ bzr add -q d/a $ bzr commit -q -m 'add d/a' $ cd .. $ hg convert source source-hg initializing destination source-hg repository scanning source... sorting... converting... 2 add d file 1 replace with d dir 0 add d/a $ manifest source-hg tip % manifest of tip 644 d/a $ cd source-hg $ hg update 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd ../..