Mercurial > hg
view tests/test-hgcia.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 |
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Test the CIA extension $ cat >> $HGRCPATH <<EOF > [extensions] > hgcia= > > [hooks] > changegroup.cia = python:hgext.hgcia.hook > > [web] > baseurl = http://hgserver/ > > [cia] > user = testuser > project = testproject > test = True > EOF $ hg init src $ hg init cia $ cd src $ echo foo > foo $ hg ci -Amfoo adding foo $ hg push ../cia pushing to ../cia searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files <message> <generator> <name>Mercurial (hgcia)</name> <version>0.1</version> <url>http://hg.kublai.com/mercurial/hgcia</url> <user>testuser</user> </generator> <source> <project>testproject</project> <branch>default</branch> </source> <body> <commit> <author>test</author> <version>0:e63c23eaa88a</version> <log>foo</log> <url>http://hgserver/rev/e63c23eaa88a</url> <files><file uri="http://hgserver/file/e63c23eaa88a/foo" action="add">foo</file></files> </commit> </body> <timestamp>0</timestamp> </message> $ cat >> $HGRCPATH <<EOF > strip = 0 > EOF $ echo bar > bar $ hg ci -Ambar adding bar $ hg push ../cia pushing to ../cia searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files <message> <generator> <name>Mercurial (hgcia)</name> <version>0.1</version> <url>http://hg.kublai.com/mercurial/hgcia</url> <user>testuser</user> </generator> <source> <project>testproject</project> <branch>default</branch> </source> <body> <commit> <author>test</author> <version>1:c0c7cf58edc5</version> <log>bar</log> <url>http://hgserver/$TESTTMP/cia/rev/c0c7cf58edc5</url> <files><file uri="http://hgserver/$TESTTMP/cia/file/c0c7cf58edc5/bar" action="add">bar</file></files> </commit> </body> <timestamp>0</timestamp> </message> $ cd ..