Mercurial > hg
view tests/test-issue3084.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 | c9db897d5a43 |
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$ echo "[extensions]" >> $HGRCPATH $ echo "largefiles =" >> $HGRCPATH Create the repository outside $HOME since largefiles write to $HOME/.cache/largefiles. $ hg init test $ cd test $ echo "root" > root $ hg add root $ hg commit -m "Root commit" $ echo "large" > foo $ hg add --large foo $ hg commit -m "Add foo as a largefile" $ hg update -r 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved getting changed largefiles 0 largefiles updated, 1 removed $ echo "normal" > foo $ hg add foo $ hg commit -m "Add foo as normal file" created new head Normal file in the working copy, keeping the normal version: $ echo "n" | hg merge --config ui.interactive=Yes foo has been turned into a largefile use (l)argefile or keep as (n)ormal file? 0 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg status $ cat foo normal Normal file in the working copy, keeping the largefile version: $ hg update -q -C $ echo "l" | hg merge --config ui.interactive=Yes foo has been turned into a largefile use (l)argefile or keep as (n)ormal file? 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) getting changed largefiles 1 largefiles updated, 0 removed $ hg status M foo $ hg diff --nodates diff -r fa129ab6b5a7 .hglf/foo --- /dev/null +++ b/.hglf/foo @@ -0,0 +1,1 @@ +7f7097b041ccf68cc5561e9600da4655d21c6d18 diff -r fa129ab6b5a7 foo --- a/foo +++ /dev/null @@ -1,1 +0,0 @@ -normal $ cat foo large Largefile in the working copy, keeping the normal version: $ hg update -q -C -r 1 $ echo "n" | hg merge --config ui.interactive=Yes foo has been turned into a normal file keep as (l)argefile or use (n)ormal file? 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) getting changed largefiles 0 largefiles updated, 0 removed $ hg status M foo $ hg diff --nodates diff -r ff521236428a .hglf/foo --- a/.hglf/foo +++ /dev/null @@ -1,1 +0,0 @@ -7f7097b041ccf68cc5561e9600da4655d21c6d18 diff -r ff521236428a foo --- /dev/null +++ b/foo @@ -0,0 +1,1 @@ +normal $ cat foo normal Largefile in the working copy, keeping the largefile version: $ hg update -q -C -r 1 $ echo "l" | hg merge --config ui.interactive=Yes foo has been turned into a normal file keep as (l)argefile or use (n)ormal file? 0 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) getting changed largefiles 1 largefiles updated, 0 removed $ hg status $ cat foo large $ cd ..