Mercurial > hg
view tests/test-flags.t @ 16120:47ee41fcf42b
largefiles: optimize update speed by only updating changed largefiles
Historically, during 'hg update', every largefile in the working copy was
hashed (which is a very expensive operation on big files) and any
largefiles that did not have a hash that matched their standin were
updated.
This patch optimizes 'hg update' by keeping track of what standins have
changed between the old and new revisions, and only updating the largefiles
that have changed. This saves a lot of time by avoiding the unecessary
calculation of a list of sha1 hashes for big files.
With this patch, the time 'hg update' takes to complete is a function of
how many largefiles need to be updated and what their size is.
Performance tests on a repository with about 80 largefiles ranging from
a few MB to about 97 MB are shown below. The tests show how long it takes
to run 'hg update' with no changes actually being updated.
Mercurial 2.1 release:
$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
getting changed largefiles
0 largefiles updated, 0 removed
real 0m10.045s
user 0m9.367s
sys 0m0.674s
With this patch:
$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
real 0m0.965s
user 0m0.845s
sys 0m0.115s
The same repsoitory, without the largefiles extension enabled:
$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
real 0m0.799s
user 0m0.684s
sys 0m0.111s
So before the patch, 'hg update' with no changes was approximately 9.25s
slower with largefiles enabled. With this patch, it is approximately 0.165s
slower.
author | Na'Tosha Bard <natosha@unity3d.com> |
---|---|
date | Mon, 13 Feb 2012 18:37:07 +0100 |
parents | db0340f4b507 |
children | f2719b387380 |
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$ "$TESTDIR/hghave" execbit || exit 80 $ umask 027 $ hg init test1 $ cd test1 $ touch a b $ hg add a b $ hg ci -m "added a b" $ cd .. $ hg clone test1 test3 updating to branch default 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg init test2 $ cd test2 $ hg pull ../test1 pulling from ../test1 requesting all changes adding changesets adding manifests adding file changes added 1 changesets with 2 changes to 2 files (run 'hg update' to get a working copy) $ hg co 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ chmod +x a $ hg ci -m "chmod +x a" the changelog should mention file a: $ hg tip --template '{files}\n' a $ cd ../test1 $ echo 123 >>a $ hg ci -m "a updated" $ hg pull ../test2 pulling from ../test2 searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg heads changeset: 2:7f4313b42a34 tag: tip parent: 0:22a449e20da5 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: chmod +x a changeset: 1:c6ecefc45368 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: a updated $ hg history changeset: 2:7f4313b42a34 tag: tip parent: 0:22a449e20da5 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: chmod +x a changeset: 1:c6ecefc45368 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: a updated changeset: 0:22a449e20da5 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: added a b $ hg -v merge resolving manifests 0 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cd ../test3 $ echo 123 >>b $ hg ci -m "b updated" $ hg pull ../test2 pulling from ../test2 searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg heads changeset: 2:7f4313b42a34 tag: tip parent: 0:22a449e20da5 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: chmod +x a changeset: 1:dc57ead75f79 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: b updated $ hg history changeset: 2:7f4313b42a34 tag: tip parent: 0:22a449e20da5 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: chmod +x a changeset: 1:dc57ead75f79 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: b updated changeset: 0:22a449e20da5 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: added a b $ hg -v merge resolving manifests 0 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ ls -l ../test[123]/a > foo $ cut -b 1-10 < foo -rwxr-x--- -rwxr-x--- -rwxr-x--- $ hg debugindex a rev offset length base linkrev nodeid p1 p2 0 0 0 0 0 b80de5d13875 000000000000 000000000000 $ hg debugindex -R ../test2 a rev offset length base linkrev nodeid p1 p2 0 0 0 0 0 b80de5d13875 000000000000 000000000000 $ hg debugindex -R ../test1 a rev offset length base linkrev nodeid p1 p2 0 0 0 0 0 b80de5d13875 000000000000 000000000000 1 0 5 1 1 7fe919cc0336 b80de5d13875 000000000000