bundle2: avoid unbound read when seeking
Currently, seekableunbundlepart.seek() will perform a read() during
seek operations. This will allocate a buffer to hold the raw data
over the seek distance. This can lead to very large allocations
and cause performance to suffer.
We change the code to perform read(32768) in a loop to avoid
potentially large allocations.
`hg perfbundleread` on an uncompressed Firefox bundle reveals
a performance impact:
! bundle2 iterparts()
! wall 2.992605 comb 2.990000 user 2.260000 sys 0.730000 (best of 4)
! bundle2 iterparts() seekable
! wall 3.863810 comb 3.860000 user 3.000000 sys 0.860000 (best of 3)
! bundle2 part seek()
! wall 6.213387 comb 6.200000 user 3.350000 sys 2.850000 (best of 3)
! wall 3.820347 comb 3.810000 user 2.980000 sys 0.830000 (best of 3)
Since seekable bundle parts are (only) used by bundlerepo, this /may/
speed up initial loading of bundle-based repos. But any improvement
will likely only be noticed on very large bundles.
Differential Revision: https://phab.mercurial-scm.org/D1394
$ hg init repo
$ cd repo
$ echo foo > foo
$ hg ci -qAm 'add foo'
$ echo >> foo
$ hg ci -m 'change foo'
$ hg up -qC 0
$ echo bar > bar
$ hg ci -qAm 'add bar'
$ hg log
changeset: 2:effea6de0384
tag: tip
parent: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add bar
changeset: 1:ed1b79f46b9a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: change foo
changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ cd ..
don't show "(+1 heads)" message when pulling closed head
$ hg clone -q repo repo2
$ hg clone -q repo2 repo3
$ cd repo2
$ hg up -q 0
$ echo hello >> foo
$ hg ci -mx1
created new head
$ hg ci -mx2 --close-branch
$ cd ../repo3
$ hg heads -q --closed
2:effea6de0384
1:ed1b79f46b9a
$ hg pull
pulling from $TESTTMP/repo2 (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files
new changesets 8c900227dd5d:00cfe9073916
(run 'hg update' to get a working copy)
$ hg heads -q --closed
4:00cfe9073916
2:effea6de0384
1:ed1b79f46b9a
$ cd ..
$ hg init copy
$ cd copy
Pull a missing revision:
$ hg pull -qr missing ../repo
abort: unknown revision 'missing'!
[255]
Pull multiple revisions with update:
$ hg pull -qu -r 0 -r 1 ../repo
$ hg -q parents
0:bbd179dfa0a7
$ hg rollback
repository tip rolled back to revision -1 (undo pull)
working directory now based on revision -1
$ hg pull -qr 0 ../repo
$ hg log
changeset: 0:bbd179dfa0a7
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ hg pull -qr 1 ../repo
$ hg log
changeset: 1:ed1b79f46b9a
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: change foo
changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
This used to abort: received changelog group is empty:
$ hg pull -qr 1 ../repo
Test race condition with -r and -U (issue4707)
We pull '-U -r <name>' and the name change right after/during the changegroup emission.
We use http because http is better is our racy-est option.
$ echo babar > ../repo/jungle
$ cat <<EOF > ../repo/.hg/hgrc
> [hooks]
> outgoing.makecommit = hg ci -Am 'racy commit'; echo committed in pull-race
> EOF
$ hg serve -R ../repo -p $HGPORT2 -d --pid-file=../repo.pid
$ cat ../repo.pid >> $DAEMON_PIDS
$ hg pull --rev default --update http://localhost:$HGPORT2/
pulling from http://localhost:$HGPORT2/
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets effea6de0384
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log -G
@ changeset: 2:effea6de0384
| tag: tip
| parent: 0:bbd179dfa0a7
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: add bar
|
| o changeset: 1:ed1b79f46b9a
|/ user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: change foo
|
o changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ cd ..