annotate tests/test-pull-r.t @ 30212:260af19891f2

changegroup: increase write buffer size to 128k

By default, Python defers to the operating system for choosing the
default buffer size on opened files. On my Linux machine, the default
is 4k, which is really small for 2016.

This patch bumps the write buffer size when writing
changegroups/bundles to 128k. This matches the 128k read buffer
we already use on revlogs.

It's worth noting that this only impacts when writing to an explicit
file (such as during `hg bundle`). Buffers when writing to bundle
files via the repo vfs or to a temporary file are not impacted.

When producing a none-v2 bundle file of the mozilla-unified repository,
this change caused the number of write() system calls to drop from
952,449 to 29,788. After this change, the most frequent system
calls are fstat(), read(), lseek(), and open(). There were
2,523,672 system calls after this patch (so a net decrease of
~950k is statistically significant).

This change shows no performance change on my system. But I have a
high-end system with a fast SSD. It is quite possible this change
will have a significant impact on network file systems, where
extra network round trips due to excessive I/O system calls could
introduce significant latency.

  $ 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
  (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)
  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 ..