view tests/test-histedit-outgoing.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.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > EOF

  $ initrepos ()
  > {
  >     hg init r
  >     cd r
  >     for x in a b c ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  >     cd ..
  >     hg clone r r2 | grep -v updating
  >     cd r2
  >     for x in d e f ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  >     cd ..
  >     hg init r3
  >     cd r3
  >     for x in g h i ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  >     cd ..
  > }

  $ initrepos
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

show the edit commands offered by outgoing
  $ cd r2
  $ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
  pick 055a42cdd887 3 d
  pick e860deea161a 4 e
  pick 652413bf663e 5 f
  
  # Edit history between 055a42cdd887 and 652413bf663e
  #
  # Commits are listed from least to most recent
  #
  # You can reorder changesets by reordering the lines
  #
  # Commands:
  #
  #  e, edit = use commit, but stop for amending
  #  m, mess = edit commit message without changing commit content
  #  p, pick = use commit
  #  d, drop = remove commit from history
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description
  #
  $ cd ..

show the error from unrelated repos
  $ cd r3
  $ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
  abort: repository is unrelated
  [1]
  $ cd ..

show the error from unrelated repos
  $ cd r3
  $ HGEDITOR=cat hg histedit --force --outgoing ../r
  comparing with ../r
  searching for changes
  warning: repository is unrelated
  pick 2a4042b45417 0 g
  pick 68c46b4927ce 1 h
  pick 51281e65ba79 2 i
  
  # Edit history between 2a4042b45417 and 51281e65ba79
  #
  # Commits are listed from least to most recent
  #
  # You can reorder changesets by reordering the lines
  #
  # Commands:
  #
  #  e, edit = use commit, but stop for amending
  #  m, mess = edit commit message without changing commit content
  #  p, pick = use commit
  #  d, drop = remove commit from history
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description
  #
  $ cd ..

test sensitivity to branch in URL:

  $ cd r2
  $ hg -q update 2
  $ hg -q branch foo
  $ hg commit -m 'create foo branch'
  $ HGEDITOR=cat hg histedit --outgoing '../r#foo' | grep -v comparing | grep -v searching
  pick f26599ee3441 6 create foo branch
  
  # Edit history between f26599ee3441 and f26599ee3441
  #
  # Commits are listed from least to most recent
  #
  # You can reorder changesets by reordering the lines
  #
  # Commands:
  #
  #  e, edit = use commit, but stop for amending
  #  m, mess = edit commit message without changing commit content
  #  p, pick = use commit
  #  d, drop = remove commit from history
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description
  #

test to check number of roots in outgoing revisions

  $ hg -q outgoing -G --template '{node|short}({branch})' '../r'
  @  f26599ee3441(foo)
  
  o  652413bf663e(default)
  |
  o  e860deea161a(default)
  |
  o  055a42cdd887(default)
  
  $ HGEDITOR=cat hg -q histedit --outgoing '../r'
  abort: there are ambiguous outgoing revisions
  (see 'hg help histedit' for more detail)
  [255]

  $ hg -q update -C 2
  $ echo aa >> a
  $ hg -q commit -m 'another head on default'
  $ hg -q outgoing -G --template '{node|short}({branch})' '../r#default'
  @  3879dc049647(default)
  
  o  652413bf663e(default)
  |
  o  e860deea161a(default)
  |
  o  055a42cdd887(default)
  
  $ HGEDITOR=cat hg -q histedit --outgoing '../r#default'
  abort: there are ambiguous outgoing revisions
  (see 'hg help histedit' for more detail)
  [255]

  $ cd ..