view tests/test-journal-share.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.

Journal extension test: tests the share extension support

  $ cat >> testmocks.py << EOF
  > # mock out util.getuser() and util.makedate() to supply testable values
  > import os
  > from mercurial import util
  > def mockgetuser():
  >     return 'foobar'
  > 
  > def mockmakedate():
  >     filename = os.path.join(os.environ['TESTTMP'], 'testtime')
  >     try:
  >         with open(filename, 'rb') as timef:
  >             time = float(timef.read()) + 1
  >     except IOError:
  >         time = 0.0
  >     with open(filename, 'wb') as timef:
  >         timef.write(str(time))
  >     return (time, 0)
  > 
  > util.getuser = mockgetuser
  > util.makedate = mockmakedate
  > EOF

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > journal=
  > share=
  > testmocks=`pwd`/testmocks.py
  > [remotenames]
  > rename.default=remote
  > EOF

  $ hg init repo
  $ cd repo
  $ hg bookmark bm
  $ touch file0
  $ hg commit -Am 'file0 added'
  adding file0
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  5640b525682e  .         commit -Am 'file0 added'
  5640b525682e  bm        commit -Am 'file0 added'

A shared working copy initially receives the same bookmarks and working copy

  $ cd ..
  $ hg share repo shared1
  updating working directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd shared1
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  5640b525682e  .         share repo shared1

unless you explicitly share bookmarks

  $ cd ..
  $ hg share --bookmarks repo shared2
  updating working directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd shared2
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  5640b525682e  .         share --bookmarks repo shared2
  5640b525682e  bm        commit -Am 'file0 added'

Moving the bookmark in the original repository is only shown in the repository
that shares bookmarks

  $ cd ../repo
  $ touch file1
  $ hg commit -Am "file1 added"
  adding file1
  $ cd ../shared1
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  5640b525682e  .         share repo shared1
  $ cd ../shared2
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  6432d239ac5d  bm        commit -Am 'file1 added'
  5640b525682e  .         share --bookmarks repo shared2
  5640b525682e  bm        commit -Am 'file0 added'

But working copy changes are always 'local'

  $ cd ../repo
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (leaving bookmark bm)
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  5640b525682e  .         up 0
  6432d239ac5d  .         commit -Am 'file1 added'
  6432d239ac5d  bm        commit -Am 'file1 added'
  5640b525682e  .         commit -Am 'file0 added'
  5640b525682e  bm        commit -Am 'file0 added'
  $ cd ../shared2
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  6432d239ac5d  bm        commit -Am 'file1 added'
  5640b525682e  .         share --bookmarks repo shared2
  5640b525682e  bm        commit -Am 'file0 added'
  $ hg up tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg journal
  previous locations of '.':
  5640b525682e  up 0
  6432d239ac5d  up tip
  5640b525682e  share --bookmarks repo shared2

Unsharing works as expected; the journal remains consistent

  $ cd ../shared1
  $ hg unshare
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  5640b525682e  .         share repo shared1
  $ cd ../shared2
  $ hg unshare
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  5640b525682e  .         up 0
  6432d239ac5d  .         up tip
  6432d239ac5d  bm        commit -Am 'file1 added'
  5640b525682e  .         share --bookmarks repo shared2
  5640b525682e  bm        commit -Am 'file0 added'

New journal entries in the source repo no longer show up in the other working copies

  $ cd ../repo
  $ hg bookmark newbm -r tip
  $ hg journal newbm
  previous locations of 'newbm':
  6432d239ac5d  bookmark newbm -r tip
  $ cd ../shared2
  $ hg journal newbm
  previous locations of 'newbm':
  no recorded locations

This applies for both directions

  $ hg bookmark shared2bm -r tip
  $ hg journal shared2bm
  previous locations of 'shared2bm':
  6432d239ac5d  bookmark shared2bm -r tip
  $ cd ../repo
  $ hg journal shared2bm
  previous locations of 'shared2bm':
  no recorded locations