annotate tests/test-journal-share.t @ 30435:b86a448a2965

zstd: vendor python-zstandard 0.5.0

As the commit message for the previous changeset says, we wish
for zstd to be a 1st class citizen in Mercurial. To make that
happen, we need to enable Python to talk to the zstd C API. And
that requires bindings.

This commit vendors a copy of existing Python bindings. Why do we
need to vendor? As the commit message of the previous commit says,
relying on systems in the wild to have the bindings or zstd present
is a losing proposition. By distributing the zstd and bindings with
Mercurial, we significantly increase our chances that zstd will
work. Since zstd will deliver a better end-user experience by
achieving better performance, this benefits our users. Another
reason is that the Python bindings still aren't stable and the
API is somewhat fluid. While Mercurial could be coded to target
multiple versions of the Python bindings, it is safer to bundle
an explicit, known working version.

The added Python bindings are mostly a fully-featured interface
to the zstd C API. They allow one-shot operations, streaming,
reading and writing from objects implements the file object
protocol, dictionary compression, control over low-level compression
parameters, and more. The Python bindings work on Python 2.6,
2.7, and 3.3+ and have been tested on Linux and Windows. There are
CFFI bindings, but they are lacking compared to the C extension.
Upstream work will be needed before we can support zstd with PyPy.
But it will be possible.

The files added in this commit come from Git commit
e637c1b214d5f869cf8116c550dcae23ec13b677 from
https://github.com/indygreg/python-zstandard and are added without
modifications. Some files from the upstream repository have been
omitted, namely files related to continuous integration.

In the spirit of full disclosure, I'm the maintainer of the
"python-zstandard" project and have authored 100% of the code
added in this commit. Unfortunately, the Python bindings have
not been formally code reviewed by anyone. While I've tested
much of the code thoroughly (I even have tests that fuzz APIs),
there's a good chance there are bugs, memory leaks, not well
thought out APIs, etc. If someone wants to review the code and
send feedback to the GitHub project, it would be greatly
appreciated.

Despite my involvement with both projects, my opinions of code
style differ from Mercurial's. The code in this commit introduces
numerous code style violations in Mercurial's linters. So, the code
is excluded from most lints. However, some violations I agree with.
These have been added to the known violations ignore list for now.

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:
  0fd3805711f9  .         commit -Am file0-added
  0fd3805711f9  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:
  0fd3805711f9  .         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:
  0fd3805711f9  .         share --bookmarks repo shared2
  0fd3805711f9  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:
  0fd3805711f9  .         share repo shared1
  $ cd ../shared2
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  4f354088b094  bm        commit -Am file1-added
  0fd3805711f9  .         share --bookmarks repo shared2
  0fd3805711f9  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:
  0fd3805711f9  .         up 0
  4f354088b094  .         commit -Am file1-added
  4f354088b094  bm        commit -Am file1-added
  0fd3805711f9  .         commit -Am file0-added
  0fd3805711f9  bm        commit -Am file0-added
  $ cd ../shared2
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  4f354088b094  bm        commit -Am file1-added
  0fd3805711f9  .         share --bookmarks repo shared2
  0fd3805711f9  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 '.':
  0fd3805711f9  up 0
  4f354088b094  up tip
  0fd3805711f9  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:
  0fd3805711f9  .         share repo shared1
  $ cd ../shared2
  $ hg unshare
  $ hg journal --all
  previous locations of the working copy and bookmarks:
  0fd3805711f9  .         up 0
  4f354088b094  .         up tip
  4f354088b094  bm        commit -Am file1-added
  0fd3805711f9  .         share --bookmarks repo shared2
  0fd3805711f9  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':
  4f354088b094  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':
  4f354088b094  bookmark shared2bm -r tip
  $ cd ../repo
  $ hg journal shared2bm
  previous locations of 'shared2bm':
  no recorded locations