view tests/test-hardlinks.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.

#require hardlink

  $ cat > nlinks.py <<EOF
  > import sys
  > from mercurial import util
  > for f in sorted(sys.stdin.readlines()):
  >     f = f[:-1]
  >     print util.nlinks(f), f
  > EOF

  $ nlinksdir()
  > {
  >     find $1 -type f | python $TESTTMP/nlinks.py
  > }

Some implementations of cp can't create hardlinks (replaces 'cp -al' on Linux):

  $ cat > linkcp.py <<EOF
  > from mercurial import util
  > import sys
  > util.copyfiles(sys.argv[1], sys.argv[2], hardlink=True)
  > EOF

  $ linkcp()
  > {
  >     python $TESTTMP/linkcp.py $1 $2
  > }

Prepare repo r1:

  $ hg init r1
  $ cd r1

  $ echo c1 > f1
  $ hg add f1
  $ hg ci -m0

  $ mkdir d1
  $ cd d1
  $ echo c2 > f2
  $ hg add f2
  $ hg ci -m1
  $ cd ../..

  $ nlinksdir r1/.hg/store
  1 r1/.hg/store/00changelog.i
  1 r1/.hg/store/00manifest.i
  1 r1/.hg/store/data/d1/f2.i
  1 r1/.hg/store/data/f1.i
  1 r1/.hg/store/fncache
  1 r1/.hg/store/phaseroots
  1 r1/.hg/store/undo
  1 r1/.hg/store/undo.backup.fncache
  1 r1/.hg/store/undo.backupfiles
  1 r1/.hg/store/undo.phaseroots


Create hardlinked clone r2:

  $ hg clone -U --debug r1 r2 --config progress.debug=true
  linking: 1
  linking: 2
  linking: 3
  linking: 4
  linking: 5
  linking: 6
  linking: 7
  linked 7 files

Create non-hardlinked clone r3:

  $ hg clone --pull r1 r3
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved


Repos r1 and r2 should now contain hardlinked files:

  $ nlinksdir r1/.hg/store
  2 r1/.hg/store/00changelog.i
  2 r1/.hg/store/00manifest.i
  2 r1/.hg/store/data/d1/f2.i
  2 r1/.hg/store/data/f1.i
  2 r1/.hg/store/fncache
  1 r1/.hg/store/phaseroots
  1 r1/.hg/store/undo
  1 r1/.hg/store/undo.backup.fncache
  1 r1/.hg/store/undo.backupfiles
  1 r1/.hg/store/undo.phaseroots

  $ nlinksdir r2/.hg/store
  2 r2/.hg/store/00changelog.i
  2 r2/.hg/store/00manifest.i
  2 r2/.hg/store/data/d1/f2.i
  2 r2/.hg/store/data/f1.i
  2 r2/.hg/store/fncache

Repo r3 should not be hardlinked:

  $ nlinksdir r3/.hg/store
  1 r3/.hg/store/00changelog.i
  1 r3/.hg/store/00manifest.i
  1 r3/.hg/store/data/d1/f2.i
  1 r3/.hg/store/data/f1.i
  1 r3/.hg/store/fncache
  1 r3/.hg/store/phaseroots
  1 r3/.hg/store/undo
  1 r3/.hg/store/undo.backupfiles
  1 r3/.hg/store/undo.phaseroots


Create a non-inlined filelog in r3:

  $ cd r3/d1
  >>> f = open('data1', 'wb')
  >>> for x in range(10000):
  ...     f.write("%s\n" % str(x))
  >>> f.close()
  $ for j in 0 1 2 3 4 5 6 7 8 9; do
  >   cat data1 >> f2
  >   hg commit -m$j
  > done
  $ cd ../..

  $ nlinksdir r3/.hg/store
  1 r3/.hg/store/00changelog.i
  1 r3/.hg/store/00manifest.i
  1 r3/.hg/store/data/d1/f2.d
  1 r3/.hg/store/data/d1/f2.i
  1 r3/.hg/store/data/f1.i
  1 r3/.hg/store/fncache
  1 r3/.hg/store/phaseroots
  1 r3/.hg/store/undo
  1 r3/.hg/store/undo.backup.fncache
  1 r3/.hg/store/undo.backup.phaseroots
  1 r3/.hg/store/undo.backupfiles
  1 r3/.hg/store/undo.phaseroots

Push to repo r1 should break up most hardlinks in r2:

  $ hg -R r2 verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 2 changesets, 2 total revisions

  $ cd r3
  $ hg push
  pushing to $TESTTMP/r1 (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 10 changesets with 10 changes to 1 files

  $ cd ..

  $ nlinksdir r2/.hg/store
  1 r2/.hg/store/00changelog.i
  1 r2/.hg/store/00manifest.i
  1 r2/.hg/store/data/d1/f2.i
  2 r2/.hg/store/data/f1.i
  1 r2/.hg/store/fncache

  $ hg -R r2 verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 2 changesets, 2 total revisions


  $ cd r1
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Committing a change to f1 in r1 must break up hardlink f1.i in r2:

  $ echo c1c1 >> f1
  $ hg ci -m00
  $ cd ..

  $ nlinksdir r2/.hg/store
  1 r2/.hg/store/00changelog.i
  1 r2/.hg/store/00manifest.i
  1 r2/.hg/store/data/d1/f2.i
  1 r2/.hg/store/data/f1.i
  1 r2/.hg/store/fncache


  $ cd r3
  $ hg tip --template '{rev}:{node|short}\n'
  11:a6451b6bc41f
  $ echo bla > f1
  $ hg ci -m1
  $ cd ..

Create hardlinked copy r4 of r3 (on Linux, we would call 'cp -al'):

  $ linkcp r3 r4

r4 has hardlinks in the working dir (not just inside .hg):

  $ nlinksdir r4
  2 r4/.hg/00changelog.i
  2 r4/.hg/branch
  2 r4/.hg/cache/branch2-served
  2 r4/.hg/cache/rbc-names-v1
  2 r4/.hg/cache/rbc-revs-v1
  2 r4/.hg/dirstate
  2 r4/.hg/hgrc
  2 r4/.hg/last-message.txt
  2 r4/.hg/requires
  2 r4/.hg/store/00changelog.i
  2 r4/.hg/store/00manifest.i
  2 r4/.hg/store/data/d1/f2.d
  2 r4/.hg/store/data/d1/f2.i
  2 r4/.hg/store/data/f1.i
  2 r4/.hg/store/fncache
  2 r4/.hg/store/phaseroots
  2 r4/.hg/store/undo
  2 r4/.hg/store/undo.backup.fncache
  2 r4/.hg/store/undo.backup.phaseroots
  2 r4/.hg/store/undo.backupfiles
  2 r4/.hg/store/undo.phaseroots
  2 r4/.hg/undo.backup.dirstate
  2 r4/.hg/undo.bookmarks
  2 r4/.hg/undo.branch
  2 r4/.hg/undo.desc
  2 r4/.hg/undo.dirstate
  2 r4/d1/data1
  2 r4/d1/f2
  2 r4/f1

Update back to revision 11 in r4 should break hardlink of file f1:

  $ hg -R r4 up 11
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ nlinksdir r4
  2 r4/.hg/00changelog.i
  1 r4/.hg/branch
  2 r4/.hg/cache/branch2-served
  2 r4/.hg/cache/rbc-names-v1
  2 r4/.hg/cache/rbc-revs-v1
  1 r4/.hg/dirstate
  2 r4/.hg/hgrc
  2 r4/.hg/last-message.txt
  2 r4/.hg/requires
  2 r4/.hg/store/00changelog.i
  2 r4/.hg/store/00manifest.i
  2 r4/.hg/store/data/d1/f2.d
  2 r4/.hg/store/data/d1/f2.i
  2 r4/.hg/store/data/f1.i
  2 r4/.hg/store/fncache
  2 r4/.hg/store/phaseroots
  2 r4/.hg/store/undo
  2 r4/.hg/store/undo.backup.fncache
  2 r4/.hg/store/undo.backup.phaseroots
  2 r4/.hg/store/undo.backupfiles
  2 r4/.hg/store/undo.phaseroots
  2 r4/.hg/undo.backup.dirstate
  2 r4/.hg/undo.bookmarks
  2 r4/.hg/undo.branch
  2 r4/.hg/undo.desc
  2 r4/.hg/undo.dirstate
  2 r4/d1/data1
  2 r4/d1/f2
  1 r4/f1


Test hardlinking outside hg:

  $ mkdir x
  $ echo foo > x/a

  $ linkcp x y
  $ echo bar >> y/a

No diff if hardlink:

  $ diff x/a y/a

Test mq hardlinking:

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init a
  $ cd a

  $ hg qimport -n foo - << EOF
  > # HG changeset patch
  > # Date 1 0
  > diff -r 2588a8b53d66 a
  > --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  > +++ b/a	Wed Jul 23 15:54:29 2008 +0200
  > @@ -0,0 +1,1 @@
  > +a
  > EOF
  adding foo to series file

  $ hg qpush
  applying foo
  now at: foo

  $ cd ..
  $ linkcp a b
  $ cd b

  $ hg qimport -n bar - << EOF
  > # HG changeset patch
  > # Date 2 0
  > diff -r 2588a8b53d66 a
  > --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  > +++ b/b	Wed Jul 23 15:54:29 2008 +0200
  > @@ -0,0 +1,1 @@
  > +b
  > EOF
  adding bar to series file

  $ hg qpush
  applying bar
  now at: bar

  $ cat .hg/patches/status
  430ed4828a74fa4047bc816a25500f7472ab4bfe:foo
  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c:bar

  $ cat .hg/patches/series
  foo
  bar

  $ cat ../a/.hg/patches/status
  430ed4828a74fa4047bc816a25500f7472ab4bfe:foo

  $ cat ../a/.hg/patches/series
  foo

Test tags hardlinking:

  $ hg qdel -r qbase:qtip
  patch foo finalized without changeset message
  patch bar finalized without changeset message

  $ hg tag -l lfoo
  $ hg tag foo

  $ cd ..
  $ linkcp b c
  $ cd c

  $ hg tag -l -r 0 lbar
  $ hg tag -r 0 bar

  $ cat .hgtags
  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c foo
  430ed4828a74fa4047bc816a25500f7472ab4bfe bar

  $ cat .hg/localtags
  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c lfoo
  430ed4828a74fa4047bc816a25500f7472ab4bfe lbar

  $ cat ../b/.hgtags
  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c foo

  $ cat ../b/.hg/localtags
  4e7abb4840c46a910f6d7b4d3c3fc7e5209e684c lfoo

  $ cd ..