view tests/test-bundle-type.t @ 32697:19b9fc40cc51

revlog: skeleton support for version 2 revlogs

There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.

It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.

This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.

An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.

To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.

Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.

There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.

  $ cat << EOF >> $HGRCPATH
  > [format]
  > usegeneraldelta=yes
  > EOF

bundle w/o type option

  $ hg init t1
  $ hg init t2
  $ cd t1
  $ echo blablablablabla > file.txt
  $ hg ci -Ama
  adding file.txt
  $ hg log | grep summary
  summary:     a
  $ hg bundle ../b1 ../t2
  searching for changes
  1 changesets found

  $ cd ../t2
  $ hg pull ../b1
  pulling from ../b1
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log | grep summary
  summary:     a
  $ cd ..

Unknown compression type is rejected

  $ hg init t3
  $ cd t3
  $ hg -q pull ../b1
  $ hg bundle -a -t unknown out.hg
  abort: unknown is not a recognized bundle specification
  (see 'hg help bundlespec' for supported values for --type)
  [255]

  $ hg bundle -a -t unknown-v2 out.hg
  abort: unknown compression is not supported
  (see 'hg help bundlespec' for supported values for --type)
  [255]

  $ cd ..

test bundle types

  $ testbundle() {
  >   echo % test bundle type $1
  >   hg init t$1
  >   cd t1
  >   hg bundle -t $1 ../b$1 ../t$1
  >   f -q -B6 -D ../b$1; echo
  >   cd ../t$1
  >   hg debugbundle ../b$1
  >   hg debugbundle --spec ../b$1
  >   echo
  >   cd ..
  > }

  $ for t in "None" "bzip2" "gzip" "none-v2" "v2" "v1" "gzip-v1"; do
  >   testbundle $t
  > done
  % test bundle type None
  searching for changes
  1 changesets found
  HG20\x00\x00 (esc)
  Stream params: {}
  changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
      c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  none-v2
  
  % test bundle type bzip2
  searching for changes
  1 changesets found
  HG20\x00\x00 (esc)
  Stream params: sortdict([('Compression', 'BZ')])
  changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
      c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  bzip2-v2
  
  % test bundle type gzip
  searching for changes
  1 changesets found
  HG20\x00\x00 (esc)
  Stream params: sortdict([('Compression', 'GZ')])
  changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
      c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  gzip-v2
  
  % test bundle type none-v2
  searching for changes
  1 changesets found
  HG20\x00\x00 (esc)
  Stream params: {}
  changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
      c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  none-v2
  
  % test bundle type v2
  searching for changes
  1 changesets found
  HG20\x00\x00 (esc)
  Stream params: sortdict([('Compression', 'BZ')])
  changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
      c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  bzip2-v2
  
  % test bundle type v1
  searching for changes
  1 changesets found
  HG10BZ
  c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  bzip2-v1
  
  % test bundle type gzip-v1
  searching for changes
  1 changesets found
  HG10GZ
  c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  gzip-v1
  

Compression level can be adjusted for bundle2 bundles

  $ hg init test-complevel
  $ cd test-complevel

  $ cat > file0 << EOF
  > this is a file
  > with some text
  > and some more text
  > and other content
  > EOF
  $ cat > file1 << EOF
  > this is another file
  > with some other content
  > and repeated, repeated, repeated, repeated content
  > EOF
  $ hg -q commit -A -m initial

  $ hg bundle -a -t gzip-v2 gzip-v2.hg
  1 changesets found
  $ f --size gzip-v2.hg
  gzip-v2.hg: size=427

  $ hg --config experimental.bundlecomplevel=1 bundle -a -t gzip-v2 gzip-v2-level1.hg
  1 changesets found
  $ f --size gzip-v2-level1.hg
  gzip-v2-level1.hg: size=435

  $ cd ..

#if zstd

  $ for t in "zstd" "zstd-v2"; do
  >   testbundle $t
  > done
  % test bundle type zstd
  searching for changes
  1 changesets found
  HG20\x00\x00 (esc)
  Stream params: sortdict([('Compression', 'ZS')])
  changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
      c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  zstd-v2
  
  % test bundle type zstd-v2
  searching for changes
  1 changesets found
  HG20\x00\x00 (esc)
  Stream params: sortdict([('Compression', 'ZS')])
  changegroup -- "sortdict([('version', '02'), ('nbchanges', '1')])"
      c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
  zstd-v2
  

Explicit request for zstd on non-generaldelta repos

  $ hg --config format.usegeneraldelta=false init nogd
  $ hg -q -R nogd pull t1
  $ hg -R nogd bundle -a -t zstd nogd-zstd
  1 changesets found

zstd-v1 always fails

  $ hg -R tzstd bundle -a -t zstd-v1 zstd-v1
  abort: compression engine zstd is not supported on v1 bundles
  (see 'hg help bundlespec' for supported values for --type)
  [255]

#else

zstd is a valid engine but isn't available

  $ hg -R t1 bundle -a -t zstd irrelevant.hg
  abort: compression engine zstd could not be loaded
  [255]

#endif

test garbage file

  $ echo garbage > bgarbage
  $ hg init tgarbage
  $ cd tgarbage
  $ hg pull ../bgarbage
  pulling from ../bgarbage
  abort: ../bgarbage: not a Mercurial bundle
  [255]
  $ cd ..

test invalid bundle type

  $ cd t1
  $ hg bundle -a -t garbage ../bgarbage
  abort: garbage is not a recognized bundle specification
  (see 'hg help bundlespec' for supported values for --type)
  [255]
  $ cd ..