view tests/test-convert-hg-startrev.t @ 31793:69d8fcf20014

help: document bundle specifications

I softly formalized the concept of a "bundle specification" a while
ago when I was working on clone bundles and stream clone bundles and
wanted a more robust way to define what exactly is in a bundle file.

The concept has existed for a while. Since it is part of the clone
bundles feature and exposed to the user via the "-t" argument to
`hg bundle`, it is something we need to support for the long haul.

After the 4.1 release, I heard a few people comment that they didn't
realize you could generate zstd bundles with `hg bundle`. I'm
partially to blame for not documenting it in bundle's docstring.

Additionally, I added a hacky, experimental feature for controlling
the compression level of bundles in 76104a4899ad. As the commit
message says, I went with a quick and dirty solution out of time
constraints. Furthermore, I wanted to eventually store this
configuration in the "bundlespec" so it could be made more flexible.

Given:

a) bundlespecs are here to stay
b) we don't have great documentation over what they are, despite being
   a user-facing feature
c) the list of available compression engines and their behavior isn't
   exposed
d) we need an extensible place to modify behavior of compression
   engines

I want to move forward with formalizing bundlespecs as a user-facing
feature. This commit does that by introducing a "bundlespec" help
page. Leaning on the just-added compression engine documentation
and API, the topic also conveniently lists available compression
engines and details about them. This makes features like zstd
bundle compression more discoverable. e.g. you can now
`hg help -k zstd` and it lists the "bundlespec" topic.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert =
  > [convert]
  > hg.saverev = yes
  > EOF

  $ glog()
  > {
  >     hg -R "$1" log -G --template '{rev} "{desc}" files: {files}\n'
  > }

  $ hg init source
  $ cd source

  $ echo a > a
  $ echo b > b
  $ echo f > f
  $ hg ci -d '0 0' -qAm '0: add a b f'
  $ echo c > c
  $ hg move f d
  $ hg ci -d '1 0' -qAm '1: add c, move f to d'
  $ hg copy a e
  $ echo b >> b
  $ hg ci -d '2 0' -qAm '2: copy e from a, change b'
  $ hg up -C 0
  2 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ echo a >> a
  $ hg ci -d '3 0' -qAm '3: change a'
  $ hg merge
  merging a and e to e
  3 files updated, 1 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -d '4 0' -qAm '4: merge 2 and 3'
  $ echo a >> a
  $ hg ci -d '5 0' -qAm '5: change a'
  $ cd ..

Convert from null revision

  $ hg convert --config convert.hg.startrev=null source full
  initializing destination full repository
  scanning source...
  sorting...
  converting...
  5 0: add a b f
  4 1: add c, move f to d
  3 2: copy e from a, change b
  2 3: change a
  1 4: merge 2 and 3
  0 5: change a

  $ glog full
  o  5 "5: change a" files: a
  |
  o    4 "4: merge 2 and 3" files: e f
  |\
  | o  3 "3: change a" files: a
  | |
  o |  2 "2: copy e from a, change b" files: b e
  | |
  o |  1 "1: add c, move f to d" files: c d f
  |/
  o  0 "0: add a b f" files: a b f
  
  $ rm -Rf full

Convert from zero revision

  $ hg convert --config convert.hg.startrev=0 source full
  initializing destination full repository
  scanning source...
  sorting...
  converting...
  5 0: add a b f
  4 1: add c, move f to d
  3 2: copy e from a, change b
  2 3: change a
  1 4: merge 2 and 3
  0 5: change a

  $ glog full
  o  5 "5: change a" files: a
  |
  o    4 "4: merge 2 and 3" files: e f
  |\
  | o  3 "3: change a" files: a
  | |
  o |  2 "2: copy e from a, change b" files: b e
  | |
  o |  1 "1: add c, move f to d" files: c d f
  |/
  o  0 "0: add a b f" files: a b f
  
Convert from merge parent

  $ hg convert --config convert.hg.startrev=1 source conv1
  initializing destination conv1 repository
  scanning source...
  sorting...
  converting...
  3 1: add c, move f to d
  2 2: copy e from a, change b
  1 4: merge 2 and 3
  0 5: change a

  $ glog conv1
  o  3 "5: change a" files: a
  |
  o  2 "4: merge 2 and 3" files: a e
  |
  o  1 "2: copy e from a, change b" files: b e
  |
  o  0 "1: add c, move f to d" files: a b c d
  
  $ cd conv1
  $ hg up -q

Check copy preservation

  $ hg st -C --change 2 e
  M e
  $ hg st -C --change 1 e
  A e
    a
  $ hg st -C --change 0 a
  A a

(It seems like a bug in log that the following doesn't show rev 1.)

  $ hg log --follow --copies e
  changeset:   2:82bbac3d2cf4
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     4: merge 2 and 3
  
  changeset:   0:23c3be426dce
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     1: add c, move f to d
  
Check copy removal on missing parent

  $ hg log --follow --copies d
  changeset:   0:23c3be426dce
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     1: add c, move f to d
  
  $ hg cat -r tip a b
  a
  a
  a
  b
  b
  $ hg -q verify
  $ cd ..

Convert from merge

  $ hg convert --config convert.hg.startrev=4 source conv4
  initializing destination conv4 repository
  scanning source...
  sorting...
  converting...
  1 4: merge 2 and 3
  0 5: change a
  $ glog conv4
  o  1 "5: change a" files: a
  |
  o  0 "4: merge 2 and 3" files: a b c d e
  
  $ cd conv4
  $ hg up -C
  5 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg cat -r tip a b
  a
  a
  a
  b
  b
  $ hg -q verify
  $ cd ..

Convert from revset in convert.hg.revs

  $ hg convert --config convert.hg.revs='3:4+0' source revsetrepo
  initializing destination revsetrepo repository
  scanning source...
  sorting...
  converting...
  2 0: add a b f
  1 3: change a
  0 4: merge 2 and 3

  $ glog revsetrepo
  o  2 "4: merge 2 and 3" files: b c d e f
  |
  o  1 "3: change a" files: a
  |
  o  0 "0: add a b f" files: a b f
  
Convert from specified revs

  $ hg convert --rev 3 --rev 2 source multiplerevs
  initializing destination multiplerevs repository
  scanning source...
  sorting...
  converting...
  3 0: add a b f
  2 1: add c, move f to d
  1 2: copy e from a, change b
  0 3: change a
  $ glog multiplerevs
  o  3 "3: change a" files: a
  |
  | o  2 "2: copy e from a, change b" files: b e
  | |
  | o  1 "1: add c, move f to d" files: c d f
  |/
  o  0 "0: add a b f" files: a b f
  
Convert in multiple steps that doesn't overlap - the link to the parent is
preserved anyway

  $ hg convert --config convert.hg.revs=::1 source multistep
  initializing destination multistep repository
  scanning source...
  sorting...
  converting...
  1 0: add a b f
  0 1: add c, move f to d
  $ hg convert --config convert.hg.revs=2 source multistep
  scanning source...
  sorting...
  converting...
  0 2: copy e from a, change b
  $ glog multistep
  o  2 "2: copy e from a, change b" files: b e
  |
  o  1 "1: add c, move f to d" files: c d f
  |
  o  0 "0: add a b f" files: a b f