view tests/test-convert-tla.t @ 38486:4c0683655599

namespaces: let namespaces override singlenode() definition

Some namespaces have multiple nodes per name (meaning that their
namemap() returns multiple nodes). One such namespace is the "topics"
namespace (from the evolve repo). We also have our own internal
namespace at Google (for review units) that has multiple nodes per
name. These namespaces may not want to use the default "pick highest
revnum" resolution that we currently use when resolving a name to a
single node. As an example, they may decide that `hg co <name>` should
check out a commit that's last in some sense even if an earlier commit
had just been amended and thus had a higher revnum [1]. This patch
gives the namespace the option to continue to return multiple nodes
and to override how the best node is picked. Allowing namespaces to
override that may also be useful as an optimization (it may be cheaper
for the namespace to find just that node).

I have been arguing (in D3715) for using all the nodes returned from
namemap() when resolving the symbol to a revset, so e.g. `hg log -r
stable` would resolve to *all* nodes on stable, not just the one with
the highest revnum (except that I don't actually think we should
change it for the branch namespace because of BC). Most people seem
opposed to that. If we decide not to do it, I think we can deprecate
the namemap() function in favor of the new singlenode() (I find it
weird to have namespaces, like the branch namespace, where namemap()
isn't nodemap()'s inverse). I therefore think this patch makes sense
regardless of what we decide on that issue.


 [1] Actually, even the branch namespace would have wanted to override
     singlenode() if it had supported multiple nodes. That's because
     closes branch heads are mostly ignored, so "hg co default" will
     not check out the highest-revnum node if that's a closed head.

Differential Revision: https://phab.mercurial-scm.org/D3852

#require tla symlink

  $ tla my-id "mercurial <[e-mail]>"
  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert=" >> $HGRCPATH

create tla archive

  $ tla make-archive tla@mercurial--convert `pwd`/hg-test-convert-tla

initialize tla repo

  $ mkdir tla-repo
  $ cd tla-repo/
  $ tla init-tree tla@mercurial--convert/tla--test--0
  $ tla import
  * creating version tla@mercurial--convert/tla--test--0
  * imported tla@mercurial--convert/tla--test--0

create initial files

  $ echo 'this is a file' > a
  $ tla add a
  $ mkdir src
  $ tla add src
  $ cd src
  $ dd count=1 if=/dev/zero of=b > /dev/null 2> /dev/null
  $ tla add b
  $ tla commit -s "added a file, src and src/b (binary)"
  A/ .arch-ids
  A/ src
  A/ src/.arch-ids
  A  .arch-ids/a.id
  A  a
  A  src/.arch-ids/=id
  A  src/.arch-ids/b.id
  A  src/b
  * update pristine tree (tla@mercurial--convert/tla--test--0--base-0 => tla--test--0--patch-1)
  * committed tla@mercurial--convert/tla--test--0--patch-1

create link file and modify a

  $ ln -s ../a a-link
  $ tla add a-link
  $ echo 'this a modification to a' >> ../a
  $ tla commit -s "added link to a and modify a"
  A  src/.arch-ids/a-link.id
  A  src/a-link
  M  a
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-1 => tla--test--0--patch-2)
  * committed tla@mercurial--convert/tla--test--0--patch-2

create second link and modify b

  $ ln -s ../a a-link-2
  $ tla add a-link-2
  $ dd count=1 seek=1 if=/dev/zero of=b > /dev/null 2> /dev/null
  $ tla commit -s "added second link and modify b"
  A  src/.arch-ids/a-link-2.id
  A  src/a-link-2
  Mb src/b
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-2 => tla--test--0--patch-3)
  * committed tla@mercurial--convert/tla--test--0--patch-3

b file to link and a-link-2 to regular file

  $ rm -f a-link-2
  $ echo 'this is now a regular file' > a-link-2
  $ ln -sf ../a b
  $ tla commit -s "file to link and link to file test"
  fl src/b
  lf src/a-link-2
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-3 => tla--test--0--patch-4)
  * committed tla@mercurial--convert/tla--test--0--patch-4

move a-link-2 file and src directory

  $ cd ..
  $ tla mv src/a-link-2 c
  $ tla mv src test
  $ tla commit -s "move and rename a-link-2 file and src directory"
  D/ src/.arch-ids
  A/ test/.arch-ids
  /> src	test
  => src/.arch-ids/a-link-2.id	.arch-ids/c.id
  => src/a-link-2	c
  => src/.arch-ids/=id	test/.arch-ids/=id
  => src/.arch-ids/a-link.id	test/.arch-ids/a-link.id
  => src/.arch-ids/b.id	test/.arch-ids/b.id
  * update pristine tree (tla@mercurial--convert/tla--test--0--patch-4 => tla--test--0--patch-5)
  * committed tla@mercurial--convert/tla--test--0--patch-5
  $ cd ..

converting tla repo to Mercurial

  $ hg convert tla-repo tla-repo-hg
  initializing destination tla-repo-hg repository
  analyzing tree version tla@mercurial--convert/tla--test--0...
  scanning source...
  sorting...
  converting...
  5 initial import
  4 added a file, src and src/b (binary)
  3 added link to a and modify a
  2 added second link and modify b
  1 file to link and link to file test
  0 move and rename a-link-2 file and src directory
  $ tla register-archive -d tla@mercurial--convert
  $ glog()
  > {
  >     hg log -G --template '{rev} "{desc|firstline}" files: {files}\n' "$@"
  > }

show graph log

  $ glog -R tla-repo-hg
  o  5 "move and rename a-link-2 file and src directory" files: c src/a-link src/a-link-2 src/b test/a-link test/b
  |
  o  4 "file to link and link to file test" files: src/a-link-2 src/b
  |
  o  3 "added second link and modify b" files: src/a-link-2 src/b
  |
  o  2 "added link to a and modify a" files: a src/a-link
  |
  o  1 "added a file, src and src/b (binary)" files: a src/b
  |
  o  0 "initial import" files:
  
  $ hg up -q -R tla-repo-hg
  $ hg -R tla-repo-hg manifest --debug
  c4072c4b72e1cabace081888efa148ee80ca3cbb 644   a
  0201ac32a3a8e86e303dff60366382a54b48a72e 644   c
  c0067ba5ff0b7c9a3eb17270839d04614c435623 644 @ test/a-link
  375f4263d86feacdea7e3c27100abd1560f2a973 644 @ test/b