view tests/test-revlog-v2.t @ 35237:8df8ce2cc5dd

remotenames: add functionality to store remotenames under .hg/hgremotenames/

This patch moves the functionality from remotenames extension to store
remotenames to core.

Storage format used by remotenames extension:

A single file `.hg/remotenames` with an entry in each line where each line is of
format:
`node nametype remotepath/name`
where nametype is either 'bookmarks' or 'branches'.

This was not the best way to store data, so while moving to core the storage
format was changed but yet not the final format. The storage format used by core
after this patch will be:

* A file for each type of name i.e. bookmarks and branches in .hg/remotenames/
  directory
* A version number on the top of the file. The version for current format is 0.
* An entry in each line where each line is of the format
`node\0remotepath\0name`

The logic to sync with existing remotenames file and saving journals and other
related things will be moved to core in next patches incrementally.

Thanks to Ryan, Augie and Durham for suggestions on storage format.

Previously reviewed as D939.

Differential Revision: https://phab.mercurial-scm.org/D1548

A repo with unknown revlogv2 requirement string cannot be opened

  $ hg init invalidreq
  $ cd invalidreq
  $ echo exp-revlogv2.unknown >> .hg/requires
  $ hg log
  abort: repository requires features unknown to this Mercurial: exp-revlogv2.unknown!
  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
  [255]
  $ cd ..

Can create and open repo with revlog v2 requirement

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > revlogv2 = enable-unstable-format-and-corrupt-my-data
  > EOF

  $ hg init empty-repo
  $ cd empty-repo
  $ cat .hg/requires
  dotencode
  exp-revlogv2.0
  fncache
  store

  $ hg log

Unknown flags to revlog are rejected

  >>> with open('.hg/store/00changelog.i', 'wb') as fh:
  ...     fh.write('\x00\x04\xde\xad')

  $ hg log
  abort: unknown flags (0x04) in version 57005 revlog 00changelog.i!
  [255]

  $ cd ..

Writing a simple revlog v2 works

  $ hg init simple
  $ cd simple
  $ touch foo
  $ hg -q commit -A -m initial

  $ hg log
  changeset:   0:96ee1d7354c4
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     initial
  
Header written as expected (changelog always disables generaldelta)

  $ f --hexdump --bytes 4 .hg/store/00changelog.i
  .hg/store/00changelog.i:
  0000: 00 01 de ad                                     |....|

  $ f --hexdump --bytes 4 .hg/store/data/foo.i
  .hg/store/data/foo.i:
  0000: 00 03 de ad                                     |....|