comparison tests/test-repo-compengines.t @ 44382:f0027a3dd7cb

revlog-compression: update the config to be a list

format.revlog-compression is now a list of engine, the first supported one is to
be used. Doing this have several benefits:

1) this is fully backward compatible, config using a single entry will be read
as a single item list, not changing any behavior.

2) This open the way to use zstd by default without impacting platform were it
is not available. This will be done in a later changesets.

Using zstd provide a significant performance boost explained in : bb271ec2fbfb.
However zstd is not available in some cases, A notable example is the `--pure`
version of Mercurial which doesn't come with zstd support.

Differential Revision: https://phab.mercurial-scm.org/D8148

44381:454bc51f114c

  $ cd ..

Unknown compression engine to format.compression aborts

  $ hg --config format.revlog-compression=unknown init unknown
  abort: compression engine unknown defined by format.revlog-compression not available
  (run "hg debuginstall" to list available compression engines)
  [255]

A requirement specifying an unknown compression engine results in bail

  $ hg init unknownrequirement
  $ cd unknownrequirement

44382:f0027a3dd7cb

  $ cd ..

Unknown compression engine to format.compression aborts

  $ hg --config format.revlog-compression=unknown init unknown
  abort: compression engines "unknown" defined by format.revlog-compression not available
  (run "hg debuginstall" to list available compression engines)
  [255]

unknown compression engine in a list with known one works fine

  $ hg --config format.revlog-compression=zlib,unknown init zlib-before-unknow
  $ hg --config format.revlog-compression=unknown,zlib init unknown-before-zlib

A requirement specifying an unknown compression engine results in bail

  $ hg init unknownrequirement
  $ cd unknownrequirement