comparison mercurial/localrepo.py @ 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

        if ui.configbool(b'format', b'usefncache'):
            requirements.add(b'fncache')
            if ui.configbool(b'format', b'dotencode'):
                requirements.add(b'dotencode')

    compengine = ui.config(b'format', b'revlog-compression')
    if compengine not in util.compengines:
        raise error.Abort(
            _(
                b'compression engine %s defined by '
                b'format.revlog-compression not available'
            )
            % compengine,
            hint=_(
                b'run "hg debuginstall" to list available '
                b'compression engines'
            ),
        )

    # zlib is the historical default and doesn't need an explicit requirement.
    elif compengine == b'zstd':
        requirements.add(b'revlog-compression-zstd')
    elif compengine != b'zlib':
        requirements.add(b'exp-compression-%s' % compengine)

    if scmutil.gdinitconfig(ui):

44382:f0027a3dd7cb

        if ui.configbool(b'format', b'usefncache'):
            requirements.add(b'fncache')
            if ui.configbool(b'format', b'dotencode'):
                requirements.add(b'dotencode')

    compengines = ui.configlist(b'format', b'revlog-compression')
    for compengine in compengines:
        if compengine in util.compengines:
            break
    else:
        raise error.Abort(
            _(
                b'compression engines %s defined by '
                b'format.revlog-compression not available'
            )
            % b', '.join(b'"%s"' % e for e in compengines),
            hint=_(
                b'run "hg debuginstall" to list available '
                b'compression engines'
            ),
        )

    # zlib is the historical default and doesn't need an explicit requirement.
    if compengine == b'zstd':
        requirements.add(b'revlog-compression-zstd')
    elif compengine != b'zlib':
        requirements.add(b'exp-compression-%s' % compengine)

    if scmutil.gdinitconfig(ui):