comparison mercurial/helptext/config.txt @ 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

``revlog-compression``
    Compression algorithm used by revlog. Supported values are `zlib` and
    `zstd`. The `zlib` engine is the historical default of Mercurial. `zstd` is
    a newer format that is usually a net win over `zlib`, operating faster at
    better compression rates. Use `zstd` to reduce CPU usage.

    On some systems, the Mercurial installation may lack `zstd` support.

    Default is `zlib`.

44382:f0027a3dd7cb

``revlog-compression``
    Compression algorithm used by revlog. Supported values are `zlib` and
    `zstd`. The `zlib` engine is the historical default of Mercurial. `zstd` is
    a newer format that is usually a net win over `zlib`, operating faster at
    better compression rates. Use `zstd` to reduce CPU usage. Multiple values
    can be specified, the first available one will be used.

    On some systems, the Mercurial installation may lack `zstd` support.

    Default is `zlib`.