pub const SNAPSHOT_FORMAT_VERSION: u16 = 0;Expand description
Format version at the head of every snapshot file.
Part of the 1.x on-disk contract: a 1.x broker reads every snapshot that
any earlier 1.x broker wrote, so a change to the layout bumps this version
and keeps a decoder arm for every earlier 1.x version. See
docs/persisted_formats.md.