Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
Not necessitating these to be extracted from the sstable dir path. This
practically allows for la/mx sstables at non-standard paths to be
opened. This will be used by the `scylla-sstable` tool which wants to be
flexible about where the sstables it opens are located.
sstables/sstables.hh is one of our heaviest headers and it's better that we don't
include it if possible. For some users, like distributed_loader, we are mostly
interested in knowing the shape of structures used to open an SSTable.
They are:
- the entry_descriptor, representing an SSTable that we are scanning on-disk
- the sstable_open_info, representing information about a local, opened SSTable
- the foreign_sstable_open_info, representing information about an opened SSTable
that can cross shard boundaries.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
