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
Deserialisation function returns a structure containing both the value
and its length in the input buffer. In the vast majority of the cases
the caller will already know the length and having this structure will
make it harder for the compiler to emit good code, especially if the
function is not inlined.
In practice I've seen the structure causing register pressure problems
that lead to spilling variables to memory.
This method takes first byte and determins how many bytes
are used to represent an unsigned variant integer.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Version 5 of the native protocol for CQL [1] adds the `vint` and `unsigned vint`
types.
An unsigned integer encoded as a `vint` has a variable size based on the
magnitude of the value. The first byte indicates the total number of bytes.
For signed integers, a "zig-zag" encoding scheme ensures that small negative
values are encoded as short-length `vint`s (0 -> 0, -1 -> 1, 1 -> 2, 2 -> 3, -2
-> 4, etc).
[1] https://github.com/apache/cassandra/blob/trunk/doc/native_protocol_v5.spec
