In order to support ByteOrderedPartitioner, we need to implement the
missing describe_ownership and midpoint function in
byte_ordered_partitioner class.
As a starter, this path uses a simple node token distance based method
to calculate ownership. C* uses a complicated key samples based method.
We can switch to what C* does later.
Tests are added to tests/partitioner_test.cc.
Fixes#1378
Make sharding partitioner-specific, since different partitioners interpret
the byte content differently.
Implement it by extracting the shard from the most significant bits, which
can be used to minimize cross shard traffic for range queries, and reduces
sstable sharing.
Some of the tests in DTEST take advantage of the fact that
ByteOrderedPartitioner guarantees certain ordering of partition keys.
Signed-off-by: Paweł Dziepak <pdziepak@cloudius-systems.com>
