Allow returning fewer random clustering keys than requested since
the schema may limit the total number we can generate, for example,
if there is only one boolean clustering column.
Fixes#5161
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
When generating data, the user can now also generate ttls and
expiry for all generated atoms. This happens in a controlled way, via a
generator functor, very similar to how the timestamps are generated.
This functor is also used by `random_schema` to generate `deletion_time`
for all tombstones, so the user now has full control of when all of the
atoms can be GC'd.
Use an internally create instance of random engine. Passing a readily
seeded engine from the outside is pointless now that we have a mechanism
to seed entire test suites with a command line algorithm: the internal
engine is seeded from tests::random, so the seed of the test suite
determines the internal seed as well.
Update the sole user of this method (mutation_writer_test.cc) to not
generate local seeds anymore.
random_schema is a utility class that provides methods for generating
random schemas as well as generating data (mutations) for them. The aim
is to make using random schemas in tests as simple and convenient as
is using `simple_schema`. For this reason the interface of
`random_schema` follows closely that of `simple_schema` to the extent
that it makes sense. An important difference is that `random_schema`
relies on `data_model` to actually build mutations. So all its
mutation-related operations work with `data_model::mutation_descrition`
instead of actual `mutation` objects. Once the user arrived at the
desired mutation description they can generate an actual mutation via
`data_model::mutation_description::build()`.
In addition to the `random_schema` class, the `random_schema.hh` header
exposes the generic utility classes for generating types and values
that it internally uses.
random_schema is fully deterministic. Using the same seed and the same
set of operations is guaranteed to result in generating the same schema
and data.
