SSTables already have a priority argument wired to their read path. However,
most of our reads do not call that interface directly, but employ the services
of a mutation reader instead.
Some of those readers will be used to read through a mutation_source, and those
have to patched as well.
Right now, whenever we need to pass a class, we pass Seastar's default priority
class.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Its definition as a lambda function is inconvenient, because it does not allow
us to use default values for parameters.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Combined key reader, just like its mutation equivalents, combines
output from multiple key_readers and provides a single sorted stream
of decorated keys.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
key_readers provide an interface analogous to mutation_readers, but the
only data they return are decorated keys.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>