Using streamed_mutation::operator() is undesirable as it introduces an
indirect call and a continuation overhead for each emitted mutation
fragment. Consumer interface is the preferred method of reading streamed
mutations.
All test perf_fast_forward test cases currently live in the main
function. This patch moves the state they rely on to a global scope
so that it will be easier to extract these tests to individual
functions.
- introcduced "seastarx.hh" header, which does a "using namespace seastar";
- 'net' namespace conflicts with seastar::net, renamed to 'netw'.
- 'transport' namespace conflicts with seastar::transport, renamed to
cql_transport.
- "logger" global variables now conflict with logger global type, renamed
to xlogger.
- other minor changes
make_pkeys() needs to be invoked with n equal to the number of keys
which the table was populated with. Otherwise the extra keys, which
are missing in the table, may be placed anywhere in the vector due to
ring order sorting, and break the assumption that the table contains
all keys from the array up to index n. This resulted in the test
reading slighlty less fragments than it would follow from the desired
count.
Another problem is that we should not skip the fast_forward_to() call
for the inital range (workaround for a bug in sstable mutation
reader), otherwise we will read slightly less than expected as well.
