handle all exceptions in read_exactly, seek, and close
and specify them as noexcept.
Also, specify eof() as noexcept as it trivially is.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
And adjust its callers to wait on the returned future.
With this, there is no need for a gate to serialize close()
with the background work seek() used to leave behind.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Define a close_if_needed() helper function, to be called
from seek() and close().
A future patch will call it with a possibly disengaged
`_in` so it will close it only if it was engaged.
close_if_needed() captures the input stream unique ptr
so it will remain valid throughout close.
This was missing from close().
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Allow file_random_access_reader constructor to set the
input stream to prepare for futurizing seek() by adding
a protected set() method.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
