Previously since a char* can have any length, this was managed by FMT by converting it into a std::string.
Now we store it into a configurable size node that can store a fixed size string, otherwise it falls back to std::string.
the current value of 256 limits the number of PDCP SDUs that can be
notified from RLC. The limit is quickly hit when too many SDUs
are in flight. This can cause unwanted log entries and weird PDCP
behaviour.
the patch increases the value to 1024, which still can be too few if
many smaller SDUs are traveling.
The patch also set the log level to warning to quicker spot
misconfigs in logs.
Fixes#2616
the created RLC PDU was too large to fit inside the MAC grant
because only the header room for the short L field was used.
The patch determines the correct size before passing the opportunity to RLC.
It also improves logging in error case by using the MAC logger instead of
stderr/stdout when error occurs.
building on the previous refactor this patch now adds support
for peridoic BSR reporting (using short BSR). It furthermore does
the following changes:
* add BSR packing
* add proc_bsr_nr unit test
* move mac_nr test code into test folder under src (needs to be done with other test code too)
previously we were only counting retx if we retx the start of a segment.
this could lead to unwanted behaviour, i.e., not counting retx
correctly and thus not triggering the maxretx attempt, if the receive
always sends NACKs with a SO_start.
The RLC spec is not clear on how this should be handled correctly but
IMHO using an integer number of retx is reasonable, even for segments
that might be retransmitted more often.
The alternative of using a fractional retx counter that may be increamented
proportional to the segment size that is retx is another alternative
but considered too complex to implement (and test correctly).