Useful to check if the next item to receive is wrapped or not.
This is valid only if the ring buffer is initialised with type
RINGBUF_TYPE_ALLOWSPLIT.
This is as per the feature request here:
https://github.com/espressif/esp-idf/issues/806
Signed-off-by: Piyush Shah <piyush@espressif.com>
The earlier available API (xRingbufferGetMaxItemSize())just gives
a static max entry value possible for given ring buffer.
There was a feature request for an API which could provide
a real time available buffer size. See below:
https://github.com/espressif/esp-idf/issues/806
Signed-off-by: Piyush Shah <piyush@espressif.com>
It was observed that if the ring buffer size provided by application
is not a multiple of 4, some checks were failing (as read_ptr and write_ptr
could shoot beyond the ring buffer boundary), thereby causing asserts.
Simply wrapping around the pointers for such cases fixes the issue.
Moreover, because of the logic for maintaining 4-byte boundary,
it was also possible that a wrap-around occurred for some data,
even when the actual size remaining was sufficient for it.
Eg. Buffer available: 34, data size: 34, 4-byte aligned size: 36
Since the logic compares against 36, it writes 34 bytes and does a
wraparound. But since all 34 bytes are already written, there is
nothing to write after wrapping. It is better to just re-set the
write pointer to the dtart of ring buffer in such cases.
Tested send/receive for various arbitrary sizes of data and for
arbitrary sizes of ring buffer.
Alternative Solutions:
1) Allow only sizes which are multiples of 4, and return error otherwise.
Appropriate code and documentation change would be required
2) Allow arbitrary sizes, but internally add upto 3 bytes to make
the total size a multiple of 4
Signed-off-by: Piyush Shah <piyush@espressif.com>
Default esp-idf builds now show -Wextra warnings (except for a few:
signed/unsigned comparison, unused parameters, old-style C declarations.)
CI building of examples runs with that level raised to -Werror, to catch
those changes going into the main repo.
