core: Extend rate_ctr by helper functions

For global value reporting, some additional helper functions are
needed. The statsd protocol expects differential counter values,
which are currently not provided by rate_ctr (except for s/m/h/d
intervals).

This commit adds several helper functions to rate_ctr:

- rate_ctr_difference  returns the counter delta since the last
                       call to this function for a given counter
- rate_ctr_for_each_counter
                       iterates through each counter of a group
- rate_ctr_for_each_group
                       iterates through all globally registered
                       counter groups

Note that the rate_ctr_difference function can only be used by a
single backend, since it modifies the 'previous' field in the
rate_ctr obj.

Sponsored-by: On-Waves ehf

0 files changed, 0 insertions, 0 deletions