Support cache manager and watch table in rdc_lib
RdcCacheManagerImpl.cc is added to implement cache of metrics. Currently, only
integer mertics are supported. The cache manager provids function to retrieve the
latest and history metrics from cache. It also provides interfaces to update and evict the cache.
RdcWatchTableImpl.cc is added to implement watch and unwatch fields. It uses the
field settings to control how frequently a field needs to be updated. We have a preliminarily
performance optimization for this class as it may be called very frequently.
RdcMetricsUpdaterImpl.cc is added to run the update at background thread when
RDC_OPERATION_MODE_AUTO is set.
After this code change, the rdcd/rdci should be able to implement basic discovery, group and dmon
function. The job management function is not implemented in the skeleton rdc_lib yet.
Change-Id: I26cff8c2ec85d1ad8e7df24c66b02f0060838d37
Bill(Shuzhou) Liu
1ff1c7b617