MB-10033 use stats to obtain file and data sizes
MB-10033 use stats to obtain file and data sizes

to determine if the compaction is needed

Change-Id: Ic11155ba494801f4751384d1f8a1d5158420945e
Reviewed-on: http://review.couchbase.org/33098
Tested-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

ceejatec/ns_server,mschoch/ns_server,daverigby/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,membase/ns_server,daverigby/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,daverigby/ns_server,nimishzynga/ns_server,membase/ns_server,nimishzynga/ns_server,mschoch/ns_server,daverigby/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,ceejatec/ns_server,mschoch/ns_server,ceejatec/ns_server,membase/ns_server,ceejatec/ns_server,t3rm1n4l/ns_server,daverigby/ns_server,membase/ns_server,membase/ns_server,ceejatec/ns_server,membase/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,ceejatec/ns_server,nimishzynga/ns_server,mschoch/ns_server