tree b0d1b85c9612838afe5299b00f0204833f599f1e
parent 39e79d9f54581b7ec6b2ffa7d3a7017f4caa4240
author Eamonn O'Brien-Strain <eobrain@google.com> 1464394233 -0700
committer Eamonn O'Brien-Strain <eobrain@google.com> 1464394233 -0700

Use stats to monitor LevelDb file usage.

This adds the following four stats for a syncbase service:
  syncbase/leveldb/service/{hash}/file_count
  syncbase/leveldb/service/{hash}/filesystem_bytes
  syncbase/leveldb/blobmap/{hash}/file_count
  syncbase/leveldb/blobmap/{hash}/filesystem_bytes
and the following two stats metrics per database:
  syncbase/leveldb/db/{blessing}/{DB-name}/{hash}/file_count
  syncbase/leveldb/db/{blessing}/{DB-name}/{hash}/filesystem_bytes
where {hash} is a hash of the file path of the store.

Also fixes a bug: the service store was not being closed when these
service was closed.

Change-Id: I844786c105d2671df1013cd29b2534eeedefb495