private static long calculateOverhead(long maxSize, long blockSize, int concurrency) {
    // FindBugs ICAST_INTEGER_MULTIPLY_CAST_TO_LONG
    return CACHE_FIXED_OVERHEAD + ClassSize.CONCURRENT_HASHMAP
      + ((long) Math.ceil(maxSize * 1.2 / blockSize) * ClassSize.CONCURRENT_HASHMAP_ENTRY)
      + ((long) concurrency * ClassSize.CONCURRENT_HASHMAP_SEGMENT);
  }
Get counter statistics for this cache.
<p>
Includes: total accesses, hits, misses, evicted blocks, and runs of the eviction processes.
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/LruBlockCache.java