org.apache.hadoop.hbase.io

Interface HeapSize

All Known Subinterfaces:

Cacheable, ExtendedCell, SizedCellScanner

All Known Implementing Classes:

Append, BlockCacheKey, BucketCache, BufferedDataBlockEncoder.OffheapDecodedExtendedCell, BufferedDataBlockEncoder.OnheapDecodedCell, ByteBufferChunkKeyValue, ByteBufferExtendedCell, ByteBufferKeyOnlyKeyValue, ByteBufferKeyValue, CombinedBlockCache, Delete, HFileBlock, HFileBlockIndex.BlockIndexReader, HFileBlockIndex.ByteArrayKeyBlockIndexReader, HFileBlockIndex.CellBasedKeyBlockIndexReader, HFileContext, HMobStore, HRegion, HStore, InclusiveCombinedBlockCache, Increment, IndividualBytesFieldCell, KeyOnlyFilter.KeyOnlyByteBufferExtendedCell, KeyValue, KeyValue.KeyOnlyKeyValue, LruBlockCache, LruCachedBlock, LruCachedBlockQueue, MapReduceExtendedCell, Mutation, Mutation.CellWrapper, NoTagByteBufferChunkKeyValue, NoTagsByteBufferKeyValue, NoTagsKeyValue, PrivateCellUtil.EmptyByteBufferExtendedCell, PrivateCellUtil.EmptyCell, PrivateCellUtil.FirstOnRowByteBufferExtendedCell, PrivateCellUtil.FirstOnRowCell, PrivateCellUtil.FirstOnRowColByteBufferExtendedCell, PrivateCellUtil.FirstOnRowColCell, PrivateCellUtil.FirstOnRowColTSByteBufferExtendedCell, PrivateCellUtil.FirstOnRowColTSCell, PrivateCellUtil.FirstOnRowDeleteFamilyCell, PrivateCellUtil.LastOnRowByteBufferExtendedCell, PrivateCellUtil.LastOnRowCell, PrivateCellUtil.LastOnRowColByteBufferExtendedCell, PrivateCellUtil.LastOnRowColCell, PrivateCellUtil.TagRewriteByteBufferExtendedCell, PrivateCellUtil.TagRewriteCell, PrivateCellUtil.ValueAndTagRewriteByteBufferExtendedCell, PrivateCellUtil.ValueAndTagRewriteCell, Put, SizeCachedKeyValue, SizeCachedNoTagsKeyValue, WALEdit, WALSplitter.RegionEntryBuffer

@InterfaceAudience.Private
public interface HeapSize

Implementations can be asked for an estimate of their size in bytes.

Useful for sizing caches. Its a given that implementation approximations do not account for 32 vs 64 bit nor for different VM implementations.

An Object's size is determined by the non-static data members in it, as well as the fixed Object overhead.

For example:

 public class SampleObject implements HeapSize {

   int [] numbers;
   int x;
 }
 

Method Summary

Modifier and Type	Method and Description
long	heapSize()

Method Detail

heapSize

long heapSize()

Returns:

Approximate 'exclusive deep size' of implementing object. Includes count of payload and hosting object sizings.