org.apache.hadoop.hbase

Class SizeCachedKeyValue

java.lang.Object

org.apache.hadoop.hbase.KeyValue

org.apache.hadoop.hbase.SizeCachedKeyValue

All Implemented Interfaces:

Cloneable, Cell, ExtendedCell, HeapSize, RawCell

Direct Known Subclasses:

SizeCachedNoTagsKeyValue

@InterfaceAudience.Private
public class SizeCachedKeyValue
extends KeyValue

This class is an extension to KeyValue where rowLen and keyLen are cached. Parsing the backing byte[] every time to get these values will affect the performance. In read path, we tend to read these values many times in Comparator, SQM etc. Note: Please do not use these objects in write path as it will increase the heap space usage. See https://issues.apache.org/jira/browse/HBASE-13448

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.KeyValue

KeyValue.KeyOnlyKeyValue, KeyValue.KVComparator, KeyValue.MetaComparator, KeyValue.SamePrefixComparator<T>, KeyValue.Type

Field Summary

Fields

Modifier and Type	Field and Description
private static int	FIXED_OVERHEAD
private int	keyLen
private short	rowLen

Fields inherited from class org.apache.hadoop.hbase.KeyValue

bytes, COLUMN_FAMILY_DELIM_ARRAY, COLUMN_FAMILY_DELIMITER, COMPARATOR, FAMILY_LENGTH_SIZE, KEY_INFRASTRUCTURE_SIZE, KEY_LENGTH_SIZE, KEYVALUE_INFRASTRUCTURE_SIZE, KEYVALUE_WITH_TAGS_INFRASTRUCTURE_SIZE, length, LOWESTKEY, META_COMPARATOR, offset, ROW_KEY_OFFSET, ROW_LENGTH_SIZE, ROW_OFFSET, TAGS_LENGTH_SIZE, TIMESTAMP_SIZE, TIMESTAMP_TYPE_SIZE, TYPE_SIZE

Fields inherited from interface org.apache.hadoop.hbase.ExtendedCell

CELL_NOT_BASED_ON_CHUNK

Fields inherited from interface org.apache.hadoop.hbase.RawCell

MAX_TAGS_LENGTH

Constructor Summary

Constructors

Constructor and Description
SizeCachedKeyValue(byte[] bytes, int offset, int length, long seqId)

Method Summary

Modifier and Type	Method and Description
int	getKeyLength()
short	getRowLength()
int	getSerializedSize() Override by just returning the length for saving cost of method dispatching.
long	heapSize() HeapSize implementation We do not count the bytes in the rowCache because it should be empty for a KeyValue in the MemStore.

Methods inherited from class org.apache.hadoop.hbase.KeyValue

checkParameters, clone, create, create, createKeyOnly, deepClone, equals, getBuffer, getDelimiter, getDelimiterInReverse, getFamilyArray, getFamilyLength, getFamilyLength, getFamilyOffset, getKey, getKeyDataStructureSize, getKeyOffset, getKeyString, getKeyValueDataStructureSize, getKeyValueDataStructureSize, getKeyValueDataStructureSize, getLength, getOffset, getQualifierArray, getQualifierLength, getQualifierOffset, getRowArray, getRowOffset, getSequenceId, getSerializedSize, getTagsArray, getTagsLength, getTagsOffset, getTimestamp, getTimestamp, getTimestampOffset, getTypeByte, getValueArray, getValueLength, getValueOffset, hashCode, humanReadableTimestamp, isLatestTimestamp, keyToString, keyToString, oswrite, setSequenceId, setTimestamp, setTimestamp, shallowCopy, toString, toStringMap, updateLatestStamp, write, write, write, writeByteArray

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.hadoop.hbase.ExtendedCell

getChunkId

Methods inherited from interface org.apache.hadoop.hbase.RawCell

checkForTagsLength, cloneTags, getTag, getTags

Methods inherited from interface org.apache.hadoop.hbase.Cell

getType

Field Detail

FIXED_OVERHEAD

private static final int FIXED_OVERHEAD

See Also:

Constant Field Values

rowLen

private short rowLen

keyLen

private int keyLen

Constructor Detail

SizeCachedKeyValue

public SizeCachedKeyValue(byte[] bytes,
                          int offset,
                          int length,
                          long seqId)

Method Detail

getRowLength

public short getRowLength()

Specified by:

getRowLength in interface Cell

Overrides:

getRowLength in class KeyValue

Returns:

Row length

getKeyLength

public int getKeyLength()

Overrides:

getKeyLength in class KeyValue

Returns:

Length of key portion.

heapSize

public long heapSize()

Description copied from class: KeyValue

HeapSize implementation We do not count the bytes in the rowCache because it should be empty for a KeyValue in the MemStore.

Specified by:

heapSize in interface HeapSize

Overrides:

heapSize in class KeyValue

Returns:

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

getSerializedSize

public int getSerializedSize()

Override by just returning the length for saving cost of method dispatching. If not, it will call ExtendedCell.getSerializedSize() firstly, then forward to KeyValue.getSerializedSize(boolean). (See HBASE-21657)

Specified by:

getSerializedSize in interface Cell

Specified by:

getSerializedSize in interface ExtendedCell

Overrides:

getSerializedSize in class KeyValue

Returns:

Serialized size (defaults to include tag length).