org.apache.hadoop.hbase.io.encoding

Class PrefixKeyDeltaEncoder

java.lang.Object

org.apache.hadoop.hbase.io.encoding.AbstractDataBlockEncoder

org.apache.hadoop.hbase.io.encoding.BufferedDataBlockEncoder

org.apache.hadoop.hbase.io.encoding.PrefixKeyDeltaEncoder

All Implemented Interfaces:

DataBlockEncoder

@InterfaceAudience.Private
public class PrefixKeyDeltaEncoder
extends BufferedDataBlockEncoder

Compress key by storing size of common prefix with previous KeyValue and storing raw size of rest. Format: 1-5 bytes: compressed key length minus prefix (7-bit encoding) 1-5 bytes: compressed value length (7-bit encoding) 1-3 bytes: compressed length of common key prefix ... bytes: rest of key (including timestamp) ... bytes: value In a worst case compressed KeyValue will be three bytes longer than original.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.io.encoding.BufferedDataBlockEncoder

BufferedDataBlockEncoder.BufferedEncodedSeeker<STATE extends BufferedDataBlockEncoder.SeekerState>, BufferedDataBlockEncoder.OffheapDecodedExtendedCell, BufferedDataBlockEncoder.OnheapDecodedCell, BufferedDataBlockEncoder.SeekerState

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.io.encoding.AbstractDataBlockEncoder

AbstractDataBlockEncoder.AbstractEncodedSeeker

Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.io.encoding.DataBlockEncoder

DataBlockEncoder.EncodedSeeker

Constructor Summary

Constructors

Constructor and Description
PrefixKeyDeltaEncoder()

Method Summary

Modifier and Type	Method and Description
DataBlockEncoder.EncodedSeeker	createSeeker(CellComparator comparator, HFileBlockDecodingContext decodingCtx) Create a HFileBlock seeker which find KeyValues within a block.
private int	decodeKeyValue(DataInputStream source, ByteBuffer buffer, int prevKeyOffset)
Cell	getFirstKeyCellInBlock(ByteBuff block) Return first key in block as a cell.
protected ByteBuffer	internalDecodeKeyValues(DataInputStream source, int allocateHeaderLength, int skipLastBytes, HFileBlockDefaultDecodingContext decodingCtx)
int	internalEncode(Cell cell, HFileBlockDefaultEncodingContext encodingContext, DataOutputStream out)
String	toString()
private void	writeKeyExcludingCommon(Cell cell, int commonPrefix, DataOutputStream out)

Methods inherited from class org.apache.hadoop.hbase.io.encoding.BufferedDataBlockEncoder

afterDecodingKeyValue, afterEncodingKeyValue, compareCommonFamilyPrefix, compareCommonQualifierPrefix, compareCommonRowPrefix, decodeKeyValues, encode, endBlockEncoding, ensureSpace, startBlockEncoding

Methods inherited from class org.apache.hadoop.hbase.io.encoding.AbstractDataBlockEncoder

createFirstKeyCell, newDataBlockDecodingContext, newDataBlockEncodingContext, postEncoding

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

PrefixKeyDeltaEncoder

public PrefixKeyDeltaEncoder()

Method Detail

internalEncode

public int internalEncode(Cell cell,
                          HFileBlockDefaultEncodingContext encodingContext,
                          DataOutputStream out)
                   throws IOException

Specified by:

internalEncode in class BufferedDataBlockEncoder

Throws:

IOException

writeKeyExcludingCommon

private void writeKeyExcludingCommon(Cell cell,
                                     int commonPrefix,
                                     DataOutputStream out)
                              throws IOException

Throws:

IOException

internalDecodeKeyValues

protected ByteBuffer internalDecodeKeyValues(DataInputStream source,
                                             int allocateHeaderLength,
                                             int skipLastBytes,
                                             HFileBlockDefaultDecodingContext decodingCtx)
                                      throws IOException

Specified by:

internalDecodeKeyValues in class BufferedDataBlockEncoder

Throws:

IOException

decodeKeyValue

private int decodeKeyValue(DataInputStream source,
                           ByteBuffer buffer,
                           int prevKeyOffset)
                    throws IOException,
                           EncoderBufferTooSmallException

Throws:

IOException

EncoderBufferTooSmallException

getFirstKeyCellInBlock

public Cell getFirstKeyCellInBlock(ByteBuff block)

Description copied from interface: DataBlockEncoder

Return first key in block as a cell. Useful for indexing. Typically does not make a deep copy but returns a buffer wrapping a segment of the actual block's byte array. This is because the first key in block is usually stored unencoded.

Parameters:

block - encoded block we want index, the position will not change

Returns:

First key in block as a cell.

toString

public String toString()

Overrides:

toString in class Object

createSeeker

public DataBlockEncoder.EncodedSeeker createSeeker(CellComparator comparator,
                                                   HFileBlockDecodingContext decodingCtx)

Description copied from interface: DataBlockEncoder

Create a HFileBlock seeker which find KeyValues within a block.

Parameters:

comparator - what kind of comparison should be used

Returns:

A newly created seeker.