org.apache.hadoop.hbase.codec.prefixtree

Class PrefixTreeCodec

java.lang.Object

org.apache.hadoop.hbase.codec.prefixtree.PrefixTreeCodec

All Implemented Interfaces:

DataBlockEncoder

@InterfaceAudience.Private
public class PrefixTreeCodec
extends Object
implements DataBlockEncoder

This class is created via reflection in DataBlockEncoding enum. Update the enum if class name or package changes.

PrefixTreeDataBlockEncoder implementation of DataBlockEncoder. This is the primary entry point for PrefixTree encoding and decoding. Encoding is delegated to instances of PrefixTreeEncoder, and decoding is delegated to instances of CellSearcher. Encoder and decoder instances are created and recycled by static PtEncoderFactory and PtDecoderFactory.

Nested Class Summary

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

DataBlockEncoder.EncodedSeeker

Constructor Summary

Constructors

Constructor and Description
PrefixTreeCodec() no-arg constructor for reflection

Method Summary

Modifier and Type	Method and Description
DataBlockEncoder.EncodedSeeker	createSeeker(KeyValue.KVComparator comparator, HFileBlockDecodingContext decodingCtx) Is this the correct handling of an illegal comparator? How to prevent that from getting all the way to this point.
ByteBuffer	decodeKeyValues(DataInputStream source, HFileBlockDecodingContext decodingCtx) Decode.
ByteBuffer	decodeKeyValues(DataInputStream source, int allocateHeaderLength, int skipLastBytes, HFileBlockDecodingContext decodingCtx) I don't think this method is called during normal HBase operation, so efficiency is not important.
int	encode(Cell cell, HFileBlockEncodingContext encodingCtx, DataOutputStream out) Encodes a KeyValue.
void	endBlockEncoding(HFileBlockEncodingContext encodingCtx, DataOutputStream out, byte[] uncompressedBytesWithHeader) Ends encoding for a block of KeyValues.
ByteBuffer	getFirstKeyInBlock(ByteBuffer block) Return first key in block.
HFileBlockDecodingContext	newDataBlockDecodingContext(HFileContext meta) Creates an encoder specific decoding context, which will prepare the data before actual decoding
HFileBlockEncodingContext	newDataBlockEncodingContext(DataBlockEncoding encoding, byte[] header, HFileContext meta) Creates a encoder specific encoding context
void	startBlockEncoding(HFileBlockEncodingContext blkEncodingCtx, DataOutputStream out) Starts encoding for a block of KeyValues.

Methods inherited from class java.lang.Object

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

Constructor Detail

PrefixTreeCodec

public PrefixTreeCodec()

no-arg constructor for reflection

Method Detail

decodeKeyValues

public ByteBuffer decodeKeyValues(DataInputStream source,
                                  HFileBlockDecodingContext decodingCtx)
                           throws IOException

Description copied from interface: DataBlockEncoder

Decode.

Specified by:

decodeKeyValues in interface DataBlockEncoder

Parameters:

source - Compressed stream of KeyValues.

Returns:

Uncompressed block of KeyValues.

Throws:

IOException - If there is an error in source.

decodeKeyValues

public ByteBuffer decodeKeyValues(DataInputStream source,
                                  int allocateHeaderLength,
                                  int skipLastBytes,
                                  HFileBlockDecodingContext decodingCtx)
                           throws IOException

I don't think this method is called during normal HBase operation, so efficiency is not important.

Throws:

IOException

getFirstKeyInBlock

public ByteBuffer getFirstKeyInBlock(ByteBuffer block)

Description copied from interface: DataBlockEncoder

Return first key in block. 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.

Specified by:

getFirstKeyInBlock in interface DataBlockEncoder

Parameters:

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

Returns:

First key in block.

newDataBlockEncodingContext

public HFileBlockEncodingContext newDataBlockEncodingContext(DataBlockEncoding encoding,
                                                             byte[] header,
                                                             HFileContext meta)

Description copied from interface: DataBlockEncoder

Creates a encoder specific encoding context

Specified by:

newDataBlockEncodingContext in interface DataBlockEncoder

Parameters:

encoding - encoding strategy used

header - header bytes to be written, put a dummy header here if the header is unknown

meta - HFile meta data

Returns:

a newly created encoding context

newDataBlockDecodingContext

public HFileBlockDecodingContext newDataBlockDecodingContext(HFileContext meta)

Description copied from interface: DataBlockEncoder

Creates an encoder specific decoding context, which will prepare the data before actual decoding

Specified by:

newDataBlockDecodingContext in interface DataBlockEncoder

Parameters:

meta - HFile meta data

Returns:

a newly created decoding context

createSeeker

public DataBlockEncoder.EncodedSeeker createSeeker(KeyValue.KVComparator comparator,
                                                   HFileBlockDecodingContext decodingCtx)

Is this the correct handling of an illegal comparator? How to prevent that from getting all the way to this point.

Specified by:

createSeeker in interface DataBlockEncoder

Parameters:

comparator - what kind of comparison should be used

Returns:

A newly created seeker.

encode

public int encode(Cell cell,
                  HFileBlockEncodingContext encodingCtx,
                  DataOutputStream out)
           throws IOException

Description copied from interface: DataBlockEncoder

Encodes a KeyValue.

Specified by:

encode in interface DataBlockEncoder

Returns:

unencoded kv size written

Throws:

IOException

startBlockEncoding

public void startBlockEncoding(HFileBlockEncodingContext blkEncodingCtx,
                               DataOutputStream out)
                        throws IOException

Description copied from interface: DataBlockEncoder

Starts encoding for a block of KeyValues. Call DataBlockEncoder.endBlockEncoding(HFileBlockEncodingContext, DataOutputStream, byte[]) to finish encoding of a block.

Specified by:

startBlockEncoding in interface DataBlockEncoder

Throws:

IOException

endBlockEncoding

public void endBlockEncoding(HFileBlockEncodingContext encodingCtx,
                             DataOutputStream out,
                             byte[] uncompressedBytesWithHeader)
                      throws IOException

Description copied from interface: DataBlockEncoder

Ends encoding for a block of KeyValues. Gives a chance for the encoder to do the finishing stuff for the encoded block. It must be called at the end of block encoding.

Specified by:

endBlockEncoding in interface DataBlockEncoder

Throws:

IOException