org.apache.hadoop.hbase.io.hfile

Class HFileDataBlockEncoderImpl

java.lang.Object

org.apache.hadoop.hbase.io.hfile.HFileDataBlockEncoderImpl

All Implemented Interfaces:

HFileDataBlockEncoder

@InterfaceAudience.Private
public class HFileDataBlockEncoderImpl
extends Object
implements HFileDataBlockEncoder

Do different kinds of data block encoding according to column family options.

Field Summary

Fields inherited from interface org.apache.hadoop.hbase.io.hfile.HFileDataBlockEncoder

DATA_BLOCK_ENCODING

Constructor Summary

Constructors

Constructor and Description
HFileDataBlockEncoderImpl(DataBlockEncoding encoding) Do data block encoding with specified options.

Method Summary

Methods

Modifier and Type	Method and Description
void	beforeWriteToDisk(ByteBuffer in, HFileBlockEncodingContext encodeCtx, BlockType blockType) Precondition: a non-encoded buffer.
static HFileDataBlockEncoder	createFromFileInfo(HFile.FileInfo fileInfo)
DataBlockEncoding	getDataBlockEncoding()
HFileBlockDecodingContext	newDataBlockDecodingContext(HFileContext fileContext) create a encoder specific decoding context for reading.
HFileBlockEncodingContext	newDataBlockEncodingContext(byte[] dummyHeader, HFileContext fileContext) Create an encoder specific encoding context object for writing.
void	saveMetadata(HFile.Writer writer) Save metadata in HFile which will be written to disk
String	toString()
boolean	useEncodedScanner() Decides whether we should use a scanner over encoded blocks.

Methods inherited from class java.lang.Object

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

Constructor Detail

HFileDataBlockEncoderImpl

public HFileDataBlockEncoderImpl(DataBlockEncoding encoding)

Do data block encoding with specified options.

Parameters:

encoding - What kind of data block encoding will be used.

Method Detail

createFromFileInfo

public static HFileDataBlockEncoder createFromFileInfo(HFile.FileInfo fileInfo)
                                                throws IOException

Throws:

IOException

saveMetadata

public void saveMetadata(HFile.Writer writer)
                  throws IOException

Description copied from interface: HFileDataBlockEncoder

Save metadata in HFile which will be written to disk

Specified by:

saveMetadata in interface HFileDataBlockEncoder

Parameters:

writer - writer for a given HFile

Throws:

IOException - on disk problems

getDataBlockEncoding

public DataBlockEncoding getDataBlockEncoding()

Specified by:

getDataBlockEncoding in interface HFileDataBlockEncoder

Returns:

the data block encoding

beforeWriteToDisk

public void beforeWriteToDisk(ByteBuffer in,
                     HFileBlockEncodingContext encodeCtx,
                     BlockType blockType)
                       throws IOException

Precondition: a non-encoded buffer. Postcondition: on-disk encoding. The encoded results can be stored in HFileBlockEncodingContext.

Specified by:

beforeWriteToDisk in interface HFileDataBlockEncoder

Parameters:

in - KeyValues next to each other

encodeCtx - the encoded result

blockType - block type

Throws:

IOException

useEncodedScanner

public boolean useEncodedScanner()

Description copied from interface: HFileDataBlockEncoder

Decides whether we should use a scanner over encoded blocks.

Specified by:

useEncodedScanner in interface HFileDataBlockEncoder

Returns:

Whether to use encoded scanner.

toString

public String toString()

Overrides:

toString in class Object

newDataBlockEncodingContext

public HFileBlockEncodingContext newDataBlockEncodingContext(byte[] dummyHeader,
                                                    HFileContext fileContext)

Description copied from interface: HFileDataBlockEncoder

Create an encoder specific encoding context object for writing. And the encoding context should also perform compression if compressionAlgorithm is valid.

Specified by:

newDataBlockEncodingContext in interface HFileDataBlockEncoder

Parameters:

dummyHeader - header bytes

fileContext - HFile meta data

Returns:

a new HFileBlockEncodingContext object

newDataBlockDecodingContext

public HFileBlockDecodingContext newDataBlockDecodingContext(HFileContext fileContext)

Description copied from interface: HFileDataBlockEncoder

create a encoder specific decoding context for reading. And the decoding context should also do decompression if compressionAlgorithm is valid.

Specified by:

newDataBlockDecodingContext in interface HFileDataBlockEncoder

Parameters:

fileContext - - HFile meta data

Returns:

a new HFileBlockDecodingContext object