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

java.lang.Object
  extended by 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
HFileDataBlockEncoderImpl(DataBlockEncoding encoding)
          Do data block encoding with specified options.
 
Method Summary
 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


Copyright © 2015 The Apache Software Foundation. All rights reserved.