org.apache.accumulo.core.file.rfile.bcfile
Class BCFile.Writer

java.lang.Object
  org.apache.accumulo.core.file.rfile.bcfile.BCFile.Writer

All Implemented Interfaces:

Closeable

Enclosing class:

BCFile

public static class BCFile.Writer
extends Object
implements Closeable

BCFile writer, the entry point for creating a new BCFile.

Nested Class Summary

class

BCFile.Writer.BlockAppender Access point to stuff data into a block.

Constructor Summary

BCFile.Writer(org.apache.hadoop.fs.FSDataOutputStream fout, String compressionName, org.apache.hadoop.conf.Configuration conf, boolean trackDataBlocks)
Constructor

Method Summary

void	close() Close the BCFile Writer.
BCFile.Writer.BlockAppender	prepareDataBlock() Create a Data Block and obtain an output stream for adding data into the block.
BCFile.Writer.BlockAppender	prepareMetaBlock(String name) Create a Meta Block and obtain an output stream for adding data into the block.
BCFile.Writer.BlockAppender	prepareMetaBlock(String name, String compressionName) Create a Meta Block and obtain an output stream for adding data into the block.

Methods inherited from class java.lang.Object

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

Constructor Detail

BCFile.Writer

public BCFile.Writer(org.apache.hadoop.fs.FSDataOutputStream fout,
                     String compressionName,
                     org.apache.hadoop.conf.Configuration conf,
                     boolean trackDataBlocks)
              throws IOException

Constructor

Parameters:

fout - FS output stream.

compressionName - Name of the compression algorithm, which will be used for all data blocks.

Throws:

IOException

See Also:

Compression.getSupportedAlgorithms()

Method Detail

close

public void close()
           throws IOException

Close the BCFile Writer. Attempting to use the Writer after calling close is not allowed and may lead to undetermined results.

Specified by:

close in interface Closeable

Throws:

IOException

prepareMetaBlock

public BCFile.Writer.BlockAppender prepareMetaBlock(String name,
                                                    String compressionName)
                                             throws IOException,
                                                    MetaBlockAlreadyExists

Create a Meta Block and obtain an output stream for adding data into the block. There can only be one BlockAppender stream active at any time. Regular Blocks may not be created after the first Meta Blocks. The caller must call BlockAppender.close() to conclude the block creation.

Parameters:

name - The name of the Meta Block. The name must not conflict with existing Meta Blocks.

compressionName - The name of the compression algorithm to be used.

Returns:

The BlockAppender stream

Throws:

IOException

MetaBlockAlreadyExists - If the meta block with the name already exists.

prepareMetaBlock

public BCFile.Writer.BlockAppender prepareMetaBlock(String name)
                                             throws IOException,
                                                    MetaBlockAlreadyExists

Create a Meta Block and obtain an output stream for adding data into the block. The Meta Block will be compressed with the same compression algorithm as data blocks. There can only be one BlockAppender stream active at any time. Regular Blocks may not be created after the first Meta Blocks. The caller must call BlockAppender.close() to conclude the block creation.

Parameters:

name - The name of the Meta Block. The name must not conflict with existing Meta Blocks.

Returns:

The BlockAppender stream

Throws:

MetaBlockAlreadyExists - If the meta block with the name already exists.

IOException

prepareDataBlock

public BCFile.Writer.BlockAppender prepareDataBlock()
                                             throws IOException

Create a Data Block and obtain an output stream for adding data into the block. There can only be one BlockAppender stream active at any time. Data Blocks may not be created after the first Meta Blocks. The caller must call BlockAppender.close() to conclude the block creation.

Returns:

The BlockAppender stream

Throws:

IOException