org.apache.hadoop.io
Class BloomMapFile

java.lang.Object
  extended by org.apache.hadoop.io.BloomMapFile

public class BloomMapFile
extends Object

This class extends MapFile and provides very much the same functionality. However, it uses dynamic Bloom filters to provide quick membership test for keys, and it offers a fast version of BloomMapFile.Reader.get(WritableComparable, Writable) operation, especially in case of sparsely populated MapFile-s.


Nested Class Summary
static class BloomMapFile.Reader
           
static class BloomMapFile.Writer
           
 
Field Summary
static String BLOOM_FILE_NAME
           
static int HASH_COUNT
           
 
Constructor Summary
BloomMapFile()
           
 
Method Summary
static void delete(FileSystem fs, String name)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

BLOOM_FILE_NAME

public static final String BLOOM_FILE_NAME
See Also:
Constant Field Values

HASH_COUNT

public static final int HASH_COUNT
See Also:
Constant Field Values
Constructor Detail

BloomMapFile

public BloomMapFile()
Method Detail

delete

public static void delete(FileSystem fs,
                          String name)
                   throws IOException
Throws:
IOException


Copyright © 2009 The Apache Software Foundation