org.apache.accumulo.core.file.map

Class MyMapFile

java.lang.Object

org.apache.accumulo.core.file.map.MyMapFile

Deprecated.

since 1.4, replaced by RFile

public class MyMapFile
extends Object

A file-based map from keys to values.

A map is a directory containing two files, the data file, containing all keys and values in the map, and a smaller index file, containing a fraction of the keys. The fraction is determined by MyMapFile.Writer.getIndexInterval().

The index file is read entirely into memory. Thus key implementations should try to keep themselves small.

Map files are created by adding entries in-order. To maintain a large database, perform updates by copying the previous version of a database and merging in a sorted change list, to create a new version of the database in a new file. Sorting large change lists can be done with MySequenceFile.Sorter.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MyMapFile.Reader Deprecated. Provide access to an existing map.
static class	MyMapFile.Writer Deprecated. Writes a new map.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DATA_FILE_NAME Deprecated. The name of the data file.
static String	EXTENSION Deprecated. since 1.4, replaced by Constants.MAPFILE_EXTENSION
static String	INDEX_FILE_NAME Deprecated. The name of the index file.
static Stat	mapFileSeekScanCompareTime Deprecated.
static Stat	mapFileSeekScans Deprecated.
static Stat	mapFileSeekScanTime Deprecated.
static Stat	mapFileSeekTimeStat Deprecated.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MyMapFile() Deprecated.

Method Summary

Methods

Modifier and Type	Method and Description
static void	delete(org.apache.hadoop.fs.FileSystem fs, String name) Deprecated. Deletes the named map file.
static long	fix(org.apache.hadoop.fs.FileSystem fs, org.apache.hadoop.fs.Path dir, Class<? extends org.apache.hadoop.io.WritableComparable> keyClass, Class<? extends org.apache.hadoop.io.Writable> valueClass, boolean dryrun, org.apache.hadoop.conf.Configuration conf) Deprecated. This method attempts to fix a corrupt MapFile by re-creating its index.
static int	getIndexInterval() Deprecated.
static void	main(String[] args) Deprecated.
static void	rename(org.apache.hadoop.fs.FileSystem fs, String oldName, String newName) Deprecated. Renames an existing map directory.

Methods inherited from class java.lang.Object

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

Field Detail

EXTENSION

public static final String EXTENSION

Deprecated. since 1.4, replaced by Constants.MAPFILE_EXTENSION

See Also:

Constant Field Values

INDEX_FILE_NAME

public static final String INDEX_FILE_NAME

Deprecated.

The name of the index file.

See Also:

Constant Field Values

DATA_FILE_NAME

public static final String DATA_FILE_NAME

Deprecated.

The name of the data file.

See Also:

Constant Field Values

mapFileSeekTimeStat

public static final Stat mapFileSeekTimeStat

Deprecated.

mapFileSeekScans

public static final Stat mapFileSeekScans

Deprecated.

mapFileSeekScanTime

public static final Stat mapFileSeekScanTime

Deprecated.

mapFileSeekScanCompareTime

public static final Stat mapFileSeekScanCompareTime

Deprecated.

Constructor Detail

MyMapFile

protected MyMapFile()

Deprecated.

Method Detail

rename

public static void rename(org.apache.hadoop.fs.FileSystem fs,
          String oldName,
          String newName)
                   throws IOException

Deprecated.

Renames an existing map directory.

Throws:

IOException

delete

public static void delete(org.apache.hadoop.fs.FileSystem fs,
          String name)
                   throws IOException

Deprecated.

Deletes the named map file.

Throws:

IOException

getIndexInterval

public static int getIndexInterval()

Deprecated.

fix

public static long fix(org.apache.hadoop.fs.FileSystem fs,
       org.apache.hadoop.fs.Path dir,
       Class<? extends org.apache.hadoop.io.WritableComparable> keyClass,
       Class<? extends org.apache.hadoop.io.Writable> valueClass,
       boolean dryrun,
       org.apache.hadoop.conf.Configuration conf)
                throws Exception

Deprecated.

This method attempts to fix a corrupt MapFile by re-creating its index. Code copied from hadoop (0.18.0) because it was broken there. This is a fixed version. Do not want to loose changes if MyMapFile is updated.

Parameters:

fs - filesystem

dir - directory containing the MapFile data and index

keyClass - key class (has to be a subclass of Writable)

valueClass - value class (has to be a subclass of Writable)

dryrun - do not perform any changes, just report what needs to be done

Returns:

number of valid entries in this MapFile, or -1 if no fixing was needed

Throws:

Exception

main

public static void main(String[] args)
                 throws Exception

Deprecated.

Throws:

Exception