org.apache.lucene.store

Class RAMDirectory

Implemented Interfaces:
Serializable

public class RAMDirectory
extends Directory
implements Serializable

A memory-resident Directory implementation. Locking implementation is by default the SingleInstanceLockFactory but can be changed with RAMDirectory.
Version:
$Id: RAMDirectory.java 503911 2007-02-05 22:49:42Z dnaber $

Field Summary

Fields inherited from class org.apache.lucene.store.Directory

lockFactory

Constructor Summary

RAMDirectory()
Constructs an empty Directory.
RAMDirectory(File dir)
Creates a new RAMDirectory instance from the FSDirectory.
RAMDirectory(String dir)
Creates a new RAMDirectory instance from the FSDirectory.
RAMDirectory(Directory dir)
Creates a new RAMDirectory instance from a different Directory implementation.

Method Summary

void
close()
Closes the store to future operations, releasing associated memory.
IndexOutput
createOutput(String name)
Creates a new, empty file in the directory with the given name.
void
deleteFile(String name)
Removes an existing file in the directory.
boolean
fileExists(String name)
Returns true iff the named file exists in this directory.
long
fileLength(String name)
Returns the length in bytes of a file in the directory.
long
fileModified(String name)
Returns the time the named file was last modified.
String[]
list()
Returns an array of strings, one for each file in the directory.
IndexInput
openInput(String name)
Returns a stream reading an existing file.
void
renameFile(String from, String to)
Deprecated.
long
sizeInBytes()
Return total size in bytes of all files in this directory.
void
touchFile(String name)
Set the modified time of an existing file to now.

Methods inherited from class org.apache.lucene.store.Directory

clearLock, close, copy, createOutput, deleteFile, fileExists, fileLength, fileModified, getLockFactory, getLockID, list, makeLock, openInput, renameFile, setLockFactory, touchFile

Constructor Details

RAMDirectory

public RAMDirectory()

RAMDirectory

public RAMDirectory(File dir)
            throws IOException
Parameters:
dir - a File specifying the index directory

RAMDirectory

public RAMDirectory(String dir)
            throws IOException
Parameters:
dir - a String specifying the full index directory path

RAMDirectory

public RAMDirectory(Directory dir)
            throws IOException
Creates a new RAMDirectory instance from a different Directory implementation. This can be used to load a disk-based index into memory.

This should be used only with indices that can fit into memory.

Note that the resulting RAMDirectory instance is fully independent from the original Directory (it is a complete copy). Any subsequent changes to the original Directory will not be visible in the RAMDirectory instance.

Parameters:
dir - a Directory value

Method Details

close

public final void close()
Closes the store to future operations, releasing associated memory.
Overrides:
close in interface Directory

createOutput

public IndexOutput createOutput(String name)
Creates a new, empty file in the directory with the given name. Returns a stream writing this file.
Overrides:
createOutput in interface Directory

deleteFile

public final void deleteFile(String name)
            throws IOException
Removes an existing file in the directory.
Overrides:
deleteFile in interface Directory

fileExists

public final boolean fileExists(String name)
Returns true iff the named file exists in this directory.
Overrides:
fileExists in interface Directory

fileLength

public final long fileLength(String name)
            throws IOException
Returns the length in bytes of a file in the directory.
Overrides:
fileLength in interface Directory

fileModified

public final long fileModified(String name)
            throws IOException
Returns the time the named file was last modified.
Overrides:
fileModified in interface Directory

list

public final String[] list()
Returns an array of strings, one for each file in the directory.
Overrides:
list in interface Directory

openInput

public final IndexInput openInput(String name)
            throws IOException
Returns a stream reading an existing file.
Overrides:
openInput in interface Directory

renameFile

public final void renameFile(String from,
                             String to)
            throws IOException

Deprecated.

Renames an existing file in the directory.
Overrides:
renameFile in interface Directory

sizeInBytes

public final long sizeInBytes()
Return total size in bytes of all files in this directory. This is currently quantized to BufferedIndexOutput.BUFFER_SIZE.

touchFile

public void touchFile(String name)
            throws IOException
Set the modified time of an existing file to now.
Overrides:
touchFile in interface Directory

Copyright © 2000-2007 Apache Software Foundation. All Rights Reserved.