org.apache.lucene.store

Class FSDirectory

java.lang.Object

org.apache.lucene.store.Directory

org.apache.lucene.store.FSDirectory

Direct Known Subclasses:

MMapDirectory

public class FSDirectory
extends Directory

Straightforward implementation of Directory as a directory of files.

Author:

Doug Cutting

See Also:

Directory

Field Summary

Fields

Modifier and Type	Field and Description
static String	LOCK_DIR Directory specified by org.apache.lucene.lockDir or java.io.tmpdir system property

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FSDirectory()

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the store to future operations.
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 a file with the given name exists.
long	fileLength(String name) Returns the length in bytes of a file in the directory.
static long	fileModified(File directory, String name) Returns the time the named file was last modified.
long	fileModified(String name) Returns the time the named file was last modified.
static FSDirectory	getDirectory(File file, boolean create) Returns the directory instance for the named location.
static FSDirectory	getDirectory(String path, boolean create) Returns the directory instance for the named location.
static boolean	getDisableLocks() Returns whether Lucene's use of lock files is disabled.
File	getFile()
String[]	list() Returns an array of strings, one for each file in the directory.
Lock	makeLock(String name) Constructs a Lock with the specified name.
IndexInput	openInput(String name) Returns a stream reading an existing file.
void	renameFile(String from, String to) Renames an existing file in the directory.
static void	setDisableLocks(boolean doDisableLocks) Set whether Lucene's use of lock files is disabled.
String	toString() For debug output.
void	touchFile(String name) Set the modified time of an existing file to now.

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

createFile, openFile

Methods inherited from class java.lang.Object

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

Field Detail

LOCK_DIR

public static final String LOCK_DIR

Directory specified by org.apache.lucene.lockDir or java.io.tmpdir system property

Constructor Detail

FSDirectory

protected FSDirectory()

Method Detail

setDisableLocks

public static void setDisableLocks(boolean doDisableLocks)

Set whether Lucene's use of lock files is disabled. By default, lock files are enabled. They should only be disabled if the index is on a read-only medium like a CD-ROM.

getDisableLocks

public static boolean getDisableLocks()

Returns whether Lucene's use of lock files is disabled.

Returns:

true if locks are disabled, false if locks are enabled.

getDirectory

public static FSDirectory getDirectory(String path,
                       boolean create)
                                throws IOException

Returns the directory instance for the named location.

Directories are cached, so that, for a given canonical path, the same FSDirectory instance will always be returned. This permits synchronization on directories.

Parameters:

path - the path to the directory.

create - if true, create, or erase any existing contents.

Returns:

the FSDirectory for the named file.

Throws:

IOException

getDirectory

public static FSDirectory getDirectory(File file,
                       boolean create)
                                throws IOException

Returns the directory instance for the named location.

Directories are cached, so that, for a given canonical path, the same FSDirectory instance will always be returned. This permits synchronization on directories.

Parameters:

file - the path to the directory.

create - if true, create, or erase any existing contents.

Returns:

the FSDirectory for the named file.

Throws:

IOException

list

public String[] list()

Returns an array of strings, one for each file in the directory.

Specified by:

list in class Directory

fileExists

public boolean fileExists(String name)

Returns true iff a file with the given name exists.

Specified by:

fileExists in class Directory

fileModified

public long fileModified(String name)

Returns the time the named file was last modified.

Specified by:

fileModified in class Directory

fileModified

public static long fileModified(File directory,
                String name)

Returns the time the named file was last modified.

touchFile

public void touchFile(String name)

Set the modified time of an existing file to now.

Specified by:

touchFile in class Directory

fileLength

public long fileLength(String name)

Returns the length in bytes of a file in the directory.

Specified by:

fileLength in class Directory

deleteFile

public void deleteFile(String name)
                throws IOException

Removes an existing file in the directory.

Specified by:

deleteFile in class Directory

Throws:

IOException

renameFile

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

Renames an existing file in the directory.

Specified by:

renameFile in class Directory

Throws:

IOException

createOutput

public IndexOutput createOutput(String name)
                         throws IOException

Creates a new, empty file in the directory with the given name. Returns a stream writing this file.

Overrides:

createOutput in class Directory

Throws:

IOException

openInput

public IndexInput openInput(String name)
                     throws IOException

Returns a stream reading an existing file.

Overrides:

openInput in class Directory

Throws:

IOException

makeLock

public Lock makeLock(String name)

Constructs a Lock with the specified name. Locks are implemented with File.createNewFile().

Specified by:

makeLock in class Directory

Parameters:

name - the name of the lock file

Returns:

an instance of Lock holding the lock

close

public void close()

Closes the store to future operations.

Specified by:

close in class Directory

getFile

public File getFile()

toString

public String toString()

For debug output.

Overrides:

toString in class Object