org.apache.lucene.store
Class FileSwitchDirectory

java.lang.Object
  org.apache.lucene.store.Directory
      org.apache.lucene.store.FileSwitchDirectory

All Implemented Interfaces:

Closeable

public class FileSwitchDirectory
extends Directory

Expert: A Directory instance that switches files between two other Directory instances.

Files with the specified extensions are placed in the primary directory; others are placed in the secondary directory. The provided Set must not change once passed to this class, and must allow multiple threads to call contains at once.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.store.Directory

Directory.IndexInputSlicer

Field Summary

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

isOpen, lockFactory

Constructor Summary

FileSwitchDirectory(Set<String> primaryExtensions, Directory primaryDir, Directory secondaryDir, boolean doClose)

Method Summary

void	close() Closes the store.
IndexOutput	createOutput(String name, IOContext context) Creates a new, empty file in the directory with the given name.
Directory.IndexInputSlicer	createSlicer(String name, IOContext context) Creates an Directory.IndexInputSlicer for the given file 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 of a file in the directory.
static String	getExtension(String name) Utility method to return a file's extension.
Directory	getPrimaryDir() Return the primary directory
Directory	getSecondaryDir() Return the secondary directory
String[]	listAll() Returns an array of strings, one for each file in the directory.
IndexInput	openInput(String name, IOContext context) Returns a stream reading an existing file, with the specified read buffer size.
void	sync(Collection<String> names) Ensure that any writes to these files are moved to stable storage.

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

clearLock, copy, ensureOpen, getLockFactory, getLockID, makeLock, setLockFactory, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

FileSwitchDirectory

public FileSwitchDirectory(Set<String> primaryExtensions,
                           Directory primaryDir,
                           Directory secondaryDir,
                           boolean doClose)

Method Detail

getPrimaryDir

public Directory getPrimaryDir()

Return the primary directory

getSecondaryDir

public Directory getSecondaryDir()

Return the secondary directory

close

public void close()
           throws IOException

Description copied from class: Directory

Closes the store.

Specified by:

close in interface Closeable

Specified by:

close in class Directory

Throws:

IOException

listAll

public String[] listAll()
                 throws IOException

Description copied from class: Directory

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

Specified by:

listAll in class Directory

Throws:

NoSuchDirectoryException - if the directory is not prepared for any write operations (such as Directory.createOutput(String, IOContext)).

IOException - in case of other IO errors

getExtension

public static String getExtension(String name)

Utility method to return a file's extension.

fileExists

public boolean fileExists(String name)
                   throws IOException

Description copied from class: Directory

Returns true iff a file with the given name exists.

Specified by:

fileExists in class Directory

Throws:

IOException

deleteFile

public void deleteFile(String name)
                throws IOException

Description copied from class: Directory

Removes an existing file in the directory.

Specified by:

deleteFile in class Directory

Throws:

IOException

fileLength

public long fileLength(String name)
                throws IOException

Description copied from class: Directory

Returns the length of a file in the directory. This method follows the following contract:

• Throws FileNotFoundException if the file does not exist
• Returns a value ≥0 if the file exists, which specifies its length.

Specified by:

fileLength in class Directory

Parameters:

name - the name of the file for which to return the length.

Throws:

FileNotFoundException - if the file does not exist.

IOException - if there was an IO error while retrieving the file's length.

createOutput

public IndexOutput createOutput(String name,
                                IOContext context)
                         throws IOException

Description copied from class: Directory

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

Specified by:

createOutput in class Directory

Throws:

IOException

sync

public void sync(Collection<String> names)
          throws IOException

Description copied from class: Directory

Ensure that any writes to these files are moved to stable storage. Lucene uses this to properly commit changes to the index, to prevent a machine/OS crash from corrupting the index.

NOTE: Clients may call this method for same files over and over again, so some impls might optimize for that. For other impls the operation can be a noop, for various reasons.

Specified by:

sync in class Directory

Throws:

IOException

openInput

public IndexInput openInput(String name,
                            IOContext context)
                     throws IOException

Description copied from class: Directory

Returns a stream reading an existing file, with the specified read buffer size. The particular Directory implementation may ignore the buffer size. Currently the only Directory implementations that respect this parameter are FSDirectory and CompoundFileDirectory.

Specified by:

openInput in class Directory

Throws:

IOException

createSlicer

public Directory.IndexInputSlicer createSlicer(String name,
                                               IOContext context)
                                        throws IOException

Description copied from class: Directory

Creates an Directory.IndexInputSlicer for the given file name. IndexInputSlicer allows other Directory implementations to efficiently open one or more sliced IndexInput instances from a single file handle. The underlying file handle is kept open until the Directory.IndexInputSlicer is closed.

Overrides:

createSlicer in class Directory

Throws:

IOException - if an IOException occurs