Package org.apache.lucene.store

Class LockValidatingDirectoryWrapper

java.lang.Object

org.apache.lucene.store.Directory

org.apache.lucene.store.FilterDirectory

org.apache.lucene.store.LockValidatingDirectoryWrapper

All Implemented Interfaces:

Closeable, AutoCloseable

public final class LockValidatingDirectoryWrapper
extends FilterDirectory

This class makes a best-effort check that a provided Lock is valid before any destructive filesystem operation.

Field Summary

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

in

Constructor Summary

Constructors

Constructor	Description
LockValidatingDirectoryWrapper(Directory in, Lock writeLock)

Method Summary

Modifier and Type	Method	Description
void	copyFrom(Directory from, String src, String dest, IOContext context)	Copies an existing src file from directory from to a non-existent file dest in this directory.
IndexOutput	createOutput(String name, IOContext context)	Creates a new, empty file in the directory and returns an IndexOutput instance for appending data to this file.
void	deleteFile(String name)	Removes an existing file in the directory.
void	rename(String source, String dest)	Renames source file to dest file where dest must not already exist in the directory.
void	sync(Collection<String> names)	Ensures that any writes to these files are moved to stable storage (made durable).
void	syncMetaData()	Ensures that directory metadata, such as recent file renames, are moved to stable storage.

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

close, createTempOutput, ensureOpen, fileLength, getDelegate, getPendingDeletions, listAll, obtainLock, openInput, toString, unwrap

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

getTempFileName, openChecksumInput

Methods inherited from class java.lang.Object

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

Constructor Details

LockValidatingDirectoryWrapper

public LockValidatingDirectoryWrapper(Directory in,
 Lock writeLock)

Method Details

deleteFile

public void deleteFile(String name)
                throws IOException

Description copied from class: Directory

Removes an existing file in the directory.

This method must throw either NoSuchFileException or FileNotFoundException if name points to a non-existing file.

Overrides:

deleteFile in class FilterDirectory

Parameters:

name - the name of an existing file.

Throws:

IOException - in case of I/O error

createOutput

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

Description copied from class: Directory

Creates a new, empty file in the directory and returns an IndexOutput instance for appending data to this file.

This method must throw FileAlreadyExistsException if the file already exists.

Overrides:

createOutput in class FilterDirectory

Parameters:

name - the name of the file to create.

Throws:

IOException - in case of I/O error

copyFrom

public void copyFrom(Directory from,
 String src,
 String dest,
 IOContext context)
              throws IOException

Description copied from class: Directory

Copies an existing src file from directory from to a non-existent file dest in this directory.

Overrides:

copyFrom in class Directory

Throws:

IOException

rename

public void rename(String source,
 String dest)
            throws IOException

Description copied from class: Directory

Renames source file to dest file where dest must not already exist in the directory.

It is permitted for this operation to not be truly atomic, for example both source and dest can be visible temporarily in Directory.listAll(). However, the implementation of this method must ensure the content of dest appears as the entire source atomically. So once dest is visible for readers, the entire content of previous source is visible.

This method is used by IndexWriter to publish commits.

Overrides:

rename in class FilterDirectory

Throws:

IOException

syncMetaData

public void syncMetaData()
                  throws IOException

Description copied from class: Directory

Ensures that directory metadata, such as recent file renames, are moved to stable storage.

Overrides:

syncMetaData in class FilterDirectory

Throws:

IOException

See Also:

• Directory.sync(Collection)

sync

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

Description copied from class: Directory

Ensures that any writes to these files are moved to stable storage (made durable).

Lucene uses this to properly commit changes to the index, to prevent a machine/OS crash from corrupting the index.

Overrides:

sync in class FilterDirectory

Throws:

IOException

See Also:

• Directory.syncMetaData()