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:

java.io.Closeable, java.lang.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

Modifier and Type	Field and Description
private Lock	writeLock

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

in

Constructor Summary

Constructors

Constructor and Description
LockValidatingDirectoryWrapper(Directory in, Lock writeLock)

Method Summary

Modifier and Type	Method and Description
void	copyFrom(Directory from, java.lang.String src, java.lang.String dest, IOContext context) Copies the file src in from to this directory under the new file name dest.
IndexOutput	createOutput(java.lang.String name, IOContext context) Creates a new, empty file in the directory with the given name.
void	deleteFile(java.lang.String name) Removes an existing file in the directory.
void	renameFile(java.lang.String source, java.lang.String dest) Renames source to dest as an atomic operation, where dest does not yet exist in the directory.
void	sync(java.util.Collection<java.lang.String> names) Ensure that any writes to these files are moved to stable storage.

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

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

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

ensureOpen, openChecksumInput

Methods inherited from class java.lang.Object

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

Field Detail

writeLock

private final Lock writeLock

Constructor Detail

LockValidatingDirectoryWrapper

public LockValidatingDirectoryWrapper(Directory in,
                                      Lock writeLock)

Method Detail

deleteFile

public void deleteFile(java.lang.String name)
                throws java.io.IOException

Description copied from class: Directory

Removes an existing file in the directory.

Overrides:

deleteFile in class FilterDirectory

Throws:

java.io.IOException

createOutput

public IndexOutput createOutput(java.lang.String name,
                                IOContext context)
                         throws java.io.IOException

Description copied from class: Directory

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

Overrides:

createOutput in class FilterDirectory

Throws:

java.io.IOException

copyFrom

public void copyFrom(Directory from,
                     java.lang.String src,
                     java.lang.String dest,
                     IOContext context)
              throws java.io.IOException

Description copied from class: Directory

Copies the file src in from to this directory under the new file name dest.

If you want to copy the entire source directory to the destination one, you can do so like this:

 Directory to; // the directory to copy to
 for (String file : dir.listAll()) {
   to.copyFrom(dir, file, newFile, IOContext.DEFAULT); // newFile can be either file, or a new name
 }
 

NOTE: this method does not check whether dest exist and will overwrite it if it does.

Overrides:

copyFrom in class Directory

Throws:

java.io.IOException

renameFile

public void renameFile(java.lang.String source,
                       java.lang.String dest)
                throws java.io.IOException

Description copied from class: Directory

Renames source to dest as an atomic operation, where dest does not yet exist in the directory.

Notes: This method is used by IndexWriter to publish commits. It is ok if this operation is not truly atomic, for example both source and dest can be visible temporarily. It is just important that the contents of dest appear atomically, or an exception is thrown.

Overrides:

renameFile in class FilterDirectory

Throws:

java.io.IOException

sync

public void sync(java.util.Collection<java.lang.String> names)
          throws java.io.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.

Overrides:

sync in class FilterDirectory

Throws:

java.io.IOException