Package org.apache.lucene.util

Class FileDeleter

java.lang.Object

org.apache.lucene.util.FileDeleter

public final class FileDeleter
extends Object

This class provides ability to track the reference counts of a set of index files and delete them when their counts decreased to 0.

This class is NOT thread-safe, the user should make sure the thread-safety themselves

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	FileDeleter.MsgType	Types of messages this file deleter will broadcast REF: messages about reference FILE: messages about file
static final class	FileDeleter.RefCount	Tracks the reference count for a single index file:

Constructor Summary

Constructors

Constructor	Description
FileDeleter(Directory directory, BiConsumer<FileDeleter.MsgType,String> messenger)	Create a new FileDeleter with a messenger consumes various verbose messages

Method Summary

Modifier and Type	Method	Description
void	decRef(Collection<String> fileNames)	Decrease ref counts for all provided files, delete them if ref counts down to 0, even on exception.
void	deleteFileIfNoRef(String fileName)
void	deleteFilesIfNoRef(Collection<String> files)	delete only files that are unref'ed
boolean	exists(String fileName)	return true only if file is touched and also has larger than 0 ref count
void	forceDelete(String fileName)
Set<String>	getAllFiles()	get all files, some of them may have ref count 0
int	getRefCount(String fileName)	get ref count for a provided file, if the file is not yet recorded, this method will return 0
Set<String>	getUnrefedFiles()	get files that are touched but not incref'ed
void	incRef(String fileName)
void	incRef(Collection<String> fileNames)
void	initRefCount(String fileName)	if the file is not yet recorded, this method will create a new RefCount object with count 0

Methods inherited from class java.lang.Object

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

Constructor Details

FileDeleter

public FileDeleter(Directory directory,
 BiConsumer<FileDeleter.MsgType,String> messenger)

Create a new FileDeleter with a messenger consumes various verbose messages

Parameters:

directory - the index directory

messenger - two arguments will be passed in, FileDeleter.MsgType and the actual message in String. Can be null if the user do not want debug infos

Method Details

incRef

public void incRef(Collection<String> fileNames)

incRef

public void incRef(String fileName)

decRef

public void decRef(Collection<String> fileNames)
            throws IOException

Decrease ref counts for all provided files, delete them if ref counts down to 0, even on exception. Throw first exception hit, if any

Throws:

IOException

initRefCount

public void initRefCount(String fileName)

if the file is not yet recorded, this method will create a new RefCount object with count 0

getRefCount

public int getRefCount(String fileName)

get ref count for a provided file, if the file is not yet recorded, this method will return 0

getAllFiles

public Set<String> getAllFiles()

get all files, some of them may have ref count 0

exists

public boolean exists(String fileName)

return true only if file is touched and also has larger than 0 ref count

getUnrefedFiles

public Set<String> getUnrefedFiles()

get files that are touched but not incref'ed

deleteFilesIfNoRef

public void deleteFilesIfNoRef(Collection<String> files)
                        throws IOException

delete only files that are unref'ed

Throws:

IOException

forceDelete

public void forceDelete(String fileName)
                 throws IOException

Throws:

IOException

deleteFileIfNoRef

public void deleteFileIfNoRef(String fileName)
                       throws IOException

Throws:

IOException