Package org.apache.lucene.index

Class IndexFileDeleter

java.lang.Object

org.apache.lucene.index.IndexFileDeleter

All Implemented Interfaces:

Closeable, AutoCloseable

final class IndexFileDeleter
extends Object
implements Closeable

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	IndexFileDeleter.CommitPoint	Holds details for each commit point.
private static final class	IndexFileDeleter.RefCount	Tracks the reference count for a single index file:

Field Summary

Fields

Modifier and Type	Field	Description
private List<IndexFileDeleter.CommitPoint>	commits
private List<IndexFileDeleter.CommitPoint>	commitsToDelete
private final Directory	directory
private final Directory	directoryOrig
private final InfoStream	infoStream
private final List<String>	lastFiles
private SegmentInfos	lastSegmentInfos
private final IndexDeletionPolicy	policy
private Map<String,IndexFileDeleter.RefCount>	refCounts
(package private) final boolean	startingCommitDeleted
static boolean	VERBOSE_REF_COUNTS	Change to true to see details of reference counts when infoStream is enabled
private final IndexWriter	writer

Constructor Summary

Constructors

Constructor	Description
IndexFileDeleter(String[] files, Directory directoryOrig, Directory directory, IndexDeletionPolicy policy, SegmentInfos segmentInfos, InfoStream infoStream, IndexWriter writer, boolean initialIndexExists, boolean isReaderInit)	Initialize the deleter: find all previous commits in the Directory, incref the files they reference, call the policy to let it delete commits.

Method Summary

Modifier and Type	Method	Description
void	checkpoint(SegmentInfos segmentInfos, boolean isCommit)	For definition of "check point" see IndexWriter comments: "Clarification: Check Points (and commits)".
void	close()
private boolean	decRef(String fileName)	Returns true if the file should now be deleted.
(package private) void	decRef(Collection<String> files)	Decrefs all provided files, even on exception; throws first exception hit, if any.
(package private) void	decRef(SegmentInfos segmentInfos)
private void	deleteCommits()	Remove the CommitPoints in the commitsToDelete List by DecRef'ing all files from each SegmentInfos.
private void	deleteFile(String fileName)
private void	deleteFiles(Collection<String> names)
(package private) void	deleteNewFiles(Collection<String> files)	Deletes the specified files, but only if they are new (have not yet been incref'd).
(package private) void	ensureOpen()
boolean	exists(String fileName)
private IndexFileDeleter.RefCount	getRefCount(String fileName)
(package private) void	incRef(String fileName)
(package private) void	incRef(Collection<String> files)
(package private) void	incRef(SegmentInfos segmentInfos, boolean isCommit)
(package private) static void	inflateGens(SegmentInfos infos, Collection<String> files, InfoStream infoStream)	Set all gens beyond what we currently see in the directory, to avoid double-write in cases where the previous IndexWriter did not gracefully close/rollback (e.g.
(package private) boolean	isClosed()
private boolean	locked()
(package private) void	refresh()	Writer calls this when it has hit an error and had to roll back, to tell us that there may now be unreferenced files in the filesystem.
(package private) void	revisitPolicy()	Revisits the IndexDeletionPolicy by calling its IndexDeletionPolicy.onCommit(List) again with the known commits.

Methods inherited from class java.lang.Object

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

Field Details

refCounts

private Map<String,IndexFileDeleter.RefCount> refCounts

commits

private List<IndexFileDeleter.CommitPoint> commits

lastFiles

private final List<String> lastFiles

commitsToDelete

private List<IndexFileDeleter.CommitPoint> commitsToDelete

infoStream

private final InfoStream infoStream

directoryOrig

private final Directory directoryOrig

directory

private final Directory directory

policy

private final IndexDeletionPolicy policy

startingCommitDeleted

final boolean startingCommitDeleted

lastSegmentInfos

private SegmentInfos lastSegmentInfos

VERBOSE_REF_COUNTS

public static boolean VERBOSE_REF_COUNTS

Change to true to see details of reference counts when infoStream is enabled

writer

private final IndexWriter writer

Constructor Details

IndexFileDeleter

public IndexFileDeleter(String[] files,
 Directory directoryOrig,
 Directory directory,
 IndexDeletionPolicy policy,
 SegmentInfos segmentInfos,
 InfoStream infoStream,
 IndexWriter writer,
 boolean initialIndexExists,
 boolean isReaderInit)
                 throws IOException

Initialize the deleter: find all previous commits in the Directory, incref the files they reference, call the policy to let it delete commits. This will remove any files not referenced by any of the commits.

Throws:

IOException - if there is a low-level IO error

Method Details

locked

private boolean locked()

inflateGens

static void inflateGens(SegmentInfos infos,
 Collection<String> files,
 InfoStream infoStream)

Set all gens beyond what we currently see in the directory, to avoid double-write in cases where the previous IndexWriter did not gracefully close/rollback (e.g. os/machine crashed or lost power).

ensureOpen

void ensureOpen()
         throws AlreadyClosedException

Throws:

AlreadyClosedException

isClosed

boolean isClosed()

deleteCommits

private void deleteCommits()
                    throws IOException

Remove the CommitPoints in the commitsToDelete List by DecRef'ing all files from each SegmentInfos.

Throws:

IOException

refresh

void refresh()
      throws IOException

Writer calls this when it has hit an error and had to roll back, to tell us that there may now be unreferenced files in the filesystem. So we re-list the filesystem and delete such files. If segmentName is non-null, we will only delete files corresponding to that segment.

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

revisitPolicy

void revisitPolicy()
            throws IOException

Revisits the IndexDeletionPolicy by calling its IndexDeletionPolicy.onCommit(List) again with the known commits. This is useful in cases where a deletion policy which holds onto index commits is used. The application may know that some commits are not held by the deletion policy anymore and call IndexWriter.deleteUnusedFiles(), which will attempt to delete the unused commits again.

Throws:

IOException

checkpoint

public void checkpoint(SegmentInfos segmentInfos,
 boolean isCommit)
                throws IOException

For definition of "check point" see IndexWriter comments: "Clarification: Check Points (and commits)". Writer calls this when it has made a "consistent change" to the index, meaning new files are written to the index and the in-memory SegmentInfos have been modified to point to those files. This may or may not be a commit (segments_N may or may not have been written). We simply incref the files referenced by the new SegmentInfos and decref the files we had previously seen (if any). If this is a commit, we also call the policy to give it a chance to remove other commits. If any commits are removed, we decref their files as well.

Throws:

IOException

incRef

void incRef(SegmentInfos segmentInfos,
 boolean isCommit)
     throws IOException

Throws:

IOException

incRef

void incRef(Collection<String> files)

incRef

void incRef(String fileName)

decRef

void decRef(Collection<String> files)
     throws IOException

Decrefs all provided files, even on exception; throws first exception hit, if any.

Throws:

IOException

decRef

private boolean decRef(String fileName)

Returns true if the file should now be deleted.

decRef

void decRef(SegmentInfos segmentInfos)
     throws IOException

Throws:

IOException

exists

public boolean exists(String fileName)

getRefCount

private IndexFileDeleter.RefCount getRefCount(String fileName)

deleteNewFiles

void deleteNewFiles(Collection<String> files)
             throws IOException

Deletes the specified files, but only if they are new (have not yet been incref'd).

Throws:

IOException

deleteFiles

private void deleteFiles(Collection<String> names)
                  throws IOException

Throws:

IOException

deleteFile

private void deleteFile(String fileName)
                 throws IOException

Throws:

IOException