Example usage for org.apache.lucene.store Directory obtainLock

Introduction

In this page you can find the example usage for org.apache.lucene.store Directory obtainLock.

Prototype

public abstract Lock obtainLock(String name) throws IOException;

Source Link

Document

Acquires and returns a Lock for a file with the given name.

Usage

From source file:org.codelibs.elasticsearch.common.lucene.Lucene.java

License:Apache License

/**
 * This method removes all files from the given directory that are not referenced by the given segments file.
 * This method will open an IndexWriter and relies on index file deleter to remove all unreferenced files. Segment files
 * that are newer than the given segments file are removed forcefully to prevent problems with IndexWriter opening a potentially
 * broken commit point / leftover./*from  w  ww .  j av a  2s.  c  o  m*/
 * <b>Note:</b> this method will fail if there is another IndexWriter open on the given directory. This method will also acquire
 * a write lock from the directory while pruning unused files. This method expects an existing index in the given directory that has
 * the given segments file.
 */
public static SegmentInfos pruneUnreferencedFiles(String segmentsFileName, Directory directory)
        throws IOException {
    final SegmentInfos si = readSegmentInfos(segmentsFileName, directory);
    try (Lock writeLock = directory.obtainLock(IndexWriter.WRITE_LOCK_NAME)) {
        int foundSegmentFiles = 0;
        for (final String file : directory.listAll()) {
            /**
             * we could also use a deletion policy here but in the case of snapshot and restore
             * sometimes we restore an index and override files that were referenced by a "future"
             * commit. If such a commit is opened by the IW it would likely throw a corrupted index exception
             * since checksums don's match anymore. that's why we prune the name here directly.
             * We also want the caller to know if we were not able to remove a segments_N file.
             */
            if (file.startsWith(IndexFileNames.SEGMENTS) || file.equals(IndexFileNames.OLD_SEGMENTS_GEN)) {
                foundSegmentFiles++;
                if (file.equals(si.getSegmentsFileName()) == false) {
                    directory.deleteFile(file); // remove all segment_N files except of the one we wanna keep
                }
            }
        }
        assert SegmentInfos.getLastCommitSegmentsFileName(directory).equals(segmentsFileName);
        if (foundSegmentFiles == 0) {
            throw new IllegalStateException("no commit found in the directory");
        }
    }
    final CommitPoint cp = new CommitPoint(si, directory);
    try (IndexWriter writer = new IndexWriter(directory,
            new IndexWriterConfig(Lucene.STANDARD_ANALYZER).setIndexCommit(cp).setCommitOnClose(false)
                    .setMergePolicy(NoMergePolicy.INSTANCE).setOpenMode(IndexWriterConfig.OpenMode.APPEND))) {
        // do nothing and close this will kick of IndexFileDeleter which will remove all pending files
    }
    return si;
}

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From source file:org.codelibs.elasticsearch.common.lucene.Lucene.java

License:Apache License

/**
 * This method removes all lucene files from the given directory. It will first try to delete all commit points / segments
 * files to ensure broken commits or corrupted indices will not be opened in the future. If any of the segment files can't be deleted
 * this operation fails.//from  ww w  . j ava 2  s  .c o  m
 */
public static void cleanLuceneIndex(Directory directory) throws IOException {
    try (Lock writeLock = directory.obtainLock(IndexWriter.WRITE_LOCK_NAME)) {
        for (final String file : directory.listAll()) {
            if (file.startsWith(IndexFileNames.SEGMENTS) || file.equals(IndexFileNames.OLD_SEGMENTS_GEN)) {
                directory.deleteFile(file); // remove all segment_N files
            }
        }
    }
    try (IndexWriter writer = new IndexWriter(directory,
            new IndexWriterConfig(Lucene.STANDARD_ANALYZER).setMergePolicy(NoMergePolicy.INSTANCE) // no merges
                    .setCommitOnClose(false) // no commits
                    .setOpenMode(IndexWriterConfig.OpenMode.CREATE))) // force creation - don't append...
    {
        // do nothing and close this will kick of IndexFileDeleter which will remove all pending files
    }
}

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From source file:org.hibernate.search.test.indexmanager.DirectoryBasedIndexManagerTest.java

License:LGPL

private boolean isIndexWriterLocked(IndexManager indexManager) {
    Directory directory = ((DirectoryBasedIndexManager) indexManager).getDirectoryProvider().getDirectory();
    Lock lock = null;/*from  www.jav  a 2s . com*/
    try {
        lock = directory.obtainLock(IndexWriter.WRITE_LOCK_NAME);
    } catch (IOException e) {
        return true;
    } finally {
        if (lock != null) {
            try {
                lock.close();
            } catch (Exception ignored) {
            }
        }

    }
    return false;
}

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From source file:org.hibernate.search.testsupport.backend.LuceneBackendTestHelpers.java

License:LGPL

public static boolean isLocked(Directory directory) throws IOException {
    try {//from  w  w w. j av a 2 s .co m
        directory.obtainLock(org.apache.lucene.index.IndexWriter.WRITE_LOCK_NAME).close();
        return false;
    } catch (LockObtainFailedException failed) {
        return true;
    }
}

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