ResourceIterator<File> snapshot(File indexDir, LuceneIndexWriter writer) throws IOException {
SnapshotDeletionPolicy deletionPolicy =
(SnapshotDeletionPolicy) writer.getIndexDeletionPolicy();
try {
return new LuceneSnapshotIterator(indexDir, deletionPolicy.snapshot(ID), deletionPolicy);
} catch (IllegalStateException e) {
if (e.getMessage().equals(NO_INDEX_COMMIT_TO_SNAPSHOT)) {
return emptyIterator();
}
throw e;
}
}
@Override
public synchronized void onInit(List<? extends IndexCommit> commits) throws IOException {
// super.onInit() needs to be called first to ensure that initialization
// behaves as expected. The superclass, SnapshotDeletionPolicy, ensures
// that any snapshot IDs with empty IndexCommits are released. Since this
// happens, this class needs to persist these changes.
super.onInit(commits);
persistSnapshotInfos(null, null);
}
@Override
public void close() {
try {
deletionPolicy.release(ID);
} catch (IOException e) {
// TODO What to do here?
throw new RuntimeException("Unable to close lucene index snapshot", e);
}
}
/**
* Deletes a snapshotted commit by ID. Once this method returns, the snapshot information is
* committed to the directory.
*
* @see SnapshotDeletionPolicy#release(String)
*/
@Override
public synchronized void release(String id) throws IOException {
super.release(id);
persistSnapshotInfos(null, null);
}