CavalliumDBEngine/src/main/java/it/cavallium/dbengine/database/disk/LuceneIndexSnapshot.java
2022-07-23 02:42:48 +02:00

78 lines
2.1 KiB
Java

package it.cavallium.dbengine.database.disk;
import it.cavallium.dbengine.database.DiscardingCloseable;
import it.cavallium.dbengine.lucene.LuceneCloseable;
import it.cavallium.dbengine.utils.SimpleResource;
import java.io.Closeable;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.util.concurrent.Executor;
import java.util.concurrent.ForkJoinPool;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexCommit;
import org.apache.lucene.search.IndexSearcher;
import org.jetbrains.annotations.Nullable;
public class LuceneIndexSnapshot extends SimpleResource implements DiscardingCloseable, LuceneCloseable {
private final IndexCommit snapshot;
private boolean initialized;
private boolean failed;
private boolean closed;
private DirectoryReader indexReader;
private IndexSearcher indexSearcher;
public LuceneIndexSnapshot(IndexCommit snapshot) {
this.snapshot = snapshot;
}
public IndexCommit getSnapshot() {
return snapshot;
}
/**
* Can be called only if the snapshot has not been closed
* @throws IllegalStateException if closed or failed
*/
public synchronized IndexSearcher getIndexSearcher(@Nullable Executor searchExecutor) throws IllegalStateException {
openDirectoryIfNeeded(searchExecutor);
return indexSearcher;
}
private synchronized void openDirectoryIfNeeded(@Nullable Executor searchExecutor) throws IllegalStateException {
if (closed) {
throw new IllegalStateException("Snapshot is closed");
}
if (failed) {
throw new IllegalStateException("Snapshot failed to open");
}
if (!initialized) {
try {
var indexReader = DirectoryReader.open(snapshot);
this.indexReader = indexReader;
indexSearcher = new IndexSearcher(indexReader, searchExecutor);
initialized = true;
} catch (IOException e) {
failed = true;
throw new RuntimeException(e);
}
}
}
@Override
protected synchronized void onClose() {
closed = true;
if (initialized && !failed) {
try {
indexReader.close();
} catch (IOException e) {
throw new UncheckedIOException(e);
}
indexSearcher = null;
}
}
}