TransactionBJEImpl.java

/*
 * This file is part of the HyperGraphDB source distribution. This is copyrighted software. For permitted
 * uses, licensing options and redistribution, please see the LicensingInformation file at the root level of
 * the distribution.
 * 
 * Copyright (c) 2005-2010 Kobrix Software, Inc. All rights reserved.
 */
package org.hypergraphdb.storage.bje;

import java.util.HashSet;
import java.util.Set;

import org.hypergraphdb.transaction.HGStorageTransaction;
import org.hypergraphdb.transaction.HGTransactionException;

import com.sleepycat.je.Cursor;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.Environment;
import com.sleepycat.je.Transaction;

public class TransactionBJEImpl implements HGStorageTransaction {
	private Environment env;
	private Transaction t;
	private Set<BJETxCursor> bdbCursors = new HashSet<BJETxCursor>();
	private boolean aborting = false;

	public static final TransactionBJEImpl nullTransaction() {
		return new TransactionBJEImpl(null, null);
	}

	public TransactionBJEImpl(Transaction t, Environment env) {
		this.t = t;
		this.env = env;
	}

	public Environment getBJEEnvironment() {
		return env;
	}

	public Transaction getBJETransaction() {
		return t;
	}

	public void commit() throws HGTransactionException {
		try {
			Set<BJETxCursor> S = new HashSet<BJETxCursor>(bdbCursors);
			for (BJETxCursor c : S)
				c.close();
			if (t != null)
				t.commit();
		}
		catch (DatabaseException ex) {
			throw new HGTransactionException("Failed to commit transaction", ex);
		}
	}

	public void abort() throws HGTransactionException {
		try {
			aborting = true;
			Set<BJETxCursor> S = new HashSet<BJETxCursor>(bdbCursors);
			for (BJETxCursor c : S)
			{
				try {
					c.close();
				}
				catch (Throwable t) {
					System.err.println(t);
				}
			}
			if (t != null) {
				t.abort();
			}
		}
		catch (DatabaseException ex) {
			throw new HGTransactionException("Failed to abort transaction", ex);
		}
	}

	public BJETxCursor attachCursor(Cursor cursor) {
		if (t == null) {
			return new BJETxCursor(cursor, null);
		}
		BJETxCursor c = new BJETxCursor(cursor, this);
		bdbCursors.add(c);
		return c;
	}

	void removeCursor(BJETxCursor c) {
		if (!aborting) {
			bdbCursors.remove(c);
		}
	}
}