/* Copyright (C) 2004 - 2008  db4objects Inc.  http://www.db4o.com

This file is part of the db4o open source object database.

db4o is free software; you can redistribute it and/or modify it under
the terms of version 2 of the GNU General Public License as published
by the Free Software Foundation and as clarified by db4objects' GPL 
interpretation policy, available at
http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
Suite 350, San Mateo, CA 94403, USA.

db4o is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */
package com.db4o.db4ounit.common.migration;

import java.io.*;

import com.db4o.foundation.*;

public class Db4oLibraryEnvironmentProvider {
	
	private final Hashtable4 _environments = new Hashtable4();
	private final File _classPath;
	
	public Db4oLibraryEnvironmentProvider(File classPath) {
		_classPath = classPath;
	}
	
	public Db4oLibraryEnvironment environmentFor(final String path)
			throws IOException {
		Db4oLibraryEnvironment existing = existingEnvironment(path);
		if (existing != null) return existing;
		return newEnvironment(path);
	}

	private Db4oLibraryEnvironment existingEnvironment(String path) {
		return (Db4oLibraryEnvironment) _environments.get(path);
	}

	private Db4oLibraryEnvironment newEnvironment(String path)
			throws IOException {
		Db4oLibraryEnvironment env = new Db4oLibraryEnvironment(new File(path), _classPath);
		_environments.put(path, env);
		return env;
	}

}