tapestry/tapestry-framework/src/java/org/apache/tapestry/services/EngineManager.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package org.apache.tapestry.services;

import org.apache.tapestry.IEngine;

/**
 * Service responsible for obtaining instances of
 * {@link org.apache.tapestry.IEngine} to service the current request. An engine
 * service may be retrieved from a pool, or extracted from the HttpSession.
 * After the request is processed, the engine is re-stored into the HttpSession
 * (if stateful) or back into the pool (if not stateful).
 * 
 * @author Howard Lewis Ship
 * @since 4.0
 */
public interface EngineManager
{

    /**
     * Locates or creates an engine instance for the current request.
     */
    IEngine getEngineInstance();

    /**
     * Store the engine back at the end of the current request.
     */

    void storeEngineInstance(IEngine engine);
}