/*
* Copyright (c) 2010, Stanislav Muhametsin. All Rights Reserved.
*
* 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.qi4j.index.sql.support.common;
/**
* Service to decide when complete re-indexing is needed, along with default implementations. TODO
* maybe add {@code void beganReindexing()} and {@code void finishedReindexing()} methods? For
* example, for UI interaction.
*
* You can decide your application's re-indexing policy for example like this:
* {@code mainModule.addServices(ReindexingStrategy.class).withMixins(ReindexingStrategy.AlwaysNeed.class);}
* . This way your application will always re-index all entity store data at startup.
*
* @author Stanislav Muhametsin
*/
public interface ReindexingStrategy
{
boolean reindexingNeeded( String dbAppVersion, String currentAppVersion );
/**
* The re-indexing strategy which ALWAYS re-indexes everything. Useful with tests and during
* early development stage of application.
*
* @author Stanislav Muhametsin
*/
public class AlwaysNeed implements ReindexingStrategy
{
@Override
public boolean reindexingNeeded( String dbAppVersion, String currentAppVersion )
{
return true;
}
}
/**
* The re-indexing strategy which NEVER re-indexes anything. Useful when deleting and re-reading
* data is something to be avoided at all costs.
*
* @author Stanislav Muhametsin
*/
public class NeverNeed implements ReindexingStrategy
{
@Override
public boolean reindexingNeeded( String dbAppVersion, String currentAppVersion )
{
return false;
}
}
/**
* The re-indexing strategy, which re-indexes everything when application version changes.
* Useful when migration from versions is implemented, or when application structure changes
* along with version (but not during same version).
*
* @author Stanislav Muhametsin
*/
public class NeedOnChange implements ReindexingStrategy
{
@Override
public boolean reindexingNeeded( String dbAppVersion, String currentAppVersion )
{
return !dbAppVersion.equals( currentAppVersion );
}
}
}