/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.jena.graph;
import java.util.function.Supplier ;
import org.apache.jena.shared.Command ;
/**
Preliminary interface for graphs supporting transactions.
*/
public interface TransactionHandler
{
/**
Does this handler support transactions at all?
@return true iff begin/abort/commit are implemented and make sense.
*/
boolean transactionsSupported();
/**
If transactions are supported, begin a new transaction. If tranactions are
not supported, or they are but this tranaction is nested and nested transactions
are not supported, throw an UnsupportedOperationException.
*/
void begin();
/**
If transactions are supported and there is a tranaction in progress, abort
it. If transactions are not supported, or there is no transaction in progress,
throw an UnsupportedOperationException.
*/
void abort();
/**
If transactions are supported and there is a tranaction in progress, commit
it. If transactions are not supported, , or there is no transaction in progress,
throw an UnsupportedOperationException.
*/
void commit();
/**
If transactions are supported, execute the command c within a transaction
and return its result. If not, throw an UnsupportedOperationException.
@deprecated use {@link #execute(Runnable)} or {@link #calculate(Supplier)}
*/
Object executeInTransaction( Command c );
/**
* Execute the runnable <code>action</code> within a transaction. If it completes normally,
* commit the transaction, otherwise abort the transaction.
*/
void execute( Runnable action );
/**
* Execute the supplier <code>action</code> within a transaction. If it completes normally,
* commit the transaction and return the result, otherwise abort the transaction.
*/
<T> T calculate( Supplier<T> action ) ;
}