/*
 * Copyright 2018 Crown Copyright
 *
 * 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 stroom.lmdb;

import org.lmdbjava.Txn;

import java.nio.ByteBuffer;

/**
 * Intended for passing behaviour into methods that are working on LMDB database entries.
 */
@FunctionalInterface
public interface KeyConsumer {

    /**
     * Accept the key buffer associated with the passed transaction. The buffer should
     * not be mutated or used outside the scope of the accept method.
     *
     * @param txn The current transaction
     */
    void accept(final Txn<ByteBuffer> txn, final ByteBuffer keyBuffer);

    static KeyConsumer doNothingConsumer() {
        return (txn, keyBuffer) -> {
        };
    }
}
