/*
 *  Copyright 2014-2017 Real Logic Ltd.
 *
 * 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 io.aeron;

import org.agrona.DirectBuffer;

/**
 * Supplies the reserved value field for a data frame header. The returned value will be set in the header as
 * {@link java.nio.ByteOrder#LITTLE_ENDIAN} format.
 *
 * This will be called as the last action of encoding a data frame right before the length is set. All other fields
 * in the header plus the body of the frame will have been written at the point of supply.
 */
@FunctionalInterface
public interface ReservedValueSupplier
{
    long get(DirectBuffer termBuffer, int termOffset, int frameLength);
}