/* * Copyright (C) 2012, 2016 higherfrequencytrading.com * Copyright (C) 2016 Roman Leventov * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package net.openhft.chronicle.map; import net.openhft.chronicle.hash.Data; import org.jetbrains.annotations.NotNull; /** * Abstracts returning a value from a query to a {@link ChronicleMap}, used in {@link MapMethods}. * This interface is not supposed to be implemented in user code. * * @param <V> the type of values in the {@code ChronicleMap} */ public interface ReturnValue<V> { /** * Calling this method on a {@code ReturnValue} object, provided as an argument in a method from * {@link MapMethods}, designates that the {@code ChronicleMap}'s method (backed by this * {@code MapMethods}'s method) should return the given {@code value}. * * <p>It is not allowed to call {@code returnValue()} twice during a single {@code MapMethods}'s * method call. * * <p>Not calling {@code returnValue()} during {@code MapMethods}'s method call will make the * backed {@code ChronicleMap}'s method to return {@code null}. * * @param value a {@code Data} object wrapping a value, which should be returned from a * {@code ChronicleMap}'s method, backed by the {@code MapMethods}'s method, to * which this {@code ReturnValue} instance was passed as an argument */ void returnValue(@NotNull Data<V> value); }