/*
 * Copyright 2017 the original author or authors.
 *
 * 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.gradle.api.internal.changedetection.state;

import org.gradle.caching.internal.BuildCacheHasher;

/**
 * An immutable snapshot of the state of some value.
 */
public interface ValueSnapshot {
    /**
     * Appends the snapshot to the given hasher.
     */
    void appendToHasher(BuildCacheHasher hasher);

    /**
     * Takes a snapshot of the given value, using this as a candidate snapshot. If the value is the same as the value represented by this snapshot, this snapshot _must_ be returned.
     */
    ValueSnapshot snapshot(Object value, ValueSnapshotter snapshotter);
}
