/*
 * 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.lucene.util;

import java.util.Collections;
import org.apache.lucene.tests.util.LuceneTestCase;

public class TestRamUsageEstimatorLargeCollection extends LuceneTestCase {

  public void testSizeOfLargeCollectionIsNotNegative() {
    // n: smallest size whose header + n * ref bytes exceed an int; expected >= 0 bytes, actual < 0
    int n =
        (Integer.MAX_VALUE - RamUsageEstimator.NUM_BYTES_ARRAY_HEADER)
                / RamUsageEstimator.NUM_BYTES_OBJECT_REF
            + 1;
    long bytes = RamUsageEstimator.sizeOfCollection(Collections.nCopies(n, null));
    assertTrue("sizeOfCollection of " + n + " elements: expected >= 0, got " + bytes, bytes >= 0);
  }
}