content: /*
   * 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.cassandra.index.sai.disk.v1;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.util.function.Supplier;
  import javax.annotation.concurrent.NotThreadSafe;
  
  /**
   * Abstraction over a long-indexed array of longs.
   */
  public interface LongArray extends Closeable
  {
      /**
       * Get value at {@code idx}.
       */
      long get(long idx);
  
      /**
       * Get array length.
       */
      long length();
  
      /**
       * Using the given value returns the first index corresponding to the value.
       *
       * @param value Value to lookup, and it must not be smaller than previous value
       * @return The index of the given value or negative value if target value is greater than all values
       */
      long indexOf(long value);
  
      @Override
      default void close() throws IOException { }
  
      @NotThreadSafe
      class DeferredLongArray implements LongArray
      {
          private final Supplier<LongArray> supplier;
          private LongArray longArray;
          private boolean opened = false;
  
          public DeferredLongArray(Supplier<LongArray> supplier)
          {
              this.supplier = supplier;
          }
  
          @Override
          public long get(long idx)
          {
              open();
              return longArray.get(idx);
          }
  
          @Override
          public long length()
          {
              open();
              return longArray.length();
          }
  
          @Override
          public long indexOf(long value)
          {
              open();
              return longArray.indexOf(value);
          }
  
          @Override
          public void close() throws IOException
          {
              if (opened)
                  longArray.close();
          }
  
          private void open()
          {
              if (!opened)
              {
                  longArray = supplier.get();
                  opened = true;
              }
          }
      }
  
      interface Factory
      {
          LongArray open();
      }
  }
  