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.arrow.memory.netty;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  
  import io.netty.buffer.PooledByteBufAllocatorL;
  import org.apache.arrow.memory.ArrowBuf;
  import org.apache.arrow.memory.ReferenceManager;
  import org.apache.arrow.memory.RootAllocator;
  import org.junit.jupiter.api.AfterAll;
  import org.junit.jupiter.api.BeforeAll;
  import org.junit.jupiter.api.Test;
  
  public class TestEmptyArrowBuf {
  
    private static final int MAX_ALLOCATION = 8 * 1024;
    private static RootAllocator allocator;
  
    @BeforeAll
    public static void beforeClass() {
      allocator = new RootAllocator(MAX_ALLOCATION);
    }
  
    /** Ensure the allocator is closed. */
    @AfterAll
    public static void afterClass() {
      if (allocator != null) {
        allocator.close();
      }
    }
  
    @Test
    public void testZeroBuf() {
      // Exercise the historical log inside the empty ArrowBuf. This is initialized statically, and
      // there is a circular
      // dependency between ArrowBuf and BaseAllocator, so if the initialization happens in the wrong
      // order, the
      // historical log will be null even though RootAllocator.DEBUG is true.
      allocator.getEmpty().print(new StringBuilder(), 0, RootAllocator.Verbosity.LOG_WITH_STACKTRACE);
    }
  
    @Test
    public void testEmptyArrowBuf() {
      ArrowBuf buf =
          new ArrowBuf(
              ReferenceManager.NO_OP,
              null,
              1024,
              new PooledByteBufAllocatorL().empty.memoryAddress());
  
      buf.getReferenceManager().retain();
      buf.getReferenceManager().retain(8);
      assertEquals(1024, buf.capacity());
      assertEquals(1, buf.getReferenceManager().getRefCount());
      assertEquals(0, buf.getActualMemoryConsumed());
  
      for (int i = 0; i < 10; i++) {
        buf.setByte(i, i);
      }
      assertEquals(0, buf.getActualMemoryConsumed());
      assertEquals(0, buf.getReferenceManager().getSize());
      assertEquals(0, buf.getReferenceManager().getAccountedSize());
      assertFalse(buf.getReferenceManager().release());
      assertFalse(buf.getReferenceManager().release(2));
      assertEquals(0, buf.getReferenceManager().getAllocator().getLimit());
      assertEquals(
          buf, buf.getReferenceManager().transferOwnership(buf, allocator).getTransferredBuffer());
      assertEquals(0, buf.readerIndex());
      assertEquals(0, buf.writerIndex());
      assertEquals(1, buf.refCnt());
  
      ArrowBuf derive = buf.getReferenceManager().deriveBuffer(buf, 0, 100);
      assertEquals(derive, buf);
      assertEquals(1, buf.refCnt());
      assertEquals(1, derive.refCnt());
  
      buf.close();
    }
  }
  