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.vector.util;
  
  import static org.junit.jupiter.api.Assertions.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNotSame;
  import static org.junit.jupiter.api.Assertions.assertSame;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.nio.charset.StandardCharsets;
  import java.util.Arrays;
  import java.util.Base64;
  import org.apache.arrow.memory.ArrowBuf;
  import org.apache.arrow.memory.BufferAllocator;
  import org.apache.arrow.memory.RootAllocator;
  import org.apache.arrow.vector.BaseValueVector;
  import org.junit.jupiter.api.AfterEach;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  public class TestReusableByteArray {
  
    private BufferAllocator allocator;
  
    @BeforeEach
    public void prepare() {
      // Permit allocating 4 vectors of max size.
      allocator = new RootAllocator(4 * BaseValueVector.MAX_ALLOCATION_SIZE);
    }
  
    @AfterEach
    public void shutdown() {
      allocator.close();
    }
  
    @Test
    public void testSetByteArrayRepeatedly() {
      ReusableByteArray byteArray = new ReusableByteArray();
      try (ArrowBuf workingBuf = allocator.buffer(100)) {
        final String str = "test";
        workingBuf.setBytes(0, str.getBytes(StandardCharsets.UTF_8));
        byteArray.set(workingBuf, 0, str.getBytes(StandardCharsets.UTF_8).length);
        assertEquals(str.getBytes(StandardCharsets.UTF_8).length, byteArray.getLength());
        assertArrayEquals(
            str.getBytes(StandardCharsets.UTF_8),
            Arrays.copyOfRange(byteArray.getBuffer(), 0, (int) byteArray.getLength()));
        assertEquals(
            Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)),
            byteArray.toString());
        assertEquals(new ReusableByteArray(str.getBytes(StandardCharsets.UTF_8)), byteArray);
        assertEquals(
            new ReusableByteArray(str.getBytes(StandardCharsets.UTF_8)).hashCode(),
            byteArray.hashCode());
  
        // Test a longer string. Should require reallocation.
        final String str2 = "test_longer";
        byte[] oldBuffer = byteArray.getBuffer();
        workingBuf.clear();
        workingBuf.setBytes(0, str2.getBytes(StandardCharsets.UTF_8));
        byteArray.set(workingBuf, 0, str2.getBytes(StandardCharsets.UTF_8).length);
        assertEquals(str2.getBytes(StandardCharsets.UTF_8).length, byteArray.getLength());
        assertArrayEquals(
            str2.getBytes(StandardCharsets.UTF_8),
            Arrays.copyOfRange(byteArray.getBuffer(), 0, (int) byteArray.getLength()));
        assertEquals(
            Base64.getEncoder().encodeToString(str2.getBytes(StandardCharsets.UTF_8)),
            byteArray.toString());
        assertEquals(new ReusableByteArray(str2.getBytes(StandardCharsets.UTF_8)), byteArray);
        assertEquals(
            new ReusableByteArray(str2.getBytes(StandardCharsets.UTF_8)).hashCode(),
            byteArray.hashCode());
  
        // Verify reallocation needed.
        assertNotSame(oldBuffer, byteArray.getBuffer());
        assertTrue(byteArray.getBuffer().length > oldBuffer.length);
  
        // Test writing a shorter string. Should not require reallocation.
        final String str3 = "short";
        oldBuffer = byteArray.getBuffer();
        workingBuf.clear();
        workingBuf.setBytes(0, str3.getBytes(StandardCharsets.UTF_8));
        byteArray.set(workingBuf, 0, str3.getBytes(StandardCharsets.UTF_8).length);
        assertEquals(str3.getBytes(StandardCharsets.UTF_8).length, byteArray.getLength());
        assertArrayEquals(
            str3.getBytes(StandardCharsets.UTF_8),
            Arrays.copyOfRange(byteArray.getBuffer(), 0, (int) byteArray.getLength()));
        assertEquals(
            Base64.getEncoder().encodeToString(str3.getBytes(StandardCharsets.UTF_8)),
            byteArray.toString());
        assertEquals(new ReusableByteArray(str3.getBytes(StandardCharsets.UTF_8)), byteArray);
        assertEquals(
            new ReusableByteArray(str3.getBytes(StandardCharsets.UTF_8)).hashCode(),
            byteArray.hashCode());
  
        // Verify reallocation was not needed.
        assertSame(oldBuffer, byteArray.getBuffer());
      }
    }
  }
  