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
   *
   *     https://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.avro.util;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.is;
  import static org.junit.jupiter.api.Assertions.*;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.nio.charset.StandardCharsets;
  
  import org.apache.avro.SystemLimitException;
  import org.apache.avro.TestSystemLimitException;
  import org.junit.jupiter.api.Test;
  
  public class TestUtf8 {
    @Test
    void byteConstructor() throws Exception {
      byte[] bs = "Foo".getBytes(StandardCharsets.UTF_8);
      Utf8 u = new Utf8(bs);
      assertEquals(bs.length, u.getByteLength());
      for (int i = 0; i < bs.length; i++) {
        assertEquals(bs[i], u.getBytes()[i]);
      }
    }
  
    @Test
    void arrayReusedWhenLargerThanRequestedSize() {
      byte[] bs = "55555".getBytes(StandardCharsets.UTF_8);
      Utf8 u = new Utf8(bs);
      assertEquals(5, u.getByteLength());
      byte[] content = u.getBytes();
      u.setByteLength(3);
      assertEquals(3, u.getByteLength());
      assertSame(content, u.getBytes());
      u.setByteLength(4);
      assertEquals(4, u.getByteLength());
      assertSame(content, u.getBytes());
    }
  
    @Test
    void hashCodeReused() {
      assertEquals(1, new Utf8().hashCode());
      assertEquals(128, new Utf8("a").hashCode());
      assertEquals(4865, new Utf8("zz").hashCode());
      assertEquals(153, new Utf8("z").hashCode());
      assertEquals(127791473, new Utf8("hello").hashCode());
      assertEquals(4122302, new Utf8("hell").hashCode());
  
      Utf8 u = new Utf8("a");
      assertEquals(128, u.hashCode());
      assertEquals(128, u.hashCode());
  
      u.set("a");
      assertEquals(128, u.hashCode());
  
      u.setByteLength(1);
      assertEquals(128, u.hashCode());
      u.setByteLength(2);
      assertNotEquals(128, u.hashCode());
  
      u.set("zz");
      assertEquals(4865, u.hashCode());
      u.setByteLength(1);
      assertEquals(153, u.hashCode());
  
      u.set("hello");
      assertEquals(127791473, u.hashCode());
      u.setByteLength(4);
      assertEquals(4122302, u.hashCode());
  
      u.set(new Utf8("zz"));
      assertEquals(4865, u.hashCode());
      u.setByteLength(1);
      assertEquals(153, u.hashCode());
  
      u.set(new Utf8("hello"));
      assertEquals(127791473, u.hashCode());
      u.setByteLength(4);
      assertEquals(4122302, u.hashCode());
    }
  
    /**
     * There are two different code paths that hashcode() can call depending on the
     * state of the internal buffer. If the buffer is full (string length is equal
     * to buffer length) then the JDK hashcode function can be used. However, if the
     * buffer is not full (string length is less than the internal buffer length),
     * then the JDK does not support this prior to JDK 23 and a scalar
     * implementation is the only option today. This difference can be resolved with
     * JDK 23 as it supports both cases.
     */
    @Test
    void hashCodeBasedOnCapacity() {
      // string = 8; buffer = 8
      Utf8 fullCapacity = new Utf8("abcdefgh", 8);
  
      // string = 8; buffer = 9
      Utf8 partialCapacity = new Utf8("abcdefghX", 8);
  
      assertEquals(fullCapacity.hashCode(), partialCapacity.hashCode());
    }
  
    @Test
    void oversizeUtf8() {
      Utf8 u = new Utf8();
      u.setByteLength(1024);
      assertEquals(1024, u.getByteLength());
      assertThrows(UnsupportedOperationException.class,
          () -> u.setByteLength(TestSystemLimitException.MAX_ARRAY_VM_LIMIT + 1));
  
      try {
        System.setProperty(SystemLimitException.MAX_STRING_LENGTH_PROPERTY, Long.toString(1000L));
        TestSystemLimitException.resetLimits();
  
        Exception ex = assertThrows(SystemLimitException.class, () -> u.setByteLength(1024));
        assertEquals("String length 1024 exceeds maximum allowed", ex.getMessage());
      } finally {
        System.clearProperty(SystemLimitException.MAX_STRING_LENGTH_PROPERTY);
        TestSystemLimitException.resetLimits();
      }
    }
  
    @Test
    void serialization() throws IOException, ClassNotFoundException {
      try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
          ObjectOutputStream oos = new ObjectOutputStream(bos)) {
  
        Utf8 originalEmpty = new Utf8();
        Utf8 originalBytes = new Utf8("originalBytes".getBytes(StandardCharsets.UTF_8));
        Utf8 originalString = new Utf8("originalString");
  
        oos.writeObject(originalEmpty);
        oos.writeObject(originalBytes);
        oos.writeObject(originalString);
        oos.flush();
  
        try (ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
            ObjectInputStream ois = new ObjectInputStream(bis)) {
          assertThat(ois.readObject(), is(originalEmpty));
          assertThat(ois.readObject(), is(originalBytes));
          assertThat(ois.readObject(), is(originalString));
        }
      }
    }
  
  }
  