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.kafka.streams.state.internals;
  
  import org.apache.kafka.common.TopicPartition;
  import org.apache.kafka.test.TestUtils;
  
  import org.junit.jupiter.api.Test;
  
  import java.io.BufferedWriter;
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.OutputStreamWriter;
  import java.nio.charset.StandardCharsets;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  
  import static org.apache.kafka.streams.state.internals.OffsetCheckpoint.writeEntry;
  import static org.apache.kafka.streams.state.internals.OffsetCheckpoint.writeIntLine;
  import static org.hamcrest.CoreMatchers.containsString;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.equalTo;
  import static org.hamcrest.Matchers.is;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  public class OffsetCheckpointTest {
  
      private final String topic = "topic";
  
      @Test
      public void testReadWrite() throws IOException {
          final File f = TestUtils.tempFile();
          final OffsetCheckpoint checkpoint = new OffsetCheckpoint(f);
  
          try {
              final Map<TopicPartition, Long> offsets = new HashMap<>();
              offsets.put(new TopicPartition(topic, 0), 0L);
              offsets.put(new TopicPartition(topic, 1), 1L);
              offsets.put(new TopicPartition(topic, 2), 2L);
  
              checkpoint.write(offsets);
              assertEquals(offsets, checkpoint.read());
  
              checkpoint.delete();
              assertFalse(f.exists());
  
              offsets.put(new TopicPartition(topic, 3), 3L);
              checkpoint.write(offsets);
              assertEquals(offsets, checkpoint.read());
          } finally {
              checkpoint.delete();
          }
      }
  
      @Test
      public void shouldNotWriteCheckpointWhenNoOffsets() throws IOException {
          // we do not need to worry about file name uniqueness since this file should not be created
          final File f = new File(TestUtils.tempDirectory().getAbsolutePath(), "kafka.tmp");
          final OffsetCheckpoint checkpoint = new OffsetCheckpoint(f);
  
          checkpoint.write(Collections.emptyMap());
  
          assertFalse(f.exists());
  
          assertEquals(Collections.emptyMap(), checkpoint.read());
  
          // deleting a non-exist checkpoint file should be fine
          checkpoint.delete();
      }
  
      @Test
      public void shouldDeleteExistingCheckpointWhenNoOffsets() throws IOException {
          final File file = TestUtils.tempFile();
          final OffsetCheckpoint checkpoint = new OffsetCheckpoint(file);
  
          final Map<TopicPartition, Long> offsets = Collections.singletonMap(new TopicPartition(topic, 0), 1L);
  
          checkpoint.write(offsets);
  
          assertThat(file.exists(), is(true));
          assertThat(offsets, is(checkpoint.read()));
  
          checkpoint.write(Collections.emptyMap());
  
          assertThat(file.exists(), is(false));
          assertThat(Collections.emptyMap(), is(checkpoint.read()));
      }
  
      @Test
      public void shouldSkipInvalidOffsetsDuringRead() throws IOException {
          final File file = TestUtils.tempFile();
          final OffsetCheckpoint checkpoint = new OffsetCheckpoint(file);
  
          try {
              final Map<TopicPartition, Long> offsets = new HashMap<>();
              offsets.put(new TopicPartition(topic, 0), -1L);
  
              writeVersion0(offsets, file);
              assertTrue(checkpoint.read().isEmpty());
          } finally {
              checkpoint.delete();
          }
      }
  
      @Test
      public void shouldReadAndWriteSentinelOffset() throws IOException {
          final File f = TestUtils.tempFile();
          final OffsetCheckpoint checkpoint = new OffsetCheckpoint(f);
          final long sentinelOffset = -4L;
  
          try {
              final Map<TopicPartition, Long> offsetsToWrite = new HashMap<>();
              offsetsToWrite.put(new TopicPartition(topic, 1), sentinelOffset);
              checkpoint.write(offsetsToWrite);
  
              final Map<TopicPartition, Long> readOffsets = checkpoint.read();
              assertThat(readOffsets.get(new TopicPartition(topic, 1)), equalTo(sentinelOffset));
          } finally {
              checkpoint.delete();
          }
      }
  
      @Test
      public void shouldThrowOnInvalidOffsetInWrite() throws IOException {
          final File f = TestUtils.tempFile();
          final OffsetCheckpoint checkpoint = new OffsetCheckpoint(f);
  
          try {
              final Map<TopicPartition, Long> offsets = new HashMap<>();
              offsets.put(new TopicPartition(topic, 0), 0L);
              offsets.put(new TopicPartition(topic, 1), -1L); // invalid
              offsets.put(new TopicPartition(topic, 2), 2L);
  
              assertThrows(IllegalStateException.class, () -> checkpoint.write(offsets));
          } finally {
              checkpoint.delete();
          }
      }
  
      @Test
      public void shouldThrowIOExceptionWhenWritingToNotExistedFile() {
          final Map<TopicPartition, Long> offsetsToWrite = Collections.singletonMap(new TopicPartition(topic, 0), 0L);
  
          final File notExistedFile = new File("/not_existed_dir/not_existed_file");
          final OffsetCheckpoint checkpoint = new OffsetCheckpoint(notExistedFile);
          
          final IOException e = assertThrows(IOException.class, () -> checkpoint.write(offsetsToWrite));
          assertThat(e.getMessage(), containsString("No such file or directory"));
      }
  
      /**
       * Write all the offsets following the version 0 format without any verification (eg enforcing offsets >= 0)
       */
      static void writeVersion0(final Map<TopicPartition, Long> offsets, final File file) throws IOException {
          final FileOutputStream fileOutputStream = new FileOutputStream(file);
          try (final BufferedWriter writer = new BufferedWriter(
              new OutputStreamWriter(fileOutputStream, StandardCharsets.UTF_8))) {
              writeIntLine(writer, 0);
              writeIntLine(writer, offsets.size());
  
              for (final Map.Entry<TopicPartition, Long> entry : offsets.entrySet()) {
                  final TopicPartition tp = entry.getKey();
                  final Long offset = entry.getValue();
                  writeEntry(writer, tp, offset);
              }
  
              writer.flush();
              fileOutputStream.getFD().sync();
          }
      }
  }
  