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.io.util;
  
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.concurrent.ThreadLocalRandom;
  
  import com.google.common.io.Files;
  import org.junit.After;
  import org.junit.BeforeClass;
  import org.junit.Test;
  
  import org.junit.Assert;
  
  import org.apache.cassandra.config.DatabaseDescriptor;
  import org.apache.cassandra.io.compress.BufferType;
  import org.apache.cassandra.utils.concurrent.AbstractTransactionalTest;
  
  import static org.apache.commons.io.FileUtils.*;
  import static org.junit.Assert.assertEquals;
  
  public class SequentialWriterTest extends AbstractTransactionalTest
  {
  
      private final List<TestableSW> writers = new ArrayList<>();
  
      @BeforeClass
      public static void setupDD()
      {
          DatabaseDescriptor.daemonInitialization();
      }
  
      @After
      public void cleanup()
      {
          for (TestableSW sw : writers)
              sw.file.tryDelete();
          writers.clear();
      }
  
      protected TestableTransaction newTest() throws IOException
      {
          TestableSW sw = new TestableSW();
          writers.add(sw);
          return sw;
      }
  
      protected static class TestableSW extends TestableTransaction
      {
          protected static final int BUFFER_SIZE = 8 << 10;
          protected final File file;
          protected final SequentialWriter writer;
          protected final byte[] fullContents, partialContents;
  
          protected TestableSW() throws IOException
          {
              this(tempFile("sequentialwriter"));
          }
  
          protected TestableSW(File file) throws IOException
          {
              this(file, new SequentialWriter(file, SequentialWriterOption.newBuilder()
                                                                          .bufferSize(8 << 10)
                                                                          .bufferType(BufferType.OFF_HEAP)
                                                                          .build()));
          }
  
          protected TestableSW(File file, SequentialWriter sw) throws IOException
          {
              super(sw);
              this.file = file;
              this.writer = sw;
              fullContents = new byte[BUFFER_SIZE + BUFFER_SIZE / 2];
              ThreadLocalRandom.current().nextBytes(fullContents);
              partialContents = Arrays.copyOf(fullContents, BUFFER_SIZE);
              sw.write(fullContents);
          }
  
          protected void assertInProgress() throws Exception
          {
              Assert.assertTrue(file.exists());
              byte[] bytes = readFileToByteArray(file.toJavaIOFile());
              Assert.assertTrue(Arrays.equals(partialContents, bytes));
          }
  
          protected void assertPrepared() throws Exception
          {
              Assert.assertTrue(file.exists());
              byte[] bytes = readFileToByteArray(file.toJavaIOFile());
              Assert.assertTrue(Arrays.equals(fullContents, bytes));
          }
  
          protected void assertAborted() throws Exception
          {
              Assert.assertFalse(writer.isOpen());
          }
  
          protected void assertCommitted() throws Exception
          {
              assertPrepared();
              Assert.assertFalse(writer.isOpen());
          }
  
          protected static File tempFile(String prefix)
          {
              File file = FileUtils.createTempFile(prefix, "test");
              file.tryDelete();
              return file;
          }
      }
  
      @Test
      public void resetAndTruncateTest()
      {
          File tempFile = new File(Files.createTempDir().toPath(), "reset.txt");
          final int bufferSize = 48;
          final int writeSize = 64;
          byte[] toWrite = new byte[writeSize];
          SequentialWriterOption option = SequentialWriterOption.newBuilder().bufferSize(bufferSize).build();
          try (SequentialWriter writer = new SequentialWriter(tempFile, option))
          {
              // write bytes greather than buffer
              writer.write(toWrite);
              assertEquals(bufferSize, writer.getLastFlushOffset());
              assertEquals(writeSize, writer.position());
              // mark thi position
              DataPosition pos = writer.mark();
              // write another
              writer.write(toWrite);
              // another buffer should be flushed
              assertEquals(bufferSize * 2, writer.getLastFlushOffset());
              assertEquals(writeSize * 2, writer.position());
              // reset writer
              writer.resetAndTruncate(pos);
              // current position and flushed size should be changed
              assertEquals(writeSize, writer.position());
              assertEquals(writeSize, writer.getLastFlushOffset());
              // write another byte less than buffer
              writer.write(new byte[]{0});
              assertEquals(writeSize + 1, writer.position());
              // flush off set should not be increase
              assertEquals(writeSize, writer.getLastFlushOffset());
              writer.finish();
          }
          catch (IOException e)
          {
              Assert.fail();
          }
          // final file size check
          assertEquals(writeSize + 1, tempFile.length());
      }
  
      /**
       * Tests that the output stream exposed by SequentialWriter behaves as expected
       */
      @Test
      public void outputStream()
      {
          File tempFile = new File(Files.createTempDir().toPath(), "test.txt");
          Assert.assertFalse("temp file shouldn't exist yet", tempFile.exists());
  
          SequentialWriterOption option = SequentialWriterOption.newBuilder().finishOnClose(true).build();
          try (DataOutputStream os = new DataOutputStream(new SequentialWriter(tempFile, option)))
          {
              os.writeUTF("123");
          }
          catch (IOException e)
          {
              Assert.fail();
          }
  
          Assert.assertTrue("temp file should exist", tempFile.exists());
      }
  
  }
  