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.spark.io;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.lang3.RandomUtils;
  import org.junit.After;
  import org.junit.Before;
  import org.junit.Test;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  
  import static org.junit.Assert.assertEquals;
  
  /**
   * Tests functionality of {@link NioBufferedFileInputStream}
   */
  public class NioBufferedFileInputStreamSuite {
  
    private byte[] randomBytes;
  
    private File inputFile;
  
    @Before
    public void setUp() throws IOException {
      // Create a byte array of size 2 MB with random bytes
      randomBytes =  RandomUtils.nextBytes(2 * 1024 * 1024);
      inputFile = File.createTempFile("temp-file", ".tmp");
      FileUtils.writeByteArrayToFile(inputFile, randomBytes);
    }
  
    @After
    public void tearDown() {
      inputFile.delete();
    }
  
    @Test
    public void testReadOneByte() throws IOException {
      InputStream inputStream = new NioBufferedFileInputStream(inputFile);
      for (int i = 0; i < randomBytes.length; i++) {
        assertEquals(randomBytes[i], (byte) inputStream.read());
      }
    }
  
    @Test
    public void testReadMultipleBytes() throws IOException {
      InputStream inputStream = new NioBufferedFileInputStream(inputFile);
      byte[] readBytes = new byte[8 * 1024];
      int i = 0;
      while (i < randomBytes.length) {
        int read = inputStream.read(readBytes, 0, 8 * 1024);
        for (int j = 0; j < read; j++) {
          assertEquals(randomBytes[i], readBytes[j]);
          i++;
        }
      }
    }
  
    @Test
    public void testBytesSkipped() throws IOException {
      InputStream inputStream = new NioBufferedFileInputStream(inputFile);
      assertEquals(1024, inputStream.skip(1024));
      for (int i = 1024; i < randomBytes.length; i++) {
        assertEquals(randomBytes[i], (byte) inputStream.read());
      }
    }
  
    @Test
    public void testBytesSkippedAfterRead() throws IOException {
      InputStream inputStream = new NioBufferedFileInputStream(inputFile);
      for (int i = 0; i < 1024; i++) {
        assertEquals(randomBytes[i], (byte) inputStream.read());
      }
      assertEquals(1024, inputStream.skip(1024));
      for (int i = 2048; i < randomBytes.length; i++) {
        assertEquals(randomBytes[i], (byte) inputStream.read());
      }
    }
  
    @Test
    public void testNegativeBytesSkippedAfterRead() throws IOException {
      InputStream inputStream = new NioBufferedFileInputStream(inputFile);
      for (int i = 0; i < 1024; i++) {
        assertEquals(randomBytes[i], (byte) inputStream.read());
      }
      // Skipping negative bytes should essential be a no-op
      assertEquals(0, inputStream.skip(-1));
      assertEquals(0, inputStream.skip(-1024));
      assertEquals(0, inputStream.skip(Long.MIN_VALUE));
      assertEquals(1024, inputStream.skip(1024));
      for (int i = 2048; i < randomBytes.length; i++) {
        assertEquals(randomBytes[i], (byte) inputStream.read());
      }
    }
  
    @Test
    public void testSkipFromFileChannel() throws IOException {
      InputStream inputStream = new NioBufferedFileInputStream(inputFile, 10);
      // Since the buffer is smaller than the skipped bytes, this will guarantee
      // we skip from underlying file channel.
      assertEquals(1024, inputStream.skip(1024));
      for (int i = 1024; i < 2048; i++) {
        assertEquals(randomBytes[i], (byte) inputStream.read());
      }
      assertEquals(256, inputStream.skip(256));
      assertEquals(256, inputStream.skip(256));
      assertEquals(512, inputStream.skip(512));
      for (int i = 3072; i < randomBytes.length; i++) {
        assertEquals(randomBytes[i], (byte) inputStream.read());
      }
    }
  
    @Test
    public void testBytesSkippedAfterEOF() throws IOException {
      InputStream inputStream = new NioBufferedFileInputStream(inputFile);
      assertEquals(randomBytes.length, inputStream.skip(randomBytes.length + 1));
      assertEquals(-1, inputStream.read());
    }
  }
  