/**
 * 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.hadoop.hdfs;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;

import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.impl.Log4JLogger;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeys;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
import org.apache.hadoop.hdfs.server.datanode.DataNode;
import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
import org.apache.hadoop.hdfs.server.namenode.LeaseManager;
import org.apache.hadoop.hdfs.server.namenode.NameNode;
import org.apache.hadoop.hdfs.server.protocol.InterDatanodeProtocol;
import org.apache.log4j.Level;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

/** This class implements some of tests posted in HADOOP-2658. */
public class TestFileAppend3  {
  {
    ((Log4JLogger)NameNode.stateChangeLog).getLogger().setLevel(Level.ALL);
    ((Log4JLogger)LeaseManager.LOG).getLogger().setLevel(Level.ALL);
    ((Log4JLogger)LogFactory.getLog(FSNamesystem.class)).getLogger().setLevel(Level.ALL);
    ((Log4JLogger)DataNode.LOG).getLogger().setLevel(Level.ALL);
    ((Log4JLogger)DFSClient.LOG).getLogger().setLevel(Level.ALL);
    ((Log4JLogger)InterDatanodeProtocol.LOG).getLogger().setLevel(Level.ALL);
  }

  static final long BLOCK_SIZE = 64 * 1024;
  static final short REPLICATION = 3;
  static final int DATANODE_NUM = 5;

  private static Configuration conf;
  private static int buffersize;
  private static MiniDFSCluster cluster;
  private static DistributedFileSystem fs;

  @BeforeClass
  public static void setUp() throws java.lang.Exception {
    AppendTestUtil.LOG.info("setUp()");
    conf = new HdfsConfiguration();
    conf.setInt(DFSConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY, 512);
    buffersize = conf.getInt(CommonConfigurationKeys.IO_FILE_BUFFER_SIZE_KEY, 4096);
    cluster = new MiniDFSCluster.Builder(conf).numDataNodes(DATANODE_NUM).build();
    fs = cluster.getFileSystem();
  }
   
  @AfterClass
  public static void tearDown() throws Exception {
    AppendTestUtil.LOG.info("tearDown()");
    if(fs != null) fs.close();
    if(cluster != null) cluster.shutdown();
  }

  /**
   * TC1: Append on block boundary.
   * @throws IOException an exception might be thrown
   */
  @Test
  public void testTC1() throws Exception {
    final Path p = new Path("/TC1/foo");
    System.out.println("p=" + p);

    //a. Create file and write one block of data. Close file.
    final int len1 = (int)BLOCK_SIZE; 
    {
      FSDataOutputStream out = fs.create(p, false, buffersize, REPLICATION, BLOCK_SIZE);
      AppendTestUtil.write(out, 0, len1);
      out.close();
    }

    //   Reopen file to append. Append half block of data. Close file.
    final int len2 = (int)BLOCK_SIZE/2; 
    {
      FSDataOutputStream out = fs.append(p);
      AppendTestUtil.write(out, len1, len2);
      out.close();
    }
    
    //b. Reopen file and read 1.5 blocks worth of data. Close file.
    AppendTestUtil.check(fs, p, len1 + len2);
  }

  /**
   * TC2: Append on non-block boundary.
   * @throws IOException an exception might be thrown
   */
  @Test
  public void testTC2() throws Exception {
    final Path p = new Path("/TC2/foo");
    System.out.println("p=" + p);

    //a. Create file with one and a half block of data. Close file.
    final int len1 = (int)(BLOCK_SIZE + BLOCK_SIZE/2); 
    {
      FSDataOutputStream out = fs.create(p, false, buffersize, REPLICATION, BLOCK_SIZE);
      AppendTestUtil.write(out, 0, len1);
      out.close();
    }

    AppendTestUtil.check(fs, p, len1);

    //   Reopen file to append quarter block of data. Close file.
    final int len2 = (int)BLOCK_SIZE/4; 
    {
      FSDataOutputStream out = fs.append(p);
      AppendTestUtil.write(out, len1, len2);
      out.close();
    }

    //b. Reopen file and read 1.75 blocks of data. Close file.
    AppendTestUtil.check(fs, p, len1 + len2);
  }

  /**
   * TC5: Only one simultaneous append.
   * @throws IOException an exception might be thrown
   */
  @Test
  public void testTC5() throws Exception {
    final Path p = new Path("/TC5/foo");
    System.out.println("p=" + p);

    //a. Create file on Machine M1. Write half block to it. Close file.
    {
      FSDataOutputStream out = fs.create(p, false, buffersize, REPLICATION, BLOCK_SIZE);
      AppendTestUtil.write(out, 0, (int)(BLOCK_SIZE/2));
      out.close();
    }

    //b. Reopen file in "append" mode on Machine M1.
    FSDataOutputStream out = fs.append(p);

    //c. On Machine M2, reopen file in "append" mode. This should fail.
    try {
      AppendTestUtil.createHdfsWithDifferentUsername(conf).append(p);
      fail("This should fail.");
    } catch(IOException ioe) {
      AppendTestUtil.LOG.info("GOOD: got an exception", ioe);
    }

    //d. On Machine M1, close file.
    out.close();        
  }

  /**
   * TC7: Corrupted replicas are present.
   * @throws IOException an exception might be thrown
   */
  @Test
  public void testTC7() throws Exception {
    final short repl = 2;
    final Path p = new Path("/TC7/foo");
    System.out.println("p=" + p);
    
    //a. Create file with replication factor of 2. Write half block of data. Close file.
    final int len1 = (int)(BLOCK_SIZE/2); 
    {
      FSDataOutputStream out = fs.create(p, false, buffersize, repl, BLOCK_SIZE);
      AppendTestUtil.write(out, 0, len1);
      out.close();
    }
    DFSTestUtil.waitReplication(fs, p, repl);

    //b. Log into one datanode that has one replica of this block.
    //   Find the block file on this datanode and truncate it to zero size.
    final LocatedBlocks locatedblocks = fs.dfs.getNamenode().getBlockLocations(p.toString(), 0L, len1);
    assertEquals(1, locatedblocks.locatedBlockCount());
    final LocatedBlock lb = locatedblocks.get(0);
    final ExtendedBlock blk = lb.getBlock();
    assertEquals(len1, lb.getBlockSize());

    DatanodeInfo[] datanodeinfos = lb.getLocations();
    assertEquals(repl, datanodeinfos.length);
    final DataNode dn = cluster.getDataNode(datanodeinfos[0].getIpcPort());
    final File f = DataNodeTestUtils.getBlockFile(
        dn, blk.getBlockPoolId(), blk.getLocalBlock());
    final RandomAccessFile raf = new RandomAccessFile(f, "rw");
    AppendTestUtil.LOG.info("dn=" + dn + ", blk=" + blk + " (length=" + blk.getNumBytes() + ")");
    assertEquals(len1, raf.length());
    raf.setLength(0);
    raf.close();

    //c. Open file in "append mode".  Append a new block worth of data. Close file.
    final int len2 = (int)BLOCK_SIZE; 
    {
      FSDataOutputStream out = fs.append(p);
      AppendTestUtil.write(out, len1, len2);
      out.close();
    }

    //d. Reopen file and read two blocks worth of data.
    AppendTestUtil.check(fs, p, len1 + len2);
  }

  /**
   * TC11: Racing rename
   * @throws IOException an exception might be thrown
   */
  @Test
  public void testTC11() throws Exception {
    final Path p = new Path("/TC11/foo");
    System.out.println("p=" + p);

    //a. Create file and write one block of data. Close file.
    final int len1 = (int)BLOCK_SIZE; 
    {
      FSDataOutputStream out = fs.create(p, false, buffersize, REPLICATION, BLOCK_SIZE);
      AppendTestUtil.write(out, 0, len1);
      out.close();
    }

    //b. Reopen file in "append" mode. Append half block of data.
    FSDataOutputStream out = fs.append(p);
    final int len2 = (int)BLOCK_SIZE/2; 
    AppendTestUtil.write(out, len1, len2);
    out.hflush();
    
    //c. Rename file to file.new.
    final Path pnew = new Path(p + ".new");
    assertTrue(fs.rename(p, pnew));

    //d. Close file handle that was opened in (b). 
    out.close();

    //check block sizes
    final long len = fs.getFileStatus(pnew).getLen();
    final LocatedBlocks locatedblocks = fs.dfs.getNamenode().getBlockLocations(pnew.toString(), 0L, len);
    final int numblock = locatedblocks.locatedBlockCount();
    for(int i = 0; i < numblock; i++) {
      final LocatedBlock lb = locatedblocks.get(i);
      final ExtendedBlock blk = lb.getBlock();
      final long size = lb.getBlockSize();
      if (i < numblock - 1) {
        assertEquals(BLOCK_SIZE, size);
      }
      for(DatanodeInfo datanodeinfo : lb.getLocations()) {
        final DataNode dn = cluster.getDataNode(datanodeinfo.getIpcPort());
        final Block metainfo = DataNodeTestUtils.getFSDataset(dn).getStoredBlock(
            blk.getBlockPoolId(), blk.getBlockId());
        assertEquals(size, metainfo.getNumBytes());
      }
    }
  }

  /** 
   * TC12: Append to partial CRC chunk
   * @throws IOException an exception might be thrown
   */
  @Test
  public void testTC12() throws Exception {
    final Path p = new Path("/TC12/foo");
    System.out.println("p=" + p);
    
    //a. Create file with a block size of 64KB
    //   and a default io.bytes.per.checksum of 512 bytes.
    //   Write 25687 bytes of data. Close file.
    final int len1 = 25687; 
    {
      FSDataOutputStream out = fs.create(p, false, buffersize, REPLICATION, BLOCK_SIZE);
      AppendTestUtil.write(out, 0, len1);
      out.close();
    }

    //b. Reopen file in "append" mode. Append another 5877 bytes of data. Close file.
    final int len2 = 5877; 
    {
      FSDataOutputStream out = fs.append(p);
      AppendTestUtil.write(out, len1, len2);
      out.close();
    }

    //c. Reopen file and read 25687+5877 bytes of data from file. Close file.
    AppendTestUtil.check(fs, p, len1 + len2);
  }
  
  /** Append to a partial CRC chunk and 
   * the first write does not fill up the partial CRC trunk
   * *
   * @throws IOException
   */
  @Test
  public void testAppendToPartialChunk() throws IOException {
    final Path p = new Path("/partialChunk/foo");
    final int fileLen = 513;
    System.out.println("p=" + p);
    
    byte[] fileContents = AppendTestUtil.initBuffer(fileLen);

    // create a new file.
    FSDataOutputStream stm = AppendTestUtil.createFile(fs, p, 1);

    // create 1 byte file
    stm.write(fileContents, 0, 1);
    stm.close();
    System.out.println("Wrote 1 byte and closed the file " + p);

    // append to file
    stm = fs.append(p);
    // Append to a partial CRC trunk
    stm.write(fileContents, 1, 1);
    stm.hflush();
    // The partial CRC trunk is not full yet and close the file
    stm.close();
    System.out.println("Append 1 byte and closed the file " + p);

    // write the remainder of the file
    stm = fs.append(p);

    // ensure getPos is set to reflect existing size of the file
    assertEquals(2, stm.getPos());

    // append to a partial CRC trunk
    stm.write(fileContents, 2, 1);
    // The partial chunk is not full yet, force to send a packet to DN
    stm.hflush();
    System.out.println("Append and flush 1 byte");
    // The partial chunk is not full yet, force to send another packet to DN
    stm.write(fileContents, 3, 2);
    stm.hflush();
    System.out.println("Append and flush 2 byte");

    // fill up the partial chunk and close the file
    stm.write(fileContents, 5, fileLen-5);
    stm.close();
    System.out.println("Flush 508 byte and closed the file " + p);

    // verify that entire file is good
    AppendTestUtil.checkFullFile(fs, p, fileLen,
        fileContents, "Failed to append to a partial chunk");
  }
}