/**
   * @param encoding encoding used
   * @param headerBytes dummy header bytes
   * @param fileContext HFile meta data
   */
  public HFileBlockDefaultEncodingContext(
      DataBlockEncoding encoding, byte[] headerBytes, HFileContext fileContext) {
    this.encodingAlgo = encoding;
    this.fileContext = fileContext;
    Compression.Algorithm compressionAlgorithm =
        fileContext.getCompression() == null ? NONE : fileContext.getCompression();
    if (compressionAlgorithm != NONE) {
      compressor = compressionAlgorithm.getCompressor();
      compressedByteStream = new ByteArrayOutputStream();
      try {
        compressionStream =
            compressionAlgorithm.createPlainCompressionStream(compressedByteStream, compressor);
      } catch (IOException e) {
        throw new RuntimeException(
            "Could not create compression stream for algorithm " + compressionAlgorithm, e);
      }
    }

    Encryption.Context cryptoContext = fileContext.getEncryptionContext();
    if (cryptoContext != Encryption.Context.NONE) {
      cryptoByteStream = new ByteArrayOutputStream();
      iv = new byte[cryptoContext.getCipher().getIvLength()];
      new SecureRandom().nextBytes(iv);
    }

    dummyHeader =
        Preconditions.checkNotNull(
            headerBytes,
            "Please pass HConstants.HFILEBLOCK_DUMMY_HEADER instead of null for param headerBytes");
  }
示例#2
0
  /**
   * Decompresses data from the given stream using the configured compression algorithm. It will
   * throw an exception if the dest buffer does not have enough space to hold the decompressed data.
   *
   * @param dest the output bytes buffer
   * @param destOffset start writing position of the output buffer
   * @param bufferedBoundedStream a stream to read compressed data from, bounded to the exact amount
   *     of compressed data
   * @param compressedSize compressed data size, header not included
   * @param uncompressedSize uncompressed data size, header not included
   * @param compressAlgo compression algorithm used
   * @throws IOException
   */
  public static void decompress(
      byte[] dest,
      int destOffset,
      InputStream bufferedBoundedStream,
      int compressedSize,
      int uncompressedSize,
      Compression.Algorithm compressAlgo)
      throws IOException {

    if (dest.length - destOffset < uncompressedSize) {
      throw new IllegalArgumentException(
          "Output buffer does not have enough space to hold "
              + uncompressedSize
              + " decompressed bytes, available: "
              + (dest.length - destOffset));
    }

    Decompressor decompressor = null;
    try {
      decompressor = compressAlgo.getDecompressor();
      InputStream is =
          compressAlgo.createDecompressionStream(bufferedBoundedStream, decompressor, 0);

      IOUtils.readFully(is, dest, destOffset, uncompressedSize);
      is.close();
    } finally {
      if (decompressor != null) {
        compressAlgo.returnDecompressor(decompressor);
      }
    }
  }
 @Override
 public String toString() {
   return "reader="
       + path.toString()
       + (!isFileInfoLoaded()
           ? ""
           : ", compression="
               + compressAlgo.getName()
               + ", cacheConf="
               + cacheConf
               + ", firstKey="
               + toStringFirstKey()
               + ", lastKey="
               + toStringLastKey())
       + ", avgKeyLen="
       + avgKeyLen
       + ", avgValueLen="
       + avgValueLen
       + ", entries="
       + trailer.getEntryCount()
       + ", length="
       + fileSize;
 }
示例#4
0
文件: HFile.java 项目: joshua-g/c5
/**
 * File format for hbase. A file of sorted key/value pairs. Both keys and values are byte arrays.
 *
 * <p>The memory footprint of a HFile includes the following (below is taken from the <a
 * href=https://issues.apache.org/jira/browse/HADOOP-3315>TFile</a> documentation but applies also
 * to HFile):
 *
 * <ul>
 *   <li>Some constant overhead of reading or writing a compressed block.
 *       <ul>
 *         <li>Each compressed block requires one compression/decompression codec for I/O.
 *         <li>Temporary space to buffer the key.
 *         <li>Temporary space to buffer the value.
 *       </ul>
 *   <li>HFile index, which is proportional to the total number of Data Blocks. The total amount of
 *       memory needed to hold the index can be estimated as (56+AvgKeySize)*NumBlocks.
 * </ul>
 *
 * Suggestions on performance optimization.
 *
 * <ul>
 *   <li>Minimum block size. We recommend a setting of minimum block size between 8KB to 1MB for
 *       general usage. Larger block size is preferred if files are primarily for sequential access.
 *       However, it would lead to inefficient random access (because there are more data to
 *       decompress). Smaller blocks are good for random access, but require more memory to hold the
 *       block index, and may be slower to create (because we must flush the compressor stream at
 *       the conclusion of each data block, which leads to an FS I/O flush). Further, due to the
 *       internal caching in Compression codec, the smallest possible block size would be around
 *       20KB-30KB.
 *   <li>The current implementation does not offer true multi-threading for reading. The
 *       implementation uses FSDataInputStream seek()+read(), which is shown to be much faster than
 *       positioned-read call in single thread mode. However, it also means that if multiple threads
 *       attempt to access the same HFile (using multiple scanners) simultaneously, the actual I/O
 *       is carried out sequentially even if they access different DFS blocks (Reexamine! pread
 *       seems to be 10% faster than seek+read in my testing -- stack).
 *   <li>Compression codec. Use "none" if the data is not very compressable (by compressable, I mean
 *       a compression ratio at least 2:1). Generally, use "lzo" as the starting point for
 *       experimenting. "gz" overs slightly better compression ratio over "lzo" but requires 4x CPU
 *       to compress and 2x CPU to decompress, comparing to "lzo".
 * </ul>
 *
 * For more on the background behind HFile, see <a
 * href=https://issues.apache.org/jira/browse/HBASE-61>HBASE-61</a>.
 *
 * <p>File is made of data blocks followed by meta data blocks (if any), a fileinfo block, data
 * block index, meta data block index, and a fixed size trailer which records the offsets at which
 * file changes content type.
 *
 * <pre>&lt;data blocks>&lt;meta blocks>&lt;fileinfo>&lt;data index>&lt;meta index>&lt;trailer>
 * </pre>
 *
 * Each block has a bit of magic at its start. Block are comprised of key/values. In data blocks,
 * they are both byte arrays. Metadata blocks are a String key and a byte array value. An empty file
 * looks like this:
 *
 * <pre>&lt;fileinfo>&lt;trailer></pre>
 *
 * . That is, there are not data nor meta blocks present.
 *
 * <p>TODO: Do scanners need to be able to take a start and end row? TODO: Should BlockIndex know
 * the name of its file? Should it have a Path that points at its file say for the case where an
 * index lives apart from an HFile instance?
 */
@InterfaceAudience.Private
public class HFile {
  static final Log LOG = LogFactory.getLog(HFile.class);

  /** Maximum length of key in HFile. */
  public static final int MAXIMUM_KEY_LENGTH = Integer.MAX_VALUE;

  /** Default compression: none. */
  public static final Compression.Algorithm DEFAULT_COMPRESSION_ALGORITHM =
      Compression.Algorithm.NONE;

  /** Minimum supported HFile format version */
  public static final int MIN_FORMAT_VERSION = 2;

  /** Maximum supported HFile format version */
  public static final int MAX_FORMAT_VERSION = 2;

  /** Default compression name: none. */
  public static final String DEFAULT_COMPRESSION = DEFAULT_COMPRESSION_ALGORITHM.getName();

  /** Meta data block name for bloom filter bits. */
  public static final String BLOOM_FILTER_DATA_KEY = "BLOOM_FILTER_DATA";

  /**
   * We assume that HFile path ends with ROOT_DIR/TABLE_NAME/REGION_NAME/CF_NAME/HFILE, so it has at
   * least this many levels of nesting. This is needed for identifying table and CF name from an
   * HFile path.
   */
  public static final int MIN_NUM_HFILE_PATH_LEVELS = 5;

  /** The number of bytes per checksum. */
  public static final int DEFAULT_BYTES_PER_CHECKSUM = 16 * 1024;

  public static final ChecksumType DEFAULT_CHECKSUM_TYPE = ChecksumType.CRC32;

  // For measuring latency of "sequential" reads and writes
  private static final AtomicInteger readOps = new AtomicInteger();
  private static final AtomicLong readTimeNano = new AtomicLong();
  private static final AtomicInteger writeOps = new AtomicInteger();
  private static final AtomicLong writeTimeNano = new AtomicLong();

  // For measuring latency of pread
  private static final AtomicInteger preadOps = new AtomicInteger();
  private static final AtomicLong preadTimeNano = new AtomicLong();

  // For measuring number of checksum failures
  static final AtomicLong checksumFailures = new AtomicLong();

  // For getting more detailed stats on FS latencies
  // If, for some reason, the metrics subsystem stops polling for latencies,
  // I don't want data to pile up in a memory leak
  // so, after LATENCY_BUFFER_SIZE items have been enqueued for processing,
  // fs latency stats will be dropped (and this behavior will be logged)
  private static final int LATENCY_BUFFER_SIZE = 5000;
  private static final BlockingQueue<Long> fsReadLatenciesNanos =
      new ArrayBlockingQueue<Long>(LATENCY_BUFFER_SIZE);
  private static final BlockingQueue<Long> fsWriteLatenciesNanos =
      new ArrayBlockingQueue<Long>(LATENCY_BUFFER_SIZE);
  private static final BlockingQueue<Long> fsPreadLatenciesNanos =
      new ArrayBlockingQueue<Long>(LATENCY_BUFFER_SIZE);

  public static final void offerReadLatency(long latencyNanos, boolean pread) {
    if (pread) {
      fsPreadLatenciesNanos.offer(latencyNanos); // might be silently dropped, if the queue is full
      preadOps.incrementAndGet();
      preadTimeNano.addAndGet(latencyNanos);
    } else {
      fsReadLatenciesNanos.offer(latencyNanos); // might be silently dropped, if the queue is full
      readTimeNano.addAndGet(latencyNanos);
      readOps.incrementAndGet();
    }
  }

  public static final void offerWriteLatency(long latencyNanos) {
    fsWriteLatenciesNanos.offer(latencyNanos); // might be silently dropped, if the queue is full

    writeTimeNano.addAndGet(latencyNanos);
    writeOps.incrementAndGet();
  }

  public static final Collection<Long> getReadLatenciesNanos() {
    final List<Long> latencies = Lists.newArrayListWithCapacity(fsReadLatenciesNanos.size());
    fsReadLatenciesNanos.drainTo(latencies);
    return latencies;
  }

  public static final Collection<Long> getPreadLatenciesNanos() {
    final List<Long> latencies = Lists.newArrayListWithCapacity(fsPreadLatenciesNanos.size());
    fsPreadLatenciesNanos.drainTo(latencies);
    return latencies;
  }

  public static final Collection<Long> getWriteLatenciesNanos() {
    final List<Long> latencies = Lists.newArrayListWithCapacity(fsWriteLatenciesNanos.size());
    fsWriteLatenciesNanos.drainTo(latencies);
    return latencies;
  }

  // for test purpose
  public static volatile AtomicLong dataBlockReadCnt = new AtomicLong(0);

  // number of sequential reads
  public static final int getReadOps() {
    return readOps.getAndSet(0);
  }

  public static final long getReadTimeMs() {
    return readTimeNano.getAndSet(0) / 1000000;
  }

  // number of positional reads
  public static final int getPreadOps() {
    return preadOps.getAndSet(0);
  }

  public static final long getPreadTimeMs() {
    return preadTimeNano.getAndSet(0) / 1000000;
  }

  public static final int getWriteOps() {
    return writeOps.getAndSet(0);
  }

  public static final long getWriteTimeMs() {
    return writeTimeNano.getAndSet(0) / 1000000;
  }

  /** Number of checksum verification failures. It also clears the counter. */
  public static final long getChecksumFailuresCount() {
    return checksumFailures.getAndSet(0);
  }

  /** API required to write an {@link HFile} */
  public interface Writer extends Closeable {

    /** Add an element to the file info map. */
    void appendFileInfo(byte[] key, byte[] value) throws IOException;

    void append(KeyValue kv) throws IOException;

    void append(byte[] key, byte[] value) throws IOException;

    /** @return the path to this {@link HFile} */
    Path getPath();

    /**
     * Adds an inline block writer such as a multi-level block index writer or a compound Bloom
     * filter writer.
     */
    void addInlineBlockWriter(InlineBlockWriter bloomWriter);

    // The below three methods take Writables.  We'd like to undo Writables but undoing the below
    // would be pretty
    // painful.  Could take a byte [] or a Message but we want to be backward compatible around
    // hfiles so would need
    // to map between Message and Writable or byte [] and current Writable serialization.  This
    // would be a bit of work
    // to little gain.  Thats my thinking at moment.  St.Ack 20121129

    void appendMetaBlock(String bloomFilterMetaKey, Writable metaWriter);

    /**
     * Store general Bloom filter in the file. This does not deal with Bloom filter internals but is
     * necessary, since Bloom filters are stored differently in HFile version 1 and version 2.
     */
    void addGeneralBloomFilter(BloomFilterWriter bfw);

    /** Store delete family Bloom filter in the file, which is only supported in HFile V2. */
    void addDeleteFamilyBloomFilter(BloomFilterWriter bfw) throws IOException;
  }

  /**
   * This variety of ways to construct writers is used throughout the code, and we want to be able
   * to swap writer implementations.
   */
  public abstract static class WriterFactory {
    protected final Configuration conf;
    protected final CacheConfig cacheConf;
    protected FileSystem fs;
    protected Path path;
    protected FSDataOutputStream ostream;
    protected int blockSize = HColumnDescriptor.DEFAULT_BLOCKSIZE;
    protected Compression.Algorithm compression = HFile.DEFAULT_COMPRESSION_ALGORITHM;
    protected HFileDataBlockEncoder encoder = NoOpDataBlockEncoder.INSTANCE;
    protected KVComparator comparator = KeyValue.COMPARATOR;
    protected InetSocketAddress[] favoredNodes;
    protected ChecksumType checksumType = HFile.DEFAULT_CHECKSUM_TYPE;
    protected int bytesPerChecksum = DEFAULT_BYTES_PER_CHECKSUM;
    protected boolean includeMVCCReadpoint = true;

    WriterFactory(Configuration conf, CacheConfig cacheConf) {
      this.conf = conf;
      this.cacheConf = cacheConf;
    }

    public WriterFactory withPath(FileSystem fs, Path path) {
      Preconditions.checkNotNull(fs);
      Preconditions.checkNotNull(path);
      this.fs = fs;
      this.path = path;
      return this;
    }

    public WriterFactory withOutputStream(FSDataOutputStream ostream) {
      Preconditions.checkNotNull(ostream);
      this.ostream = ostream;
      return this;
    }

    public WriterFactory withBlockSize(int blockSize) {
      this.blockSize = blockSize;
      return this;
    }

    public WriterFactory withCompression(Compression.Algorithm compression) {
      Preconditions.checkNotNull(compression);
      this.compression = compression;
      return this;
    }

    public WriterFactory withCompression(String compressAlgo) {
      Preconditions.checkNotNull(compression);
      this.compression = AbstractHFileWriter.compressionByName(compressAlgo);
      return this;
    }

    public WriterFactory withDataBlockEncoder(HFileDataBlockEncoder encoder) {
      Preconditions.checkNotNull(encoder);
      this.encoder = encoder;
      return this;
    }

    public WriterFactory withComparator(KVComparator comparator) {
      Preconditions.checkNotNull(comparator);
      this.comparator = comparator;
      return this;
    }

    public WriterFactory withFavoredNodes(InetSocketAddress[] favoredNodes) {
      // Deliberately not checking for null here.
      this.favoredNodes = favoredNodes;
      return this;
    }

    public WriterFactory withChecksumType(ChecksumType checksumType) {
      Preconditions.checkNotNull(checksumType);
      this.checksumType = checksumType;
      return this;
    }

    public WriterFactory withBytesPerChecksum(int bytesPerChecksum) {
      this.bytesPerChecksum = bytesPerChecksum;
      return this;
    }

    /**
     * @param includeMVCCReadpoint whether to write the mvcc readpoint to the file for each KV
     * @return this (for chained invocation)
     */
    public WriterFactory includeMVCCReadpoint(boolean includeMVCCReadpoint) {
      this.includeMVCCReadpoint = includeMVCCReadpoint;
      return this;
    }

    public Writer create() throws IOException {
      if ((path != null ? 1 : 0) + (ostream != null ? 1 : 0) != 1) {
        throw new AssertionError("Please specify exactly one of " + "filesystem/path or path");
      }
      if (path != null) {
        ostream = AbstractHFileWriter.createOutputStream(conf, fs, path, favoredNodes);
      }
      return createWriter(
          fs,
          path,
          ostream,
          blockSize,
          compression,
          encoder,
          comparator,
          checksumType,
          bytesPerChecksum,
          includeMVCCReadpoint);
    }

    protected abstract Writer createWriter(
        FileSystem fs,
        Path path,
        FSDataOutputStream ostream,
        int blockSize,
        Compression.Algorithm compress,
        HFileDataBlockEncoder dataBlockEncoder,
        KVComparator comparator,
        ChecksumType checksumType,
        int bytesPerChecksum,
        boolean includeMVCCReadpoint)
        throws IOException;
  }

  /** The configuration key for HFile version to use for new files */
  public static final String FORMAT_VERSION_KEY = "hfile.format.version";

  public static int getFormatVersion(Configuration conf) {
    int version = conf.getInt(FORMAT_VERSION_KEY, MAX_FORMAT_VERSION);
    checkFormatVersion(version);
    return version;
  }

  /**
   * Returns the factory to be used to create {@link HFile} writers. Disables block cache access for
   * all writers created through the returned factory.
   */
  public static final WriterFactory getWriterFactoryNoCache(Configuration conf) {
    Configuration tempConf = new Configuration(conf);
    tempConf.setFloat(HConstants.HFILE_BLOCK_CACHE_SIZE_KEY, 0.0f);
    return HFile.getWriterFactory(conf, new CacheConfig(tempConf));
  }

  /** Returns the factory to be used to create {@link HFile} writers */
  public static final WriterFactory getWriterFactory(Configuration conf, CacheConfig cacheConf) {
    int version = getFormatVersion(conf);
    switch (version) {
      case 2:
        return new HFileWriterV2.WriterFactoryV2(conf, cacheConf);
      default:
        throw new IllegalArgumentException(
            "Cannot create writer for HFile " + "format version " + version);
    }
  }

  /** An abstraction used by the block index */
  public interface CachingBlockReader {
    HFileBlock readBlock(
        long offset,
        long onDiskBlockSize,
        boolean cacheBlock,
        final boolean pread,
        final boolean isCompaction,
        BlockType expectedBlockType)
        throws IOException;
  }

  /** An interface used by clients to open and iterate an {@link HFile}. */
  public interface Reader extends Closeable, CachingBlockReader {
    /**
     * Returns this reader's "name". Usually the last component of the path. Needs to be constant as
     * the file is being moved to support caching on write.
     */
    String getName();

    KVComparator getComparator();

    HFileScanner getScanner(boolean cacheBlocks, final boolean pread, final boolean isCompaction);

    ByteBuffer getMetaBlock(String metaBlockName, boolean cacheBlock) throws IOException;

    Map<byte[], byte[]> loadFileInfo() throws IOException;

    byte[] getLastKey();

    byte[] midkey() throws IOException;

    long length();

    long getEntries();

    byte[] getFirstKey();

    long indexSize();

    byte[] getFirstRowKey();

    byte[] getLastRowKey();

    FixedFileTrailer getTrailer();

    HFileBlockIndex.BlockIndexReader getDataBlockIndexReader();

    HFileScanner getScanner(boolean cacheBlocks, boolean pread);

    Compression.Algorithm getCompressionAlgorithm();

    /**
     * Retrieves general Bloom filter metadata as appropriate for each {@link HFile} version. Knows
     * nothing about how that metadata is structured.
     */
    DataInput getGeneralBloomFilterMetadata() throws IOException;

    /**
     * Retrieves delete family Bloom filter metadata as appropriate for each {@link HFile} version.
     * Knows nothing about how that metadata is structured.
     */
    DataInput getDeleteBloomFilterMetadata() throws IOException;

    Path getPath();

    /** Close method with optional evictOnClose */
    void close(boolean evictOnClose) throws IOException;

    DataBlockEncoding getDataBlockEncoding();

    boolean hasMVCCInfo();
  }

  /**
   * Method returns the reader given the specified arguments. TODO This is a bad abstraction. See
   * HBASE-6635.
   *
   * @param path hfile's path
   * @param fsdis stream of path's file
   * @param size max size of the trailer.
   * @param cacheConf Cache configuation values, cannot be null.
   * @param hfs
   * @return an appropriate instance of HFileReader
   * @throws IOException If file is invalid, will throw CorruptHFileException flavored IOException
   */
  private static Reader pickReaderVersion(
      Path path, FSDataInputStreamWrapper fsdis, long size, CacheConfig cacheConf, HFileSystem hfs)
      throws IOException {
    FixedFileTrailer trailer = null;
    try {
      boolean isHBaseChecksum = fsdis.shouldUseHBaseChecksum();
      assert !isHBaseChecksum; // Initially we must read with FS checksum.
      trailer = FixedFileTrailer.readFromStream(fsdis.getStream(isHBaseChecksum), size);
      switch (trailer.getMajorVersion()) {
        case 2:
          return new HFileReaderV2(path, trailer, fsdis, size, cacheConf, hfs);
        default:
          throw new CorruptHFileException("Invalid HFile version " + trailer.getMajorVersion());
      }
    } catch (Throwable t) {
      try {
        fsdis.close();
      } catch (Throwable t2) {
        LOG.warn("Error closing fsdis FSDataInputStreamWrapper", t2);
      }
      throw new CorruptHFileException("Problem reading HFile Trailer from file " + path, t);
    }
  }

  /**
   * @param fs A file system
   * @param path Path to HFile
   * @param fsdis a stream of path's file
   * @param size max size of the trailer.
   * @param cacheConf Cache configuration for hfile's contents
   * @return A version specific Hfile Reader
   * @throws IOException If file is invalid, will throw CorruptHFileException flavored IOException
   */
  public static Reader createReader(
      FileSystem fs, Path path, FSDataInputStreamWrapper fsdis, long size, CacheConfig cacheConf)
      throws IOException {
    HFileSystem hfs = null;

    // If the fs is not an instance of HFileSystem, then create an
    // instance of HFileSystem that wraps over the specified fs.
    // In this case, we will not be able to avoid checksumming inside
    // the filesystem.
    if (!(fs instanceof HFileSystem)) {
      hfs = new HFileSystem(fs);
    } else {
      hfs = (HFileSystem) fs;
    }
    return pickReaderVersion(path, fsdis, size, cacheConf, hfs);
  }

  /**
   * @param fs filesystem
   * @param path Path to file to read
   * @param cacheConf This must not be null. @see {@link
   *     org.apache.hadoop.hbase.io.hfile.CacheConfig#CacheConfig(Configuration)}
   * @return an active Reader instance
   * @throws IOException Will throw a CorruptHFileException (DoNotRetryIOException subtype) if hfile
   *     is corrupt/invalid.
   */
  public static Reader createReader(FileSystem fs, Path path, CacheConfig cacheConf)
      throws IOException {
    Preconditions.checkNotNull(cacheConf, "Cannot create Reader with null CacheConf");
    FSDataInputStreamWrapper stream = new FSDataInputStreamWrapper(fs, path);
    return pickReaderVersion(path, stream, fs.getFileStatus(path).getLen(), cacheConf, null);
  }

  /** This factory method is used only by unit tests */
  static Reader createReaderFromStream(
      Path path, FSDataInputStream fsdis, long size, CacheConfig cacheConf) throws IOException {
    FSDataInputStreamWrapper wrapper = new FSDataInputStreamWrapper(fsdis);
    return pickReaderVersion(path, wrapper, size, cacheConf, null);
  }

  /** Metadata for this file. Conjured by the writer. Read in by the reader. */
  static class FileInfo implements SortedMap<byte[], byte[]> {
    static final String RESERVED_PREFIX = "hfile.";
    static final byte[] RESERVED_PREFIX_BYTES = Bytes.toBytes(RESERVED_PREFIX);
    static final byte[] LASTKEY = Bytes.toBytes(RESERVED_PREFIX + "LASTKEY");
    static final byte[] AVG_KEY_LEN = Bytes.toBytes(RESERVED_PREFIX + "AVG_KEY_LEN");
    static final byte[] AVG_VALUE_LEN = Bytes.toBytes(RESERVED_PREFIX + "AVG_VALUE_LEN");
    static final byte[] COMPARATOR = Bytes.toBytes(RESERVED_PREFIX + "COMPARATOR");
    private final SortedMap<byte[], byte[]> map =
        new TreeMap<byte[], byte[]>(Bytes.BYTES_COMPARATOR);

    public FileInfo() {
      super();
    }

    /**
     * Append the given key/value pair to the file info, optionally checking the key prefix.
     *
     * @param k key to add
     * @param v value to add
     * @param checkPrefix whether to check that the provided key does not start with the reserved
     *     prefix
     * @return this file info object
     * @throws IOException if the key or value is invalid
     */
    public FileInfo append(final byte[] k, final byte[] v, final boolean checkPrefix)
        throws IOException {
      if (k == null || v == null) {
        throw new NullPointerException("Key nor value may be null");
      }
      if (checkPrefix && isReservedFileInfoKey(k)) {
        throw new IOException("Keys with a " + FileInfo.RESERVED_PREFIX + " are reserved");
      }
      put(k, v);
      return this;
    }

    public void clear() {
      this.map.clear();
    }

    public Comparator<? super byte[]> comparator() {
      return map.comparator();
    }

    public boolean containsKey(Object key) {
      return map.containsKey(key);
    }

    public boolean containsValue(Object value) {
      return map.containsValue(value);
    }

    public Set<java.util.Map.Entry<byte[], byte[]>> entrySet() {
      return map.entrySet();
    }

    public boolean equals(Object o) {
      return map.equals(o);
    }

    public byte[] firstKey() {
      return map.firstKey();
    }

    public byte[] get(Object key) {
      return map.get(key);
    }

    public int hashCode() {
      return map.hashCode();
    }

    public SortedMap<byte[], byte[]> headMap(byte[] toKey) {
      return this.map.headMap(toKey);
    }

    public boolean isEmpty() {
      return map.isEmpty();
    }

    public Set<byte[]> keySet() {
      return map.keySet();
    }

    public byte[] lastKey() {
      return map.lastKey();
    }

    public byte[] put(byte[] key, byte[] value) {
      return this.map.put(key, value);
    }

    public void putAll(Map<? extends byte[], ? extends byte[]> m) {
      this.map.putAll(m);
    }

    public byte[] remove(Object key) {
      return this.map.remove(key);
    }

    public int size() {
      return map.size();
    }

    public SortedMap<byte[], byte[]> subMap(byte[] fromKey, byte[] toKey) {
      return this.map.subMap(fromKey, toKey);
    }

    public SortedMap<byte[], byte[]> tailMap(byte[] fromKey) {
      return this.map.tailMap(fromKey);
    }

    public Collection<byte[]> values() {
      return map.values();
    }

    /**
     * Write out this instance on the passed in <code>out</code> stream. We write it as a protobuf.
     *
     * @param out
     * @throws IOException
     * @see #read(DataInputStream)
     */
    void write(final DataOutputStream out) throws IOException {
      HFileProtos.FileInfoProto.Builder builder = HFileProtos.FileInfoProto.newBuilder();
      for (Map.Entry<byte[], byte[]> e : this.map.entrySet()) {
        HBaseProtos.BytesBytesPair.Builder bbpBuilder = HBaseProtos.BytesBytesPair.newBuilder();
        bbpBuilder.setFirst(ZeroCopyLiteralByteString.wrap(e.getKey()));
        bbpBuilder.setSecond(ZeroCopyLiteralByteString.wrap(e.getValue()));
        builder.addMapEntry(bbpBuilder.build());
      }
      out.write(ProtobufUtil.PB_MAGIC);
      builder.build().writeDelimitedTo(out);
    }

    /**
     * Populate this instance with what we find on the passed in <code>in</code> stream. Can
     * deserialize protobuf of old Writables format.
     *
     * @param in
     * @throws IOException
     * @see #write(DataOutputStream)
     */
    void read(final DataInputStream in) throws IOException {
      // This code is tested over in TestHFileReaderV1 where we read an old hfile w/ this new code.
      int pblen = ProtobufUtil.lengthOfPBMagic();
      byte[] pbuf = new byte[pblen];
      if (in.markSupported()) in.mark(pblen);
      int read = in.read(pbuf);
      if (read != pblen) throw new IOException("read=" + read + ", wanted=" + pblen);
      if (ProtobufUtil.isPBMagicPrefix(pbuf)) {
        parsePB(HFileProtos.FileInfoProto.parseDelimitedFrom(in));
      } else {
        if (in.markSupported()) {
          in.reset();
          parseWritable(in);
        } else {
          // We cannot use BufferedInputStream, it consumes more than we read from the underlying IS
          ByteArrayInputStream bais = new ByteArrayInputStream(pbuf);
          SequenceInputStream sis = new SequenceInputStream(bais, in); // Concatenate input streams
          // TODO: Am I leaking anything here wrapping the passed in stream?  We are not calling
          // close on the wrapped
          // streams but they should be let go after we leave this context?  I see that we keep a
          // reference to the
          // passed in inputstream but since we no longer have a reference to this after we leave,
          // we should be ok.
          parseWritable(new DataInputStream(sis));
        }
      }
    }

    /**
     * Now parse the old Writable format. It was a list of Map entries. Each map entry was a key and
     * a value of a byte []. The old map format had a byte before each entry that held a code which
     * was short for the key or value type. We know it was a byte [] so in below we just read and
     * dump it.
     *
     * @throws IOException
     */
    void parseWritable(final DataInputStream in) throws IOException {
      // First clear the map.  Otherwise we will just accumulate entries every time this method is
      // called.
      this.map.clear();
      // Read the number of entries in the map
      int entries = in.readInt();
      // Then read each key/value pair
      for (int i = 0; i < entries; i++) {
        byte[] key = Bytes.readByteArray(in);
        // We used to read a byte that encoded the class type.  Read and ignore it because it is
        // always byte [] in hfile
        in.readByte();
        byte[] value = Bytes.readByteArray(in);
        this.map.put(key, value);
      }
    }

    /**
     * Fill our map with content of the pb we read off disk
     *
     * @param fip protobuf message to read
     */
    void parsePB(final HFileProtos.FileInfoProto fip) {
      this.map.clear();
      for (BytesBytesPair pair : fip.getMapEntryList()) {
        this.map.put(pair.getFirst().toByteArray(), pair.getSecond().toByteArray());
      }
    }
  }

  /** Return true if the given file info key is reserved for internal use. */
  public static boolean isReservedFileInfoKey(byte[] key) {
    return Bytes.startsWith(key, FileInfo.RESERVED_PREFIX_BYTES);
  }

  /**
   * Get names of supported compression algorithms. The names are acceptable by HFile.Writer.
   *
   * @return Array of strings, each represents a supported compression algorithm. Currently, the
   *     following compression algorithms are supported.
   *     <ul>
   *       <li>"none" - No compression.
   *       <li>"gz" - GZIP compression.
   *     </ul>
   */
  public static String[] getSupportedCompressionAlgorithms() {
    return Compression.getSupportedAlgorithms();
  }

  // Utility methods.
  /*
   * @param l Long to convert to an int.
   * @return <code>l</code> cast as an int.
   */
  static int longToInt(final long l) {
    // Expecting the size() of a block not exceeding 4GB. Assuming the
    // size() will wrap to negative integer if it exceeds 2GB (From tfile).
    return (int) (l & 0x00000000ffffffffL);
  }

  /**
   * Returns all files belonging to the given region directory. Could return an empty list.
   *
   * @param fs The file system reference.
   * @param regionDir The region directory to scan.
   * @return The list of files found.
   * @throws IOException When scanning the files fails.
   */
  static List<Path> getStoreFiles(FileSystem fs, Path regionDir) throws IOException {
    List<Path> res = new ArrayList<Path>();
    PathFilter dirFilter = new FSUtils.DirFilter(fs);
    FileStatus[] familyDirs = fs.listStatus(regionDir, dirFilter);
    for (FileStatus dir : familyDirs) {
      FileStatus[] files = fs.listStatus(dir.getPath());
      for (FileStatus file : files) {
        if (!file.isDir()) {
          res.add(file.getPath());
        }
      }
    }
    return res;
  }

  public static void main(String[] args) throws IOException {
    HFilePrettyPrinter prettyPrinter = new HFilePrettyPrinter();
    System.exit(prettyPrinter.run(args));
  }

  /**
   * Checks the given {@link HFile} format version, and throws an exception if invalid. Note that if
   * the version number comes from an input file and has not been verified, the caller needs to
   * re-throw an {@link IOException} to indicate that this is not a software error, but corrupted
   * input.
   *
   * @param version an HFile version
   * @throws IllegalArgumentException if the version is invalid
   */
  public static void checkFormatVersion(int version) throws IllegalArgumentException {
    if (version < MIN_FORMAT_VERSION || version > MAX_FORMAT_VERSION) {
      throw new IllegalArgumentException(
          "Invalid HFile version: "
              + version
              + " (expected to be "
              + "between "
              + MIN_FORMAT_VERSION
              + " and "
              + MAX_FORMAT_VERSION
              + ")");
    }
  }
}
  @SuppressWarnings("unchecked")
  public boolean parseOptions(String args[]) {

    Options options = new Options();
    options.addOption(OUTPUT_DIR_OPTION, true, "Output directory" + Workload.MERGE.onlyUsedFor());
    options.addOption(
        COMPRESSION_OPTION,
        true,
        " Compression type, one of "
            + Arrays.toString(Compression.Algorithm.values())
            + Workload.MERGE.onlyUsedFor());
    options.addOption(
        BLOOM_FILTER_OPTION,
        true,
        "Bloom filter type, one of "
            + Arrays.toString(StoreFile.BloomType.values())
            + Workload.MERGE.onlyUsedFor());
    options.addOption(BLOCK_SIZE_OPTION, true, "HFile block size" + Workload.MERGE.onlyUsedFor());
    options.addOption(
        DURATION_OPTION,
        true,
        "The amount of time to run the "
            + "random read workload for"
            + Workload.RANDOM_READS.onlyUsedFor());
    options.addOption(
        NUM_THREADS_OPTION,
        true,
        "The number of random " + "reader threads" + Workload.RANDOM_READS.onlyUsedFor());
    options.addOption(
        NUM_THREADS_OPTION,
        true,
        "The number of random " + "reader threads" + Workload.RANDOM_READS.onlyUsedFor());
    options.addOption(
        LoadTestTool.OPT_DATA_BLOCK_ENCODING, true, LoadTestTool.OPT_DATA_BLOCK_ENCODING_USAGE);
    options.addOption(
        LoadTestTool.OPT_ENCODE_IN_CACHE_ONLY, false, LoadTestTool.OPT_ENCODE_IN_CACHE_ONLY_USAGE);
    options.addOptionGroup(Workload.getOptionGroup());

    if (args.length == 0) {
      HelpFormatter formatter = new HelpFormatter();
      formatter.printHelp(HFileReadWriteTest.class.getSimpleName(), options, true);
      return false;
    }

    CommandLineParser parser = new PosixParser();
    CommandLine cmdLine;
    try {
      cmdLine = parser.parse(options, args);
    } catch (ParseException ex) {
      LOG.error(ex);
      return false;
    }

    workload = Workload.fromCmdLine(cmdLine);
    if (workload == null) return false;

    inputFileNames = (List<String>) cmdLine.getArgList();

    if (inputFileNames.size() == 0) {
      LOG.error("No input file names specified");
      return false;
    }

    if (inputFileNames.size() < workload.minNumInputFiles) {
      LOG.error("Too few input files: at least " + workload.minNumInputFiles + " required");
      return false;
    }

    if (inputFileNames.size() > workload.maxNumInputFiles) {
      LOG.error("Too many input files: at most " + workload.minNumInputFiles + " allowed");
      return false;
    }

    if (cmdLine.hasOption(COMPRESSION_OPTION)) {
      compression = Compression.Algorithm.valueOf(cmdLine.getOptionValue(COMPRESSION_OPTION));
    }

    if (cmdLine.hasOption(BLOOM_FILTER_OPTION)) {
      bloomType = StoreFile.BloomType.valueOf(cmdLine.getOptionValue(BLOOM_FILTER_OPTION));
    }

    encodeInCacheOnly = cmdLine.hasOption(LoadTestTool.OPT_ENCODE_IN_CACHE_ONLY);

    if (cmdLine.hasOption(LoadTestTool.OPT_DATA_BLOCK_ENCODING)) {
      dataBlockEncoding =
          DataBlockEncoding.valueOf(cmdLine.getOptionValue(LoadTestTool.OPT_DATA_BLOCK_ENCODING));
      // Optionally encode on disk, always encode in cache.
      dataBlockEncoder =
          new HFileDataBlockEncoderImpl(
              encodeInCacheOnly ? DataBlockEncoding.NONE : dataBlockEncoding, dataBlockEncoding);
    } else {
      if (encodeInCacheOnly) {
        LOG.error(
            "The -"
                + LoadTestTool.OPT_ENCODE_IN_CACHE_ONLY
                + " option does not make sense without -"
                + LoadTestTool.OPT_DATA_BLOCK_ENCODING);
        return false;
      }
    }

    blockSize = conf.getInt("hfile.min.blocksize.size", 65536);
    if (cmdLine.hasOption(BLOCK_SIZE_OPTION))
      blockSize = Integer.valueOf(cmdLine.getOptionValue(BLOCK_SIZE_OPTION));

    if (workload == Workload.MERGE) {
      String outputDirStr = cmdLine.getOptionValue(OUTPUT_DIR_OPTION);
      if (outputDirStr == null) {
        LOG.error("Output directory is not specified");
        return false;
      }
      outputDir = new Path(outputDirStr);
      // Will be checked for existence in validateConfiguration.
    }

    if (workload == Workload.RANDOM_READS) {
      if (!requireOptions(cmdLine, new String[] {DURATION_OPTION, NUM_THREADS_OPTION})) {
        return false;
      }

      durationSec = Integer.parseInt(cmdLine.getOptionValue(DURATION_OPTION));
      numReadThreads = Integer.parseInt(cmdLine.getOptionValue(NUM_THREADS_OPTION));
    }

    Collections.sort(inputFileNames);

    return true;
  }