/**
    *
    * 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.hbase.regionserver;
  
  import java.io.DataInput;
  import java.io.IOException;
  import java.net.InetSocketAddress;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.Map;
  import java.util.SortedSet;
  import java.util.UUID;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.HDFSBlocksDistribution;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.CellComparator;
  import org.apache.hadoop.hbase.KeyValueUtil;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.client.Scan;
  import org.apache.hadoop.hbase.io.FSDataInputStreamWrapper;
  import org.apache.hadoop.hbase.io.hfile.BlockType;
  import org.apache.hadoop.hbase.io.hfile.CacheConfig;
  import org.apache.hadoop.hbase.io.hfile.HFile;
  import org.apache.hadoop.hbase.io.hfile.HFileContext;
  import org.apache.hadoop.hbase.io.hfile.HFileScanner;
  import org.apache.hadoop.hbase.nio.ByteBuff;
  import org.apache.hadoop.hbase.regionserver.compactions.Compactor;
  import org.apache.hadoop.hbase.util.BloomFilter;
  import org.apache.hadoop.hbase.util.BloomFilterFactory;
  import org.apache.hadoop.hbase.util.BloomFilterWriter;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.Writables;
  import org.apache.hadoop.io.WritableUtils;
  import org.apache.hadoop.hbase.io.hfile.HFileBlock;
  
  import com.google.common.base.Function;
  import com.google.common.base.Preconditions;
  import com.google.common.collect.ImmutableList;
  import com.google.common.collect.Ordering;
  
  /**
   * A Store data file.  Stores usually have one or more of these files.  They
   * are produced by flushing the memstore to disk.  To
   * create, instantiate a writer using {@link StoreFile.WriterBuilder}
   * and append data. Be sure to add any metadata before calling close on the
   * Writer (Use the appendMetadata convenience methods). On close, a StoreFile
   * is sitting in the Filesystem.  To refer to it, create a StoreFile instance
   * passing filesystem and path.  To read, call {@link #createReader()}.
   * <p>StoreFiles may also reference store files in another Store.
   *
   * The reason for this weird pattern where you use a different instance for the
   * writer and a reader is that we write once but read a lot more.
   */
  @InterfaceAudience.LimitedPrivate("Coprocessor")
  public class StoreFile {
    private static final Log LOG = LogFactory.getLog(StoreFile.class.getName());
  
    // Keys for fileinfo values in HFile
  
    /** Max Sequence ID in FileInfo */
    public static final byte [] MAX_SEQ_ID_KEY = Bytes.toBytes("MAX_SEQ_ID_KEY");
  
    /** Major compaction flag in FileInfo */
    public static final byte[] MAJOR_COMPACTION_KEY =
        Bytes.toBytes("MAJOR_COMPACTION_KEY");
  
    /** Minor compaction flag in FileInfo */
    public static final byte[] EXCLUDE_FROM_MINOR_COMPACTION_KEY =
        Bytes.toBytes("EXCLUDE_FROM_MINOR_COMPACTION");
  
    /** Bloom filter Type in FileInfo */
    public static final byte[] BLOOM_FILTER_TYPE_KEY =
       Bytes.toBytes("BLOOM_FILTER_TYPE");
 
   /** Delete Family Count in FileInfo */
   public static final byte[] DELETE_FAMILY_COUNT =
       Bytes.toBytes("DELETE_FAMILY_COUNT");
 
   /** Last Bloom filter key in FileInfo */
   private static final byte[] LAST_BLOOM_KEY = Bytes.toBytes("LAST_BLOOM_KEY");
 
   /** Key for Timerange information in metadata*/
   public static final byte[] TIMERANGE_KEY = Bytes.toBytes("TIMERANGE");
 
   /** Key for timestamp of earliest-put in metadata*/
   public static final byte[] EARLIEST_PUT_TS = Bytes.toBytes("EARLIEST_PUT_TS");
 
   /** Key for the number of mob cells in metadata*/
   public static final byte[] MOB_CELLS_COUNT = Bytes.toBytes("MOB_CELLS_COUNT");
 
   private final StoreFileInfo fileInfo;
   private final FileSystem fs;
 
   // Block cache configuration and reference.
   private final CacheConfig cacheConf;
 
   // Keys for metadata stored in backing HFile.
   // Set when we obtain a Reader.
   private long sequenceid = -1;
 
   // max of the MemstoreTS in the KV's in this store
   // Set when we obtain a Reader.
   private long maxMemstoreTS = -1;
 
   // firstKey, lastkey and cellComparator will be set when openReader.
   private Cell firstKey;
 
   private Cell lastKey;
 
   private Comparator comparator;
 
   public Cell getFirstKey() {
     return firstKey;
   }
 
   public Cell getLastKey() {
     return lastKey;
   }
 
   public Comparator getComparator() {
     return comparator;
   }
 
   public long getMaxMemstoreTS() {
     return maxMemstoreTS;
   }
 
   public void setMaxMemstoreTS(long maxMemstoreTS) {
     this.maxMemstoreTS = maxMemstoreTS;
   }
 
   // If true, this file was product of a major compaction.  Its then set
   // whenever you get a Reader.
   private AtomicBoolean majorCompaction = null;
 
   // If true, this file should not be included in minor compactions.
   // It's set whenever you get a Reader.
   private boolean excludeFromMinorCompaction = false;
 
   /** Meta key set when store file is a result of a bulk load */
   public static final byte[] BULKLOAD_TASK_KEY =
     Bytes.toBytes("BULKLOAD_SOURCE_TASK");
   public static final byte[] BULKLOAD_TIME_KEY =
     Bytes.toBytes("BULKLOAD_TIMESTAMP");
 
   /**
    * Map of the metadata entries in the corresponding HFile
    */
   private Map<byte[], byte[]> metadataMap;
 
   // StoreFile.Reader
   private volatile Reader reader;
 
   /**
    * Bloom filter type specified in column family configuration. Does not
    * necessarily correspond to the Bloom filter type present in the HFile.
    */
   private final BloomType cfBloomType;
 
   /**
    * Key for skipping resetting sequence id in metadata.
    * For bulk loaded hfiles, the scanner resets the cell seqId with the latest one,
    * if this metadata is set as true, the reset is skipped.
    */
   public static final byte[] SKIP_RESET_SEQ_ID = Bytes.toBytes("SKIP_RESET_SEQ_ID");
 
   /**
    * Constructor, loads a reader and it's indices, etc. May allocate a
    * substantial amount of ram depending on the underlying files (10-20MB?).
    *
    * @param fs  The current file system to use.
    * @param p  The path of the file.
    * @param conf  The current configuration.
    * @param cacheConf  The cache configuration and block cache reference.
    * @param cfBloomType The bloom type to use for this store file as specified
    *          by column family configuration. This may or may not be the same
    *          as the Bloom filter type actually present in the HFile, because
    *          column family configuration might change. If this is
    *          {@link BloomType#NONE}, the existing Bloom filter is ignored.
    * @throws IOException When opening the reader fails.
    */
   public StoreFile(final FileSystem fs, final Path p, final Configuration conf,
         final CacheConfig cacheConf, final BloomType cfBloomType) throws IOException {
     this(fs, new StoreFileInfo(conf, fs, p), conf, cacheConf, cfBloomType);
   }
 
 
   /**
    * Constructor, loads a reader and it's indices, etc. May allocate a
    * substantial amount of ram depending on the underlying files (10-20MB?).
    *
    * @param fs  The current file system to use.
    * @param fileInfo  The store file information.
    * @param conf  The current configuration.
    * @param cacheConf  The cache configuration and block cache reference.
    * @param cfBloomType The bloom type to use for this store file as specified
    *          by column family configuration. This may or may not be the same
    *          as the Bloom filter type actually present in the HFile, because
    *          column family configuration might change. If this is
    *          {@link BloomType#NONE}, the existing Bloom filter is ignored.
    * @throws IOException When opening the reader fails.
    */
   public StoreFile(final FileSystem fs, final StoreFileInfo fileInfo, final Configuration conf,
       final CacheConfig cacheConf,  final BloomType cfBloomType) throws IOException {
     this.fs = fs;
     this.fileInfo = fileInfo;
     this.cacheConf = cacheConf;
 
     if (BloomFilterFactory.isGeneralBloomEnabled(conf)) {
       this.cfBloomType = cfBloomType;
     } else {
       LOG.info("Ignoring bloom filter check for file " + this.getPath() + ": " +
           "cfBloomType=" + cfBloomType + " (disabled in config)");
       this.cfBloomType = BloomType.NONE;
     }
   }
 
   /**
    * Clone
    * @param other The StoreFile to clone from
    */
   public StoreFile(final StoreFile other) {
     this.fs = other.fs;
     this.fileInfo = other.fileInfo;
     this.cacheConf = other.cacheConf;
     this.cfBloomType = other.cfBloomType;
   }
 
   /**
    * @return the StoreFile object associated to this StoreFile.
    *         null if the StoreFile is not a reference.
    */
   public StoreFileInfo getFileInfo() {
     return this.fileInfo;
   }
 
   /**
    * @return Path or null if this StoreFile was made with a Stream.
    */
   public Path getPath() {
     return this.fileInfo.getPath();
   }
 
   /**
    * @return Returns the qualified path of this StoreFile
    */
   public Path getQualifiedPath() {
     return this.fileInfo.getPath().makeQualified(fs);
   }
 
   /**
    * @return True if this is a StoreFile Reference; call
    * after {@link #open(boolean canUseDropBehind)} else may get wrong answer.
    */
   public boolean isReference() {
     return this.fileInfo.isReference();
   }
 
   /**
    * @return True if this file was made by a major compaction.
    */
   public boolean isMajorCompaction() {
     if (this.majorCompaction == null) {
       throw new NullPointerException("This has not been set yet");
     }
     return this.majorCompaction.get();
   }
 
   /**
    * @return True if this file should not be part of a minor compaction.
    */
   public boolean excludeFromMinorCompaction() {
     return this.excludeFromMinorCompaction;
   }
 
   /**
    * @return This files maximum edit sequence id.
    */
   public long getMaxSequenceId() {
     return this.sequenceid;
   }
 
   public long getModificationTimeStamp() throws IOException {
     return (fileInfo == null) ? 0 : fileInfo.getModificationTime();
   }
 
   /**
    * Only used by the Striped Compaction Policy
    * @param key
    * @return value associated with the metadata key
    */
   public byte[] getMetadataValue(byte[] key) {
     return metadataMap.get(key);
   }
 
   /**
    * Return the largest memstoreTS found across all storefiles in
    * the given list. Store files that were created by a mapreduce
    * bulk load are ignored, as they do not correspond to any specific
    * put operation, and thus do not have a memstoreTS associated with them.
    * @return 0 if no non-bulk-load files are provided or, this is Store that
    * does not yet have any store files.
    */
   public static long getMaxMemstoreTSInList(Collection<StoreFile> sfs) {
     long max = 0;
     for (StoreFile sf : sfs) {
       if (!sf.isBulkLoadResult()) {
         max = Math.max(max, sf.getMaxMemstoreTS());
       }
     }
     return max;
   }
 
   /**
    * Return the highest sequence ID found across all storefiles in
    * the given list.
    * @param sfs
    * @return 0 if no non-bulk-load files are provided or, this is Store that
    * does not yet have any store files.
    */
   public static long getMaxSequenceIdInList(Collection<StoreFile> sfs) {
     long max = 0;
     for (StoreFile sf : sfs) {
       max = Math.max(max, sf.getMaxSequenceId());
     }
     return max;
   }
 
   /**
    * Check if this storefile was created by bulk load.
    * When a hfile is bulk loaded into HBase, we append
    * '_SeqId_<id-when-loaded>' to the hfile name, unless
    * "hbase.mapreduce.bulkload.assign.sequenceNumbers" is
    * explicitly turned off.
    * If "hbase.mapreduce.bulkload.assign.sequenceNumbers"
    * is turned off, fall back to BULKLOAD_TIME_KEY.
    * @return true if this storefile was created by bulk load.
    */
   boolean isBulkLoadResult() {
     boolean bulkLoadedHFile = false;
     String fileName = this.getPath().getName();
     int startPos = fileName.indexOf("SeqId_");
     if (startPos != -1) {
       bulkLoadedHFile = true;
     }
     return bulkLoadedHFile || metadataMap.containsKey(BULKLOAD_TIME_KEY);
   }
 
   /**
    * Return the timestamp at which this bulk load file was generated.
    */
   public long getBulkLoadTimestamp() {
     byte[] bulkLoadTimestamp = metadataMap.get(BULKLOAD_TIME_KEY);
     return (bulkLoadTimestamp == null) ? 0 : Bytes.toLong(bulkLoadTimestamp);
   }
 
   /**
    * @return the cached value of HDFS blocks distribution. The cached value is
    * calculated when store file is opened.
    */
   public HDFSBlocksDistribution getHDFSBlockDistribution() {
     return this.fileInfo.getHDFSBlockDistribution();
   }
 
   /**
    * Opens reader on this store file.  Called by Constructor.
    * @return Reader for the store file.
    * @throws IOException
    * @see #closeReader(boolean)
    */
   private Reader open(boolean canUseDropBehind) throws IOException {
     if (this.reader != null) {
       throw new IllegalAccessError("Already open");
     }
 
     // Open the StoreFile.Reader
     this.reader = fileInfo.open(this.fs, this.cacheConf, canUseDropBehind);
 
     // Load up indices and fileinfo. This also loads Bloom filter type.
     metadataMap = Collections.unmodifiableMap(this.reader.loadFileInfo());
 
     // Read in our metadata.
     byte [] b = metadataMap.get(MAX_SEQ_ID_KEY);
     if (b != null) {
       // By convention, if halfhfile, top half has a sequence number > bottom
       // half. Thats why we add one in below. Its done for case the two halves
       // are ever merged back together --rare.  Without it, on open of store,
       // since store files are distinguished by sequence id, the one half would
       // subsume the other.
       this.sequenceid = Bytes.toLong(b);
       if (fileInfo.isTopReference()) {
         this.sequenceid += 1;
       }
     }
 
     if (isBulkLoadResult()){
       // generate the sequenceId from the fileName
       // fileName is of the form <randomName>_SeqId_<id-when-loaded>_
       String fileName = this.getPath().getName();
       // Use lastIndexOf() to get the last, most recent bulk load seqId.
       int startPos = fileName.lastIndexOf("SeqId_");
       if (startPos != -1) {
         this.sequenceid = Long.parseLong(fileName.substring(startPos + 6,
             fileName.indexOf('_', startPos + 6)));
         // Handle reference files as done above.
         if (fileInfo.isTopReference()) {
           this.sequenceid += 1;
         }
       }
       // SKIP_RESET_SEQ_ID only works in bulk loaded file.
       // In mob compaction, the hfile where the cells contain the path of a new mob file is bulk
       // loaded to hbase, these cells have the same seqIds with the old ones. We do not want
       // to reset new seqIds for them since this might make a mess of the visibility of cells that
       // have the same row key but different seqIds.
       this.reader.setSkipResetSeqId(isSkipResetSeqId(metadataMap.get(SKIP_RESET_SEQ_ID)));
       this.reader.setBulkLoaded(true);
     }
     this.reader.setSequenceID(this.sequenceid);
 
     b = metadataMap.get(HFile.Writer.MAX_MEMSTORE_TS_KEY);
     if (b != null) {
       this.maxMemstoreTS = Bytes.toLong(b);
     }
 
     b = metadataMap.get(MAJOR_COMPACTION_KEY);
     if (b != null) {
       boolean mc = Bytes.toBoolean(b);
       if (this.majorCompaction == null) {
         this.majorCompaction = new AtomicBoolean(mc);
       } else {
         this.majorCompaction.set(mc);
       }
     } else {
       // Presume it is not major compacted if it doesn't explicity say so
       // HFileOutputFormat explicitly sets the major compacted key.
       this.majorCompaction = new AtomicBoolean(false);
     }
 
     b = metadataMap.get(EXCLUDE_FROM_MINOR_COMPACTION_KEY);
     this.excludeFromMinorCompaction = (b != null && Bytes.toBoolean(b));
 
     BloomType hfileBloomType = reader.getBloomFilterType();
     if (cfBloomType != BloomType.NONE) {
       reader.loadBloomfilter(BlockType.GENERAL_BLOOM_META);
       if (hfileBloomType != cfBloomType) {
         LOG.info("HFile Bloom filter type for "
             + reader.getHFileReader().getName() + ": " + hfileBloomType
             + ", but " + cfBloomType + " specified in column family "
             + "configuration");
       }
     } else if (hfileBloomType != BloomType.NONE) {
       LOG.info("Bloom filter turned off by CF config for "
           + reader.getHFileReader().getName());
     }
 
     // load delete family bloom filter
     reader.loadBloomfilter(BlockType.DELETE_FAMILY_BLOOM_META);
 
     try {
       byte [] timerangeBytes = metadataMap.get(TIMERANGE_KEY);
       if (timerangeBytes != null) {
         this.reader.timeRangeTracker = new TimeRangeTracker();
         Writables.copyWritable(timerangeBytes, this.reader.timeRangeTracker);
       }
     } catch (IllegalArgumentException e) {
       LOG.error("Error reading timestamp range data from meta -- " +
           "proceeding without", e);
       this.reader.timeRangeTracker = null;
     }
     // initialize so we can reuse them after reader closed.
     firstKey = reader.getFirstKey();
     lastKey = reader.getLastKey();
     comparator = reader.getComparator();
     return this.reader;
   }
 
   public Reader createReader() throws IOException {
     return createReader(false);
   }
 
   /**
    * @return Reader for StoreFile. creates if necessary
    * @throws IOException
    */
   public Reader createReader(boolean canUseDropBehind) throws IOException {
     if (this.reader == null) {
       try {
         this.reader = open(canUseDropBehind);
       } catch (IOException e) {
         try {
           this.closeReader(true);
         } catch (IOException ee) {
         }
         throw e;
       }
 
     }
     return this.reader;
   }
 
   /**
    * @return Current reader.  Must call createReader first else returns null.
    * @see #createReader()
    */
   public Reader getReader() {
     return this.reader;
   }
 
   /**
    * @param evictOnClose whether to evict blocks belonging to this file
    * @throws IOException
    */
   public synchronized void closeReader(boolean evictOnClose)
       throws IOException {
     if (this.reader != null) {
       this.reader.close(evictOnClose);
       this.reader = null;
     }
   }
 
   /**
    * Delete this file
    * @throws IOException
    */
   public void deleteReader() throws IOException {
     closeReader(true);
     this.fs.delete(getPath(), true);
   }
 
   @Override
   public String toString() {
     return this.fileInfo.toString();
   }
 
   /**
    * @return a length description of this StoreFile, suitable for debug output
    */
   public String toStringDetailed() {
     StringBuilder sb = new StringBuilder();
     sb.append(this.getPath().toString());
     sb.append(", isReference=").append(isReference());
     sb.append(", isBulkLoadResult=").append(isBulkLoadResult());
     if (isBulkLoadResult()) {
       sb.append(", bulkLoadTS=").append(getBulkLoadTimestamp());
     } else {
       sb.append(", seqid=").append(getMaxSequenceId());
     }
     sb.append(", majorCompaction=").append(isMajorCompaction());
 
     return sb.toString();
   }
 
   /**
    * Gets whether to skip resetting the sequence id for cells.
    * @param skipResetSeqId The byte array of boolean.
    * @return Whether to skip resetting the sequence id.
    */
   private boolean isSkipResetSeqId(byte[] skipResetSeqId) {
     if (skipResetSeqId != null && skipResetSeqId.length == 1) {
       return Bytes.toBoolean(skipResetSeqId);
     }
     return false;
   }
 
   public static class WriterBuilder {
     private final Configuration conf;
     private final CacheConfig cacheConf;
     private final FileSystem fs;
 
     private CellComparator comparator = CellComparator.COMPARATOR;
     private BloomType bloomType = BloomType.NONE;
     private long maxKeyCount = 0;
     private Path dir;
     private Path filePath;
     private InetSocketAddress[] favoredNodes;
     private HFileContext fileContext;
     private boolean shouldDropCacheBehind = false;
 
     public WriterBuilder(Configuration conf, CacheConfig cacheConf,
         FileSystem fs) {
       this.conf = conf;
       this.cacheConf = cacheConf;
       this.fs = fs;
     }
 
     /**
      * Use either this method or {@link #withFilePath}, but not both.
      * @param dir Path to column family directory. The directory is created if
      *          does not exist. The file is given a unique name within this
      *          directory.
      * @return this (for chained invocation)
      */
     public WriterBuilder withOutputDir(Path dir) {
       Preconditions.checkNotNull(dir);
       this.dir = dir;
       return this;
     }
 
     /**
      * Use either this method or {@link #withOutputDir}, but not both.
      * @param filePath the StoreFile path to write
      * @return this (for chained invocation)
      */
     public WriterBuilder withFilePath(Path filePath) {
       Preconditions.checkNotNull(filePath);
       this.filePath = filePath;
       return this;
     }
 
     /**
      * @param favoredNodes an array of favored nodes or possibly null
      * @return this (for chained invocation)
      */
     public WriterBuilder withFavoredNodes(InetSocketAddress[] favoredNodes) {
       this.favoredNodes = favoredNodes;
       return this;
     }
 
     public WriterBuilder withComparator(CellComparator comparator) {
       Preconditions.checkNotNull(comparator);
       this.comparator = comparator;
       return this;
     }
 
     public WriterBuilder withBloomType(BloomType bloomType) {
       Preconditions.checkNotNull(bloomType);
       this.bloomType = bloomType;
       return this;
     }
 
     /**
      * @param maxKeyCount estimated maximum number of keys we expect to add
      * @return this (for chained invocation)
      */
     public WriterBuilder withMaxKeyCount(long maxKeyCount) {
       this.maxKeyCount = maxKeyCount;
       return this;
     }
 
     public WriterBuilder withFileContext(HFileContext fileContext) {
       this.fileContext = fileContext;
       return this;
     }
 
     public WriterBuilder withShouldDropCacheBehind(boolean shouldDropCacheBehind) {
       this.shouldDropCacheBehind = shouldDropCacheBehind;
       return this;
     }
     /**
      * Create a store file writer. Client is responsible for closing file when
      * done. If metadata, add BEFORE closing using
      * {@link Writer#appendMetadata}.
      */
     public Writer build() throws IOException {
       if ((dir == null ? 0 : 1) + (filePath == null ? 0 : 1) != 1) {
         throw new IllegalArgumentException("Either specify parent directory " +
             "or file path");
       }
 
       if (dir == null) {
         dir = filePath.getParent();
       }
 
       if (!fs.exists(dir)) {
         fs.mkdirs(dir);
       }
 
       if (filePath == null) {
         filePath = getUniqueFile(fs, dir);
         if (!BloomFilterFactory.isGeneralBloomEnabled(conf)) {
           bloomType = BloomType.NONE;
         }
       }
 
       if (comparator == null) {
         comparator = CellComparator.COMPARATOR;
       }
       return new Writer(fs, filePath,
           conf, cacheConf, comparator, bloomType, maxKeyCount, favoredNodes, fileContext);
     }
   }
 
   /**
    * @param fs
    * @param dir Directory to create file in.
    * @return random filename inside passed <code>dir</code>
    */
   public static Path getUniqueFile(final FileSystem fs, final Path dir)
       throws IOException {
     if (!fs.getFileStatus(dir).isDirectory()) {
       throw new IOException("Expecting " + dir.toString() +
         " to be a directory");
     }
     return new Path(dir, UUID.randomUUID().toString().replaceAll("-", ""));
   }
 
   public Long getMinimumTimestamp() {
     return (getReader().timeRangeTracker == null) ?
         null :
         getReader().timeRangeTracker.getMinimumTimestamp();
   }
 
   /**
    * Gets the approximate mid-point of this file that is optimal for use in splitting it.
    * @param comparator Comparator used to compare KVs.
    * @return The split point row, or null if splitting is not possible, or reader is null.
    */
   @SuppressWarnings("deprecation")
   byte[] getFileSplitPoint(CellComparator comparator) throws IOException {
     if (this.reader == null) {
       LOG.warn("Storefile " + this + " Reader is null; cannot get split point");
       return null;
     }
     // Get first, last, and mid keys.  Midkey is the key that starts block
     // in middle of hfile.  Has column and timestamp.  Need to return just
     // the row we want to split on as midkey.
     Cell midkey = this.reader.midkey();
     if (midkey != null) {
       Cell firstKey = this.reader.getFirstKey();
       Cell lastKey = this.reader.getLastKey();
       // if the midkey is the same as the first or last keys, we cannot (ever) split this region.
       if (comparator.compareRows(midkey, firstKey) == 0
           || comparator.compareRows(midkey, lastKey) == 0) {
         if (LOG.isDebugEnabled()) {
           LOG.debug("cannot split because midkey is the same as first or last row");
         }
         return null;
       }
       return CellUtil.cloneRow(midkey);
     }
     return null;
   }
 
   /**
    * A StoreFile writer.  Use this to read/write HBase Store Files. It is package
    * local because it is an implementation detail of the HBase regionserver.
    */
   public static class Writer implements Compactor.CellSink {
     private final BloomFilterWriter generalBloomFilterWriter;
     private final BloomFilterWriter deleteFamilyBloomFilterWriter;
     private final BloomType bloomType;
     private byte[] lastBloomKey;
     private int lastBloomKeyOffset, lastBloomKeyLen;
     private Cell lastCell = null;
     private long earliestPutTs = HConstants.LATEST_TIMESTAMP;
     private Cell lastDeleteFamilyCell = null;
     private long deleteFamilyCnt = 0;
 
     /** Bytes per Checksum */
     protected int bytesPerChecksum;
 
     TimeRangeTracker timeRangeTracker = new TimeRangeTracker();
     /* isTimeRangeTrackerSet keeps track if the timeRange has already been set
      * When flushing a memstore, we set TimeRange and use this variable to
      * indicate that it doesn't need to be calculated again while
      * appending KeyValues.
      * It is not set in cases of compactions when it is recalculated using only
      * the appended KeyValues*/
     boolean isTimeRangeTrackerSet = false;
 
     protected HFile.Writer writer;
     private KeyValue.KeyOnlyKeyValue lastBloomKeyOnlyKV = null;
 
     /**
      * Creates an HFile.Writer that also write helpful meta data.
      * @param fs file system to write to
      * @param path file name to create
      * @param conf user configuration
      * @param comparator key comparator
      * @param bloomType bloom filter setting
      * @param maxKeys the expected maximum number of keys to be added. Was used
      *        for Bloom filter size in {@link HFile} format version 1.
      * @param favoredNodes
      * @param fileContext - The HFile context
      * @throws IOException problem writing to FS
      */
     private Writer(FileSystem fs, Path path,
         final Configuration conf,
         CacheConfig cacheConf,
         final CellComparator comparator, BloomType bloomType, long maxKeys,
         InetSocketAddress[] favoredNodes, HFileContext fileContext)
             throws IOException {
       writer = HFile.getWriterFactory(conf, cacheConf)
           .withPath(fs, path)
           .withComparator(comparator)
           .withFavoredNodes(favoredNodes)
           .withFileContext(fileContext)
           .create();
 
       generalBloomFilterWriter = BloomFilterFactory.createGeneralBloomAtWrite(
           conf, cacheConf, bloomType,
           (int) Math.min(maxKeys, Integer.MAX_VALUE), writer);
 
       if (generalBloomFilterWriter != null) {
         this.bloomType = bloomType;
         if(this.bloomType ==  BloomType.ROWCOL) {
           lastBloomKeyOnlyKV = new KeyValue.KeyOnlyKeyValue();
         }
         if (LOG.isTraceEnabled()) LOG.trace("Bloom filter type for " + path + ": " +
           this.bloomType + ", " + generalBloomFilterWriter.getClass().getSimpleName());
       } else {
         // Not using Bloom filters.
         this.bloomType = BloomType.NONE;
       }
 
       // initialize delete family Bloom filter when there is NO RowCol Bloom
       // filter
       if (this.bloomType != BloomType.ROWCOL) {
         this.deleteFamilyBloomFilterWriter = BloomFilterFactory
             .createDeleteBloomAtWrite(conf, cacheConf,
                 (int) Math.min(maxKeys, Integer.MAX_VALUE), writer);
       } else {
         deleteFamilyBloomFilterWriter = null;
       }
       if (deleteFamilyBloomFilterWriter != null) {
         if (LOG.isTraceEnabled()) LOG.trace("Delete Family Bloom filter type for " + path + ": "
             + deleteFamilyBloomFilterWriter.getClass().getSimpleName());
       }
     }
 
     /**
      * Writes meta data.
      * Call before {@link #close()} since its written as meta data to this file.
      * @param maxSequenceId Maximum sequence id.
      * @param majorCompaction True if this file is product of a major compaction
      * @throws IOException problem writing to FS
      */
     public void appendMetadata(final long maxSequenceId, final boolean majorCompaction)
     throws IOException {
       writer.appendFileInfo(MAX_SEQ_ID_KEY, Bytes.toBytes(maxSequenceId));
       writer.appendFileInfo(MAJOR_COMPACTION_KEY,
           Bytes.toBytes(majorCompaction));
       appendTrackedTimestampsToMetadata();
     }
 
     /**
      * Writes meta data.
      * Call before {@link #close()} since its written as meta data to this file.
      * @param maxSequenceId Maximum sequence id.
      * @param majorCompaction True if this file is product of a major compaction
      * @param mobCellsCount The number of mob cells.
      * @throws IOException problem writing to FS
      */
     public void appendMetadata(final long maxSequenceId, final boolean majorCompaction,
         final long mobCellsCount) throws IOException {
       writer.appendFileInfo(MAX_SEQ_ID_KEY, Bytes.toBytes(maxSequenceId));
       writer.appendFileInfo(MAJOR_COMPACTION_KEY, Bytes.toBytes(majorCompaction));
       writer.appendFileInfo(MOB_CELLS_COUNT, Bytes.toBytes(mobCellsCount));
       appendTrackedTimestampsToMetadata();
     }
 
     /**
      * Add TimestampRange and earliest put timestamp to Metadata
      */
     public void appendTrackedTimestampsToMetadata() throws IOException {
       appendFileInfo(TIMERANGE_KEY,WritableUtils.toByteArray(timeRangeTracker));
       appendFileInfo(EARLIEST_PUT_TS, Bytes.toBytes(earliestPutTs));
     }
 
     /**
      * Set TimeRangeTracker
      * @param trt
      */
     public void setTimeRangeTracker(final TimeRangeTracker trt) {
       this.timeRangeTracker = trt;
       isTimeRangeTrackerSet = true;
     }
 
     /**
      * Record the earlest Put timestamp.
      *
      * If the timeRangeTracker is not set,
      * update TimeRangeTracker to include the timestamp of this key
      * @param cell
      */
     public void trackTimestamps(final Cell cell) {
       if (KeyValue.Type.Put.getCode() == cell.getTypeByte()) {
         earliestPutTs = Math.min(earliestPutTs, cell.getTimestamp());
       }
       if (!isTimeRangeTrackerSet) {
         timeRangeTracker.includeTimestamp(cell);
       }
     }
 
     private void appendGeneralBloomfilter(final Cell cell) throws IOException {
       if (this.generalBloomFilterWriter != null) {
         // only add to the bloom filter on a new, unique key
         boolean newKey = true;
         if (this.lastCell != null) {
           switch(bloomType) {
           case ROW:
             newKey = ! CellUtil.matchingRows(cell, lastCell);
             break;
           case ROWCOL:
             newKey = ! CellUtil.matchingRowColumn(cell, lastCell);
             break;
           case NONE:
             newKey = false;
             break;
           default:
             throw new IOException("Invalid Bloom filter type: " + bloomType +
                 " (ROW or ROWCOL expected)");
           }
         }
         if (newKey) {
           /*
            * http://2.bp.blogspot.com/_Cib_A77V54U/StZMrzaKufI/AAAAAAAAADo/ZhK7bGoJdMQ/s400/KeyValue.png
            * Key = RowLen + Row + FamilyLen + Column [Family + Qualifier] + TimeStamp
            *
            * 2 Types of Filtering:
            *  1. Row = Row
            *  2. RowCol = Row + Qualifier
            */
           byte[] bloomKey = null;
           // Used with ROW_COL bloom
           KeyValue bloomKeyKV = null;
           int bloomKeyOffset, bloomKeyLen;
 
           switch (bloomType) {
           case ROW:
             bloomKey = cell.getRowArray();
             bloomKeyOffset = cell.getRowOffset();
             bloomKeyLen = cell.getRowLength();
             break;
           case ROWCOL:
             // merge(row, qualifier)
             // TODO: could save one buffer copy in case of compound Bloom
             // filters when this involves creating a KeyValue
             // TODO : Handle while writes also
             bloomKeyKV = KeyValueUtil.createFirstOnRow(cell.getRowArray(), cell.getRowOffset(),
                 cell.getRowLength(), 
                 HConstants.EMPTY_BYTE_ARRAY, 0, 0, cell.getQualifierArray(),
                 cell.getQualifierOffset(),
                 cell.getQualifierLength());
             bloomKey = bloomKeyKV.getBuffer();
             bloomKeyOffset = bloomKeyKV.getKeyOffset();
             bloomKeyLen = bloomKeyKV.getKeyLength();
             break;
           default:
             throw new IOException("Invalid Bloom filter type: " + bloomType +
                 " (ROW or ROWCOL expected)");
           }
           generalBloomFilterWriter.add(bloomKey, bloomKeyOffset, bloomKeyLen);
           if (lastBloomKey != null) {
             int res = 0;
             // hbase:meta does not have blooms. So we need not have special interpretation
             // of the hbase:meta cells.  We can safely use Bytes.BYTES_RAWCOMPARATOR for ROW Bloom
             if (bloomType == BloomType.ROW) {
               res = Bytes.BYTES_RAWCOMPARATOR.compare(bloomKey, bloomKeyOffset, bloomKeyLen,
                   lastBloomKey, lastBloomKeyOffset, lastBloomKeyLen);
             } else {
               // TODO : Caching of kv components becomes important in these cases
               res = CellComparator.COMPARATOR.compare(bloomKeyKV, lastBloomKeyOnlyKV);
             }
             if (res <= 0) {
               throw new IOException("Non-increasing Bloom keys: "
                   + Bytes.toStringBinary(bloomKey, bloomKeyOffset, bloomKeyLen) + " after "
                   + Bytes.toStringBinary(lastBloomKey, lastBloomKeyOffset, lastBloomKeyLen));
             }
           }
           lastBloomKey = bloomKey;
           lastBloomKeyOffset = bloomKeyOffset;
           lastBloomKeyLen = bloomKeyLen;
           if (bloomType == BloomType.ROWCOL) {
             lastBloomKeyOnlyKV.setKey(bloomKey, bloomKeyOffset, bloomKeyLen);
           }
           this.lastCell = cell;
         }
       }
     }
 
     private void appendDeleteFamilyBloomFilter(final Cell cell)
         throws IOException {
       if (!CellUtil.isDeleteFamily(cell) && !CellUtil.isDeleteFamilyVersion(cell)) {
         return;
       }
 
       // increase the number of delete family in the store file
       deleteFamilyCnt++;
       if (null != this.deleteFamilyBloomFilterWriter) {
         boolean newKey = true;
         if (lastDeleteFamilyCell != null) {
           // hbase:meta does not have blooms. So we need not have special interpretation
           // of the hbase:meta cells
           newKey = !CellUtil.matchingRows(cell, lastDeleteFamilyCell);
         }
         if (newKey) {
           this.deleteFamilyBloomFilterWriter.add(cell.getRowArray(),
               cell.getRowOffset(), cell.getRowLength());
           this.lastDeleteFamilyCell = cell;
         }
       }
     }
 
     public void append(final Cell cell) throws IOException {
       appendGeneralBloomfilter(cell);
       appendDeleteFamilyBloomFilter(cell);
       writer.append(cell);
       trackTimestamps(cell);
     }
 
     public Path getPath() {
       return this.writer.getPath();
     }
 
     public boolean hasGeneralBloom() {
       return this.generalBloomFilterWriter != null;
     }
 
     /**
      * For unit testing only.
      *
      * @return the Bloom filter used by this writer.
      */
     BloomFilterWriter getGeneralBloomWriter() {
       return generalBloomFilterWriter;
     }
 
     private boolean closeBloomFilter(BloomFilterWriter bfw) throws IOException {
       boolean haveBloom = (bfw != null && bfw.getKeyCount() > 0);
       if (haveBloom) {
         bfw.compactBloom();
       }
       return haveBloom;
     }
 
     private boolean closeGeneralBloomFilter() throws IOException {
       boolean hasGeneralBloom = closeBloomFilter(generalBloomFilterWriter);
 
       // add the general Bloom filter writer and append file info
       if (hasGeneralBloom) {
         writer.addGeneralBloomFilter(generalBloomFilterWriter);
         writer.appendFileInfo(BLOOM_FILTER_TYPE_KEY,
             Bytes.toBytes(bloomType.toString()));
         if (lastBloomKey != null) {
           writer.appendFileInfo(LAST_BLOOM_KEY, Arrays.copyOfRange(
               lastBloomKey, lastBloomKeyOffset, lastBloomKeyOffset
                   + lastBloomKeyLen));
         }
       }
       return hasGeneralBloom;
     }
 
     private boolean closeDeleteFamilyBloomFilter() throws IOException {
       boolean hasDeleteFamilyBloom = closeBloomFilter(deleteFamilyBloomFilterWriter);
 
       // add the delete family Bloom filter writer
       if (hasDeleteFamilyBloom) {
         writer.addDeleteFamilyBloomFilter(deleteFamilyBloomFilterWriter);
       }
 
       // append file info about the number of delete family kvs
       // even if there is no delete family Bloom.
       writer.appendFileInfo(DELETE_FAMILY_COUNT,
           Bytes.toBytes(this.deleteFamilyCnt));
 
       return hasDeleteFamilyBloom;
     }
 
     public void close() throws IOException {
       boolean hasGeneralBloom = this.closeGeneralBloomFilter();
       boolean hasDeleteFamilyBloom = this.closeDeleteFamilyBloomFilter();
 
       writer.close();
 
       // Log final Bloom filter statistics. This needs to be done after close()
       // because compound Bloom filters might be finalized as part of closing.
       if (StoreFile.LOG.isTraceEnabled()) {
         StoreFile.LOG.trace((hasGeneralBloom ? "" : "NO ") + "General Bloom and " +
           (hasDeleteFamilyBloom ? "" : "NO ") + "DeleteFamily" + " was added to HFile " +
           getPath());
       }
 
     }
 
     public void appendFileInfo(byte[] key, byte[] value) throws IOException {
       writer.appendFileInfo(key, value);
     }
 
     /** For use in testing, e.g. {@link org.apache.hadoop.hbase.regionserver.CreateRandomStoreFile}
      */
     HFile.Writer getHFileWriter() {
       return writer;
     }
   }
 
   /**
    * Reader for a StoreFile.
    */
   public static class Reader {
     private static final Log LOG = LogFactory.getLog(Reader.class.getName());
 
     protected BloomFilter generalBloomFilter = null;
     protected BloomFilter deleteFamilyBloomFilter = null;
     protected BloomType bloomFilterType;
     private final HFile.Reader reader;
     protected TimeRangeTracker timeRangeTracker = null;
     protected long sequenceID = -1;
     private byte[] lastBloomKey;
     private long deleteFamilyCnt = -1;
     private boolean bulkLoadResult = false;
     private KeyValue.KeyOnlyKeyValue lastBloomKeyOnlyKV = null;
     private boolean skipResetSeqId = true;
 
     public Reader(FileSystem fs, Path path, CacheConfig cacheConf, Configuration conf)
         throws IOException {
       reader = HFile.createReader(fs, path, cacheConf, conf);
       bloomFilterType = BloomType.NONE;
     }
 
     public Reader(FileSystem fs, Path path, FSDataInputStreamWrapper in, long size,
         CacheConfig cacheConf, Configuration conf) throws IOException {
       reader = HFile.createReader(fs, path, in, size, cacheConf, conf);
       bloomFilterType = BloomType.NONE;
     }
 
     public void setReplicaStoreFile(boolean isPrimaryReplicaStoreFile) {
       reader.setPrimaryReplicaReader(isPrimaryReplicaStoreFile);
     }
     public boolean isPrimaryReplicaReader() {
       return reader.isPrimaryReplicaReader();
     }
 
     /**
      * ONLY USE DEFAULT CONSTRUCTOR FOR UNIT TESTS
      */
     Reader() {
       this.reader = null;
     }
 
     public CellComparator getComparator() {
       return reader.getComparator();
     }
 
     /**
      * Get a scanner to scan over this StoreFile. Do not use
      * this overload if using this scanner for compactions.
      *
      * @param cacheBlocks should this scanner cache blocks?
      * @param pread use pread (for highly concurrent small readers)
      * @return a scanner
      */
     public StoreFileScanner getStoreFileScanner(boolean cacheBlocks,
                                                boolean pread) {
       return getStoreFileScanner(cacheBlocks, pread, false,
         // 0 is passed as readpoint because this method is only used by test
         // where StoreFile is directly operated upon
         0);
     }
 
     /**
      * Get a scanner to scan over this StoreFile.
      *
      * @param cacheBlocks should this scanner cache blocks?
      * @param pread use pread (for highly concurrent small readers)
      * @param isCompaction is scanner being used for compaction?
      * @return a scanner
      */
     public StoreFileScanner getStoreFileScanner(boolean cacheBlocks,
                                                boolean pread,
                                                boolean isCompaction, long readPt) {
       return new StoreFileScanner(this,
                                  getScanner(cacheBlocks, pread, isCompaction),
                                  !isCompaction, reader.hasMVCCInfo(), readPt);
     }
 
     /**
      * Warning: Do not write further code which depends on this call. Instead
      * use getStoreFileScanner() which uses the StoreFileScanner class/interface
      * which is the preferred way to scan a store with higher level concepts.
      *
      * @param cacheBlocks should we cache the blocks?
      * @param pread use pread (for concurrent small readers)
      * @return the underlying HFileScanner
      */
     @Deprecated
     public HFileScanner getScanner(boolean cacheBlocks, boolean pread) {
       return getScanner(cacheBlocks, pread, false);
     }
 
     /**
      * Warning: Do not write further code which depends on this call. Instead
      * use getStoreFileScanner() which uses the StoreFileScanner class/interface
      * which is the preferred way to scan a store with higher level concepts.
      *
      * @param cacheBlocks
      *          should we cache the blocks?
      * @param pread
      *          use pread (for concurrent small readers)
      * @param isCompaction
      *          is scanner being used for compaction?
      * @return the underlying HFileScanner
      */
     @Deprecated
     public HFileScanner getScanner(boolean cacheBlocks, boolean pread,
         boolean isCompaction) {
       return reader.getScanner(cacheBlocks, pread, isCompaction);
     }
 
     public void close(boolean evictOnClose) throws IOException {
       reader.close(evictOnClose);
     }
 
     /**
      * Check if this storeFile may contain keys within the TimeRange that
      * have not expired (i.e. not older than oldestUnexpiredTS).
      * @param scan the current scan
      * @param oldestUnexpiredTS the oldest timestamp that is not expired, as
      *          determined by the column family's TTL
      * @return false if queried keys definitely don't exist in this StoreFile
      */
     boolean passesTimerangeFilter(Scan scan, long oldestUnexpiredTS) {
       if (timeRangeTracker == null) {
         return true;
       } else {
         return timeRangeTracker.includesTimeRange(scan.getTimeRange()) &&
             timeRangeTracker.getMaximumTimestamp() >= oldestUnexpiredTS;
       }
     }
 
     /**
      * Checks whether the given scan passes the Bloom filter (if present). Only
      * checks Bloom filters for single-row or single-row-column scans. Bloom
      * filter checking for multi-gets is implemented as part of the store
      * scanner system (see {@link StoreFileScanner#seekExactly}) and uses
      * the lower-level API {@link #passesGeneralRowBloomFilter(byte[], int, int)}
      * and {@link #passesGeneralRowColBloomFilter(Cell)}.
      *
      * @param scan the scan specification. Used to determine the row, and to
      *          check whether this is a single-row ("get") scan.
      * @param columns the set of columns. Only used for row-column Bloom
      *          filters.
      * @return true if the scan with the given column set passes the Bloom
      *         filter, or if the Bloom filter is not applicable for the scan.
      *         False if the Bloom filter is applicable and the scan fails it.
      */
      boolean passesBloomFilter(Scan scan,
         final SortedSet<byte[]> columns) {
       // Multi-column non-get scans will use Bloom filters through the
       // lower-level API function that this function calls.
       if (!scan.isGetScan()) {
         return true;
       }
 
       byte[] row = scan.getStartRow();
       switch (this.bloomFilterType) {
         case ROW:
           return passesGeneralRowBloomFilter(row, 0, row.length);
 
         case ROWCOL:
           if (columns != null && columns.size() == 1) {
             byte[] column = columns.first();
             // create the required fake key
             Cell kvKey = KeyValueUtil.createFirstOnRow(row, 0, row.length,
               HConstants.EMPTY_BYTE_ARRAY, 0, 0, column, 0,
               column.length);
             return passesGeneralRowColBloomFilter(kvKey);
           }
 
           // For multi-column queries the Bloom filter is checked from the
           // seekExact operation.
           return true;
 
         default:
           return true;
       }
     }
 
     public boolean passesDeleteFamilyBloomFilter(byte[] row, int rowOffset,
         int rowLen) {
       // Cache Bloom filter as a local variable in case it is set to null by
       // another thread on an IO error.
       BloomFilter bloomFilter = this.deleteFamilyBloomFilter;
 
       // Empty file or there is no delete family at all
       if (reader.getTrailer().getEntryCount() == 0 || deleteFamilyCnt == 0) {
         return false;
       }
 
       if (bloomFilter == null) {
         return true;
       }
 
       try {
         if (!bloomFilter.supportsAutoLoading()) {
           return true;
         }
         return bloomFilter.contains(row, rowOffset, rowLen, null);
       } catch (IllegalArgumentException e) {
         LOG.error("Bad Delete Family bloom filter data -- proceeding without",
             e);
         setDeleteFamilyBloomFilterFaulty();
       }
 
       return true;
     }
 
     /**
      * A method for checking Bloom filters. Called directly from
      * StoreFileScanner in case of a multi-column query.
      *
      * @param row
      * @param rowOffset
      * @param rowLen
      * @return True if passes
      */
     public boolean passesGeneralRowBloomFilter(byte[] row, int rowOffset, int rowLen) {
       BloomFilter bloomFilter = this.generalBloomFilter;
       if (bloomFilter == null) {
         return true;
       }
 
       // Used in ROW bloom
       byte[] key = null;
       if (rowOffset != 0 || rowLen != row.length) {
         throw new AssertionError(
             "For row-only Bloom filters the row " + "must occupy the whole array");
       }
       key = row;
       return checkGeneralBloomFilter(key, null, bloomFilter);
     }
 
     /**
      * A method for checking Bloom filters. Called directly from
      * StoreFileScanner in case of a multi-column query.
      *
      * @param cell
      *          the cell to check if present in BloomFilter
      * @return True if passes
      */
     public boolean passesGeneralRowColBloomFilter(Cell cell) {
       BloomFilter bloomFilter = this.generalBloomFilter;
       if (bloomFilter == null) {
         return true;
       }
       // Used in ROW_COL bloom
       Cell kvKey = null;
       // Already if the incoming key is a fake rowcol key then use it as it is
       if (cell.getTypeByte() == KeyValue.Type.Maximum.getCode() && cell.getFamilyLength() == 0) {
         kvKey = cell;
       } else {
         kvKey = CellUtil.createFirstOnRowCol(cell);
       }
       return checkGeneralBloomFilter(null, kvKey, bloomFilter);
     }
 
     private boolean checkGeneralBloomFilter(byte[] key, Cell kvKey, BloomFilter bloomFilter) {
       // Empty file
       if (reader.getTrailer().getEntryCount() == 0)
         return false;
       HFileBlock bloomBlock = null;
       try {
         boolean shouldCheckBloom;
         ByteBuff bloom;
         if (bloomFilter.supportsAutoLoading()) {
           bloom = null;
           shouldCheckBloom = true;
         } else {
           bloomBlock = reader.getMetaBlock(HFile.BLOOM_FILTER_DATA_KEY, true);
           bloom = bloomBlock.getBufferWithoutHeader();
           shouldCheckBloom = bloom != null;
         }
 
         if (shouldCheckBloom) {
           boolean exists;
 
           // Whether the primary Bloom key is greater than the last Bloom key
           // from the file info. For row-column Bloom filters this is not yet
           // a sufficient condition to return false.
           boolean keyIsAfterLast = (lastBloomKey != null);
           // hbase:meta does not have blooms. So we need not have special interpretation
           // of the hbase:meta cells.  We can safely use Bytes.BYTES_RAWCOMPARATOR for ROW Bloom
           if (keyIsAfterLast) {
             if (bloomFilterType == BloomType.ROW) {
               keyIsAfterLast = (Bytes.BYTES_RAWCOMPARATOR.compare(key, lastBloomKey) > 0);
             } else {
               keyIsAfterLast = (CellComparator.COMPARATOR.compare(kvKey, lastBloomKeyOnlyKV)) > 0;
             }
           }
 
           if (bloomFilterType == BloomType.ROWCOL) {
             // Since a Row Delete is essentially a DeleteFamily applied to all
             // columns, a file might be skipped if using row+col Bloom filter.
             // In order to ensure this file is included an additional check is
             // required looking only for a row bloom.
             Cell rowBloomKey = CellUtil.createFirstOnRow(kvKey);
             // hbase:meta does not have blooms. So we need not have special interpretation
             // of the hbase:meta cells.  We can safely use Bytes.BYTES_RAWCOMPARATOR for ROW Bloom
             if (keyIsAfterLast
                 && (CellComparator.COMPARATOR.compare(rowBloomKey, lastBloomKeyOnlyKV)) > 0) {
               exists = false;
             } else {
               exists =
                   bloomFilter.contains(kvKey, bloom) ||
                   bloomFilter.contains(rowBloomKey, bloom);
             }
           } else {
             exists = !keyIsAfterLast
                 && bloomFilter.contains(key, 0, key.length, bloom);
           }
 
           return exists;
         }
       } catch (IOException e) {
         LOG.error("Error reading bloom filter data -- proceeding without",
             e);
         setGeneralBloomFilterFaulty();
       } catch (IllegalArgumentException e) {
         LOG.error("Bad bloom filter data -- proceeding without", e);
         setGeneralBloomFilterFaulty();
       } finally {
         // Return the bloom block so that its ref count can be decremented.
         reader.returnBlock(bloomBlock);
       }
       return true;
     }
 
     /**
      * Checks whether the given scan rowkey range overlaps with the current storefile's
      * @param scan the scan specification. Used to determine the rowkey range.
      * @return true if there is overlap, false otherwise
      */
     public boolean passesKeyRangeFilter(Scan scan) {
       if (this.getFirstKey() == null || this.getLastKey() == null) {
         // the file is empty
         return false;
       }
       if (Bytes.equals(scan.getStartRow(), HConstants.EMPTY_START_ROW)
           && Bytes.equals(scan.getStopRow(), HConstants.EMPTY_END_ROW)) {
         return true;
       }
       byte[] smallestScanRow = scan.isReversed() ? scan.getStopRow() : scan.getStartRow();
       byte[] largestScanRow = scan.isReversed() ? scan.getStartRow() : scan.getStopRow();
       Cell firstKeyKV = this.getFirstKey();
       Cell lastKeyKV = this.getLastKey();
       boolean nonOverLapping = (getComparator().compareRows(firstKeyKV,
           largestScanRow, 0, largestScanRow.length) > 0 
           && !Bytes
           .equals(scan.isReversed() ? scan.getStartRow() : scan.getStopRow(),
               HConstants.EMPTY_END_ROW))
           || getComparator().compareRows(lastKeyKV, smallestScanRow, 0, smallestScanRow.length) < 0;
       return !nonOverLapping;
     }
 
     public Map<byte[], byte[]> loadFileInfo() throws IOException {
       Map<byte [], byte []> fi = reader.loadFileInfo();
 
       byte[] b = fi.get(BLOOM_FILTER_TYPE_KEY);
       if (b != null) {
         bloomFilterType = BloomType.valueOf(Bytes.toString(b));
       }
 
       lastBloomKey = fi.get(LAST_BLOOM_KEY);
       if(bloomFilterType == BloomType.ROWCOL) {
         lastBloomKeyOnlyKV = new KeyValue.KeyOnlyKeyValue(lastBloomKey, 0, lastBloomKey.length);
       }
       byte[] cnt = fi.get(DELETE_FAMILY_COUNT);
       if (cnt != null) {
         deleteFamilyCnt = Bytes.toLong(cnt);
       }
 
       return fi;
     }
 
     public void loadBloomfilter() {
       this.loadBloomfilter(BlockType.GENERAL_BLOOM_META);
       this.loadBloomfilter(BlockType.DELETE_FAMILY_BLOOM_META);
     }
 
     private void loadBloomfilter(BlockType blockType) {
       try {
         if (blockType == BlockType.GENERAL_BLOOM_META) {
           if (this.generalBloomFilter != null)
             return; // Bloom has been loaded
 
           DataInput bloomMeta = reader.getGeneralBloomFilterMetadata();
           if (bloomMeta != null) {
             // sanity check for NONE Bloom filter
             if (bloomFilterType == BloomType.NONE) {
               throw new IOException(
                   "valid bloom filter type not found in FileInfo");
             } else {
               generalBloomFilter = BloomFilterFactory.createFromMeta(bloomMeta,
                   reader);
               if (LOG.isTraceEnabled()) {
                 LOG.trace("Loaded " + bloomFilterType.toString() + " "
                   + generalBloomFilter.getClass().getSimpleName()
                   + " metadata for " + reader.getName());
               }
             }
           }
         } else if (blockType == BlockType.DELETE_FAMILY_BLOOM_META) {
           if (this.deleteFamilyBloomFilter != null)
             return; // Bloom has been loaded
 
           DataInput bloomMeta = reader.getDeleteBloomFilterMetadata();
           if (bloomMeta != null) {
             deleteFamilyBloomFilter = BloomFilterFactory.createFromMeta(
                 bloomMeta, reader);
             LOG.info("Loaded Delete Family Bloom ("
                 + deleteFamilyBloomFilter.getClass().getSimpleName()
                 + ") metadata for " + reader.getName());
           }
         } else {
           throw new RuntimeException("Block Type: " + blockType.toString()
               + "is not supported for Bloom filter");
         }
       } catch (IOException e) {
         LOG.error("Error reading bloom filter meta for " + blockType
             + " -- proceeding without", e);
         setBloomFilterFaulty(blockType);
       } catch (IllegalArgumentException e) {
         LOG.error("Bad bloom filter meta " + blockType
             + " -- proceeding without", e);
         setBloomFilterFaulty(blockType);
       }
     }
 
     private void setBloomFilterFaulty(BlockType blockType) {
       if (blockType == BlockType.GENERAL_BLOOM_META) {
         setGeneralBloomFilterFaulty();
       } else if (blockType == BlockType.DELETE_FAMILY_BLOOM_META) {
         setDeleteFamilyBloomFilterFaulty();
       }
     }
 
     /**
      * The number of Bloom filter entries in this store file, or an estimate
      * thereof, if the Bloom filter is not loaded. This always returns an upper
      * bound of the number of Bloom filter entries.
      *
      * @return an estimate of the number of Bloom filter entries in this file
      */
     public long getFilterEntries() {
       return generalBloomFilter != null ? generalBloomFilter.getKeyCount()
           : reader.getEntries();
     }
 
     public void setGeneralBloomFilterFaulty() {
       generalBloomFilter = null;
     }
 
     public void setDeleteFamilyBloomFilterFaulty() {
       this.deleteFamilyBloomFilter = null;
     }
 
     public Cell getLastKey() {
       return reader.getLastKey();
     }
 
     public byte[] getLastRowKey() {
       return reader.getLastRowKey();
     }
 
     public Cell midkey() throws IOException {
       return reader.midkey();
     }
 
     public long length() {
       return reader.length();
     }
 
     public long getTotalUncompressedBytes() {
       return reader.getTrailer().getTotalUncompressedBytes();
     }
 
     public long getEntries() {
       return reader.getEntries();
     }
 
     public long getDeleteFamilyCnt() {
       return deleteFamilyCnt;
     }
 
     public Cell getFirstKey() {
       return reader.getFirstKey();
     }
 
     public long indexSize() {
       return reader.indexSize();
     }
 
     public BloomType getBloomFilterType() {
       return this.bloomFilterType;
     }
 
     public long getSequenceID() {
       return sequenceID;
     }
 
     public void setSequenceID(long sequenceID) {
       this.sequenceID = sequenceID;
     }
 
     public void setBulkLoaded(boolean bulkLoadResult) {
       this.bulkLoadResult = bulkLoadResult;
     }
 
     public boolean isBulkLoaded() {
       return this.bulkLoadResult;
     }
 
     BloomFilter getGeneralBloomFilter() {
       return generalBloomFilter;
     }
 
     long getUncompressedDataIndexSize() {
       return reader.getTrailer().getUncompressedDataIndexSize();
     }
 
     public long getTotalBloomSize() {
       if (generalBloomFilter == null)
         return 0;
       return generalBloomFilter.getByteSize();
     }
 
     public int getHFileVersion() {
       return reader.getTrailer().getMajorVersion();
     }
 
     public int getHFileMinorVersion() {
       return reader.getTrailer().getMinorVersion();
     }
 
     public HFile.Reader getHFileReader() {
       return reader;
     }
 
     void disableBloomFilterForTesting() {
       generalBloomFilter = null;
       this.deleteFamilyBloomFilter = null;
     }
 
     public long getMaxTimestamp() {
       return timeRangeTracker == null ? Long.MAX_VALUE : timeRangeTracker.getMaximumTimestamp();
     }
 
     boolean isSkipResetSeqId() {
       return skipResetSeqId;
     }
 
     void setSkipResetSeqId(boolean skipResetSeqId) {
       this.skipResetSeqId = skipResetSeqId;
     }
   }
 
   /**
    * Useful comparators for comparing StoreFiles.
    */
   public abstract static class Comparators {
     /**
      * Comparator that compares based on the Sequence Ids of the
      * the StoreFiles. Bulk loads that did not request a seq ID
      * are given a seq id of -1; thus, they are placed before all non-
      * bulk loads, and bulk loads with sequence Id. Among these files,
      * the size is used to determine the ordering, then bulkLoadTime.
      * If there are ties, the path name is used as a tie-breaker.
      */
     public static final Comparator<StoreFile> SEQ_ID =
       Ordering.compound(ImmutableList.of(
           Ordering.natural().onResultOf(new GetSeqId()),
           Ordering.natural().onResultOf(new GetFileSize()).reverse(),
           Ordering.natural().onResultOf(new GetBulkTime()),
           Ordering.natural().onResultOf(new GetPathName())
       ));
 
     private static class GetSeqId implements Function<StoreFile, Long> {
       @Override
       public Long apply(StoreFile sf) {
         return sf.getMaxSequenceId();
       }
     }
 
     private static class GetFileSize implements Function<StoreFile, Long> {
       @Override
       public Long apply(StoreFile sf) {
         return sf.getReader().length();
       }
     }
 
     private static class GetBulkTime implements Function<StoreFile, Long> {
       @Override
       public Long apply(StoreFile sf) {
         if (!sf.isBulkLoadResult()) return Long.MAX_VALUE;
         return sf.getBulkLoadTimestamp();
       }
     }
 
     private static class GetPathName implements Function<StoreFile, String> {
       @Override
       public String apply(StoreFile sf) {
         return sf.getPath().getName();
       }
     }
   }
 }