org.apache.hadoop.hbase.io.Reference#isTopFileRegion ( )源码实例Demo

/**
 * @param fs
 * @param p
 * @param cacheConf
 * @param r
 * @param conf
 * @param indexMaintainers
 * @param viewConstants
 * @param regionInfo
 * @param regionStartKeyInHFile
 * @param splitKey
 * @throws IOException
 */
public IndexHalfStoreFileReader(final FileSystem fs, final Path p, final CacheConfig cacheConf,
        final Reference r, final Configuration conf,
        final Map<ImmutableBytesWritable, IndexMaintainer> indexMaintainers,
        final byte[][] viewConstants, final HRegionInfo regionInfo,
        final byte[] regionStartKeyInHFile, byte[] splitKey) throws IOException {
    super(fs, p, cacheConf, conf);
    this.splitkey = splitKey == null ? r.getSplitKey() : splitKey;
    // Is it top or bottom half?
    this.top = Reference.isTopFileRegion(r.getFileRegion());
    this.splitRow = CellUtil.cloneRow(KeyValue.createKeyValueFromKey(splitkey));
    this.indexMaintainers = indexMaintainers;
    this.viewConstants = viewConstants;
    this.regionInfo = regionInfo;
    this.regionStartKeyInHFile = regionStartKeyInHFile;
    this.offset = regionStartKeyInHFile.length;
}
 

/**
 * @param fs
 * @param p
 * @param cacheConf
 * @param in
 * @param size
 * @param r
 * @param conf
 * @param indexMaintainers
 * @param viewConstants
 * @param regionInfo
 * @param regionStartKeyInHFile
 * @param splitKey
 * @throws IOException
 */
public IndexHalfStoreFileReader(final FileSystem fs, final Path p, final CacheConfig cacheConf,
        final FSDataInputStreamWrapper in, long size, final Reference r,
        final Configuration conf,
        final Map<ImmutableBytesWritable, IndexMaintainer> indexMaintainers,
        final byte[][] viewConstants, final HRegionInfo regionInfo,
        byte[] regionStartKeyInHFile, byte[] splitKey) throws IOException {
    super(fs, p, in, size, cacheConf, conf);
    this.splitkey = splitKey == null ? r.getSplitKey() : splitKey;
    // Is it top or bottom half?
    this.top = Reference.isTopFileRegion(r.getFileRegion());
    this.splitRow = CellUtil.cloneRow(KeyValue.createKeyValueFromKey(splitkey));
    this.indexMaintainers = indexMaintainers;
    this.viewConstants = viewConstants;
    this.regionInfo = regionInfo;
    this.regionStartKeyInHFile = regionStartKeyInHFile;
    this.offset = regionStartKeyInHFile.length;
}
 

/**
 * helper function to compute HDFS blocks distribution of a given reference file.For reference
 * file, we don't compute the exact value. We use some estimate instead given it might be good
 * enough. we assume bottom part takes the first half of reference file, top part takes the second
 * half of the reference file. This is just estimate, given midkey ofregion != midkey of HFile,
 * also the number and size of keys vary. If this estimate isn't good enough, we can improve it
 * later.
 * @param fs The FileSystem
 * @param reference The reference
 * @param status The reference FileStatus
 * @return HDFS blocks distribution
 */
private static HDFSBlocksDistribution computeRefFileHDFSBlockDistribution(final FileSystem fs,
    final Reference reference, final FileStatus status) throws IOException {
  if (status == null) {
    return null;
  }

  long start = 0;
  long length = 0;

  if (Reference.isTopFileRegion(reference.getFileRegion())) {
    start = status.getLen() / 2;
    length = status.getLen() - status.getLen() / 2;
  } else {
    start = 0;
    length = status.getLen() / 2;
  }
  return FSUtils.computeHDFSBlocksDistribution(fs, status, start, length);
}
 

/**
 * @param fs
 * @param p
 * @param cacheConf
 * @param in
 * @param size
 * @param r
 * @param conf
 * @param indexMaintainers
 * @param viewConstants
 * @param regionInfo
 * @param regionStartKeyInHFile
 * @param splitKey
 * @throws IOException
 */
public IndexHalfStoreFileReader(final FileSystem fs, final Path p, final CacheConfig cacheConf,
        final FSDataInputStreamWrapper in, long size, final Reference r,
        final Configuration conf,
        final Map<ImmutableBytesWritable, IndexMaintainer> indexMaintainers,
        final byte[][] viewConstants, final RegionInfo regionInfo,
        byte[] regionStartKeyInHFile, byte[] splitKey, boolean primaryReplicaStoreFile,
        AtomicInteger refCount, RegionInfo currentRegion) throws IOException {
    super(fs, p, in, size, cacheConf, primaryReplicaStoreFile, refCount, false,
            conf);
    this.splitkey = splitKey == null ? r.getSplitKey() : splitKey;
    // Is it top or bottom half?
    this.top = Reference.isTopFileRegion(r.getFileRegion());
    this.splitRow = CellUtil.cloneRow(new KeyValue.KeyOnlyKeyValue(splitkey));
    this.indexMaintainers = indexMaintainers;
    this.viewConstants = viewConstants;
    this.childRegionInfo = regionInfo;
    this.regionStartKeyInHFile = regionStartKeyInHFile;
    this.offset = regionStartKeyInHFile.length;
    this.refCount = refCount;
    this.currentRegion = currentRegion;
}
 

/** @return True if the store file is a top Reference */
public boolean isTopReference() {
  return this.reference != null && Reference.isTopFileRegion(this.reference.getFileRegion());
}