Java KeyValue.KeyOnlyKeyValue方法代碼示例

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
/**
 * Binary search for keys in indexes.
 *
 * @param arr array of byte arrays to search for
 * @param key the key you want to find
 * @param comparator a comparator to compare.
 * @return zero-based index of the key, if the key is present in the array.
 *         Otherwise, a value -(i + 1) such that the key is between arr[i -
 *         1] and arr[i] non-inclusively, where i is in [0, i], if we define
 *         arr[-1] = -Inf and arr[N] = Inf for an N-element array. The above
 *         means that this function can return 2N + 1 different values
 *         ranging from -(N + 1) to N - 1.
 * @return the index of the block
 */
public static int binarySearch(byte[][] arr, Cell key, RawComparator<Cell> comparator) {
  int low = 0;
  int high = arr.length - 1;
  KeyValue.KeyOnlyKeyValue r = new KeyValue.KeyOnlyKeyValue();
  while (low <= high) {
    int mid = (low+high) >>> 1;
    // we have to compare in this order, because the comparator order
    // has special logic when the 'left side' is a special key.
    r.setKey(arr[mid], 0, arr[mid].length);
    int cmp = comparator.compare(key, r);
    // key lives above the midpoint
    if (cmp > 0)
      low = mid + 1;
    // key lives below the midpoint
    else if (cmp < 0)
      high = mid - 1;
    // BAM. how often does this really happen?
    else
      return mid;
  }
  return - (low+1);
}
 

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
@Override
public boolean seekBefore(Cell key) throws IOException {
  HFileBlock seekToBlock = reader.getDataBlockIndexReader().seekToDataBlock(key, block,
      cacheBlocks, pread, isCompaction,
      ((HFileReaderV2) reader).getEffectiveEncodingInCache(isCompaction));
  if (seekToBlock == null) {
    return false;
  }
  ByteBuffer firstKey = getFirstKeyInBlock(seekToBlock);

  if (reader.getComparator()
      .compareOnlyKeyPortion(
          new KeyValue.KeyOnlyKeyValue(firstKey.array(), firstKey.arrayOffset(),
              firstKey.limit()), key) >= 0) {
    long previousBlockOffset = seekToBlock.getPrevBlockOffset();
    // The key we are interested in
    if (previousBlockOffset == -1) {
      // we have a 'problem', the key we want is the first of the file.
      return false;
    }

    // It is important that we compute and pass onDiskSize to the block
    // reader so that it does not have to read the header separately to
    // figure out the size.  Currently, we do not have a way to do this
    // correctly in the general case however.
    // TODO: See https://issues.apache.org/jira/browse/HBASE-14576
    int prevBlockSize = -1;
    seekToBlock = reader.readBlock(previousBlockOffset,
        prevBlockSize, cacheBlocks,
        pread, isCompaction, true, BlockType.DATA, getEffectiveDataBlockEncoding());
    // TODO shortcut: seek forward in this block to the last key of the
    // block.
  }
  Cell firstKeyInCurrentBlock = new KeyValue.KeyOnlyKeyValue(Bytes.getBytes(firstKey));
  loadBlockAndSeekToKey(seekToBlock, firstKeyInCurrentBlock, true, key, true);
  return true;
}
 

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
/**
 * Creates a half file reader for a normal hfile.
 * @param fs fileystem to read from
 * @param p path to hfile
 * @param cacheConf
 * @param r original reference file (contains top or bottom)
 * @param conf Configuration
 * @throws IOException
 */
public HalfStoreFileReader(final FileSystem fs, final Path p,
    final CacheConfig cacheConf, final Reference r, final Configuration conf)
    throws IOException {
  super(fs, p, cacheConf, conf);
  // This is not actual midkey for this half-file; its just border
  // around which we split top and bottom.  Have to look in files to find
  // actual last and first keys for bottom and top halves.  Half-files don't
  // have an actual midkey themselves. No midkey is how we indicate file is
  // not splittable.
  this.splitkey = r.getSplitKey();
  this.splitCell = new KeyValue.KeyOnlyKeyValue(this.splitkey, 0, this.splitkey.length);
  // Is it top or bottom half?
  this.top = Reference.isTopFileRegion(r.getFileRegion());
}
 

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
protected int seekToOrBeforeUsingPositionAtOrBefore(byte[] keyOnlyBytes, int offset, int length,
    boolean seekBefore){
  // this does a deep copy of the key byte[] because the CellSearcher interface wants a Cell
  KeyValue kv = new KeyValue.KeyOnlyKeyValue(keyOnlyBytes, offset, length);

  return seekToOrBeforeUsingPositionAtOrBefore(kv, seekBefore);
}
 

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
protected int seekToOrBeforeUsingPositionAtOrAfter(byte[] keyOnlyBytes, int offset, int length,
    boolean seekBefore) {
  // this does a deep copy of the key byte[] because the CellSearcher
  // interface wants a Cell
  KeyValue kv = new KeyValue.KeyOnlyKeyValue(keyOnlyBytes, offset, length);
  return seekToOrBeforeUsingPositionAtOrAfter(kv, seekBefore);
}
 

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
protected void invalidate() {
  valueOffset = -1;
  tagsCompressedLength = 0;
  currentKey = new KeyValue.KeyOnlyKeyValue();
  uncompressTags = true;
  currentBuffer = null;
}