Java KeyValue.getKeyValueDataStructureSize方法代碼示例

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
/**
 * Uncompresses a KeyValue from a DataInput and returns it.
 * 
 * @param in the DataInput
 * @param readContext the compressionContext to use.
 * @return an uncompressed KeyValue
 * @throws IOException
 */

public static KeyValue readKV(DataInput in, CompressionContext readContext)
    throws IOException {
  int keylength = WritableUtils.readVInt(in);
  int vlength = WritableUtils.readVInt(in);
  int tagsLength = WritableUtils.readVInt(in);
  int length = (int) KeyValue.getKeyValueDataStructureSize(keylength, vlength, tagsLength);

  byte[] backingArray = new byte[length];
  int pos = 0;
  pos = Bytes.putInt(backingArray, pos, keylength);
  pos = Bytes.putInt(backingArray, pos, vlength);

  // the row
  int elemLen = Compressor.uncompressIntoArray(backingArray,
      pos + Bytes.SIZEOF_SHORT, in, readContext.rowDict);
  checkLength(elemLen, Short.MAX_VALUE);
  pos = Bytes.putShort(backingArray, pos, (short)elemLen);
  pos += elemLen;

  // family
  elemLen = Compressor.uncompressIntoArray(backingArray,
      pos + Bytes.SIZEOF_BYTE, in, readContext.familyDict);
  checkLength(elemLen, Byte.MAX_VALUE);
  pos = Bytes.putByte(backingArray, pos, (byte)elemLen);
  pos += elemLen;

  // qualifier
  elemLen = Compressor.uncompressIntoArray(backingArray, pos, in,
      readContext.qualifierDict);
  pos += elemLen;

  // the rest
  in.readFully(backingArray, pos, length - pos);

  return new KeyValue(backingArray, 0, length);
}
 

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
/**
 * Searches for the latest value for the specified column.
 *
 * @param kvs the array to search
 * @param family family name
 * @param foffset family offset
 * @param flength family length
 * @param qualifier column qualifier
 * @param qoffset qualifier offset
 * @param qlength qualifier length
 *
 * @return the index where the value was found, or -1 otherwise
 */
protected int binarySearch(final Cell [] kvs,
    final byte [] family, final int foffset, final int flength,
    final byte [] qualifier, final int qoffset, final int qlength) {

  double keyValueSize = (double)
      KeyValue.getKeyValueDataStructureSize(kvs[0].getRowLength(), flength, qlength, 0);

  byte[] buffer = localBuffer.get();
  if (buffer == null || keyValueSize > buffer.length) {
    // pad to the smallest multiple of the pad width
    buffer = new byte[(int) Math.ceil(keyValueSize / PAD_WIDTH) * PAD_WIDTH];
    localBuffer.set(buffer);
  }

  Cell searchTerm = KeyValueUtil.createFirstOnRow(buffer, 0,
      kvs[0].getRowArray(), kvs[0].getRowOffset(), kvs[0].getRowLength(),
      family, foffset, flength,
      qualifier, qoffset, qlength);

  // pos === ( -(insertion point) - 1)
  int pos = Arrays.binarySearch(kvs, searchTerm, KeyValue.COMPARATOR);
  // never will exact match
  if (pos < 0) {
    pos = (pos+1) * -1;
    // pos is now insertion point
  }
  if (pos == kvs.length) {
    return -1; // doesn't exist
  }
  return pos;
}
 

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
static KeyValue readCell(PositionedByteRange pbr) throws Exception {
  int kvStartPos = pbr.getPosition();
  int keyLen = pbr.getInt();
  int valLen = pbr.getInt();
  pbr.setPosition(pbr.getPosition() + keyLen + valLen); // Skip the key and value section
  int tagsLen = ((pbr.get() & 0xff) << 8) ^ (pbr.get() & 0xff);
  pbr.setPosition(pbr.getPosition() + tagsLen); // Skip the tags section
  long mvcc = pbr.getVLong();
  KeyValue kv = new KeyValue(pbr.getBytes(), kvStartPos,
      (int) KeyValue.getKeyValueDataStructureSize(keyLen, valLen, tagsLen));
  kv.setSequenceId(mvcc);
  return kv;
}
 

import org.apache.hadoop.hbase.KeyValue; //導入方法依賴的package包/類
/**
 * Provides access to compressed value.
 * @param headerSize header size of the block.
 * @return Forwards sequential iterator.
 */
public Iterator<Cell> getIterator(int headerSize) {
  final int rawSize = rawKVs.length;
  byte[] encodedDataWithHeader = getEncodedData();
  int bytesToSkip = headerSize + Bytes.SIZEOF_SHORT;
  ByteArrayInputStream bais = new ByteArrayInputStream(encodedDataWithHeader,
      bytesToSkip, encodedDataWithHeader.length - bytesToSkip);
  final DataInputStream dis = new DataInputStream(bais);

  return new Iterator<Cell>() {
    private ByteBuffer decompressedData = null;

    @Override
    public boolean hasNext() {
      if (decompressedData == null) {
        return rawSize > 0;
      }
      return decompressedData.hasRemaining();
    }

    @Override
    public Cell next() {
      if (decompressedData == null) {
        try {
          decompressedData = dataBlockEncoder.decodeKeyValues(dis, dataBlockEncoder
              .newDataBlockDecodingContext(meta));
        } catch (IOException e) {
          throw new RuntimeException("Problem with data block encoder, " +
              "most likely it requested more bytes than are available.", e);
        }
        decompressedData.rewind();
      }
      int offset = decompressedData.position();
      int klen = decompressedData.getInt();
      int vlen = decompressedData.getInt();
      int tagsLen = 0;
      ByteBufferUtils.skip(decompressedData, klen + vlen);
      // Read the tag length in case when steam contain tags
      if (meta.isIncludesTags()) {
        tagsLen = ((decompressedData.get() & 0xff) << 8) ^ (decompressedData.get() & 0xff);
        ByteBufferUtils.skip(decompressedData, tagsLen);
      }
      KeyValue kv = new KeyValue(decompressedData.array(), offset,
          (int) KeyValue.getKeyValueDataStructureSize(klen, vlen, tagsLen));
      if (meta.isIncludesMvcc()) {
        long mvccVersion = ByteBufferUtils.readVLong(decompressedData);
        kv.setSequenceId(mvccVersion);
      }
      return kv;
    }

    @Override
    public void remove() {
      throw new NotImplementedException("remove() is not supported!");
    }

    @Override
    public String toString() {
      return "Iterator of: " + dataBlockEncoder.getClass().getName();
    }

  };
}