HFileReaderV2.java 文件源码

/**
 * Actually do the mvcc read. Does no checks.
 * @param position
 */
private void _readMvccVersion(final int position) {
  // This is Bytes#bytesToVint inlined so can save a few instructions in this hot method; i.e.
  // previous if one-byte vint, we'd redo the vint call to find int size.
  // Also the method is kept small so can be inlined.
  byte firstByte = blockBuffer.array()[position];
  int len = WritableUtils.decodeVIntSize(firstByte);
  if (len == 1) {
    this.currMemstoreTS = firstByte;
  } else {
    long i = 0;
    for (int idx = 0; idx < len - 1; idx++) {
      byte b = blockBuffer.array()[position + 1 + idx];
      i = i << 8;
      i = i | (b & 0xFF);
    }
    currMemstoreTS = (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
  }
  this.currMemstoreTSLen = len;
}