Bytes.java 文件源码

/**
 * Reads a zero-compressed encoded long from input buffer and returns it.
 * @param buffer Binary array
 * @param offset Offset into array at which vint begins.
 * @return deserialized long from buffer.
 */
public static long readAsVLong(final byte [] buffer, final int offset) {
  byte firstByte = buffer[offset];
  int len = WritableUtils.decodeVIntSize(firstByte);
  if (len == 1) {
    return firstByte;
  }
  long i = 0;
  for (int idx = 0; idx < len-1; idx++) {
    byte b = buffer[offset + 1 + idx];
    i = i << 8;
    i = i | (b & 0xFF);
  }
  return (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
}