[HBASE-16880] Correct the javadoc/behaviour of the APIs in ByteBufferUtils

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Assignee: ramkrishna.s.vasudevan
• Reporter: ramkrishna.s.vasudevan
• Created: 19/Oct/16 06:23
• Updated: 25/Oct/16 10:23
• Resolved: 25/Oct/16 05:23

Description

There are some issues either with the javadoc or the actual behaviour of some APIs in BBUtils.
For eg,
BBUtil#copyFromBufferToBuffer() says

  /**
   * Copy one buffer's whole data to another. Write starts at the current position of 'out' buffer.
   * Note : This will advance the position marker of {@code out} but not change the position maker
   * for {@code in}. The position and limit of the {@code in} buffer to be set properly by caller.
   * @param in source buffer
   * @param out destination buffer

But this is true in case of UNSAFE.

    if (UNSAFE_AVAIL) {
      int length = in.remaining();
      UnsafeAccess.copy(in, in.position(), out, out.position(), length);
      out.position(out.position() + length);
    } else {
      out.put(in);
    }

But in other case where we move the else - the 'in' is also advanced. So we need to either correct the behaviour or change the doc and see all the used places. This JIRA can be used to correct all the APIs in this util class.