[HBASE-20078] MultiByteBuff : bug in reading primitives when individual buffers are too small

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha-1
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Anoop Sam John
• Reporter: Michael Stack
• Created: 25/Feb/18 07:34
• Updated: 01/Aug/18 06:20
• Resolved: 14/Mar/18 06:42

Description

Copied from the bottom of HBASE-13916, the JIRA that introduced MultiByteBuff:

anoop.hbase This bit of code needs more test. It does not seem to be doing the right thing....

Doing something like the below, it does not seem to be returning the right answers....

  @Ignore // This test fails.
  @Test
  public void testGetInt() {
    ByteBuffer bb1 = ByteBuffer.allocate(1);
    bb1.put((byte)1);
    ByteBuffer bb2 = ByteBuffer.allocate(1);
    bb2.put((byte)0);
    ByteBuffer bb3 = ByteBuffer.allocate(1);
    bb3.put((byte)0);
    ByteBuffer bb4 = ByteBuffer.allocate(1);
    bb4.put((byte)1);
    MultiByteBuff mbb = new MultiByteBuff(bb1, bb2, bb3, bb4);
    // Value is wrong here ... needs adjusting but code is doing wrong thing.
    assertEquals(256, mbb.getIntAfterPosition(0));
  }

Ignore the expected answer in the above... just a place holder as i messed with the return... but if I make buffers of one byte, we do not seem to be moving into the next buffer properly... If I make the buffers of two bytes, similar. This stuff normally works because we are not spanning buffer boundaries... but if we do, response seems like it could be off sir. I'll have a go at this. You might have input meantime.

The issue is the individual BBs are too small. Ideally that would never happen. Still better to solve this corner cases.