[HADOOP-3254] FSNamesystem.gotHeartbeat(..., Object[] xferResults, Object[] deleteList) should not use Object[] as pass-by-reference parameters

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.18.0
• Assignee: Tsz-wo Sze
• Reporter: Tsz-wo Sze
• Created: 14/Apr/08 23:55
• Updated: 08/Jul/09 16:43
• Resolved: 16/Apr/08 04:57

Description

In FSNamesystem.gotHeartbeat(..., Object[] xferResults, Object[] deleteList), xferResults initially equals to Object[]

{ null, null}

. If there are blocks to be replicated, xferResults[0] and xferResults[1] will be set to a Block[] and DatanodeInfo[][], respectively. The caller of gotHeartbeat will cast these object to the original classes. For example, in NameNode.sendHeartbeat(...),

    if (xferResults[0] != null) {
      assert(deleteList[0] == null);
      return new BlockCommand((Block[]) xferResults[0], (DatanodeInfo[][]) xferResults[1]);
    }

The use of deleteList is similar.

Issue Links

• blocks: HADOOP-3201 namenode should be able to retrieve block metadata from a datanode