[HBASE-18986] Remove unnecessary null check after CellUtil.cloneQualifier()

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.0.0-alpha-4, 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Xiang Li
• Reporter: Xiang Li
• Created: 11/Oct/17 12:16
• Updated: 21/Mar/18 22:18
• Resolved: 15/Oct/17 20:41

Description

In master branch,

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java

// From line 2858
public void prepareDeleteTimestamps(Mutation mutation, Map<byte[], List<Cell>> familyMap,
      byte[] byteNow) throws IOException {
    for (Map.Entry<byte[], List<Cell>> e : familyMap.entrySet()) {
      // ...
      for (int i=0; i < listSize; i++) {
        // ...
        if (cell.getTimestamp() == HConstants.LATEST_TIMESTAMP && CellUtil.isDeleteType(cell)) {
          byte[] qual = CellUtil.cloneQualifier(cell);
          if (qual == null) qual = HConstants.EMPTY_BYTE_ARRAY; // <-- here
          ...

Might if (qual == null) qual = HConstants.EMPTY_BYTE_ARRAY; be removed?
Could it be null after CellUtil.cloneQualifier()?

hbase-common/src/main/java/org/apache/hadoop/hbase/CellUtil.java

public static byte[] cloneQualifier(Cell cell){
  byte[] output = new byte[cell.getQualifierLength()];
  copyQualifierTo(cell, output, 0);
  return output;
}