[ORC-976] Optimize compute zigZagLiterals

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.7.0
• Fix Version/s: 1.7.0
• Component/s: Java
• Assignee: Unassigned
• Reporter: Yiqun Zhang
• Created: 28/Aug/21 12:18
• Updated: 21/Sep/21 20:45
• Resolved: 30/Aug/21 02:54

Description

  private void computeZigZagLiterals() {
    // populate zigzag encoded literals
    long zzEncVal = 0;
    for (int i = 0; i < numLiterals; i++) {
      if (signed) {
        zzEncVal = utils.zigzagEncode(literals[i]);
      } else {
        zzEncVal = literals[i];
      }
      zigzagLiterals[i] = zzEncVal;
    }
  }

Avoid conditional judgments in loops.
The unsigned case can use literals instead of zigzagLiterals. The number of copies is proportional to the amount of user writes, which optimizes write performance.

Issue Links

• links to: GitHub Pull Request #887