[ORC-931] Optimize RunLengthIntegerWriterV2 code for better readability

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 1.7.0, 1.8.0
• Fix Version/s: 1.7.0, 1.8.0
• Component/s: Java
• Assignee: Yiqun Zhang
• Reporter: Yiqun Zhang
• Created: 10/Aug/21 09:23
• Updated: 21/Sep/21 20:44
• Resolved: 10/Aug/21 18:26

Description

RunLengthIntegerWriterV2.java
512-546 line

  if (diffBitsLH > 1) {
      for (int i = 0; i < numLiterals; i++) {
        baseRedLiterals[i] = literals[i] - min;
      }
      brBits95p = utils.percentileBits(baseRedLiterals, 0, numLiterals, 0.95);
      brBits100p = utils.percentileBits(baseRedLiterals, 0, numLiterals, 1.0);
      if ((brBits100p - brBits95p) != 0 && Math.abs(min) < BASE_VALUE_LIMIT) {
        encoding = EncodingType.PATCHED_BASE;
        preparePatchedBlob();
        return;
      } else {
        encoding = EncodingType.DIRECT;
        return;
      }
    } else {
      // if difference in bits between 95th percentile and 100th percentile is
      // 0, then patch length will become 0. Hence we will fallback to direct
      encoding = EncodingType.DIRECT;
      return;
    }

All three conditional branch logics have been completed and the return statement is redundant.

691-704 line

      if (fixedRunLength < MIN_REPEAT) {
          variableRunLength = fixedRunLength;
          fixedRunLength = 0;
          determineEncoding();
          writeValues();
        } else if (fixedRunLength >= MIN_REPEAT
            && fixedRunLength <= MAX_SHORT_REPEAT_LENGTH) {
          encoding = EncodingType.SHORT_REPEAT;
          writeValues();
        } else {
          encoding = EncodingType.DELTA;
          isFixedDelta = true;
          writeValues();
        }

fixedRunLength >= MIN_REPEAT is redundant, the previous condition already ensures this. Extract the writeValues() method to the end. It seems better for conditional judgements to deal only with encoding and state.

772-781 line

          if (fixedRunLength >= MIN_REPEAT) {
            if (fixedRunLength <= MAX_SHORT_REPEAT_LENGTH) {
              encoding = EncodingType.SHORT_REPEAT;
              writeValues();
            } else {
              encoding = EncodingType.DELTA;
              isFixedDelta = true;
              writeValues();
            }
          }

Ditto

Issue Links

• links to: GitHub Pull Request #845