public static boolean doBinaryToDecimalConversion()

in kyuubi-hive-jdbc/src/main/java/org/apache/kyuubi/jdbc/hive/common/FastHiveDecimalImpl.java [1415:1540]
94 lines of code
12 McCabe index (conditional complexity)

  public static boolean doBinaryToDecimalConversion(
      long lowerWord,
      long middleWord,
      long highWord,
      FastHiveDecimal middleWordMultiplier,
      FastHiveDecimal highWordMultiplier,
      FastHiveDecimal fastResult) {

    /*
     * Challenge: How to do the math to get this raw binary back to our decimal form.
     *
     * Briefly, for the middle and upper binary words, convert the middle/upper word into a decimal
     * long words and then multiply those by the binary word's power of 2.
     *
     * And, add the multiply results into the result decimal longwords.
     *
     */
    long result0 = lowerWord % MULTIPLER_LONGWORD_DECIMAL;
    long result1 = lowerWord / MULTIPLER_LONGWORD_DECIMAL;
    long result2 = 0;

    if (middleWord != 0 || highWord != 0) {

      if (highWord == 0) {

        // Form result from lower and middle words.

        if (!fastMultiply5x5HalfWords(
            middleWord % MULTIPLER_LONGWORD_DECIMAL,
            middleWord / MULTIPLER_LONGWORD_DECIMAL,
            0,
            middleWordMultiplier.fast0,
            middleWordMultiplier.fast1,
            middleWordMultiplier.fast2,
            fastResult)) {
          return false;
        }

        final long calc0 = result0 + fastResult.fast0;
        result0 = calc0 % MULTIPLER_LONGWORD_DECIMAL;
        final long calc1 = calc0 / MULTIPLER_LONGWORD_DECIMAL + result1 + fastResult.fast1;
        result1 = calc1 % MULTIPLER_LONGWORD_DECIMAL;
        result2 = calc1 / MULTIPLER_LONGWORD_DECIMAL + fastResult.fast2;

      } else if (middleWord == 0) {

        // Form result from lower and high words.

        if (!fastMultiply5x5HalfWords(
            highWord % MULTIPLER_LONGWORD_DECIMAL,
            highWord / MULTIPLER_LONGWORD_DECIMAL,
            0,
            highWordMultiplier.fast0,
            highWordMultiplier.fast1,
            highWordMultiplier.fast2,
            fastResult)) {
          return false;
        }

        final long calc0 = result0 + fastResult.fast0;
        result0 = calc0 % MULTIPLER_LONGWORD_DECIMAL;
        final long calc1 = calc0 / MULTIPLER_LONGWORD_DECIMAL + result1 + fastResult.fast1;
        result1 = calc1 % MULTIPLER_LONGWORD_DECIMAL;
        result2 = calc1 / MULTIPLER_LONGWORD_DECIMAL + fastResult.fast2;

      } else {

        // Form result from lower, middle, and middle words.

        if (!fastMultiply5x5HalfWords(
            middleWord % MULTIPLER_LONGWORD_DECIMAL,
            middleWord / MULTIPLER_LONGWORD_DECIMAL,
            0,
            middleWordMultiplier.fast0,
            middleWordMultiplier.fast1,
            middleWordMultiplier.fast2,
            fastResult)) {
          return false;
        }

        long middleResult0 = fastResult.fast0;
        long middleResult1 = fastResult.fast1;
        long middleResult2 = fastResult.fast2;

        if (!fastMultiply5x5HalfWords(
            highWord % MULTIPLER_LONGWORD_DECIMAL,
            highWord / MULTIPLER_LONGWORD_DECIMAL,
            0,
            highWordMultiplier.fast0,
            highWordMultiplier.fast1,
            highWordMultiplier.fast2,
            fastResult)) {
          return false;
        }

        long calc0 = result0 + middleResult0 + fastResult.fast0;
        result0 = calc0 % MULTIPLER_LONGWORD_DECIMAL;
        long calc1 =
            calc0 / MULTIPLER_LONGWORD_DECIMAL + result1 + middleResult1 + fastResult.fast1;
        result1 = calc1 % MULTIPLER_LONGWORD_DECIMAL;
        result2 = calc1 / MULTIPLER_LONGWORD_DECIMAL + middleResult2 + fastResult.fast2;
      }
    }

    // Let caller set negative sign if necessary.
    if (result2 != 0) {
      fastResult.fastIntegerDigitCount =
          TWO_X_LONGWORD_DECIMAL_DIGITS + fastHighWordPrecision(result2);
      fastResult.fastSignum = 1;
    } else if (result1 != 0) {
      fastResult.fastIntegerDigitCount = LONGWORD_DECIMAL_DIGITS + fastHighWordPrecision(result1);
      fastResult.fastSignum = 1;
    } else if (result0 != 0) {
      fastResult.fastIntegerDigitCount = fastHighWordPrecision(result0);
      fastResult.fastSignum = 1;
    } else {
      fastResult.fastIntegerDigitCount = 0;
      fastResult.fastSignum = 0;
    }

    fastResult.fast0 = result0;
    fastResult.fast1 = result1;
    fastResult.fast2 = result2;

    return true;
  }