Method round

core/src/main/java/io/questdb/std/Decimal256.java:1655–1702

Round to specified scale. @param targetScale the target scale @param roundingMode the rounding mode @throws NumericException if target scale is invalid

(int targetScale, RoundingMode roundingMode)

     * @throws NumericException if target scale is invalid
     */
    public void round(int targetScale, RoundingMode roundingMode) {
        if (isNull()) {
            return;
        }

        if (targetScale == this.scale) {
            // No rounding needed
            return;
        }

        validateScale(targetScale);

        if (isZero()) {
            this.scale = targetScale;
            return;
        }

        if (this.scale < targetScale) {
            boolean isNegative = isNegative();
            if (isNegative) {
                negateNonNull();
            }

            // Need to increase scale (add trailing zeros)
            int scaleIncrease = targetScale - this.scale;
            multiplyByPowerOf10InPlace(scaleIncrease);
            this.scale = targetScale;

            if (isNegative) {
                negateNonNull();
            }
            return;
        }

        // TODO: optimize the rounding logic by replacing the division by a multiply + shift
        final long hh = this.hh;
        final long hl = this.hl;
        final long lh = this.lh;
        final long ll = this.ll;
        final int scale = this.scale;
        try {
            divide(divider, hh, hl, lh, ll, scale, 0L, 0L, 0L, 1L, 0, this, targetScale, roundingMode);
        } catch (NumericException e) {
            // restore dividend value
            of(hh, hl, lh, ll, scale);
            throw e;
        }
    }

    /**
     * Set the scale forcefully without doing any rescaling operations