private static String format()

in util/src/main/java/com/epam/deltix/util/text/DecimalFormatter.java [86:152]
58 lines of code
20 McCabe index (conditional complexity)

    private static String format (double number, int precision, int maxLength, long factor) {
        if (precision < 0 || precision > MAX_PRECISION)
            throw new IllegalArgumentException("Precision");
        if (maxLength < 0 || maxLength > MAX_WIDTH)
            throw new IllegalArgumentException("Length");
        if (Double.isNaN(number)) // Infinity will be checked a bit later
            throw new IllegalArgumentException("NaN");

        boolean sign = false;
        double factoredNumber = number;
        if (number < 0) {
            sign = true;
            factoredNumber = Math.abs(number);
        }
        factoredNumber = factoredNumber*factor;
        if (Double.isInfinite(factoredNumber) || factoredNumber > MAX)
            return formatLargeNumber (number);


        //long numberAsDecimal = Math.round(factoredNumber);  // this call costs 8% of total time we spend in this method on avg.
        long numberAsDecimal;
        {
            factoredNumber = factoredNumber * 10;
            numberAsDecimal = (long) factoredNumber;
            int smallestDigit = (int) (numberAsDecimal % 10);
            numberAsDecimal = numberAsDecimal / 10;
            if (smallestDigit >=5 )
                numberAsDecimal ++; // round up;
        }
        if (numberAsDecimal == 0)
            return "0";

        char [] buffer = new char [MAX_WIDTH];
        int i = MAX_WIDTH;
        int fractional_part = precision;

        boolean needLeadingZero = (fractional_part > 0);
        while (numberAsDecimal > 0) {
            int digit = (int) (numberAsDecimal % 10);
            if (digit != 0 || i != MAX_WIDTH || fractional_part == 0) // skip trailing zeros
                buffer [--i] = DIGITS [digit];

            numberAsDecimal = numberAsDecimal / 10;
            if (fractional_part > 0) {
                fractional_part --;
                if (fractional_part == 0) {
                    if (i != MAX_WIDTH)
                        buffer [--i] = '.';
                    needLeadingZero = (numberAsDecimal == 0);
                }
            }
        }
        if (needLeadingZero) {
            if (fractional_part > 0) { // if number was less than zero
                while (fractional_part-- > 0)
                    buffer [--i] = '0';
                buffer [--i] = '.';
            }
            buffer [--i] = '0';
        }

        if (sign)
            buffer [--i] = '-';

        int len = Math.min(MAX_WIDTH - i, maxLength);
        return new String (buffer, i, len);
    }