public static void canonicalizePath()

in commons-vfs2/src/main/java/org/apache/commons/vfs2/provider/UriParser.java [78:120]
35 lines of code
9 McCabe index (conditional complexity)

    public static void canonicalizePath(final StringBuilder buffer, final int offset, final int length,
            final FileNameParser fileNameParser) throws FileSystemException {
        int index = offset;
        int count = length;
        for (; count > 0; count--, index++) {
            final char ch = buffer.charAt(index);
            if (ch == '%') {
                if (count < 3) {
                    throw new FileSystemException("vfs.provider/invalid-escape-sequence.error",
                            buffer.substring(index, index + count));
                }

                // Decode
                final int dig1 = Character.digit(buffer.charAt(index + 1), HEX_BASE);
                final int dig2 = Character.digit(buffer.charAt(index + 2), HEX_BASE);
                if (dig1 == -1 || dig2 == -1) {
                    throw new FileSystemException("vfs.provider/invalid-escape-sequence.error",
                            buffer.substring(index, index + 3));
                }
                final char value = (char) (dig1 << BITS_IN_HALF_BYTE | dig2);

                final boolean match = value == '%' || fileNameParser.encodeCharacter(value);

                if (match) {
                    // this is a reserved character, not allowed to decode
                    index += 2;
                    count -= 2;
                    continue;
                }

                // Replace
                buffer.setCharAt(index, value);
                buffer.delete(index + 1, index + 3);
                count -= 2;
            } else if (fileNameParser.encodeCharacter(ch)) {
                // Encode
                final char[] digits = {Character.forDigit(ch >> BITS_IN_HALF_BYTE & LOW_MASK, HEX_BASE), Character.forDigit(ch & LOW_MASK, HEX_BASE)};
                buffer.setCharAt(index, '%');
                buffer.insert(index + 1, digits);
                index += 2;
            }
        }
    }