I encountered a problem while learning about the netty memory pool. In the newSizeClass method of the SizeClasses class, log2Group、log2Delta、nDelta、pageShifts， And how to calculate isSubpage and log2DeltaLookup, I’m a bit confused about this code. Can someone help me explain it? Thank you very much.🥺

    private static short[] newSizeClass(int index, int log2Group, int log2Delta, int nDelta, int pageShifts) {
        short isMultiPageSize;
        if (log2Delta >= pageShifts) {
            isMultiPageSize = yes;
        } else {
            int pageSize = 1 << pageShifts;
            int size = calculateSize(log2Group, nDelta, log2Delta);

            isMultiPageSize = size == size / pageSize * pageSize? yes : no;
        }

        int log2Ndelta = nDelta == 0? 0 : log2(nDelta);

        byte remove = 1 << log2Ndelta < nDelta? yes : no;

        int log2Size = log2Delta + log2Ndelta == log2Group? log2Group + 1 : log2Group;
        if (log2Size == log2Group) {
            remove = yes;
        }

        short isSubpage = log2Size < pageShifts + LOG2_SIZE_CLASS_GROUP? yes : no;

        int log2DeltaLookup = log2Size < LOG2_MAX_LOOKUP_SIZE ||
                              log2Size == LOG2_MAX_LOOKUP_SIZE && remove == no
                ? log2Delta : no;

        return new short[] {
                (short) index, (short) log2Group, (short) log2Delta,
                (short) nDelta, isMultiPageSize, isSubpage, (short) log2DeltaLookup
        };
    }

I have read the code many times, but I still haven’t understood it. I hope you can help me explain the meanings of these variables and how they are used.