System.util.zlib.Tree.gen_codes C# (CSharp) Method

        internal static void gen_codes(short[] tree, // the tree to decorate
            int max_code, // largest code with non zero frequency
            short[] bl_count // number of codes at each bit length
            ){
            short[] next_code=new short[MAX_BITS+1]; // next code value for each bit length
            short code = 0;            // running code value
            int bits;                  // bit index
            int n;                     // code index

            // The distribution counts are first used to generate the code values
            // without bit reversal.
            for (bits = 1; bits <= MAX_BITS; bits++) {
                next_code[bits] = code = (short)((code + bl_count[bits-1]) << 1);
            }

            // Check that the bit counts in bl_count are consistent. The last code
            // must be all ones.
            //Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
            //        "inconsistent bit counts");
            //Tracev((stderr,"\ngen_codes: max_code %d ", max_code));

            for (n = 0;  n <= max_code; n++) {
                int len = tree[n*2+1];
                if (len == 0) continue;
                // Now reverse the bits
                tree[n*2] = (short)(bi_reverse(next_code[len]++, len));
            }
        }