Ionic.Zlib.DeflateManager.SetDictionary C# (CSharp) Method

        internal int SetDictionary(byte[] dictionary)
        {
            int length = dictionary.Length;
            int index = 0;

            if (dictionary == null || status != INIT_STATE)
                throw new ZlibException("Stream error.");

            _codec._Adler32 = Adler.Adler32(_codec._Adler32, dictionary, 0, dictionary.Length);

            if (length < MIN_MATCH)
                return ZlibConstants.Z_OK;
            if (length > w_size - MIN_LOOKAHEAD)
            {
                length = w_size - MIN_LOOKAHEAD;
                index = dictionary.Length - length; // use the tail of the dictionary
            }
            Array.Copy(dictionary, index, window, 0, length);
            strstart = length;
            block_start = length;

            // Insert all strings in the hash table (except for the last two bytes).
            // s->lookahead stays null, so s->ins_h will be recomputed at the next
            // call of fill_window.

            ins_h = window[0] & 0xff;
            ins_h = (((ins_h) << hash_shift) ^ (window[1] & 0xff)) & hash_mask;

            for (int n = 0; n <= length - MIN_MATCH; n++)
            {
                ins_h = (((ins_h) << hash_shift) ^ (window[(n) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
                prev[n & w_mask] = head[ins_h];
                head[ins_h] = (short)n;
            }
            return ZlibConstants.Z_OK;
        }

        /// <summary>
        /// Set the dictionary to be used for either Inflation or Deflation.
        /// </summary>
        /// <param name="dictionary">The dictionary bytes to use.</param>
        /// <returns>Z_OK if all goes well.</returns>
        public int SetDictionary(byte[] dictionary)
        {
            if (istate != null)
            {
                return(istate.SetDictionary(dictionary));
            }

            if (dstate != null)
            {
                return(dstate.SetDictionary(dictionary));
            }

            throw new ZlibException("No Inflate or Deflate state!");
        }