ComponentAce.Compression.Libs.ZLib.Deflate._tr_flush_block C# (CSharp) Method

        private void _tr_flush_block(int buf, int stored_len, bool eof)
        {
            int opt_lenb, static_lenb; // opt_len and static_len in bytes
            int max_blindex = 0; // index of last bit length code of non zero freq

            // Build the Huffman trees unless a stored block is forced
            if (level > 0)
            {
                // Check if the file is ascii or binary
                if (data_type == BlockType.Z_UNKNOWN)
                    set_data_type();

                // Construct the literal and distance trees
                l_desc.build_tree(this);

                d_desc.build_tree(this);

                // At this point, opt_len and static_len are the total bit lengths of
                // the compressed block data, excluding the tree representations.

                // Build the bit length tree for the above two trees, and get the index
                // in bl_order of the last bit length code to send.
                max_blindex = build_bl_tree();

                // Determine the best encoding. Compute first the block length in bytes
                opt_lenb = ZLibUtil.URShift((opt_len + 3 + 7), 3);
                static_lenb = ZLibUtil.URShift((static_len + 3 + 7), 3);

                if (static_lenb <= opt_lenb)
                    opt_lenb = static_lenb;
            }
            else
            {
                opt_lenb = static_lenb = stored_len + 5; // force a stored block
            }

            if (stored_len + 4 <= opt_lenb && buf != -1)
            {
                // 4: two words for the lengths
                // The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
                // Otherwise we can't have processed more than WSIZE input bytes since
                // the last block internalFlush, because compression would have been
                // successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
                // transform a block into a stored block.
                _tr_stored_block(buf, stored_len, eof);
            }
            else if (static_lenb == opt_lenb)
            {
                send_bits((STATIC_TREES << 1) + (eof ? 1 : 0), 3);
                compress_block(StaticTree.static_ltree, StaticTree.static_dtree);
            }
            else
            {
                send_bits((DYN_TREES << 1) + (eof ? 1 : 0), 3);
                send_all_trees(l_desc.MaxCode + 1, d_desc.MaxCode + 1, max_blindex + 1);
                compress_block(dyn_ltree, dyn_dtree);
            }

            // The above check is made mod 2^32, for files larger than 512 MB
            // and uLong implemented on 32 bits.

            init_block();

            if (eof)
            {
                bi_windup();
            }
        }