function zip_ct_tally()

in themes/docsy/static/js/deflate.js [1459:1511]

• 34 lines of code
• 9 McCabe index (conditional complexity)

    function zip_ct_tally(
        dist, // distance of matched string
        lc) { // match length-MIN_MATCH or unmatched char (if dist==0)
        zip_l_buf[zip_last_lit++] = lc;
        if (dist == 0) {
            // lc is the unmatched char
            zip_dyn_ltree[lc].fc++;
        } else {
            // Here, lc is the match length - MIN_MATCH
            dist--;		    // dist = match distance - 1
            //      Assert((ush)dist < (ush)MAX_DIST &&
            //	     (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
            //	     (ush)D_CODE(dist) < (ush)D_CODES,  "ct_tally: bad match");

            zip_dyn_ltree[zip_length_code[lc] + zip_LITERALS + 1].fc++;
            zip_dyn_dtree[zip_D_CODE(dist)].fc++;

            zip_d_buf[zip_last_dist++] = dist;
            zip_flags |= zip_flag_bit;
        }
        zip_flag_bit <<= 1;

        // Output the flags if they fill a byte
        if ((zip_last_lit & 7) == 0) {
            zip_flag_buf[zip_last_flags++] = zip_flags;
            zip_flags = 0;
            zip_flag_bit = 1;
        }
        // Try to guess if it is profitable to stop the current block here
        if (zip_compr_level > 2 && (zip_last_lit & 0xfff) == 0) {
            // Compute an upper bound for the compressed length
            var out_length = zip_last_lit * 8;
            var in_length = zip_strstart - zip_block_start;
            var dcode;

            for (dcode = 0; dcode < zip_D_CODES; dcode++) {
                out_length += zip_dyn_dtree[dcode].fc * (5 + zip_extra_dbits[dcode]);
            }
            out_length >>= 3;
            //      Trace((stderr,"\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
            //	     encoder->last_lit, encoder->last_dist, in_length, out_length,
            //	     100L - out_length*100L/in_length));
            if (zip_last_dist < parseInt(zip_last_lit / 2) &&
                out_length < parseInt(in_length / 2))
                return true;
        }
        return (zip_last_lit == zip_LIT_BUFSIZE - 1 ||
            zip_last_dist == zip_DIST_BUFSIZE);
        /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
            * on 16 bit machines and because stored blocks are restricted to
            * 64K-1 bytes.
            */
    }