Plupload.PngEncoder.DeflaterEngine.FindLongestMatch C# (CSharp) Method

        bool FindLongestMatch(int curMatch)
        {
            int chainLength = this.max_chain;
            int niceLength = this.niceLength;
            short[] prev = this.prev;
            int scan = this.strstart;
            int match;
            int best_end = this.strstart + matchLen;
            int best_len = Math.Max(matchLen, MIN_MATCH - 1);

            int limit = Math.Max(strstart - MAX_DIST, 0);

            int strend = strstart + MAX_MATCH - 1;
            byte scan_end1 = window[best_end - 1];
            byte scan_end = window[best_end];

            // Do not waste too much time if we already have a good match:
            if (best_len >= this.goodLength) {
                chainLength >>= 2;
            }

            /* Do not look for matches beyond the end of the input. This is necessary
            * to make deflate deterministic.
            */
            if (niceLength > lookahead) {
                niceLength = lookahead;
            }

            #if DebugDeflation

            if (DeflaterConstants.DEBUGGING && (strstart > 2 * WSIZE - MIN_LOOKAHEAD))
            {
                throw new InvalidOperationException("need lookahead");
            }
            #endif

            do {

            #if DebugDeflation

                if (DeflaterConstants.DEBUGGING && (curMatch >= strstart) )
                {
                    throw new InvalidOperationException("no future");
                }
            #endif
                if (window[curMatch + best_len] != scan_end ||
                    window[curMatch + best_len - 1] != scan_end1 ||
                    window[curMatch] != window[scan] ||
                    window[curMatch + 1] != window[scan + 1]) {
                    continue;
                }

                match = curMatch + 2;
                scan += 2;

                /* We check for insufficient lookahead only every 8th comparison;
                * the 256th check will be made at strstart + 258.
                */
                while (
                    window[++scan] == window[++match] &&
                    window[++scan] == window[++match] &&
                    window[++scan] == window[++match] &&
                    window[++scan] == window[++match] &&
                    window[++scan] == window[++match] &&
                    window[++scan] == window[++match] &&
                    window[++scan] == window[++match] &&
                    window[++scan] == window[++match] &&
                    (scan < strend)) {
                    // Do nothing
                }

                if (scan > best_end) {
            #if DebugDeflation
                    if (DeflaterConstants.DEBUGGING && (ins_h == 0) )
                        Console.Error.WriteLine("Found match: " + curMatch + "-" + (scan - strstart));
            #endif
                    matchStart = curMatch;
                    best_end = scan;
                    best_len = scan - strstart;

                    if (best_len >= niceLength) {
                        break;
                    }

                    scan_end1 = window[best_end - 1];
                    scan_end = window[best_end];
                }
                scan = strstart;
            } while ((curMatch = (prev[curMatch & WMASK] & 0xffff)) > limit && --chainLength != 0);

            matchLen = Math.Min(best_len, lookahead);
            return matchLen >= MIN_MATCH;
        }