マルチコア対応、改行コードごとに行を分割するコード

gistfile1.txt

        //ForEachLinesの内容ははLineToIndex.csを参照すること
        IList<LineToIndexTableData> CreateLineList(long index, long length,bool setdirtyflag = false, int lineLimitLength = -1)
        {
            const int CoreNum = 4;
            const long thresholdParallelCreateList = CoreNum + 1;
            //const long thresholdParallelCreateList = 1024 * 1024;
            //const long thresholdParallelCreateList = int.MaxValue - 1;

            if (length < thresholdParallelCreateList)
            {
                long startIndex = index;
                long endIndex = index + length - 1;
                List<LineToIndexTableData> output = new List<LineToIndexTableData>();
                foreach (var range in this.ForEachLines(startIndex, endIndex, lineLimitLength))
                {
                    long lineHeadIndex = range.Item1;
                    long lineLength = range.Item2;
                    char c = this.Document[lineHeadIndex + lineLength - 1];
                    bool hasNewLine = range.Item3 != string.Empty;
                    LineToIndexTableData result = new LineToIndexTableData(lineHeadIndex, lineLength, hasNewLine, setdirtyflag, null);
                    output.Add(result);
                }

                return output;
            }
            else
            {
                var spilitLength = length / CoreNum;
                var spilitStartIndex = index;
                List<(long startIndex, long length)> spilitter = new List<(long startIndex, long length)>();
                for (int i = 0; i < CoreNum; i++)
                {
                    var actualSpilitLength = spilitLength;
                    while(true)
                    {
                        var currentIndex = spilitStartIndex + actualSpilitLength - 1;
                        if (currentIndex > index + length - 1)
                            break;
                        if(this.Document[currentIndex] == Document.CR_CHAR)
                        {
                            if(currentIndex + 1 < this.Document.Length && this.Document[currentIndex + 1] == Document.LF_CHAR)
                            {
                                actualSpilitLength++;
                                break;
                            }
                            else
                            {
                                break; 
                            }
                        }
                        if (this.Document[currentIndex] == Document.LF_CHAR)
                            break;
                        actualSpilitLength++;
                    }
                    if (spilitStartIndex + actualSpilitLength > index + length - 1)
                        actualSpilitLength = index + length -1 - spilitStartIndex + 1;
                    spilitter.Add((spilitStartIndex, actualSpilitLength));
                    spilitStartIndex += actualSpilitLength;
                }

                var result = spilitter.AsParallel().Select((item) => {
                    var startIndex = item.startIndex;
                    var endIndex = startIndex + item.length - 1;
                    List<LineToIndexTableData> output = new List<LineToIndexTableData>();
                    foreach (var range in this.ForEachLines(startIndex, endIndex, lineLimitLength))
                    {
                        long lineHeadIndex = range.Item1;
                        long lineLength = range.Item2;
                        char c = this.Document[lineHeadIndex + lineLength - 1];
                        bool hasNewLine = range.Item3 != string.Empty;
                        LineToIndexTableData result = new LineToIndexTableData(lineHeadIndex, lineLength, hasNewLine, setdirtyflag, null);
                        output.Add(result);
                    }
                    return (startIndex, output);
                })
                .OrderBy(item => item.startIndex)
                .SelectMany(item => item.output)
                .ToList();

                return result;
            }
        }