WingServerCommon/Interfaces/FileTransfer/FileTransferService.cs

using System.Collections.Concurrent;
using WingServerCommon.Log;
using System.Net;
using System.Net.Http.Headers;
using System.Security.Cryptography;
using System.Text;
using WingServerCommon.Config;
using WingServerCommon.Config.Parameters;

namespace WingServerCommon.Interfaces.FileTransfer
{
    /// <summary>
    /// 文件传输服务
    /// </summary>
    public class FileTransferService
    {
        private readonly HttpClient _httpClient;
        private readonly UploadFile _uploadFile;
        private string _folderBase = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "FileTransferRecord");  
        private int _autoSliceSizeForUpload = 0;
        private long _manualDivisionForUpload = 0;
        
        /// <summary>
        /// Init service
        /// </summary>
        public FileTransferService()
        {
            _httpClient = new HttpClient();
            _httpClient.Timeout = TimeSpan.FromMinutes(100);
            _uploadFile = new UploadFile(_httpClient);
        }

        /// <summary>
        /// copy文件到其他节点
        /// </summary>
        /// <param name="fileUrl">源文件地址，例如北京节点文件地址，需要源文件而不是cdn</param>
        /// <param name="fileName">文件名</param>
        /// <returns>是否存在</returns>
        public async Task<List<string>> CopyToOtherNode(string fileUrl, string fileName)
        {
            var res = await _uploadFile.DoCopyFileAsync(fileUrl, fileName);
            return res;
        }

        /// <summary>
        /// 请求验证文件是否存在
        /// </summary>
        /// <param name="oriFileName">FileName</param>
        /// <param name="fileSize">文件大小</param>
        /// <returns>是否存在</returns>
        public async Task<bool> CheckFileIsExist(string oriFileName, long fileSize, bool isNeedPartUpload = true, bool isUpgradePackage = false)
        {
            bool result = true;
            if (!isNeedPartUpload)
            {
                var newFirstName = Path.GetFileNameWithoutExtension(oriFileName);
                var newFileExtension = Path.GetExtension(oriFileName);
                var newFileName = newFirstName + newFileExtension; 
                var newAuthTuple = SignatureHelper.GetAuthorizationAsync(newFileName, false, "head", null, null, false, isUpgradePackage);
                if (newAuthTuple == null) 
                {
                    Logger.WriteLineInfo("Head Create Signature Fail");
                    return false;
                }
                var newRequestHeads = new Dictionary<string, string>();
                newRequestHeads.Add("Authorization", newAuthTuple.Item1);
                var fileUrl = newAuthTuple.Item2;
                using (var newRequest = new HttpRequestMessage())
                {
                    newRequest.RequestUri = new Uri(fileUrl);
                    newRequest.Method = HttpMethod.Head;
                    foreach (var newHead in newRequestHeads)
                    {
                        newRequest.Headers.TryAddWithoutValidation(newHead.Key, newHead.Value);
                    }
                    var newResponse = await _httpClient.SendAsync(newRequest);
                    if (newResponse != null && newResponse.StatusCode == HttpStatusCode.OK)
                    {
                        //read response content
                        if (fileUrl.Contains("/SystemUpgradePackage/"))//表示vinno
                        {
                            var resultContent = newResponse.Content.Headers.ContentLength > 0;
                            if (resultContent)
                            {
                                result = result & true;
                            }
                            else
                            {
                                result = result & false;
                            }
                        }
                        else
                        {
                            var newETag = newResponse.Headers?.ETag?.Tag ?? string.Empty;;
                            if (!string.IsNullOrEmpty(newETag))
                            {
                                result = result & true;
                            }
                            else
                            {
                                result = result & false;
                            }
                        }
                    }
                    else 
                    {
                        result = result & false;
                    } 
                } 
                return result;
            }
            if (_manualDivisionForUpload <= 0) 
            {
                _manualDivisionForUpload = EnvironmentConfigManager.GetParammeter<IntParameter>("Storage", "ManualDivisionForUpload").Value;
                if (_manualDivisionForUpload <= 0) 
                {
                    _manualDivisionForUpload = 200 * 1024 * 1024;
                }
            }
            var partCount = (int)((fileSize / _manualDivisionForUpload) + (fileSize % _manualDivisionForUpload > 0 ? 1 : 0));
            if (partCount > 0) 
            {
                var firstName = Path.GetFileNameWithoutExtension(oriFileName);
                var fileExtension = Path.GetExtension(oriFileName);
                for (var i = 0; i < partCount; i++)
                {
                    var fileName = "";
                    if (partCount == 1) 
                    {
                        fileName = firstName + fileExtension; 
                    }
                    else
                    {
                        fileName = firstName + "_" + i + fileExtension; 
                    }
                    var authTuple = SignatureHelper.GetAuthorizationAsync(fileName, false, "head", null, null, false, isUpgradePackage);
                    if (authTuple == null) 
                    {
                        Logger.WriteLineInfo("Head Create Signature Fail");
                        return false;
                    }
                    var requestHeads = new Dictionary<string, string>();
                    requestHeads.Add("Authorization", authTuple.Item1);
                    var fileUrl = authTuple.Item2;
                    using (var request = new HttpRequestMessage())
                    {
                        request.RequestUri = new Uri(fileUrl);
                        request.Method = HttpMethod.Head;
                        foreach (var head in requestHeads)
                        {
                            request.Headers.TryAddWithoutValidation(head.Key, head.Value);
                        }
                        var response = await _httpClient.SendAsync(request);
                        if (response != null && response.StatusCode == HttpStatusCode.OK)
                        {
                            //read response content
                            if (fileUrl.Contains("/SystemUpgradePackage/"))//表示vinno
                            {
                                var resultContent = response.Content.Headers.ContentLength > 0;
                                if (resultContent)
                                {
                                    result = result & true;
                                }
                                else
                                {
                                    result = result & false;
                                }
                            }
                            else
                            {
                                var eTag = response.Headers?.ETag?.Tag ?? string.Empty;;
                                if (!string.IsNullOrEmpty(eTag))
                                {
                                    result = result & true;
                                }
                                else
                                {
                                    result = result & false;
                                    break;
                                }
                            }
                        }
                        else 
                        {
                            result = result & false;
                            break;
                        } 
                    } 
                }   
            }
            return result;
        }

        /// <summary>
        /// 分块传输上传文件 
        /// </summary>
        /// <param name="sourceFilePath">源文件地址 </param>
        /// <param name="isRechristen">Rename</param>
        /// <param name="isCopy">is Copy to OtherNode</param>
        /// <returns>FileUrl List</returns>
        public async Task<List<string>> FileTransferAsync(string sourceFilePath, bool isRechristen = true, bool isNeedPartUpload = true, bool isCopy = false)
        {
            var returnFileUrlList = new List<string>();
            FileTransferRecorder record = new FileTransferRecorder();
            try 
            {
                if (string.IsNullOrEmpty(sourceFilePath) || !File.Exists(sourceFilePath)) 
                {
                    Logger.WriteLineWarn("File Absolute Path Error!");
                    return new List<string>();
                }
                //读取缓存文件, 如果存在就是需要断点upload
                var recorderFilePath = Path.Combine(_folderBase, ToMD5(sourceFilePath) + ".json");
                if (File.Exists(recorderFilePath))
                {
                    //调用断点续传
                    return await FileTransferAgainAsync(sourceFilePath, recorderFilePath);
                }
                string oriFilename = Path.GetFileNameWithoutExtension(sourceFilePath);
                var factName = oriFilename;
                var factNameExtension = Path.GetExtension(sourceFilePath);
                if (string.IsNullOrEmpty(factNameExtension)) 
                {
                    factNameExtension = ".dat";
                }
                if (isRechristen) 
                { 
                    factName = Guid.NewGuid().ToString("N").ToUpper();
                }
                if (_manualDivisionForUpload <= 0) 
                {
                    _manualDivisionForUpload = EnvironmentConfigManager.GetParammeter<IntParameter>("Storage", "ManualDivisionForUpload").Value;
                    if (_manualDivisionForUpload <= 0) 
                    {
                        _manualDivisionForUpload = 200 * 1024 * 1024;
                    }
                }
                if (!isNeedPartUpload)
                {
                    var fileInfo = new System.IO.FileInfo(sourceFilePath);
                    if (fileInfo.Length >= 5000000000)
                    {
                        Logger.WriteLineWarn($"CommonServer FileTransferAsync isNeedPartUpload Error,sourceFilePath: { sourceFilePath }, FileSize: { fileInfo.Length }!");
                        return new List<string>();
                    }
                }
                //读取文件 ConcurrentDictionary
                var dic = new Dictionary<int, byte[]>();
                dic = ReadFileData(sourceFilePath, _manualDivisionForUpload);
                if (dic == null || dic.Count <= 0)
                {
                    Logger.WriteLineWarn("File Data Empty Error!");
                    return new List<string>();
                }    
                //记录文件信息
                record.FilePath = sourceFilePath;
                record.FileName = oriFilename;
                record.ObjectName = factName;
                record.FileExtension = factNameExtension;
                record.SliceSizeForUpload = _manualDivisionForUpload;
                record.PartList = new List<FileTransferRecorderDetail>();
                record.IsNeedPartUpload = isNeedPartUpload;
                
                var partNums = dic.Keys.OrderBy(c => c).ToList();
                foreach(var i in partNums)
                {
                    var partDetail = new FileTransferRecorderDetail();
                    if (partNums.Count == 1) 
                    {
                        partDetail.PartFileName =  factName + factNameExtension; 
                    }
                    else
                    {
                        partDetail.PartFileName =  factName + "_" + i + factNameExtension; 
                    }
                    partDetail.PartNumber = i;
                    partDetail.IsUploadComplete = false;
                    partDetail.PartFileSize = dic[i].Length;
                    record.PartList.Add(partDetail);
                    record.FileSize += partDetail.PartFileSize;
                }
                await SaveTransferRecord(record);
                if (record?.PartList?.Count > 0)
                {
                    try
                    {
                        if (isNeedPartUpload)
                        {
                            //todo 可尝试优化为Multi Thread
                            foreach (var partDetail in record.PartList) 
                            {
                                var fileUrl = await _uploadFile.DoUploadFileAsync(partDetail.PartFileName, dic[partDetail.PartNumber], false, factNameExtension);
                                if (!string.IsNullOrEmpty(fileUrl)) 
                                {
                                    record.Host = fileUrl.Replace(partDetail.PartFileName, "");
                                    partDetail.IsUploadComplete = true;
                                    if (isCopy) 
                                    {
                                        //后续可以改成异步
                                        await _uploadFile.DoCopyFileAsync(fileUrl, partDetail.PartFileName);
                                    }
                                }
                                await SaveTransferRecord(record);
                            }
                        }
                        else
                        {
                            var fileUrl = await _uploadFile.ManualMultiPartUploadFileAsync(record, dic, false);
                            if (isCopy) 
                            {
                                //后续可以改成异步
                                string fileName = record.ObjectName + record.FileExtension;
                                await _uploadFile.DoCopyFileAsync(fileUrl, fileName);
                            }
                            await SaveTransferRecord(record);
                            returnFileUrlList = new List<string>() { fileUrl };
                        }
                    }
                    catch (Exception e)
                    {
                        await SaveTransferRecord(record);
                        //文件上传错误
                        Logger.WriteLineWarn($"File Upload Error, {e}");                            
                    }
                    if (record.PartList.Count(c => c.IsUploadComplete) == record.PartList.Count) 
                    {
                        record.IsUploadComplete = true;
                    }
                    else 
                    {
                        record.IsUploadComplete = false;
                    }
                }
                if (record.IsUploadComplete) 
                {
                    //删除缓存记录
                    if (File.Exists(recorderFilePath))
                    {
                        //存在删除
                        File.Delete(recorderFilePath);
                    }
                    //返回多个链接列表
                    if (isNeedPartUpload)
                    {
                        returnFileUrlList = record.PartList.OrderBy(c => c.PartFileName).Select(c => record.Host + c.PartFileName).ToList();
                    }
                }
            }
            catch (Exception ex) 
            {
                Logger.WriteLineError($"File Transfer Fail, {ex}");
            }
            finally
            {
                GC.Collect();
            }
            return returnFileUrlList;
        }

        /// <summary>
        /// 保存上传记录文件 
        /// </summary>
        /// <param name="request">请求对象</param>
        /// <returns>是否成功</returns>
        private async Task<bool> SaveTransferRecord(FileTransferRecorder record) 
        {
            if (!Directory.Exists(_folderBase))
            {
                Directory.CreateDirectory(_folderBase);
            }
            var recorderFilePath = Path.Combine(_folderBase, ToMD5(record.FilePath) + ".json");
            if (File.Exists(recorderFilePath))
            {
                //存在删除
                File.Delete(recorderFilePath);
            }
            var json = Newtonsoft.Json.JsonConvert.SerializeObject(record);
            if (!string.IsNullOrWhiteSpace(json)) 
            {
                byte[] fileData = System.Text.Encoding.UTF8.GetBytes(json);
                //存储文件
                using (var fw = File.Open(recorderFilePath, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite))
                {
                    fw.Write(fileData, 0, fileData.Length);
                }  
            }
            return true;
        }

        /// <summary>
        /// 文件续传
        /// </summary>
        /// <param name="sourceFilePath">源文件地址</param>
        /// <returns>Part FileUrl List</returns>
        public async Task<List<string>> FileTransferAgainAsync(string sourceFilePath, string recorderFilePath)
        {
            var returnFileUrlList = new List<string>();
            FileTransferRecorder record = new FileTransferRecorder();
            try 
            {
                var jsonContent = File.ReadAllText(recorderFilePath);
                if (!string.IsNullOrEmpty(jsonContent)) 
                {
                    record = Newtonsoft.Json.JsonConvert.DeserializeObject<FileTransferRecorder>(jsonContent);
                }
                //读取文件
                if (record?.PartList?.Count > 0) 
                {
                    var waitUploadFileList = record.PartList.FindAll(c => c.IsUploadComplete == false);
                    var dic = new Dictionary<int, byte[]>();
                    dic = ReadFileData(sourceFilePath, record.SliceSizeForUpload);
                    if (dic == null || dic.Count <= 0)
                    {
                        Logger.WriteLineWarn("File Data Empty Error!");
                        return new List<string>();
                    }     
                    var isNeedPartUpload = record.IsNeedPartUpload;
                    try
                    {
                        if (isNeedPartUpload)
                        {
                            foreach (var partDetail in waitUploadFileList)
                            {
                                var fileUrl = await _uploadFile.DoUploadFileAsync(partDetail.PartFileName, dic[partDetail.PartNumber], false, record.FileExtension);
                                if (!string.IsNullOrEmpty(fileUrl)) 
                                {
                                    record.Host = fileUrl.Replace(partDetail.PartFileName, "");
                                    partDetail.IsUploadComplete = true;
                                    if (record.IsCopy) 
                                    {
                                        //后续可以改成异步
                                        await _uploadFile.DoCopyFileAsync(fileUrl, partDetail.PartFileName);
                                    }
                                }
                                await SaveTransferRecord(record);
                            }
                        }
                        else
                        {
                            var fileUrl = await _uploadFile.ManualMultiPartUploadFileAsync(record, dic, false);
                            if (record.IsCopy) 
                            {
                                //后续可以改成异步
                                string fileName = record.ObjectName + record.FileExtension;
                                await _uploadFile.DoCopyFileAsync(fileUrl, fileName);
                            }
                            await SaveTransferRecord(record);
                            returnFileUrlList = new List<string>() { fileUrl };
                        }
                    }
                    catch (Exception e)
                    {
                        await SaveTransferRecord(record);
                        //文件上传错误
                        Logger.WriteLineWarn($"File Upload Again Error, {e}");                            
                    }
                    if (record.PartList.Count(c => c.IsUploadComplete) == record.PartList.Count) 
                    {
                        record.IsUploadComplete = true;
                    }
                    else 
                    {
                        record.IsUploadComplete = false;
                    }
        
                    if (record.IsUploadComplete) 
                    {
                        //删除缓存记录
                        if (File.Exists(recorderFilePath))
                        {
                            //存在删除
                            File.Delete(recorderFilePath);
                        }
                        //返回多个链接列表;
                        if (isNeedPartUpload)
                        {
                            returnFileUrlList = record.PartList.OrderBy(c => c.PartFileName).Select(c => record.Host + c.PartFileName).ToList();
                        }
                    }
                }
            }
            catch (Exception ex) 
            {
                Logger.WriteLineError($"File Transfer Again Fail, {ex}");
            }
            finally
            {
                GC.Collect();
            }
            return returnFileUrlList;
        }

        /// <summary>
        /// 合并文件并保存到指定目录
        /// </summary>
        /// <param name="partFileUrlList">分片地址列表</param>
        /// <param name="savePath">保存指定文件地址(不包含文件名)</param>
        /// <param name="saveFileName">保存指定文件(无需带扩展名)</param>
        /// <returns>保存地址文件</returns>
        public async Task<string> DownloadFileAsync(List<string> partFileUrlList, string savePath, string saveFileName = "")
        {
            var newSaveFileName = "";
            try 
            {
                if (string.IsNullOrEmpty(savePath)) 
                {
                    Logger.WriteLineWarn("Save Path Error!");
                    return "";
                }
                if (partFileUrlList == null || partFileUrlList.Count <= 0) 
                {
                    Logger.WriteLineWarn("Download File List Error!");                    
                    return "";
                }
                if (_autoSliceSizeForUpload <= 0) 
                {
                    _autoSliceSizeForUpload = EnvironmentConfigManager.GetParammeter<IntParameter>("Storage", "AutoSliceSizeForUpload").Value;
                }
                var fileExtension = "";
                if (partFileUrlList[0].Split('.').Length > 0)
                {
                    fileExtension = partFileUrlList[0].Split('.')[(partFileUrlList[0].Split('.').Length - 1)];
                }
                else
                {
                    fileExtension = "dat";
                }
                //验证文件是否存在
                var fileName = saveFileName;
                if (string.IsNullOrEmpty(fileName)) 
                {
                    fileName = Guid.NewGuid().ToString("N").ToUpper() + "." + fileExtension;
                }
                var recorderFilePath = Path.Combine(savePath, fileName);
                if (File.Exists(recorderFilePath))
                {
                    File.Delete(recorderFilePath);
                }
                if (partFileUrlList.Count == 1) 
                {
                    var url = partFileUrlList.FirstOrDefault() ?? string.Empty;
                    var tempArray = await DownloadPartFileAsync(url);
                    newSaveFileName = await SaveDownloadFile(savePath, fileExtension, tempArray, saveFileName);
                }
                else 
                {
                    var dic = new ConcurrentDictionary<string, byte[]>();
                    long dataLength = 0;
                    partFileUrlList.Sort();
                    var parallelOption = new ParallelOptions() { MaxDegreeOfParallelism = 3 };
                    Parallel.ForEach(partFileUrlList, parallelOption, item =>
                    {
                        var tempArray = DownloadPartFileAsync(item).GetAwaiter().GetResult();
                        dataLength += tempArray.Length;
                        dic.TryAdd(item, tempArray);
                    });
                    
                    byte[] btArr = new byte[dataLength];
                    int index = 0;
                    foreach (var item in partFileUrlList)
                    {
                        Array.Copy(dic[item], 0, btArr, index, dic[item].Length);
                        index += Convert.ToInt32(dic[item].Length);
                    }
                    newSaveFileName = await SaveDownloadFile(savePath, fileExtension, btArr, saveFileName);
                }
            }
            catch (Exception ex) 
            {
                Logger.WriteLineError($"Download And Save File fail, {ex}");
                return string.Empty;
            }
            finally
            {
                GC.Collect();
            }
            return newSaveFileName;
        }

        /// <summary>
        /// 分块下载文件
        /// </summary>
        private async Task<byte[]> DownloadPartFileAsync(string fileUrl)
        {
            byte[] byteArr = null;
            using (var request = new HttpRequestMessage())
            {
                request.RequestUri = new Uri(fileUrl);
                request.Method = HttpMethod.Head;
                var response = await _httpClient.SendAsync(request);
                long allStreamLength = 0;
                if (response != null && response.StatusCode == HttpStatusCode.OK && response.Content != null && response.Content.Headers != null)
                {
                    allStreamLength = response.Content.Headers.ContentLength.Value;
                }
                if (allStreamLength == 0)
                {
                    Logger.WriteLineWarn($"file length is empty, token:{fileUrl}");
                    return null;
                }
                byteArr = new byte[allStreamLength];
                try
                {
                    for (int fileIndex = 0; true; fileIndex += _autoSliceSizeForUpload)
                    {
                        if (fileIndex >= allStreamLength)
                        {
                            Logger.WriteLineInfo("download fileIndex:"+ fileIndex);
                            break;
                        } 
                        var newChunk = fileIndex + _autoSliceSizeForUpload;
                        var newLength = newChunk > allStreamLength ? allStreamLength : newChunk;
                        var doRes = await _uploadFile.DoHttpRequest(fileUrl, byteArr, fileIndex, newLength, allStreamLength);
                        if (!doRes)
                        {
                            Logger.WriteLineInfo("download doRes:"+ doRes);
                            break;
                        }
                    }
                }
                catch (Exception ex)
                {
                    Logger.WriteLineError($"Downloding file error {ex}");
                    return null;
                }
            }
            GC.Collect();
            return byteArr;
        }

        /// <summary>
        /// 保存下载文件
        /// </summary>
        /// <param name="srcPath">保存路径</param>
        /// <param name="fileExtension">File Name Extension</param>
        /// <param name="fileData">数据</param>
        /// <param name="saveFileName">指定保存文件</param>
        /// <returns>保存文件</returns>
        private async Task<string> SaveDownloadFile(string srcPath, string fileExtension, byte[] fileData, string saveFileName = "") 
        {
            if (!Directory.Exists(srcPath))
            {
                Directory.CreateDirectory(srcPath);
            }
            var fileName = saveFileName;
            if (string.IsNullOrEmpty(fileName)) 
            {
                fileName = Guid.NewGuid().ToString("N").ToUpper() + "." + fileExtension;
            }
            var recorderFilePath = Path.Combine(srcPath, fileName);
            if (File.Exists(recorderFilePath))
            {
                //存在删除
                File.Delete(recorderFilePath);
            }
            //存储文件
            using (var fw = File.Open(recorderFilePath, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite))
            {
                fw.Write(fileData, 0, fileData.Length);
            }  
            return fileName;
        }

        /// <summary>
        /// 读取文件
        /// </summary>
        private Dictionary<int, byte[]> ReadFileData(string filePath, long manualDivisionForUpload)
        {
            var dic = new Dictionary<int, byte[]>();
            using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))
            {
                var partCount = (int)((fs.Length / manualDivisionForUpload) + (fs.Length % manualDivisionForUpload > 0 ? 1 : 0));
                //大于1.7G的问题，用分块读取File 
                if (fs.Length > 1782579200)
                {
                    var byteSize = 10;
                    byte[] buffer = new byte[byteSize * 1024 * 1024];//10M的缓冲byte
                    int fileCursor = 0;
                    int readerCursor = 0;
                    var splitFileTimes = manualDivisionForUpload / buffer.Length + (manualDivisionForUpload % buffer.Length > 0 ? 1 : 0);
                    var fileSplitFileTimes = fs.Length / buffer.Length + (fs.Length % buffer.Length > 0 ? 1 : 0);
                    if (fileSplitFileTimes < splitFileTimes)
                    {
                        splitFileTimes = fileSplitFileTimes;
                    }
                    //超过200就不能读取了，会溢出
                    if (splitFileTimes > 200)
                    {
                        return dic;
                    }
                    NextFileBegin:
                    using (MemoryStream ms = new MemoryStream())
                    {
                        int readLength = 0;
                        while ((readLength = fs.Read(buffer, 0, buffer.Length)) > 0)
                        {
                            readerCursor++;
                            ms.Write(buffer, 0, readLength);
                            if (readerCursor >= splitFileTimes)
                            {
                                var allBytes = ms.ToArray();
                                dic.Add(fileCursor, allBytes);
                                readerCursor = 0;
                                fileCursor++;
                                break;
                            }
                            else
                            {
                                if (readLength < buffer.Length && readerCursor > 0 && readerCursor < splitFileTimes)
                                {
                                    //表示最后一个了
                                    var allBytes = ms.ToArray();
                                    dic.Add(fileCursor, allBytes);
                                    readerCursor = 0;
                                    fileCursor++;
                                    break;
                                }
                            }
                        }
                    }
                    if (fileCursor < partCount)
                    {
                        goto NextFileBegin;
                    }
                }
                else 
                {
                    //读取文件
                    byte[] btArr = new byte[fs.Length];
                    fs.Read(btArr, 0, btArr.Length);
                    if (partCount > 1) 
                    {
                        long offsetIndex = 0;
                        for (var i = 0; i < partCount; i++)
                        {
                            var tempLength = manualDivisionForUpload;
                            if ((partCount - 1) == i) 
                            {
                                //最后一个分块File 
                                tempLength = btArr.Length - (partCount - 1) * manualDivisionForUpload;
                            }
                            var tempByte = new byte[tempLength];
                            offsetIndex = i * manualDivisionForUpload;
                            Array.Copy(btArr, offsetIndex, tempByte, 0, tempByte.Length);
                            dic.Add(i, tempByte);
                        }
                    }
                    else 
                    {
                        var partDetail = new FileTransferRecorderDetail();
                        dic.TryAdd(0, btArr);
                    }
                }
            }
            return dic;
        }

        /// <summary>
        /// Encrypt to MD5 string
        /// </summary>
        /// <param name="str">source string</param>
        /// <returns></returns>
        private string ToMD5(string str)
        {
            if (string.IsNullOrWhiteSpace(str)) return string.Empty;
            System.Security.Cryptography.MD5 md5 = new MD5CryptoServiceProvider();
            byte[] bPwd = Encoding.UTF8.GetBytes(str);
            byte[] bMD5 = md5.ComputeHash(bPwd);
            md5.Clear();
            StringBuilder sbMD5Pwd = new StringBuilder();
            for (int i = 0; i < bMD5.Length; i++)
            {
                sbMD5Pwd.Append(bMD5[i].ToString("x2"));
            }
            return sbMD5Pwd.ToString();
        }
    }

}