private void _Download()
{
try
{
if (UnCompeleteSize <= 0)
{
IsCompleted = true;
BlockEvents.OnProgress(100, 100);
BlockEvents.OnCompleted();
Request.Abort();
return;
}
Log.Debug(BlockIndex.ToString() + "号文件块开始下载.");
Request.Timeout = Timeout.Infinite;
Request.Accept = "*/*";
Request.AllowAutoRedirect = true;
Request.AddRange(StartPosition + _CompletedPosition);
Log.Debug(BlockIndex.ToString() + "号块正在获取网络回应.");
var response = (HttpWebResponse)Request.GetResponse();
Log.Debug(BlockIndex.ToString() + "号块正在获取流.");
Stream stream = response.GetResponseStream();
if (stream == null)
{
IsCompleted = true;
BlockEvents.OnProgress(100, 100);
BlockEvents.OnCompleted();
Request.Abort();
Log.Debug("无法获取到WebRequest请求的相应文件流~");
return;
}
Log.Debug(BlockIndex.ToString() + "号块正在创建暂存文件.");
using (var filestream = new FileStream(FilePath, FileMode.Append, FileAccess.Write, FileShare.ReadWrite))
{
var buffersize = DownloadState.BufferSize;
var buffer = new byte[buffersize];
Log.Debug(BlockIndex.ToString() + "号块初始化完毕.");
try
{
while (UnCompeleteSize > 0)
{
Log.Debug(BlockIndex.ToString() + "号块开始从" + _CompletedPosition.ToString() + "处读取流数据.");
int receiveCount = stream.Read(buffer, 0, (int)buffersize);
Log.Debug(BlockIndex.ToString() + "号块本次读取流数据长度为" + receiveCount.ToString() + "字节.");
if (receiveCount <= 0)
{
var sb = new StringBuilder();
sb.Append("发生下载阻塞" + "\t");
sb.Append("BlockIndex：" + BlockIndex.ToString() + "\t");
sb.Append("StartPosition：" + (StartPosition + CompletedPosition).ToString() + "\t");
sb.Append("BufferSize：" + BlockSize.ToString() + "\t");
sb.Append("ReceiveCount：" + receiveCount.ToString());
Log.Debug(sb.ToString());
Thread.Sleep(5000);
continue;
}
int availbleReceiveCount = (UnCompeleteSize < receiveCount ? UnCompeleteSize : receiveCount);
filestream.Write(buffer, 0, availbleReceiveCount);
filestream.Flush();
_CompletedPosition += availbleReceiveCount;
Log.Debug(BlockIndex.ToString() +
"号块已完成" + _CompletedPosition.ToString() + "/" + this.BlockSize.ToString() + "字节的下载.");
BlockEvents.CompletedBytesCount += availbleReceiveCount;
if (UnCompeleteSize <= 0 || DownloadState.StopDownload)
{
break;
}
}
buffer = null;
response.Close();
stream.Close();
if (DownloadState.StopDownload)
{
return;
}
Log.Debug(BlockIndex.ToString() + "号文件块下载完成.");
this.IsCompleted = true;
BlockEvents.OnCompleted();
this.Request.Abort();
filestream.Close();
}
catch (Exception err)
{
buffer = null;
response.Close();
stream.Close();
filestream.Close();
BlockEvents.OnException(err);
this.Request.Abort();
}
}
}
catch (Exception err)
{
BlockEvents.OnException(err);
this.Request.Abort();
}
}
private void DownloadFile(TransferParameter parameter)
{
try
{
string logstr = "下载任务开始,正在创建临时目录.";
Log.Debug(logstr);
string[] tempList = Directory.GetDirectories(Logger.TemporaryDirectory);
DirectoryInfo di = null;
if (tempList.Length > 0)
{
foreach (string item in tempList)
{
di = new DirectoryInfo(item);
if (di.LastWriteTime <= DateTime.Now.AddMonths(-6))
{
FileUtil.DeleteDirectory(item);
}
}
}
logstr = "正在创建本地保存目录.";
Log.Debug(logstr);
string localDir = Path.GetDirectoryName(parameter.LocalFile);
if (!string.IsNullOrEmpty(localDir))
{
di = new DirectoryInfo(localDir);
if (!di.Exists)
{
di.Create();
}
}
logstr = "正在初始化...";
Log.Debug(logstr + "\r\n" + parameter.ToString());
DownloadState.BlockList.Clear();
var currentApply = new Apply();
DownloadState.BlockList = DownloadRequst.GetBlocks(parameter, ref currentApply);
Log.Debug(currentApply.ToString());
DownloadState.AllowAppend = false;
DownloadState.StopDownload = false;
DownloadState.HasFinished = false;
DownloadState.IsCompleted = false;
DownloadState.OutputDebugLog = true;
BlockEvents.CompletedBytesCount = 0;
BlockEvents.TotalBytes = currentApply.FileSize;
ServicePointManager.DefaultConnectionLimit = 100;
var historyApply = new Apply();
var historyFileItem = new FileItem();
var historyparameter = new TransferParameter();
if (DownloadHistory.Exists(parameter.RemoteFile, ref historyFileItem, ref historyApply, ref historyparameter, false) &&
DownloadState.CurrentApply.Equals(historyApply) &&
!File.Exists(parameter.LocalFile))
{
logstr = "已恢复下载.";
Log.Debug(logstr);
DownloadState.AllowAppend = true;
historyFileItem.HasBreaked = true;
if (string.IsNullOrEmpty(historyFileItem.BreakInfo))
{
historyFileItem.BreakInfo = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
}
else
{
historyFileItem.BreakInfo += ";" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
}
DownloadHistory.Update(parameter.RemoteFile, historyFileItem);
}
else if (DownloadHistory.Exists(parameter.RemoteFile, ref historyFileItem, ref historyApply, ref historyparameter, true) &&
parameter.Equals(historyparameter) &&
File.Exists(historyparameter.LocalFile))
{
var fileInfo = new FileInfo(parameter.LocalFile);
if (fileInfo.Length == DownloadState.CurrentApply.FileSize &&
fileInfo.LastWriteTime == DownloadState.CurrentApply.LastModified)
{
logstr = parameter.TransferUrl + "此前已完成下载.";
Log.Debug(logstr);
DownloadState.HasFinished = true;
BlockEvents.CompletedBytesCount = fileInfo.Length;
BlockEvents.OnProgress(100, 100);
BlockEvents.OnCompleted();
return;
}
}
if (!DownloadState.AllowAppend && !DownloadState.HasFinished)
{
DownloadHistory.Insert(parameter.RemoteFile);
logstr = "已将本次下载任务追加到历史.";
Log.Debug(logstr);
}
if (BlockEvents.Begining != null)
{
BlockEvents.Begining(parameter.LocalFile);
}
logstr = "开始处理分块";
Log.Warn(logstr);
foreach (Blocks item in DownloadState.BlockList)
{
item.ReStore();
item.Download();
logstr += item.ToString() + "\r\n";
Log.Debug(logstr);
}
Log.Info("文件下载完毕");
}
catch (Exception err)
{
BlockEvents.OnException(err);
}
}