private async Task FileUpload_Change(IEnumerable <IFileReference> files)
{
foreach (var file in files)
{
var fileInfo = await file.ReadFileInfoAsync();
if (fileInfo.Size > _maxSize)
{
return;
}
string filename = FormatFilename(fileInfo.Name);
Stream uploadStream = await file.OpenReadAsync();
Func <Stream, CancellationToken, IProgress <IUploadProgress>, Task> uploadTask = async(stream, cancellationToken, progress) =>
{
await downloadFiles.AddAsync(_download.Id, filename, stream, cancellationToken, progress);
};
var progressTask = new FileUploadTask(filename, _download, uploadStream, uploadTask);
progressTask.OnComplete += async t => await RefreshFileList();
taskState.Add(progressTask);
}
}
private void ReadCallback(IAsyncResult a)
{
Tuple <HttpWebRequest, FileUploadTask, int> args = (Tuple <HttpWebRequest, FileUploadTask, int>)a.AsyncState;
HttpWebRequest webrequest = args.Item1;
FileUploadTask fileTask = args.Item2;
try
{
using (Stream requestStream = webrequest.EndGetRequestStream(a))
{
using (FileStream fs = m_FileInfo.OpenRead())
{
fs.Seek(fileTask.StartPosition, SeekOrigin.Begin);
byte[] buffer = new Byte[4096];
long tempTotal = 0;
while (tempTotal < fileTask.Length)
{
long bytesRead = fileTask.Length - tempTotal;
if (bytesRead > buffer.Length)
{
bytesRead = buffer.Length;
}
fs.Read(buffer, 0, (int)bytesRead);
requestStream.Write(buffer, 0, (int)bytesRead);
tempTotal += bytesRead;
}
fs.Close();
}
requestStream.Close();
}
webrequest.BeginGetResponse(new AsyncCallback(WriteCallback), args);
}
catch (Exception ex)
{
ComponentFactory.GetComponent <ILog>().LogError(ex);
var tmp = new UploadErrorOccuredEventEventArgs
{
FileIdentity = m_FileIdentity,
FileInfo = m_FileInfo,
Exception = ex
};
m_Exception = tmp;
lock (m_TaskQueue_SyncObj)
{
m_TaskQueue.Enqueue(fileTask);
}
ExecuteUploadTask(args.Item3); // 继续任务处理
}
}
private void ExecuteUploadTask(int threadID)
{
// 判断ToCancel的优先级最高，不管是否发生了异常，还是最后一个task都已经上传完毕，
// 一旦调用Cancel，异常、上传完毕都可以被忽略，都认为上传被取消
if (m_UploadStatus == UploadStatus.ToCancel)
{
if (EndThread())
{
DeleteFileFromServer();
m_UploadStatus = UploadStatus.Stopped;
OnUploadCanceled(new UploadCanceledEventArgs
{
FileIdentity = m_FileIdentity,
FileInfo = m_FileInfo,
TotalUploadedDataLength = m_CurrentUploadLength
});
}
return;
}
if (m_Exception != null)
{
if (EndThread())
{
m_Exception.TotalUploadedDataLength = m_CurrentUploadLength;
var tmp = m_Exception;
m_Exception = null;
m_UploadStatus = UploadStatus.Suspended;
OnUploadErrorOccured(tmp);
}
return;
}
// 在判断是否需要暂停前，要先判断一下任务是否已经都完成了；如果不首先判断任务是否都完成，可能会出现一种情况：
// 当最后一个任务在上传时，才调用了Suspend方法将状态置为ToSuspend；然后线程执行到这里判断状态为ToSuspend了后就进入暂停状态；
// 而当调用了Resume方法的时候，状态会再次变为Uploading，但是此时Queue里已经没有任务了，那么也就不会再开启上传线程，
// 那么状态永远都是Uploading，永远无法完成
// 所以为了避免这种情况发生，在判断ToSuspend之前需要先看看任务是否都已经上传完毕，如果是则直接变成已上传完毕了，之前发生的暂停操作就无效了
if (m_TaskQueue.Count <= 0)
{
if (EndThread())
{
m_UploadStatus = UploadStatus.Stopped;
CallServiceUploadStopped();
}
return;
}
if (m_UploadStatus == UploadStatus.ToSuspend)
{
if (EndThread())
{
m_UploadStatus = UploadStatus.Suspended;
OnUploadSuspended(new UploadSuspendedEventArgs
{
FileIdentity = m_FileIdentity,
FileInfo = m_FileInfo,
TotalUploadedDataLength = m_CurrentUploadLength
});
}
return;
}
FileUploadTask task = null;
if (m_TaskQueue.Count > 0)
{
lock (m_TaskQueue_SyncObj)
{
if (m_TaskQueue.Count > 0)
{
task = m_TaskQueue.Dequeue();
}
}
}
if (task == null)
{
if (EndThread())
{
m_UploadStatus = UploadStatus.Stopped;
CallServiceUploadStopped();
}
return;
}
try
{
string url = m_Url + "?FileIdentity=" + HttpUtility.UrlEncode(m_FileIdentity) + "&StartPosition=" + task.StartPosition;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "POST";
request.BeginGetRequestStream(new AsyncCallback(ReadCallback),
new Tuple <HttpWebRequest, FileUploadTask, int>(request, task, threadID));
}
catch (Exception ex)
{
ComponentFactory.GetComponent <ILog>().LogError(ex);
var tmp = new UploadErrorOccuredEventEventArgs
{
FileIdentity = m_FileIdentity,
FileInfo = m_FileInfo,
Exception = ex
};
m_Exception = tmp;
lock (m_TaskQueue_SyncObj)
{
m_TaskQueue.Enqueue(task);
}
ExecuteUploadTask(threadID); // 继续任务处理
}
}
