private async Task DownloadFileAsync(Uri fullUrl, string filename)
{
string finalFilePath = Path.Combine(_config.SavingDirectory, filename);
string tmpFilePath = Path.Combine(_config.TemporaryDirectory, filename);
// skip if exists
if (File.Exists(finalFilePath))
{
return;
}
_logger.LogInformation($"Downloading ({fullUrl.AbsoluteUri})");
bool isSuccess = false;
int numberOfAttempts = 0;
TimeSpan timeCost = TimeSpan.FromTicks(0);
// BUG: If those fileinfo initialized here, it will be more likely to trigger IO error below
// FileInfo tmpFileToWrite = new FileInfo(tmpFilePath);
// FileInfo finalFileToWrite = new FileInfo(finalFilePath);
while (true)
{
// BUG/WORKAROUND: If those fileinfo initialized here, it will seldom trigger IO error below
FileInfo tmpFileToWrite = new FileInfo(tmpFilePath);
FileInfo finalFileToWrite = new FileInfo(finalFilePath);
// busy waiting
while (tmpFileToWrite.Exists && tmpFileToWrite.IsFileLocked())
{
GC.Collect();
GC.WaitForPendingFinalizers();
}
if (isSuccess)
{
while (finalFileToWrite.Exists && finalFileToWrite.IsFileLocked())
{
GC.Collect();
GC.WaitForPendingFinalizers();
}
// finalFileToWrite.Delete();
// File.Move(tmpFilePath, finalFilePath);
tmpFileToWrite.MoveTo(finalFilePath, true);
_logger.LogInformation($"Time cost: {timeCost.TotalSeconds}s. ({fullUrl.AbsoluteUri})");
break;
}
if (numberOfAttempts >= _config.NumberOfAttemptsPreLink)
{
// File.Delete(tmpFilePath);
tmpFileToWrite.Delete();
_logger.LogError($"Run out of attempts. ({fullUrl.AbsoluteUri})");
break;
}
try
{
// File.Delete(tmpFilePath);
tmpFileToWrite.Delete();
using (var client = new WebDownload((int)TimeSpan.FromSeconds(_config.SecondsBeforeTimeout).TotalMilliseconds))
{
var stopwatch = new Stopwatch();
// using (var timer = new Timer())
// {
// timer.Interval = TimeSpan.FromSeconds(_config.SecondsBeforeTimeout).TotalMilliseconds;
// timer.Start();
var downloadTask = client.DownloadFileTaskAsync(fullUrl, tmpFilePath);
// bool isTimeout = false;
// timer.Elapsed += (sender, e) => this.Timeout(sender, e, downloadTask, out isTimeout);
// client.DownloadFile(fullUrl, filePath);
stopwatch.Start();
downloadTask.Wait(TimeSpan.FromSeconds(_config.SecondsBeforeTimeout));
stopwatch.Stop();
timeCost = stopwatch.Elapsed;
// timer.Stop();
// timeCostInSeconds = _config.SecondsBeforeTimeout - TimeSpan.FromMilliseconds(timer.Interval).TotalSeconds;
// isSuccess = !isTimeout;
isSuccess = downloadTask.IsCompleted;
// }
}
}
catch (IOException)
{
throw;
}
// // BUG: not catching
// catch (WebException)
// {
// // System.Net.WebException : The operation has timed out.
// isSuccess = false;
// }
catch (Exception)
{
isSuccess = false;
}
if (!isSuccess)
{
_logger.LogError($"Timeout! ({fullUrl.AbsoluteUri})");
}
numberOfAttempts++;
}
}