private Downloader StartDownload(FSItem item, string path)
{
var downloader = new Downloader(item, path);
lock (DownloadersLock)
{
Downloader result;
if (Downloaders.TryGetValue(item.Path, out result))
{
if (result.Task == null)
{
throw new Exception("Downloader Task is Null");
}
return(result);
}
Directory.CreateDirectory(cachePath);
var fileinfo = new FileInfo(path);
if (fileinfo.Exists && fileinfo.Length == item.Length)
{
return(Downloader.CreateCompleted(item, path, item.Length));
}
Stream writer;
if (!fileinfo.Exists || fileinfo.Length < item.Length)
{
writer = new FileStream(
path,
FileMode.Append,
FileAccess.Write,
FileShare.ReadWrite,
4096,
FileOptions.Asynchronous | FileOptions.SequentialScan);
if (writer.Length > 0)
{
Log.Warn(
$"File was not totally downloaded before. Should be {item.Length} but was {writer.Length}: {item.Path} - {item.Id}");
downloader.Downloaded = writer.Length;
}
}
else
{
writer = new FileStream(
path,
FileMode.Create,
FileAccess.Write,
FileShare.ReadWrite,
4096,
FileOptions.Asynchronous | FileOptions.SequentialScan);
}
downloader.Task = Task.Factory.StartNew(async() => await Download(item, writer, downloader), TaskCreationOptions.LongRunning);
Downloaders.Add(item.Path, downloader);
return(downloader);
}
}
private async Task Download(FSItem item, Stream result, Downloader downloader)
{
try
{
Log.Trace($"Started download: {item.Name} - {item.Id}");
var start = Stopwatch.StartNew();
var buf = new byte[64 << 10];
var uncommitedSize = 0;
const int commitSize = 512 << 10;
using (result)
using (var writer = new BufferedStream(result))
{
OnDownloadStarted?.Invoke(item);
while (writer.Length < item.Length)
{
var stream = await cloud.Files.Download(item.Id);
stream.Position = writer.Length;
int red;
do
{
red = await stream.ReadAsync(buf, 0, buf.Length);
if (writer.Length == 0)
{
Log.Trace($"Got first part: {item.Name} - {item.Id} in {start.ElapsedMilliseconds}");
}
await writer.WriteAsync(buf, 0, red);
uncommitedSize += red;
if (uncommitedSize <= commitSize)
{
continue;
}
uncommitedSize = 0;
await writer.FlushAsync();
downloader.Downloaded = writer.Length;
}while (red > 0);
}
await writer.FlushAsync();
downloader.Downloaded = writer.Length;
}
Log.Trace($"Finished download: {item.Name} - {item.Id}");
OnDownloaded?.Invoke(item);
BoschHelper.Decrypt(downloader.Path);
if (access.TryAdd(
item.Id,
new CacheEntry {
Id = item.Id, AccessTime = DateTime.UtcNow, Length = item.Length
}))
{
TotalSizeIncrease(item.Length);
}
if (TotalSize > CacheSize)
{
var task = cleanSizeWorker.Run(TotalSize - CacheSize);
}
if (start.ElapsedMilliseconds > 29000)
{
Log.Warn($"Downloading {item.Path} took: {start.ElapsedMilliseconds}");
}
}
catch (Exception ex)
{
Log.ErrorTrace($"Download failed: {item.Name} - {item.Id}\r\n{ex}");
await downloader.Failed();
OnDownloadFailed?.Invoke(item);
}
finally
{
lock (DownloadersLock)
{
Downloaders.Remove(item.Path);
}
}
}