public void UpdateStatus(FileStatus status)
{
Status = status;
DatabaseClient.UpdateFileStatus(ToDto());
}
public async Task DownloadAsync()
{
if (status == FileStatus.Finished)
{
throw new InvalidOperationException();
}
if (status == FileStatus.Error)
{
Status = FileStatus.NotDownloaded;
}
try
{
var dir = Path.GetDirectoryName(FullFileName);
Directory.CreateDirectory(dir);
if (status == FileStatus.NotDownloaded)
{
File.WriteAllText(FullFileName + ".downloading", string.Empty);
UpdateStatus(FileStatus.Downloading);
var numChunks = (Size + WebServiceClient.CHUNKSIZE - 1) / WebServiceClient.CHUNKSIZE;
for (var i = 0; i < numChunks; i++)
{
Chunks.Add(new ChunkModel
{
FileId = Id,
Id = i,
Status = ChunkStatus.New,
});
}
DatabaseClient.SaveChunks(Chunks);
}
else if (status == FileStatus.Downloading)
{
}
using (var fs = new FileStream(FullFileName + ".downloading", FileMode.OpenOrCreate, FileAccess.Write, FileShare.Read, 4096, FileOptions.Asynchronous | FileOptions.RandomAccess))
{
var tasks = Chunks.Where(ch => ch.Status == ChunkStatus.New).Select(ch => WebServiceClient.GetChunk(this, ch.Id));
var working = new List <Task <Tuple <int, byte[]> > >();
foreach (var task in tasks)
{
if (working.Count < 5)
{
working.Add(task);
}
else
{
var finished = await Task.WhenAny(working);
working.Remove(finished);
working.Add(task);
await ContinueWith(await finished);
}
}
while (working.Count > 0)
{
var finished = await Task.WhenAny(working);
working.Remove(finished);
await ContinueWith(await finished);
}
async Task ContinueWith(Tuple <int, byte[]> finished)
{
fs.Seek(WebServiceClient.CHUNKSIZE * finished.Item1, SeekOrigin.Begin);
await fs.WriteAsync(finished.Item2, 0, finished.Item2.Length);
Chunks[finished.Item1].UpdateStatus(ChunkStatus.Done);
FinishedSize += finished.Item2.Length;
}
}
DatabaseClient.DeleteChunks(Chunks);
if (Md5.Equals(Util.GetFileMd5(FullFileName + ".downloading"), StringComparison.InvariantCultureIgnoreCase))
{
UpdateStatus(FileStatus.Finished);
}
else
{
UpdateStatus(FileStatus.Error);
}
}
catch (WebException)
{
Status = FileStatus.Error;
}
}
public void UpdateStatus(ChunkStatus status)
{
Status = status;
DatabaseClient.UpdateChunk(this);
}