private void DecodingThread(CancellationToken token)
{
for (; ;)
{
if (token.WaitHandle.WaitOne(1000))
{
return;
}
DownloadItemInfo item = null;
lock (_lockObject)
{
item = CollectionUtils.Unite(_volatileDownloadItemInfoManager, _downloadItemInfoManager)
.Where(n => !_workingItems.Contains(n))
.Where(n => n.State == DownloadState.Decoding || n.State == DownloadState.ParityDecoding)
.OrderBy(n => (n.Depth == n.Metadata.Depth) ? 0 : 1)
.OrderBy(n => (n.State == DownloadState.Decoding) ? 0 : 1)
.FirstOrDefault();
if (item != null)
{
_workingItems.Add(item);
}
}
if (item == null)
{
continue;
}
try
{
if ((item.Depth == 0 && !_cacheManager.Contains(item.Metadata.Hash)) ||
(item.Depth > 0 && !item.Index.Groups.All(n => _existManager.GetCount(n, true) >= n.Hashes.Count() / 2)))
{
item.State = DownloadState.Downloading;
}
else
{
var hashes = new HashCollection();
var totalHashes = new HashCollection();
if (item.Depth == 0)
{
hashes.Add(item.Metadata.Hash);
totalHashes.Add(item.Metadata.Hash);
}
else
{
try
{
foreach (var group in item.Index.Groups)
{
if (item.State == DownloadState.Error)
{
throw new OperationCanceledException();
}
hashes.AddRange(_cacheManager.ParityDecoding(group, token).Result);
}
totalHashes.AddRange(item.Index.Groups.SelectMany(n => n.Hashes));
}
catch (OperationCanceledException)
{
continue;
}
item.State = DownloadState.Decoding;
}
if (item.Depth < item.Metadata.Depth)
{
Index index;
try
{
using (var stream = _cacheManager.Decoding(hashes))
using (var progressStream = new ProgressStream(stream, null, 1024 * 1024, token))
{
if (item.State == DownloadState.Error)
{
throw new OperationCanceledException();
}
if (progressStream.Length > item.MaxLength)
{
throw new ArgumentException();
}
index = Index.Import(progressStream, _bufferManager);
}
}
catch (OperationCanceledException)
{
continue;
}
lock (_lockObject)
{
if (item.Path != null)
{
_protectCacheInfoManager.Add(new ProtectedCacheInfo(DateTime.UtcNow, totalHashes));
}
this.CheckState(index);
this.UncheckState(item.Index);
item.Index = index;
item.Depth++;
item.State = DownloadState.Downloading;
}
}
else
{
if (item.Path != null)
{
string filePath = null;
try
{
token.ThrowIfCancellationRequested();
string targetPath;
if (Path.IsPathRooted(item.Path))
{
targetPath = item.Path;
}
else
{
targetPath = Path.GetFullPath(Path.Combine(_basePath, item.Path));
// ディレクトリトラバーサル対策
if (!targetPath.StartsWith(Path.GetFullPath(_basePath)))
{
targetPath = Path.GetFullPath(Path.Combine(_basePath, Path.GetFileName(item.Path)));
}
}
Directory.CreateDirectory(Path.GetDirectoryName(targetPath));
using (var inStream = _cacheManager.Decoding(hashes))
using (var outStream = DownloadManager.GetUniqueFileStream(targetPath + ".tmp"))
using (var safeBuffer = _bufferManager.CreateSafeBuffer(1024 * 1024))
{
filePath = outStream.Name;
int readLength;
while ((readLength = inStream.Read(safeBuffer.Value, 0, safeBuffer.Value.Length)) > 0)
{
if (item.State == DownloadState.Error)
{
throw new OperationCanceledException();
}
token.ThrowIfCancellationRequested();
outStream.Write(safeBuffer.Value, 0, readLength);
}
}
File.Move(filePath, DownloadManager.GetUniqueFilePath(targetPath));
}
catch (OperationCanceledException)
{
if (filePath != null)
{
File.Delete(filePath);
}
continue;
}
}
lock (_lockObject)
{
if (item.Path != null)
{
_protectCacheInfoManager.Add(new ProtectedCacheInfo(DateTime.UtcNow, totalHashes));
}
item.ResultHashes.AddRange(hashes);
item.State = DownloadState.Completed;
}
}
}
}
catch (Exception e)
{
item.State = DownloadState.Error;
Log.Error(e);
}
finally
{
_workingItems.Remove(item);
}
}
}