/// <summary>
/// Requests that an asset be fetched from the folder tree.
/// </summary>
/// <returns><c>true</c>, if get asset was found, <c>false</c> otherwise.</returns>
/// <param name="assetId">Asset identifier.</param>
/// <param name="asset">The resulting asset.</param>
public bool TryGetAsset(Guid assetId, out StratusAsset asset)
{
if (!_config.LocalStorageEnabled)
{
asset = null;
return(false);
}
// Convert the UUID into a path.
var path = UuidToLocalPath(assetId);
if (_assetsBeingWritten.TryGetValue(path, out asset))
{
LOG.Log(Logging.LogLevel.Debug, () => $"Attempted to read an asset from local storage, but another thread is writing it. Shortcutting read of {path}");
// Asset is currently being pushed to disk, so might as well return it now since I have it in memory.
return(true);
}
// Attempt to read and return that file. This needs to handle happening from multiple threads in case a given asset is read from multiple threads at the same time.
var removeFile = false;
try {
using (var stream = File.Open(path, FileMode.Open, FileAccess.Read, FileShare.Read)) {
asset = Serializer.Deserialize <StratusAsset>(stream);
}
return(true);
}
catch (PathTooLongException e) {
_config.DisableLocalStorage();
LOG.Log(Logging.LogLevel.Error, () => "[ASSET_READER] Attempted to read a locally stored asset, but the path was too long for the filesystem. Disabling local storage.", e);
}
catch (DirectoryNotFoundException) {
// Kinda expected if that's an item that's not been stored locally.
}
catch (UnauthorizedAccessException e) {
_config.DisableLocalStorage();
LOG.Log(Logging.LogLevel.Error, () => "[ASSET_READER] Attempted to read a locally stored asset, but this user is not allowed access. Disabling local storage.", e);
}
catch (FileNotFoundException) {
// Kinda expected if that's an item that's not been stored locally.
}
catch (IOException e) {
// This could be temporary.
LOG.Log(Logging.LogLevel.Warn, () => "[ASSET_READER] Attempted to read a locally stored asset, but there was an IO error.", e);
}
catch (ProtoException e) {
LOG.Log(Logging.LogLevel.Warn, () => $"[ASSET_READER] Attempted to read a locally stored asset, but there was a protobuf decoding error. Removing the offending local storage file as it is either corrupt or from an older installation: {path}", e);
removeFile = true;
}
if (removeFile)
{
try {
File.Delete(path);
// TODO: at some point the folder tree should be checked for folders that should be removed.
}
#pragma warning disable RECS0022 // A catch clause that catches System.Exception and has an empty body
catch {
// If there's a delete failure it'll just keep trying as the asset is called for again.
}
#pragma warning restore RECS0022 // A catch clause that catches System.Exception and has an empty body
}
// Nope, no ability to get the asset.
asset = null;
return(false);
}
