public async Task <bool> SaveAsync(T objectGraph)
{
if (Equals(objectGraph, null))
{
return(false);
}
//create a seperate file to write to
//so if we crash in the middle of this, we should not have corrupted the original file
IFile file = await _folder.CreateFileAsync(_filename, CreationCollisionOption.GenerateUniqueName);
bool createdUniqueFile = file.Name != _filename;
_logger.DebugEx("Created file " + file.Name);
//TODOlater file add optional transacted writes to PCLStorage
using (var stream = await file.OpenAsync(FileAccess.ReadAndWrite))
{
await _serializer.SerializeAsync(stream, objectGraph);
}
/*
* using (StorageStreamTransaction streamTx = await file.OpenTransactedWriteAsync())
* {
* using (Stream outStream = streamTx.Stream.AsStreamForWrite())
* {
* await _serializer.SerializeAsync(outStream, objectGraph);
* }
* await streamTx.CommitAsync();
* }
*/
if (createdUniqueFile)
{
//rename files
IFile existingFile = await _folder.CreateFileAsync(_filename, CreationCollisionOption.OpenIfExists);
_logger.DebugEx("Created or opened file: " + _filename);
_logger.DebugEx("Moving file " + existingFile.Name + ", to backup ");
await existingFile.MoveAsync(
PortablePath.Combine(_folder.Path, GetBackupFileName(_filename)),
NameCollisionOption.ReplaceExisting);
_logger.DebugEx("Moving file " + file.Name + ", to " + _filename);
await file.MoveAsync(
PortablePath.Combine(_folder.Path, _filename),
NameCollisionOption.ReplaceExisting);
}
return(true);
}
