/// <summary>
/// Gets an existing FileReference or creates a new one with the specified data and metadata. This method
/// filters out duplicates on two levels:
/// 1) The same data is not stored in the file system twice. Instead multiple FileReference instances
/// are given the same FileData instance (which corresponds to one physical file being stored).
/// 2) The same metadata is not stored in the FileReference table twice. If the metadata matches exactly
/// this method returns the existing FileReference.
/// </summary>
private FileReference CreateFileReference(FileType fileType, string fileName, string defaultContentType, int contentLength, byte[] contentHash, out bool isExistingFile)
{
fileName = Path.GetFileName(fileName); // Strip the path, if any.
var mediaType = MediaType.GetMediaTypeFromExtension(Path.GetExtension(fileName), defaultContentType);
// First look for an existing file reference.
var fileReference = _repository.GetFileReference(fileType, fileName, mediaType, contentLength, contentHash);
if (fileReference != null)
{
isExistingFile = true;
return(fileReference);
}
// Look for data corresponding to the file.
var fileData = _repository.GetFileData(fileType, contentLength, contentHash);
if (fileData == null)
{
// Need to create and save.
isExistingFile = false;
fileData = new FileData
{
Id = Guid.NewGuid(),
FileType = fileType,
FileExtension = Path.GetExtension(fileName).ToLower(),
ContentLength = contentLength,
ContentHash = contentHash
};
_repository.CreateFileData(fileData);
}
else
{
isExistingFile = true;
}
fileReference = new FileReference
{
Id = Guid.NewGuid(),
CreatedTime = DateTime.Now,
MediaType = mediaType,
FileName = fileName,
FileData = fileData
};
_repository.CreateFileReference(fileReference);
return(fileReference);
}
