append to the file should it already exists, otherwise create it.

create a non-existing file and write to it.

if the file already exists, truncate it to 0 bytes prior to writing.

UnimplementedDataServiceServer can be embedded to have forward compatible implementations.

UnimplementedFileServiceServer can be embedded to have forward compatible implementations.

UnimplementedMetadataServiceServer can be embedded to have forward compatible implementations.

key is send as part of header.

DataServiceClient is the client API for DataService service.

DataServiceServer is the server API for DataService service.

FileServiceClient is the client API for FileService service.

FileServiceServer is the server API for FileService service.

MetadataServiceClient is the client API for MetadataService service.

MetadataServiceServer is the server API for MetadataService service.