| [alf-dev] SCM Workspace discussion |
SCM usually involves a client that controls some local storage. Tools operate on this local storage. In ALF, the service flow may initiate a get (fex) but it doesn't control any local storage and we do not want to stream file content through BPEL. We need a workspace service that can provide storage for the get (fex) that the SCM can be instructed to get to and tools can be instructed to access to obtain the file content. There are a number of models for this.
A) ALF specifies a standard SCM client service. Participating SCMs implement this service around their existing client. This client service must run in a place where it can materialize files to a file system that can be accessed by a particular tool (build system fex). ALF can call this service to perform a get for a build tool.
B1) ALF provides a common Storage service that provides a variety of storage access methods (file share, ftp, other). Alf will ask the Storage service to perform the get. The Storage service will wrap SCM clients (possibly by providing a plugin service provider interface mode) to perform the actuall get. Tools would be told of the existence of the storage service (configuration or operation argument) and be able to negotiate access to the file content using their prefered access method.
B2) as B1 but the SCM service would be instructed to initiate the get and be given the Storage service service url as a destination. The SCM and the Storeage service would perform the file transfer using some common protocol (TBD). (sort of a remoted plugin)
B3) as B1 but SCMs provide the "common service" and provide a variety of access methods directly. There is no plugin Model since each implementation is specific to tthe SCM
C) Other models/ideas I haven't mentioned
Tim Buss,
Serena