Hey Greg, On Mar 15, 2012, at 2:49 PM, Greg Farnum wrote:
>> java: use protected getdnames(int bufSize) > > But you left it public in CephMount? Fixed. The original call chain was CephDirectory->CephMount->CephProxy, which meant that CephDirectory and CephMount each had similar methods. It's unclear what benefit putting them into CephMount had since a CephDirectory object is always required. Anyway, I removed that redundancy to fix this. >> java: document CPP macro-foo > > Looks like a couple of my line notes are still left. Am I just confused in my > opinions? :( Nope, I screwed up the email-to-todos. > There's no note that set_default_file_replication is a no-op in its > documentation. Fixed. > closedir does not explain what happens to the CephDirectory state under > success and failure. Honestly I don't even know what you're supposed to do > with it if it fails, and why the code resets it to PREPARING instead of a > CLOSED state is unclear to me. :) The motivation for closedir:success->PREPARING is that technically the CephDirectory object could be re-opened (any clean-up associated with the underlying struct ceph_dir_result is complete after closedir). On failure it remains OPEN to prevent it from being re-opened. This is the same semantics used for CephMount (re-mount is allowed only after a shutdown). After some thought, I think there is a pretty simple way to avoid this whole state-machine mess by enforcing state with the API and exceptions. For example, CephDirectory:open should not exist to avoid even asking the question 'can a CephDirectory be re-opened'. Valid states for CephDirectory can be enforced by throwing an exception in CephMount:opendir (preventing CephDirectory from being created), and some sane, documented semantics for a closed CephDirectory can be added, such as returning null from CephDirectory:getdnames. A similar approach to that of the Java 6 IO API can be taken for files in Ceph by using a CephFile (ops over paths), CephFileInputStream, and CephFileOutputStream (for opened files). I had originally not taken this path, instead valuing a close 1-1 mapping between Java and libcephfs, but now I'm reconsidering. Do you have any thoughts? > If possible for my reviewing sanity, it'd be nice if I could access the > changes you've made to things instead of trying to figure out how to run > diffs against changing filenames and stuff, too, but that's just a wish. Sorry about this! I /really/ kicked myself after pushing that rebase for the same reason... :( Thanks, - Noah-- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
