Josh, I'm cc:'ing the main list with this one as well, as I think it falls into the scope of discussions of wider interest than the rfc- and implementation-specific discussions that (I envisaged would) happen on the gittorrent list. On Sun, 2008-07-27 at 23:53 -0400, Joshua Roys wrote: > Here's some terms, as best as I understand them. > > The *Commit Reel* is a sequence of objects between two reference points, > sorted in a deterministic fashion. The two reference points are > *Reference* objects, or a signed tag containing a collection of git refs > (similar to the output from `git show-ref`). Yes, that's right. We have the two slightly ambiguous terms, "refs", which mean the same thing as the rest of git, and "References", which are more like .git/packed-refs. Perhaps this is a good time to pick a better name. "Slice" would be an accurate term, though it's certainly tempting to pick another term from the tape taxonomy, such as "Splice"¹ or "Mark"². > Commit reels can also, and generally do, include the objects required > for a specific commit. Yes. The only times where they wouldn't contain all the objects required for the commits within the reel, is when those objects happened to be contained by a previous reel. This is one of the design decisions which I think may be a mistake; a less expensive to calculate definition of a reel would be *all* objects between the starting and ending Reference objects. The current definition requires a hash index of objects in each reel, which must be consulted once for all objects when creating the reel index. > As an example, a commit reel could be the set of objects between the > v2.6.25 and v2.6.26 tags of the Linux kernel. The only thing we would > need added to those tags is the list of heads (and tags) at the time of > the tagging. Correct. It represents all of the changes in a given repository over a period of time. > Those two structures form the basis for two *Peer Wire Protocol* (PWP) > messages, Reels and References. > > Any questions, corrections, or rotten vegetables? No, I think that's all good so far... Cheers, Sam. ¹ - see http://en.wikipedia.org/wiki/Reel-to-reel_audio_tape_recording#Description ² - as used by the old unix "mt", see eg http://docs.sun.com/app/docs/doc/816-0210/6m6nb7mf3?a=view -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
