Felipe Contreras venit, vidit, dixit 27.04.2009 01:38: > 2009/4/27 Björn Steinbrink <B.Steinbrink@xxxxxx>: >> On 2009.04.24 20:48:57 -0400, David Abrahams wrote: >>> >>> On Apr 24, 2009, at 8:01 PM, Michael Witten wrote: >>> >>>>> What's wrong with just calling the object name "object name"? >>>> >>>> What's wrong with calling the object address "object address"? >>> >>> Neither captures the connection to the object's contents. I think >>> "value ID" would be closer, but it's probably too horrible. >> >> I think I asked this in another mail, but I'm quite tired, so just to >> make sure: What do you mean by "value"? I might be weird (I'm not a >> native speaker, so I probably make funny and wrong connotations from >> time to time), but while I can accept "content" to include the type and >> size of the object, the term "value" makes me want to exclude those >> pieces of meta data. So "value" somehow feels wrong to me, as the hash >> covers those two fields. > > Just to summarize. > > Do you agree that SHA-1 is not the proper term to choose? > > Do you agree that either 'id' or 'hash' would work fine? > > Personally I think there's an advantage of choosing 'hash'; if we pick > 'id' then the user might think that he can change the contents of the > object while keeping the same id, if we pick 'hash' then it's obvious > the 'id' is tied to the content and why. > Apparently a branch of that thread touched the "[PATCH 0/2] Unify use of [sha,SHA][,-]1", so I'll do a cc merge, feeling entitled to summarize the latter: - There are two SHA-1ish things we talk about: the SHA-1 hash algorithm/function on the one hand and git object names on the other hand. - The object name of a file is not the SHA-1 checksum of its contents: That's more or less obvious because there are no files in git, only objects. The object name is the SHA-1 of a representation of an object (which, for blobs, consists of header + content). - There seemed to be an implicit claim that the Doc uses SHA-1 for the algorithm and sha1/SHA1 for the object name. That's not founded by facts (see below) and is not practical. - The glossary defines SHA1 to be equivalent to the object name and does not mention any other spelling. The stats (line counts for simplicity) and facts for Documentation/ are: SHA-1: 56 Used exclusively for the object name. SHA1: 73 Used mostly for the object name, but also for the patch-id (SHA-1 checksum of patch), in the tutorial, and pack-format, i.e. in places where the actual hash algorithm/function is mentioned. sha1: 102 Used all over the place, mostly for the object name and when quoting from the source. I don't think it's used for the hash algorithm/function. sha-1: 0 So, the current confusion is mostly due to the fact that 3 different names are used for the same thing (object name) and to a much lesser degree to the fact that the same name (SHA1) is used for 2 different things (hash algorithm/function vs. object name). My patch tried to lessen the confusion by naming one thing by 1 name only (SHA-1). It continued the tradition of identifying the object name with the hash algorithm which is used in forming that name. I don't think it matters much (confusion-wise) which one we choose from those 3, it would be easy to rewrite the patch to use SHA1 or sha1 instead of SHA-1 (and I'd be willing to), but consistently so. An alternative patch would substitute most occurrences of the above by X, X being the future term for "object name" to be agreed upon, and go for say SHA-1 at the very few places where the actual algorithm is mentioned. I just don't want to bet on that agreement and patch happening. Michael -- 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