hashed truncated n-tuple tree storage hierarchy spec

[pwinckles]

This is an initial pass at a storage root extension that maps OCFL object identifiers to object root paths by first hashing the identifier. It is similar to @neilsjefferies fixed-length mapping.

I understand that the extension format is still being tweaked and I made some assumptions here about a few things that have yet to be formalized.

[awoods]

Looks good.

[pwinckles]

Looks good.

Thanks for the review @awoods! Do you have an opinion about whether caseMapping should be parameterized or if it should always be lowercase?

[awoods]

@pwinckles : Given the similarities with the related extensions pr-19, many of the comments there likely apply here as well. Would you mind giving it a look at your leisure?

[pwinckles]

@pwinckles : Given the similarities with the related extensions pr-19, many of the comments there likely apply here as well. Would you mind giving it a look at your leisure?

Yep, thanks for the thorough read @awoods!

One note about the json format. I still think that using a top level key is a bad idea, and it would be nice if there was more clarity on the reasoning in the issue.

[rosy1280]

@pwinckles if you've addressed the changes, can you dismiss stale reviews and re-request them? also it looks like there are some conflicts can you resolve those?

[zimeon]

Reads well to me

[pwinckles]

Updates:

• Parameters are now defined using constraints
• Object IDs are specified as being UTF-8 encoded
• The location and name of the extension config file is updated to reflect spec changes
• Added a JSON Schema file

[awoods]

Given the requirement that the hex-encoded strings be lowercased, maybe it would useful to add the same language here as in @bcail 's PR:
https://github.com/OCFL/extensions/pull/19/files#diff-febde49a93addbd21a93eb858fa085161bc456d0acb38f4ef992e5c88f79d9e0R16

https://github.com/OCFL/extensions/pull/19/files#diff-febde49a93addbd21a93eb858fa085161bc456d0acb38f4ef992e5c88f79d9e0R16

[awoods]

As long as you considered it.

Now to verify the json-schema...

[pwinckles]

I'll rewrite it as "encoded as lowercase hex strings"

[pwinckles]

@awoods updated the language and added a link to the json schema document.

I also ran the schema against all of the examples in the document using this site: https://www.jsonschemavalidator.net/

[zimeon]

Now https://ocfl.github.io/extensions/0004-hashed-n-tuple-storage-layout.html