Re: [PATCH v2 03/10] refs: add array of ref namespaces

[Derrick Stolee <derrickstolee@github.com>]

On 8/3/2022 2:16 AM, Junio C Hamano wrote:
> "Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
>> +	[NAMESPACE_REPLACE] = {
>> +		/*
>> +		 * This namespace allows Git to act as if one object ID
>> +		 * points to the content of another. Unlike the other
>> +		 * ref namespaces, this one can be changed by the
>> +		 * GIT_REPLACE_REF_BASE environment variable. This
>> +		 * .namespace value will be overwritten in setup_git_env().
>> +		 */
> 
> Thanks---it is a shame that we have unnecessary flexibility that
> requires us to have this code.
> 
>> +		.ref = "refs/replace/",
>> +		.decoration = DECORATION_GRAFTED,
>> +	},
>> +	[NAMESPACE_NOTES] = {
>> +		/*
>> +		 * The refs/notes/commit ref points to the tip of a
>> +		 * parallel commit history that adds metadata to commits
>> +		 * in the normal history. This branch can be overwritten
> 
> This is not "branch" but is a ref.

Thanks!

>> +		 * by the core.notesRef config variable or the
>> +		 * GIT_NOTES_REFS environment variable.
>> +		 */
>> +		.ref = "refs/notes/commit",
>> +		.exact = 1,
> 
> Allowing just "the default" to be replaced by another "custom
> default" is a good start, but we probably want to support more than
> one notes refs, to parallel how "struct display_notes_opt" has
> extra_notes_refs to allow multiple notes refs to decorate objects.

I imagine that if we allowed multiple notes refs, then we would need
to use a ref prefix to define a namespace. If we relaxed that, then
we could modify this as follows:

	.ref = "refs/notes/",
	/* .exact = 0, */

(The comment is included just to illustrate the change.)

There is additional logic in init_notes() to track multiple notes
refs, but the change to things that use ref_namespaces would be
minimal.

Thanks,
-Stolee