Re: [PATCH 08/17] refs: generalize `refs_for_each_namespaced_ref()`

> The function `refs_for_each_namespaced_ref()` iterates through all
> references that are part of the current ref namespace. This namespace
> can be configured by setting the `GIT_NAMESPACE` environment variable
> and is then retrieved by calling `get_git_namespace()`.
>
> If a namespace is configured, then we:
>
>   - Obviously only yield refs that exist in this namespace.
>
>   - Rewrite exclude patterns so that they work for the given namespace,
>     if any namespace is currently configured.
>
> Port this logic to `refs_for_each_ref_ext()` by adding a new `namespace`
> field to the options structure. This gives callers more flexibility as
> they can decide by themselves whether they want to use the globally
> configured or an arbitrary other namespace.
>
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>  refs.c | 47 +++++++++++++++++++++++++++++------------------
>  refs.h |  6 ++++++
>  2 files changed, 35 insertions(+), 18 deletions(-)
>
> diff --git a/refs.c b/refs.c
> index ac34bbe6c1..99994879d9 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -1845,9 +1845,13 @@ int refs_for_each_ref_ext(struct ref_store *refs,
>  			  refs_for_each_cb cb, void *cb_data,
>  			  const struct refs_for_each_ref_options *opts)
>  {
> +	struct strvec namespaced_exclude_patterns = STRVEC_INIT;
> +	struct strbuf namespaced_prefix = STRBUF_INIT;
>  	struct strbuf real_pattern = STRBUF_INIT;
>  	struct for_each_ref_filter filter;
>  	struct ref_iterator *iter;
> +	const char **exclude_patterns;
> +	const char *prefix;
>  	int ret;
>
>  	if (!refs)
> @@ -1876,11 +1880,29 @@ int refs_for_each_ref_ext(struct ref_store *refs,
>  		cb_data = &filter;
>  	}
>
> -	iter = refs_ref_iterator_begin(refs, opts->prefix ? opts->prefix : "",
> -				       opts->exclude_patterns,
> +	if (opts->namespace) {
> +		strbuf_addstr(&namespaced_prefix, opts->namespace);
> +		if (opts->prefix)
> +			strbuf_addstr(&namespaced_prefix, opts->prefix);
> +		else
> +			strbuf_addstr(&namespaced_prefix, "refs/");
> +

> +		prefix = namespaced_prefix.buf;
> +		exclude_patterns = get_namespaced_exclude_patterns(opts->exclude_patterns,
> +								   opts->namespace,
> +								   &namespaced_exclude_patterns);
> +	} else {
> +		prefix = opts->prefix ? opts->prefix : "";
> +		exclude_patterns = opts->exclude_patterns;
> +	}
> +
> +	iter = refs_ref_iterator_begin(refs, prefix, exclude_patterns,
>  				       opts->trim_prefix, opts->flags);
>
>  	ret = do_for_each_ref_iterator(iter, cb, cb_data);
> +
> +	strvec_clear(&namespaced_exclude_patterns);
> +	strbuf_release(&namespaced_prefix);
>  	strbuf_release(&real_pattern);
>  	return ret;
>  }
> @@ -1927,22 +1949,11 @@ int refs_for_each_namespaced_ref(struct ref_store *refs,
>  				 const char **exclude_patterns,
>  				 refs_for_each_cb cb, void *cb_data)
>  {
> -	struct refs_for_each_ref_options opts = { 0 };
> -	struct strvec namespaced_exclude_patterns = STRVEC_INIT;
> -	struct strbuf prefix = STRBUF_INIT;
> -	int ret;
> -
> -	opts.exclude_patterns = get_namespaced_exclude_patterns(exclude_patterns,
> -								get_git_namespace(),
> -								&namespaced_exclude_patterns);
> -	strbuf_addf(&prefix, "%srefs/", get_git_namespace());
> -	opts.prefix = prefix.buf;
> -
> -	ret = refs_for_each_ref_ext(refs, cb, cb_data, &opts);
> -
> -	strvec_clear(&namespaced_exclude_patterns);
> -	strbuf_release(&prefix);
> -	return ret;
> +	struct refs_for_each_ref_options opts = {
> +		.exclude_patterns = exclude_patterns,
> +		.namespace = get_git_namespace(),
> +	};
> +	return refs_for_each_ref_ext(refs, cb, cb_data, &opts);
>  }
>
>  int refs_for_each_rawref(struct ref_store *refs, refs_for_each_cb fn, void *cb_data)
> diff --git a/refs.h b/refs.h
> index a66dbf3865..2bde60aa0e 100644
> --- a/refs.h
> +++ b/refs.h
> @@ -468,6 +468,12 @@ struct refs_for_each_ref_options {
>  	 */
>  	const char *pattern;
>
> +	/*
> +	 * If set, only yield refs part of the configured namespace. Exclude
> +	 * patterns will be rewritten to apply to the namespace.
> +	 */
> +	const char *namespace;

> +
>  	/*
>  	 * Exclude any references that match any of these patterns on a
>  	 * best-effort basis. The caller needs to be prepared for the exclude
>
> --
> 2.53.0.414.gf7e9f6c205.dirty