list-objects-filter-options: make filter_spec a string_list

Make the filter_spec string a string_list rather than a raw C string.
The list of strings must be concatted together to make a complete
filter_spec. A future patch will use this capability to build "combine:"
filter specs gradually.

A strbuf would seem to be a more natural choice for this object, but it
unfortunately requires initialization besides just zero'ing out the
memory.  This results in all container structs, and all containers of
those structs, etc., to also require initialization. Initializing them
all would be more cumbersome that simply using a string_list, which
behaves properly when its contents are zero'd.

For the purposes of code simplification, change behavior in how filter
specs are conveyed over the protocol: do not normalize the tree:<depth>
filter specs since there should be no server in existence that supports
tree:# but not tree:#k etc.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 34 insertions, 16 deletions

diff --git a/list-objects-filter-options.c b/list-objects-filter-options.c
index 5fe2814841..01c0f13346 100644
--- a/list-objects-filter-options.c
+++ b/list-objects-filter-options.c
@@ -184,7 +184,7 @@ int parse_list_objects_filter(struct list_objects_filter_options *filter_options
 	struct strbuf buf = STRBUF_INIT;
 	if (filter_options->choice)
 		die(_("multiple filter-specs cannot be combined"));
-	filter_options->filter_spec = strdup(arg);
+	string_list_append(&filter_options->filter_spec, xstrdup(arg));
 	if (gently_parse_list_objects_filter(filter_options, arg, &buf))
 		die("%s", buf.buf);
 	return 0;
@@ -203,19 +203,36 @@ int opt_parse_list_objects_filter(const struct option *opt,
 	return parse_list_objects_filter(filter_options, arg);
 }
 
-void expand_list_objects_filter_spec(
-	const struct list_objects_filter_options *filter,
-	struct strbuf *expanded_spec)
+const char *list_objects_filter_spec(struct list_objects_filter_options *filter)
 {
-	strbuf_init(expanded_spec, strlen(filter->filter_spec));
-	if (filter->choice == LOFC_BLOB_LIMIT)
-		strbuf_addf(expanded_spec, "blob:limit=%lu",
+	if (!filter->filter_spec.nr)
+		BUG("no filter_spec available for this filter");
+	if (filter->filter_spec.nr != 1) {
+		struct strbuf concatted = STRBUF_INIT;
+		strbuf_add_separated_string_list(
+			&concatted, "", &filter->filter_spec);
+		string_list_clear(&filter->filter_spec, /*free_util=*/0);
+		string_list_append(
+			&filter->filter_spec, strbuf_detach(&concatted, NULL));
+	}
+
+	return filter->filter_spec.items[0].string;
+}
+
+const char *expand_list_objects_filter_spec(
+	struct list_objects_filter_options *filter)
+{
+	if (filter->choice == LOFC_BLOB_LIMIT) {
+		struct strbuf expanded_spec = STRBUF_INIT;
+		strbuf_addf(&expanded_spec, "blob:limit=%lu",
 			    filter->blob_limit_value);
-	else if (filter->choice == LOFC_TREE_DEPTH)
-		strbuf_addf(expanded_spec, "tree:%lu",
-			    filter->tree_exclude_depth);
-	else
-		strbuf_addstr(expanded_spec, filter->filter_spec);
+		string_list_clear(&filter->filter_spec, /*free_util=*/0);
+		string_list_append(
+			&filter->filter_spec,
+			strbuf_detach(&expanded_spec, NULL));
+	}
+
+	return list_objects_filter_spec(filter);
 }
 
 void list_objects_filter_release(
@@ -225,7 +242,7 @@ void list_objects_filter_release(
 
 	if (!filter_options)
 		return;
-	free(filter_options->filter_spec);
+	string_list_clear(&filter_options->filter_spec, /*free_util=*/0);
 	free(filter_options->sparse_oid_value);
 	for (sub = 0; sub < filter_options->sub_nr; sub++)
 		list_objects_filter_release(&filter_options->sub[sub]);
@@ -235,7 +252,7 @@ void list_objects_filter_release(
 
 void partial_clone_register(
 	const char *remote,
-	const struct list_objects_filter_options *filter_options)
+	struct list_objects_filter_options *filter_options)
 {
 	/*
 	 * Record the name of the partial clone remote in the
@@ -258,7 +275,7 @@ void partial_clone_register(
 	 * the default for subsequent fetches from this remote.
 	 */
 	core_partial_clone_filter_default =
-		xstrdup(filter_options->filter_spec);
+		xstrdup(expand_list_objects_filter_spec(filter_options));
 	git_config_set("core.partialclonefilter",
 		       core_partial_clone_filter_default);
 }
@@ -274,7 +291,8 @@ void partial_clone_get_default_filter_spec(
 	if (!core_partial_clone_filter_default)
 		return;
 
-	filter_options->filter_spec = strdup(core_partial_clone_filter_default);
+	string_list_append(&filter_options->filter_spec,
+			   core_partial_clone_filter_default);
 	gently_parse_list_objects_filter(filter_options,
 					 core_partial_clone_filter_default,
 					 &errbuf);