repo: Add `git_repository__cleanup`

include/git2/sys/repository.h

@@ -27,6 +27,20 @@ GIT_BEGIN_DECL
  */
 GIT_EXTERN(int) git_repository_new(git_repository **out);
 
+
+/**
+ * Reset all the internal state in a repository.
+ *
+ * This will free all the mapped memory and internal objects
+ * of the repository and leave it in a "blank" state.
+ *
+ * There's no need to call this function directly unless you're
+ * trying to aggressively cleanup the repo before its
+ * deallocation. `git_repository_free` already performs this operation
+ * before deallocation the repo.
+ */
+GIT_EXTERN(void) git_repository__cleanup(git_repository *repo);
+
 /**
  * Set the configuration file for this repository
  *

src/cache.c

@@ -77,6 +77,9 @@ static void clear_cache(git_cache *cache)
 {
 	git_cached_obj *evict = NULL;
 
+	if (kh_size(cache->map) == 0)
+		return;
+
 	kh_foreach_value(cache->map, evict, {
 		git_cached_obj_decref(evict);
 	});

src/cache.h

@@ -42,6 +42,7 @@ int git_cache_set_max_object_size(git_otype type, size_t size);
 
 int git_cache_init(git_cache *cache);
 void git_cache_free(git_cache *cache);
+void git_cache_clear(git_cache *cache);
 
 void *git_cache_store_raw(git_cache *cache, git_odb_object *entry);
 void *git_cache_store_parsed(git_cache *cache, git_object *entry);

src/repository.c

@@ -86,19 +86,28 @@ static void set_index(git_repository *repo, git_index *index)
 	}
 }
 
-void git_repository_free(git_repository *repo)
+void git_repository__cleanup(git_repository *repo)
 {
-	if (repo == NULL)
-		return;
+	assert(repo);
 
-	git_cache_free(&repo->objects);
+	git_cache_clear(&repo->objects);
 	git_attr_cache_flush(repo);
-	git_submodule_config_free(repo);
 
 	set_config(repo, NULL);
 	set_index(repo, NULL);
 	set_odb(repo, NULL);
 	set_refdb(repo, NULL);
+}
+
+void git_repository_free(git_repository *repo)
+{
+	if (repo == NULL)
+		return;
+
+	git_repository__cleanup(repo);
+
+	git_cache_free(&repo->objects);
+	git_submodule_config_free(repo);
 
 	git__free(repo->path_repository);
 	git__free(repo->workdir);