Add two hash functions specifically for unique-idswip/hughsie/unique-id-hash

3 files changed, 140 insertions, 0 deletions

diff --git a/libappstream-glib/as-self-test.c b/libappstream-glib/as-self-test.c
index bb6b0dc..71b57d7 100644
--- a/libappstream-glib/as-self-test.c
+++ b/libappstream-glib/as-self-test.c
@@ -4864,6 +4864,73 @@ as_test_store_merge_func (void)
 	g_assert_cmpstr (as_app_get_source_file (app2), ==, NULL);
 }
 
+/* shows the unique-id globbing functions at work */
+static void
+as_test_utils_unique_id_hash_func (void)
+{
+	AsApp *found;
+	g_autoptr(AsApp) app = NULL;
+	g_autoptr(GHashTable) hash = NULL;
+
+	/* create new app */
+	app = as_app_new ();
+	as_app_set_id (app, "org.gnome.Software.desktop");
+	as_app_set_branch (app, "master");
+	g_assert_cmpstr (as_app_get_unique_id (app), ==,
+			 "*/*/*/*/org.gnome.Software.desktop/master");
+
+	/* add to hash table using the unique ID as a key */
+	hash = g_hash_table_new (as_utils_unique_id_hash_safe,
+				 as_utils_unique_id_equal_safe);
+	g_hash_table_insert (hash, as_app_get_unique_id (app), app);
+
+	/* get with exact key */
+	found = g_hash_table_lookup (hash, "*/*/*/*/org.gnome.Software.desktop/master");
+	g_assert (found != NULL);
+
+	/* get with more details specified */
+	found = g_hash_table_lookup (hash, "system/*/*/*/org.gnome.Software.desktop/master");
+	g_assert (found != NULL);
+
+	/* get with less details specified */
+	found = g_hash_table_lookup (hash, "*/*/*/*/org.gnome.Software.desktop/*");
+	g_assert (found != NULL);
+
+	/* different key */
+	found = g_hash_table_lookup (hash, "*/*/*/*/gimp.desktop/*");
+	g_assert (found == NULL);
+
+	/* different branch */
+	found = g_hash_table_lookup (hash, "*/*/*/*/org.gnome.Software.desktop/stable");
+	g_assert (found == NULL);
+}
+
+/* shows the as_utils_unique_id_*_safe functions are safe with bare text */
+static void
+as_test_utils_unique_id_hash_safe_func (void)
+{
+	AsApp *found;
+	g_autoptr(AsApp) app = NULL;
+	g_autoptr(GHashTable) hash = NULL;
+
+	/* create new app */
+	app = as_app_new ();
+	as_app_set_id (app, "org.gnome.Software.desktop");
+
+	/* add to hash table using the unique ID as a key */
+	hash = g_hash_table_new (as_utils_unique_id_hash_safe,
+				 as_utils_unique_id_equal_safe);
+	g_hash_table_insert (hash, "dave", app);
+
+	/* get with exact key */
+	found = g_hash_table_lookup (hash, "dave");
+	g_assert (found != NULL);
+
+	/* different key */
+	found = g_hash_table_lookup (hash, "frank");
+	g_assert (found == NULL);
+}
+
 int
 main (int argc, char **argv)
 {
@@ -4873,6 +4940,8 @@ main (int argc, char **argv)
 	g_log_set_fatal_mask (NULL, G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL);
 
 	/* tests go here */
+	g_test_add_func ("/AppStream/utils{unique_id-hash}", as_test_utils_unique_id_hash_func);
+	g_test_add_func ("/AppStream/utils{unique_id-hash2}", as_test_utils_unique_id_hash_safe_func);
 	g_test_add_func ("/AppStream/utils{unique_id}", as_test_utils_unique_id_func);
 	g_test_add_func ("/AppStream/utils{locale-compat}", as_test_utils_locale_compat_func);
 	g_test_add_func ("/AppStream/utils{string-replace}", as_test_utils_string_replace_func);
diff --git a/libappstream-glib/as-utils.c b/libappstream-glib/as-utils.c
index c959677..fbd64ed 100644
--- a/libappstream-glib/as-utils.c
+++ b/libappstream-glib/as-utils.c
@@ -1855,3 +1855,71 @@ as_utils_unique_id_equal (const gchar *unique_id1, const gchar *unique_id2)
 	}
 	return TRUE;
 }
+
+/**
+ * as_utils_unique_id_hash_safe:
+ * @v: a unique ID
+ *
+ * Converts a unique-id to a hash value.
+ *
+ * This function implements the widely used DJB hash on the ID subset of the
+ * unique-id string.
+ *
+ * It can be passed to g_hash_table_new() as the hash_func parameter,
+ * when using non-NULL strings or unique_ids as keys in a GHashTable.
+ *
+ * Returns: a hash value corresponding to the key
+ *
+ * Since: 0.6.2
+ */
+guint
+as_utils_unique_id_hash_safe (gconstpointer v)
+{
+	const gchar *str = v;
+	gsize i;
+	guint hash = 5381;
+	guint section_cnt = 0;
+
+	/* not a unique ID */
+	if (!as_utils_unique_id_valid (v))
+		return g_str_hash (v);
+
+	/* only include the app-id */
+	for (i = 0; str[i] != '\0'; i++) {
+		if (str[i] == '/') {
+			if (++section_cnt > 4)
+				break;
+			continue;
+		}
+		if (section_cnt < 4)
+			continue;
+		hash = (guint) ((hash << 5) + hash) + (guint) (str[i]);
+	}
+	return hash;
+}
+
+/**
+ * as_utils_unique_id_equal_safe:
+ * @v1: a unique ID
+ * @v2: another unique ID
+ *
+ * Compares two unique_id's for equality and returns TRUE if they are equal.
+ * It can be passed to g_hash_table_new() as the key_equal_func parameter,
+ * when using non-NULL strings or unique-id's as keys in a GHashTable.
+ *
+ * Note that this function is primarily meant as a hash table comparison
+ * function. For a general-purpose, unique-id specific comparison function,
+ * see g_strcmp0().
+ *
+ * Returns: %TRUE if the two keys are equal
+ *
+ * Since: 0.6.2
+ */
+gboolean
+as_utils_unique_id_equal_safe (gconstpointer v1, gconstpointer v2)
+{
+	if (as_utils_unique_id_valid (v1) &&
+	    as_utils_unique_id_valid (v2))
+		return as_utils_unique_id_equal (v1, v2);
+	return g_str_equal (v1, v2);
+}
diff --git a/libappstream-glib/as-utils.h b/libappstream-glib/as-utils.h
index e38c412..35c2708 100644
--- a/libappstream-glib/as-utils.h
+++ b/libappstream-glib/as-utils.h
@@ -141,6 +141,9 @@ gchar		*as_utils_unique_id_build	(AsAppScope	 scope,
 gboolean	 as_utils_unique_id_equal	(const gchar	*unique_id1,
 						 const gchar	*unique_id2);
 gboolean	 as_utils_unique_id_valid	(const gchar	*unique_id);
+guint		 as_utils_unique_id_hash_safe	(gconstpointer	 v);
+gboolean	 as_utils_unique_id_equal_safe	(gconstpointer	 v1,
+						 gconstpointer	 v2);
 
 G_END_DECLS