1 files changed, 160 insertions, 0 deletions

diff --git a/src/nm-core-utils.c b/src/nm-core-utils.c
index 6cdd00e0d7..3529839f35 100644
--- a/src/nm-core-utils.c
+++ b/src/nm-core-utils.c
@@ -3018,3 +3018,163 @@ nm_utils_lifetime_get (guint32 timestamp,
 	return TRUE;
 }
 
+/*****************************************************************************
+ * NMRefString
+ *****************************************************************************/
+
+#ifdef NM_MORE_ASSERTS
+#define NM_STRING_CANARY(s) (GPOINTER_TO_UINT (s) ^ ((guint) 30112031329))
+#endif
+
+typedef struct _NMString {
+#ifdef NM_STRING_CANARY
+	guint _canary;
+#endif
+	int ref_count;
+	char str[1];
+} _NMString;
+
+static inline _NMString *
+_nm_ref_string_up_cast (NMRefString nmstr)
+{
+	_NMString *s;
+
+	s = (_NMString *) (((char *) nmstr) - G_STRUCT_OFFSET (_NMString, str));
+#ifdef NM_STRING_CANARY
+	g_return_val_if_fail (s->_canary == NM_STRING_CANARY (s), NULL);
+#endif
+	g_return_val_if_fail (s->ref_count > 0, NULL);
+
+	nm_assert (s->str == nmstr);
+
+	return s;
+}
+
+NMRefString
+nm_ref_string_new (const char *str)
+{
+	_NMString *s;
+	gsize len;
+
+	if (!str)
+		return NULL;
+
+	len = strlen (str) + 1;
+
+	s = g_malloc (G_STRUCT_OFFSET (_NMString, str) + len);
+	s->ref_count = 1;
+#ifdef NM_STRING_CANARY
+	s->_canary = NM_STRING_CANARY (s);
+#endif
+	memcpy (s->str, str, len);
+	return s->str;
+}
+
+NMRefString
+nm_ref_string_ref (NMRefString nmstr)
+{
+	_NMString *s;
+
+	if (!nmstr)
+		return NULL;
+
+	s = _nm_ref_string_up_cast (nmstr);
+	g_return_val_if_fail (s, NULL);
+
+	s->ref_count++;
+	return s->str;
+}
+
+void
+nm_ref_string_unref (NMRefString nmstr)
+{
+	_NMString *s;
+
+	if (!nmstr)
+		return;
+
+	s = _nm_ref_string_up_cast (nmstr);
+	g_return_if_fail (s);
+
+	if (--s->ref_count <= 0) {
+#ifdef NM_STRING_CANARY
+		s->_canary = 0;
+#endif
+		g_free (s);
+	}
+}
+
+NMRefString
+nm_ref_string_dedup (NMRefString nmstr, const char *str)
+{
+	/* The difference between replace and dedup is, that
+	 * replace in any case decrements the refcount on nmstr. Thus,
+	 * with replace you hand ownership of nmstr over.
+	 *
+	 * with dedup, the caller keeps ownership, but if possible,
+	 * the reference will be reused/shared.
+	 **/
+
+	if (!nmstr)
+		return nm_ref_string_new (str);
+	if (!str)
+		return NULL;
+
+	if (strcmp (nmstr, str) == 0)
+		return nm_ref_string_ref (nmstr);
+	return nm_ref_string_new (str);
+}
+
+NMRefString
+nm_ref_string_replace (NMRefString nmstr, const char *str)
+{
+	_NMString *s, *s2;
+	gsize len;
+
+	if (!nmstr)
+		return nm_ref_string_new (str);
+	if (!str) {
+		nm_ref_string_unref (nmstr);
+		return NULL;
+	}
+
+	s = _nm_ref_string_up_cast (nmstr);
+	g_return_val_if_fail (s, NULL);
+
+	if (strcmp (s->str, str) == 0)
+		return nmstr;
+
+	if (s->ref_count == 1) {
+		len = strlen (str) + 1;
+
+		s2 = g_realloc (s, G_STRUCT_OFFSET (_NMString, str) + len);
+
+#ifdef NM_STRING_CANARY
+		s2->_canary = NM_STRING_CANARY (s2);
+#endif
+		memcpy (s2->str, str, len);
+		return s2->str;
+	} else {
+		s->ref_count--;
+		return nm_ref_string_new (str);
+	}
+}
+
+int
+nm_ref_string_cmp (NMRefString nmstr1, NMRefString nmstr2)
+{
+	if (nmstr1 == nmstr2)
+		return 0;
+	if (!nmstr1)
+		return -1;
+	if (!nmstr2)
+		return 1;
+	return strcmp (nmstr1, nmstr2);
+}
+
+gboolean
+nm_ref_string_equal (NMRefString nmstr1, NMRefString nmstr2)
+{
+	return nm_ref_string_cmp (nmstr1, nmstr2) == 0;
+}
+