Add reference counted strings

Instead of copying strings around, we can box them using the g_ref_* API
and add reference counting to the char array.

Reference counted strings can be used with any string utility function.

glib/Makefile.am

@@ -156,6 +156,7 @@ libglib_2_0_la_SOURCES = 	\
 	gqueue.c		\
 	grand.c			\
 	grefcount.c		\
+	grefstring.c		\
 	gregex.c		\
 	gscanner.c		\
 	gscripttable.h		\
@@ -289,6 +290,7 @@ glibsubinclude_HEADERS = \
 	gqueue.h	\
 	grand.h		\
 	grefcount.h	\
+	grefstring.h	\
 	gregex.h	\
 	gscanner.h	\
 	gsequence.h	\

glib/glib.h

@@ -70,6 +70,7 @@
 #include <glib/gqueue.h>
 #include <glib/grand.h>
 #include <glib/grefcount.h>
+#include <glib/grefstring.h>
 #include <glib/gregex.h>
 #include <glib/gscanner.h>
 #include <glib/gsequence.h>

glib/grefstring.c

@@ -0,0 +1,64 @@
+/* GLib - Library of useful routines for C programming
+ * Copyright 2016  Emmanuele Bassi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * MT safe
+ */
+
+#include "config.h"
+
+#include "grefstring.h"
+
+#include <string.h>
+
+#include "gmessages.h"
+#include "grefcount.h"
+
+char *
+g_ref_string_new (const char *str)
+{
+  gsize len;
+  char *res;
+
+  g_return_val_if_fail (str != NULL || *str != '\0', NULL);
+
+  len = strlen (str);
+  res = g_ref_alloc (len + 1, NULL);
+
+  memcpy (res, str, len);
+  res[len] = '\0';
+
+  return res;
+}
+
+char *
+g_ref_string_ref (char *str)
+{
+  g_return_val_if_fail (str != NULL, NULL);
+
+  g_ref_acquire (str);
+
+  return str;
+}
+
+void
+g_ref_string_unref (char *str)
+{
+  g_return_if_fail (str != NULL);
+
+  g_ref_release (str);
+}

glib/grefstring.h

@@ -0,0 +1,39 @@
+/* GLib - Library of useful routines for C programming
+ * Copyright 2016  Emmanuele Bassi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __G_REF_STRING_H__
+#define __G_REF_STRING_H__
+
+#if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
+#error "Only <glib.h> can be included directly."
+#endif
+
+#include <glib/gutils.h>
+
+G_BEGIN_DECLS
+
+GLIB_AVAILABLE_IN_2_52
+char *  g_ref_string_new        (const char *str);
+
+GLIB_AVAILABLE_IN_2_52
+char *  g_ref_string_ref        (char       *str);
+GLIB_AVAILABLE_IN_2_52
+void    g_ref_string_unref      (char       *str);
+
+G_END_DECLS
+
+#endif /* __G_REF_STRING_H__ */