[perl-Glib] Add new C API gperl_register_boxed_synonym

[Torsten SchÃnfeld <tsch src gnome org>]

commit 63168c5fbde8066d688ccc5b2ba6a9befea1faa9
Author: Torsten SchÃnfeld <kaffeetisch gmx de>
Date:   Sat Aug 18 22:59:21 2012 +0200

    Add new C API gperl_register_boxed_synonym
    
    It lets you make a boxed GType synonymous to another boxed GType so that
    objects of the former type are treated as if they were of the latter type.

 GBoxed.xs    |   49 +++++++++++++++++++++++++++++++++++++++++++++++--
 Glib.exports |    1 +
 NEWS         |    1 +
 gperl.h      |    1 +
 4 files changed, 50 insertions(+), 2 deletions(-)
---
diff --git a/GBoxed.xs b/GBoxed.xs
index 66d346a..94f6702 100644
--- a/GBoxed.xs
+++ b/GBoxed.xs
@@ -117,7 +117,7 @@ struct _BoxedInfo {
 };
 
 
-BoxedInfo *
+static BoxedInfo *
 boxed_info_new (GType gtype,
 		const char * package,
 		GPerlBoxedWrapperClass * wrapper_class)
@@ -130,7 +130,16 @@ boxed_info_new (GType gtype,
 	return boxed_info;
 }
 
-void
+static BoxedInfo *
+boxed_info_copy (BoxedInfo * boxed_info)
+{
+	BoxedInfo * new_boxed_info;
+	new_boxed_info = g_new0 (BoxedInfo, 1);
+	memcpy (new_boxed_info, boxed_info, sizeof (BoxedInfo));
+	return new_boxed_info;
+}
+
+static void
 boxed_info_destroy (BoxedInfo * boxed_info)
 {
 	if (boxed_info) {
@@ -257,6 +266,42 @@ gperl_register_boxed_alias (GType gtype,
 	G_UNLOCK (info_by_package);
 }
 
+=item void gperl_register_boxed_synonym (GType registered_gtype, GType synonym_gtype)
+
+Registers I<synonym_gtype> as a synonym for I<registered_gtype>.  All boxed
+objects of type I<synonym_gtype> will then be treated as if they were of type
+I<registered_gtype>, and I<gperl_boxed_package_from_type> will return the
+package associated with I<registered_gtype>.
+
+I<registered_gtype> must have been registered with I<gperl_register_boxed>
+already.
+
+=cut
+
+void
+gperl_register_boxed_synonym (GType registered_gtype,
+                              GType synonym_gtype)
+{
+	BoxedInfo * registered_boxed_info, * synonym_boxed_info;
+
+	G_LOCK (info_by_gtype);
+
+	registered_boxed_info = (BoxedInfo *)
+		g_hash_table_lookup (info_by_gtype, (gpointer) registered_gtype);
+
+	if (!registered_boxed_info) {
+		croak ("cannot make %s synonymous to the unregistered type %s",
+		       g_type_name (synonym_gtype),
+		       g_type_name (registered_gtype));
+	}
+
+	synonym_boxed_info = boxed_info_copy (registered_boxed_info);
+	g_hash_table_insert (info_by_gtype, (gpointer) synonym_gtype,
+	                     synonym_boxed_info);
+
+	G_UNLOCK (info_by_gtype);
+}
+
 =item GType gperl_boxed_type_from_package (const char * package)
 
 Look up the GType associated with package I<package>.  Returns 0 if I<type> is
diff --git a/Glib.exports b/Glib.exports
index 843b95f..3ab9e66 100644
--- a/Glib.exports
+++ b/Glib.exports
@@ -76,6 +76,7 @@ gperl_param_spec_type_from_package
 gperl_prepend_isa
 gperl_register_boxed
 gperl_register_boxed_alias
+gperl_register_boxed_synonym
 gperl_register_error_domain
 gperl_register_fundamental
 gperl_register_fundamental_alias
diff --git a/NEWS b/NEWS
index 77998a6..2883c7f 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,7 @@ Overview of changes in Glib <next>
 * Make the stack handling of some marshallers more robust, in
   preparation for custom Glib::Boxed converters that call back into Perl
   code.
+* Add new C API gperl_register_boxed_synonym.
 
 Overview of changes in Glib 1.261 (stable)
 ==========================================
diff --git a/gperl.h b/gperl.h
index fc9d38f..592e332 100644
--- a/gperl.h
+++ b/gperl.h
@@ -165,6 +165,7 @@ void gperl_register_boxed (GType gtype,
 			   const char * package,
 			   GPerlBoxedWrapperClass * wrapper_class);
 void gperl_register_boxed_alias (GType gtype, const char * package);
+void gperl_register_boxed_synonym (GType registered_gtype, GType synonym_gtype);
 
 SV * gperl_new_boxed (gpointer boxed, GType gtype, gboolean own);
 SV * gperl_new_boxed_copy (gpointer boxed, GType gtype);