[PATCH wayland] server: add helper functions for wl_global

[Jonny Lamb]

The intention here is to be able to find an existing wl_global using
some search parameters and then get some information about it.
---
 src/wayland-server.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/wayland-server.h |  4 ++++
 2 files changed, 62 insertions(+)

diff --git a/src/wayland-server.c b/src/wayland-server.c
index 0558634..035b9f0 100644
--- a/src/wayland-server.c
+++ b/src/wayland-server.c
@@ -945,6 +945,64 @@ wl_global_destroy(struct wl_global *global)
 	free(global);
 }
 
+/** Get the data associated with the wl_global
+ *
+ * \param global The wl_global object
+ *
+ * This function returns the data associated with the wl_global.
+ *
+ * \memberof wl_global
+ */
+WL_EXPORT void *
+wl_global_get_data(struct wl_global *global)
+{
+	return global->data;
+}
+
+/** Find a wl_global given search parameters
+ *
+ * \param display The display object
+ * \param interface The interface to match, or NULL
+ * \param version The version to match, or 0
+ * \param data The user data to match, or NULL
+ * \param bind The function used to bind the object, or NULL
+ *
+ * The global list of a wl_display is not public so this function helps in
+ * finding a specific wl_global based on the parameters. Parameters can be
+ * missing for a broader search (NULL for interface, data, and bind, and 0 for
+ * version) but at least one must be present or no result will be returned.
+ *
+ * If no matching wl_global is found, NULL is returned.
+ *
+ * \memberof wl_global
+ */
+WL_EXPORT struct wl_global *
+wl_global_find(struct wl_display *display,
+	const struct wl_interface *interface, uint32_t version,
+	void *data, wl_global_bind_func_t bind)
+{
+	struct wl_global *global;
+
+	/* return with nothing if we have no search parameters */
+	if (interface == NULL && version == 0 && data == NULL && bind == NULL)
+		return NULL;
+
+	wl_list_for_each(global, &display->global_list, link) {
+		if (interface != NULL && global->interface != interface)
+			continue;
+		if (version != 0 && global->version != version)
+			continue;
+		if (data != NULL && global->data != data)
+			continue;
+		if (bind != NULL && global->bind != bind)
+			continue;
+
+		return global;
+	}
+
+	return NULL;
+}
+
 /** Get the current serial number
  *
  * \param display The display object
diff --git a/src/wayland-server.h b/src/wayland-server.h
index af2f03d..05449dc 100644
--- a/src/wayland-server.h
+++ b/src/wayland-server.h
@@ -113,6 +113,10 @@ struct wl_global *wl_global_create(struct wl_display *display,
 				   int version,
 				   void *data, wl_global_bind_func_t bind);
 void wl_global_destroy(struct wl_global *global);
+void *wl_global_get_data(struct wl_global *global);
+struct wl_global *wl_global_find(struct wl_display *display,
+	const struct wl_interface *interface, uint32_t version,
+	void *data, wl_global_bind_func_t bind);
 
 struct wl_client *wl_client_create(struct wl_display *display, int fd);
 void wl_client_destroy(struct wl_client *client);
-- 
2.1.4