[gtk+/gtk-3-8] broadway: Reuse surfaces passed to server

[Alexander Larsson <alexl src gnome org>]

commit 03bb44ae2f06f775e59e8d44338e307e05f3c9f9
Author: Alexander Larsson <alexl redhat com>
Date:   Fri Mar 29 09:50:59 2013 +0100

    broadway: Reuse surfaces passed to server
    
    This way we don't have to reopen all the time for pure updates,
    and we can immediately unlink the shm file to avoid "leaking" them
    on improper shutdown.

 gdk/broadway/broadway-server.c |   33 +++++++++++++++++++++++++++++++--
 1 files changed, 31 insertions(+), 2 deletions(-)
---
diff --git a/gdk/broadway/broadway-server.c b/gdk/broadway/broadway-server.c
index 433876a..22fe33d 100644
--- a/gdk/broadway/broadway-server.c
+++ b/gdk/broadway/broadway-server.c
@@ -99,6 +99,9 @@ struct BroadwayWindow {
   gint32 transient_for;
 
   cairo_surface_t *last_surface;
+
+  char *cached_surface_name;
+  cairo_surface_t *cached_surface;
 };
 
 static void broadway_server_resync_windows (BroadwayServer *server);
@@ -1416,6 +1419,12 @@ broadway_server_destroy_window (BroadwayServer *server,
       server->toplevels = g_list_remove (server->toplevels, window);
       g_hash_table_remove (server->id_ht,
                           GINT_TO_POINTER (id));
+
+      if (window->cached_surface_name != NULL)
+       g_free (window->cached_surface_name);
+      if (window->cached_surface != NULL)
+       cairo_surface_destroy (window->cached_surface);
+
       g_free (window);
     }
 }
@@ -1833,12 +1842,22 @@ broadway_server_open_surface (BroadwayServer *server,
                              int width,
                              int height)
 {
+  BroadwayWindow *window;
   ShmSurfaceData *data;
   cairo_surface_t *surface;
   gsize size;
   void *ptr;
   int fd;
 
+  window = g_hash_table_lookup (server->id_ht,
+                               GINT_TO_POINTER (id));
+  if (window == NULL)
+    return NULL;
+
+  if (window->cached_surface_name != NULL &&
+      strcmp (name, window->cached_surface_name) == 0)
+    return cairo_surface_reference (window->cached_surface);
+
   size = width * height * sizeof (guint32);
 
   fd = shm_open(name, O_RDONLY, 0600);
@@ -1848,9 +1867,11 @@ broadway_server_open_surface (BroadwayServer *server,
       return NULL;
     }
 
-  ptr = mmap(0, size, PROT_READ, MAP_SHARED, fd, 0); 
+  ptr = mmap(0, size, PROT_READ, MAP_SHARED, fd, 0);
   (void) close(fd);
 
+  shm_unlink (name);
+
   if (ptr == NULL)
     return NULL;
 
@@ -1864,10 +1885,18 @@ broadway_server_open_surface (BroadwayServer *server,
                                                 width, height,
                                                 width * sizeof (guint32));
   g_assert (surface != NULL);
-  
+
   cairo_surface_set_user_data (surface, &shm_cairo_key,
                               data, shm_data_unmap);
 
+  if (window->cached_surface_name != NULL)
+    g_free (window->cached_surface_name);
+  window->cached_surface_name = g_strdup (name);
+
+  if (window->cached_surface != NULL)
+    cairo_surface_destroy (window->cached_surface);
+  window->cached_surface = cairo_surface_reference (surface);
+
   return surface;
 }