[gegl] Remove GeglCache's knowledge of GeglNode

[Daniel Sabo <daniels src gnome org>]

commit b4ff63c4a75e8f1d90bb3d75be1c8b6c4176eb8a
Author: Daniel Sabo <DanielSabo gmail com>
Date:   Mon May 6 15:04:31 2013 -0700

    Remove GeglCache's knowledge of GeglNode
    
    Tracking which node owned the cache created a messy circular
    reference, and GeglNode was already explicitly invalidating
    the cache in most cases. This patch changes the GeglNode logic
    to always explicitly invalidate, and removes the need to keep
    a signal hookup in GeglCache.

 gegl/buffer/gegl-cache.c      |   85 +----------------------------------------
 gegl/buffer/gegl-cache.h      |    1 -
 gegl/graph/gegl-node.c        |    4 +-
 gegl/process/gegl-processor.c |    2 +-
 4 files changed, 4 insertions(+), 88 deletions(-)
---
diff --git a/gegl/buffer/gegl-cache.c b/gegl/buffer/gegl-cache.c
index 5373ed0..8d1b9ac 100644
--- a/gegl/buffer/gegl-cache.c
+++ b/gegl/buffer/gegl-cache.c
@@ -29,8 +29,6 @@
 #include "gegl-types-internal.h"
 #include "gegl-utils.h"
 
-#include "graph/gegl-node.h"
-
 #include "gegl-cache.h"
 #include "gegl-region.h"
 
@@ -40,8 +38,7 @@ enum
   PROP_X,
   PROP_Y,
   PROP_WIDTH,
-  PROP_HEIGHT,
-  PROP_NODE
+  PROP_HEIGHT
 };
 
 enum
@@ -129,14 +126,6 @@ gegl_cache_class_init (GeglCacheClass *klass)
   gobject_class->set_property = set_property;
   gobject_class->get_property = get_property;
 
-  g_object_class_install_property (gobject_class, PROP_NODE,
-                                   g_param_spec_object ("node",
-                                                        "GeglNode",
-                                                        "The GeglNode to cache results for",
-                                                        GEGL_TYPE_NODE,
-                                                        G_PARAM_WRITABLE |
-                                                        G_PARAM_CONSTRUCT_ONLY));
-
   /* overriding pspecs for properties in parent class */
   g_object_class_install_property (gobject_class, PROP_X,
                                    g_param_spec_int ("x", "x",
@@ -191,7 +180,6 @@ gegl_cache_class_init (GeglCacheClass *klass)
 static void
 gegl_cache_init (GeglCache *self)
 {
-  self->node = NULL;
   g_mutex_init (&self->mutex);
 
   /* thus providing a default value for GeglCache, that overrides the NULL
@@ -202,26 +190,8 @@ gegl_cache_init (GeglCache *self)
 static void
 dispose (GObject *gobject)
 {
-  GeglCache *self = GEGL_CACHE (gobject);
-
   while (g_idle_remove_by_data (gobject)) ;
 
-  /* Check with GEGL_IS_NODE since sometimes the node is destroyed
-   * before we get here
-   */
-  if (GEGL_IS_NODE (self->node))
-    {
-      gint handler = g_signal_handler_find (self->node, G_SIGNAL_MATCH_DATA,
-                                            g_signal_lookup ("invalidated",
-                                                             GEGL_TYPE_NODE),
-                                            0, NULL, NULL, self);
-      if (handler)
-        {
-          g_signal_handler_disconnect (self->node, handler);
-        }
-      self->node = NULL;
-    }
-
   G_OBJECT_CLASS (gegl_cache_parent_class)->dispose (gobject);
 }
 
@@ -237,58 +207,13 @@ finalize (GObject *gobject)
 }
 
 static void
-node_invalidated (GeglNode            *source,
-                  const GeglRectangle *rect,
-                  gpointer             data)
-{
-  GeglCache *cache = GEGL_CACHE (data);
-  GeglRectangle expanded = gegl_rectangle_expand (rect);
-
-  {
-    GeglRegion *region;
-    region = gegl_region_rectangle (&expanded);
-    gegl_region_subtract (cache->valid_region, region);
-    gegl_region_destroy (region);
-  }
-
-  g_mutex_lock (&cache->mutex);
-  g_signal_emit_by_name (cache, "invalidated", &expanded, NULL);
-  g_mutex_unlock (&cache->mutex);
-}
-
-static void
 set_property (GObject      *gobject,
               guint         property_id,
               const GValue *value,
               GParamSpec   *pspec)
 {
-  GeglCache *self = GEGL_CACHE (gobject);
-
   switch (property_id)
     {
-      case PROP_NODE:
-        g_mutex_lock (&self->mutex);
-        if (self->node)
-          {
-            gulong handler;
-            handler = g_signal_handler_find (self->node, G_SIGNAL_MATCH_DATA,
-                                             g_signal_lookup ("invalidated",
-                                                              GEGL_TYPE_NODE),
-                                             0, NULL, NULL, self);
-            if (handler)
-              {
-                g_signal_handler_disconnect (self->node, handler);
-              }
-          }
-        /* just getting the node, the cache holds no reference on the node,
-         * it is the node that holds reference on the cache
-         */
-        self->node = GEGL_NODE (g_value_get_object (value));
-        g_signal_connect (G_OBJECT (self->node), "invalidated",
-                          G_CALLBACK (node_invalidated), self);
-        g_mutex_unlock (&self->mutex);
-        break;
-
       case PROP_X:
         g_object_set_property (gobject, "GeglBuffer::x", value);
         break;
@@ -317,15 +242,9 @@ get_property (GObject    *gobject,
               GValue     *value,
               GParamSpec *pspec)
 {
-  GeglCache *self = GEGL_CACHE (gobject);
-
   switch (property_id)
     {
-      case PROP_NODE:
-        g_value_set_object (value, self->node);
-        break;
-
-        /* For the rest, upchaining to the property implementation in GeglBuffer */
+      /* Upchain to the property implementation in GeglBuffer */
       case PROP_X:
         g_object_get_property (gobject, "GeglBuffer::x", value);
         break;
diff --git a/gegl/buffer/gegl-cache.h b/gegl/buffer/gegl-cache.h
index 950182b..8e231e2 100644
--- a/gegl/buffer/gegl-cache.h
+++ b/gegl/buffer/gegl-cache.h
@@ -37,7 +37,6 @@ struct _GeglCache
 {
   GeglBuffer    parent_instance;
 
-  GeglNode     *node;
   const void   *format;
   GeglRegion   *valid_region;
   GMutex        mutex;
diff --git a/gegl/graph/gegl-node.c b/gegl/graph/gegl-node.c
index f330cda..4285f2f 100644
--- a/gegl/graph/gegl-node.c
+++ b/gegl/graph/gegl-node.c
@@ -2079,7 +2079,6 @@ gegl_node_get_cache (GeglNode *node)
         }
 
       node->cache = g_object_new (GEGL_TYPE_CACHE,
-                                  "node", node,
                                   "format", format,
                                   NULL);
 
@@ -2270,8 +2269,7 @@ graph_source_invalidated (GeglNode            *source,
              rect->x, rect->y,
              rect->width, rect->height);
 
-  g_signal_emit (destination, gegl_node_signals[INVALIDATED], 0,
-                 &dirty_rect, NULL);
+  gegl_node_invalidated (destination, &dirty_rect, FALSE);
 }
 
 
diff --git a/gegl/process/gegl-processor.c b/gegl/process/gegl-processor.c
index 71cb7e6..e9cb616 100644
--- a/gegl/process/gegl-processor.c
+++ b/gegl/process/gegl-processor.c
@@ -499,7 +499,7 @@ render_rectangle (GeglProcessor *processor)
               g_assert (buf);
 
               /* do the image calculations using the buffer */
-              gegl_node_blit (cache->node, 1.0, dr, cache->format, buf,
+              gegl_node_blit (processor->input, 1.0, dr, cache->format, buf,
                               GEGL_AUTO_ROWSTRIDE, GEGL_BLIT_DEFAULT);