[gegl] gegl:cache add an op that does a copy and explicit caching

[Øyvind Kolås <ok src gnome org>]

commit 84237b98cf4bcb6cbd44dfa69d48df93735c781e
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Jun 18 00:35:20 2014 +0200

    gegl:cache add an op that does a copy and explicit caching

 operations/core/Makefile.am |    3 +-
 operations/core/cache.c     |   96 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 98 insertions(+), 1 deletions(-)
---
diff --git a/operations/core/Makefile.am b/operations/core/Makefile.am
index 32985ce..88741cc 100644
--- a/operations/core/Makefile.am
+++ b/operations/core/Makefile.am
@@ -8,8 +8,9 @@ LIBS = $(op_libs)
 
 opdir = $(ext_dir)
 op_LTLIBRARIES = \
+       cache.la \
        clone.la \
        cast-format.la \
        convert-format.la \
        crop.la \
-       nop.la
\ No newline at end of file
+       nop.la
diff --git a/operations/core/cache.c b/operations/core/cache.c
new file mode 100644
index 0000000..0470244
--- /dev/null
+++ b/operations/core/cache.c
@@ -0,0 +1,96 @@
+/* This file is an image processing operation for GEGL
+ *
+ * GEGL 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 3 of the License, or (at your option) any later version.
+ *
+ * GEGL 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 GEGL; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2014 Øyvind Kolås <pippin gimp org>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+#include "gegl.h"
+#include "gegl-node-private.h" /* to fish out the cache */
+
+#ifdef GEGL_PROPERTIES
+  property_object (cache, _("Cache"), GEGL_TYPE_BUFFER)
+      description (_("NULL or a GeglBuffer containing cached rendering results, this is a special buffer 
where gegl_buffer_list_valid_rectangles returns the part of the cache that is valid."))
+#else
+
+#define GEGL_OP_POINT_FILTER
+#define GEGL_OP_C_FILE "cache.c"
+
+#include "gegl-op.h"
+
+static void
+prepare (GeglOperation *operation)
+{
+  const Babl *format = babl_format ("RGBA float");
+  const Babl *input_format = gegl_operation_get_source_format (operation, "input");
+
+  if (input_format)
+    format = input_format;
+
+  gegl_operation_set_format (operation, "input",  format);
+  gegl_operation_set_format (operation, "output", format);
+}
+
+static gboolean
+process (GeglOperation       *operation,
+         void                *in_buf,
+         void                *out_buf,
+         glong                n_pixels,
+         const GeglRectangle *roi,
+         gint                 level)
+{
+  GeglProperties *o  = GEGL_PROPERTIES (operation);
+  const Babl *format = gegl_operation_get_format (operation, "input");
+
+  memcpy (out_buf, in_buf, n_pixels * babl_format_get_bytes_per_pixel (format));
+
+  if (o->cache != (void*)operation->node->cache)
+  {
+    if (o->cache)
+    {
+      g_object_unref (o->cache);
+      o->cache = NULL;
+    }
+
+    if (operation->node->cache )
+      o->cache = g_object_ref (operation->node->cache);
+  }
+
+  return TRUE;
+}
+
+static void
+gegl_op_class_init (GeglOpClass *klass)
+{
+  GeglOperationClass            *operation_class;
+  GeglOperationPointFilterClass *point_filter_class;
+
+  operation_class    = GEGL_OPERATION_CLASS (klass);
+  point_filter_class = GEGL_OPERATION_POINT_FILTER_CLASS (klass);
+
+  operation_class->no_cache   = FALSE;
+  operation_class->prepare    = prepare;
+  point_filter_class->process = process;
+
+  gegl_operation_class_set_keys (operation_class,
+    "name",        "gegl:cache",
+    "title",       _("Explicit cache of results at this point of graph."),
+    "categories",  "programming",
+    "description", _("An explicit caching node"),
+    NULL);
+}
+
+#endif