[gegl] Revert "buffer: do COW for tiles during gegl_buffer_dup"

[Ãyvind KolÃs <ok src gnome org>]

commit d36817755d744bf273354bf7a8c3a2ade15494b9
Author: Ãyvind KolÃs <pippin gimp org>
Date:   Fri Mar 23 14:30:50 2012 +0000

    Revert "buffer: do COW for tiles during gegl_buffer_dup"
    
    This reverts commit 72e784cbc8fd474123f85786b6d4895957a773d0.
    
    Worked for the gimp goat invasion use case, but broke the gegl test :/,
    needs revisiting.

 gegl/buffer/gegl-buffer-access.c   |   85 ++++++------------------------------
 gegl/buffer/gegl-buffer-iterator.c |   18 ++++---
 gegl/buffer/gegl-buffer-private.h  |    6 ---
 3 files changed, 24 insertions(+), 85 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer-access.c b/gegl/buffer/gegl-buffer-access.c
index 9de1ba1..9631f01 100644
--- a/gegl/buffer/gegl-buffer-access.c
+++ b/gegl/buffer/gegl-buffer-access.c
@@ -1139,42 +1139,13 @@ gegl_buffer_sample_cleanup (GeglBuffer *buffer)
     }
 }
 
-static void
-gegl_buffer_copy2 (GeglBuffer          *src,
-                   const GeglRectangle *src_rect,
-                   GeglBuffer          *dst,
-                   const GeglRectangle *dst_rect)
-{
-  const Babl *fish;
-
-  g_return_if_fail (GEGL_IS_BUFFER (src));
-  g_return_if_fail (GEGL_IS_BUFFER (dst));
-  g_return_if_fail (src_rect);
-  g_return_if_fail (dst_rect);
-
-  fish = babl_fish (src->format, dst->format);
-
-  {
-    GeglRectangle dest_rect_r = *dst_rect;
-    GeglBufferIterator *i;
-    gint read;
-
-    dest_rect_r.width = src_rect->width;
-    dest_rect_r.height = src_rect->height;
-
-    i = gegl_buffer_iterator_new (dst, &dest_rect_r, dst->format, GEGL_BUFFER_WRITE);
-    read = gegl_buffer_iterator_add (i, src, src_rect, src->format, GEGL_BUFFER_READ);
-    while (gegl_buffer_iterator_next (i))
-      babl_process (fish, i->data[read], i->data[0], i->length);
-  }
-}
-
 void
 gegl_buffer_copy (GeglBuffer          *src,
                   const GeglRectangle *src_rect,
                   GeglBuffer          *dst,
                   const GeglRectangle *dst_rect)
 {
+  const Babl *fish;
   g_return_if_fail (GEGL_IS_BUFFER (src));
   g_return_if_fail (GEGL_IS_BUFFER (dst));
 
@@ -1188,49 +1159,21 @@ gegl_buffer_copy (GeglBuffer          *src,
       dst_rect = src_rect;
     }
 
-  /* for now, only doing the zero copy when we effectively are doing a buffer
-   * dup.
-   */
-  if (src->format == dst->format &&
-      _gegl_buffer_scan_compatible (src,
-                                    src_rect->x,
-                                    src_rect->y,
-                                    dst,
-                                    dst_rect->x,
-                                    dst_rect->y) &&
-      !memcmp (src_rect, dst_rect, sizeof (GeglRectangle)) &&
-      src_rect->x == 0 &&
-      src_rect->y == 0)
+  fish = babl_fish (src->format, dst->format);
+
     {
-      int x, y;
-      int tile_width = dst->tile_storage->tile_width;
-      int tile_height = dst->tile_storage->tile_height;
-      /* determine inner region that can definetly be shared */
-
-      /* share this inner region */
-      for (y = dst_rect->y; y < dst_rect->y + dst_rect->height; y += tile_height)
-      for (x = dst_rect->x; x < dst_rect->x + dst_rect->width;  x += tile_width)
-        {
-          GeglTile *src_tile;
-          GeglTile *dst_tile;
-          int res;
-          src_tile = gegl_tile_source_get_tile ((GeglTileSource *)(src),
-                                                gegl_tile_indice (x, tile_width),
-                                                gegl_tile_indice (y, tile_height),
-                                                0);
-          dst_tile = gegl_tile_dup (src_tile);
-          res = gegl_tile_source_set_tile ((GeglTileSource*)(dst),
-                                           gegl_tile_indice (x, tile_width),
-                                           gegl_tile_indice (y, tile_height),
-                                           0,
-                                           dst_tile);
-          if (res) res = 0;
-          gegl_tile_unref (src_tile);
-        }
-      /* copy up to four regions around : NYI */
-      return;
+      GeglRectangle dest_rect_r = *dst_rect;
+      GeglBufferIterator *i;
+      gint read;
+
+      dest_rect_r.width = src_rect->width;
+      dest_rect_r.height = src_rect->height;
+
+      i = gegl_buffer_iterator_new (dst, &dest_rect_r, dst->format, GEGL_BUFFER_WRITE);
+      read = gegl_buffer_iterator_add (i, src, src_rect, src->format, GEGL_BUFFER_READ);
+      while (gegl_buffer_iterator_next (i))
+        babl_process (fish, i->data[read], i->data[0], i->length);
     }
-  gegl_buffer_copy2 (src, src_rect, dst, dst_rect);
 }
 
 void
diff --git a/gegl/buffer/gegl-buffer-iterator.c b/gegl/buffer/gegl-buffer-iterator.c
index ec009f8..523b918 100644
--- a/gegl/buffer/gegl-buffer-iterator.c
+++ b/gegl/buffer/gegl-buffer-iterator.c
@@ -93,12 +93,12 @@ static gboolean  gegl_buffer_tile_iterator_next (GeglBufferTileIterator *i);
  *  check whether iterations on two buffers starting from the given coordinates with
  *  the same width and height would be able to run parallell.
  */
-gboolean _gegl_buffer_scan_compatible (GeglBuffer *bufferA,
-                                       gint        xA,
-                                       gint        yA,
-                                       GeglBuffer *bufferB,
-                                       gint        xB,
-                                       gint        yB)
+static gboolean gegl_buffer_scan_compatible (GeglBuffer *bufferA,
+                                             gint        xA,
+                                             gint        yA,
+                                             GeglBuffer *bufferB,
+                                             gint        xB,
+                                             gint        yB)
 {
   if (bufferA->tile_storage->tile_width !=
       bufferB->tile_storage->tile_width)
@@ -244,6 +244,8 @@ static glong in_direct_read = 0;
 static glong in_direct_write = 0;
 #endif
 
+
+
 gint
 gegl_buffer_iterator_add (GeglBufferIterator  *iterator,
                           GeglBuffer          *buffer,
@@ -288,8 +290,8 @@ gegl_buffer_iterator_add (GeglBufferIterator  *iterator,
       i->rect[self].width = i->rect[0].width;
       i->rect[self].height = i->rect[0].height;
 
-      if (_gegl_buffer_scan_compatible (i->buffer[0], i->rect[0].x, i->rect[0].y,
-                                        i->buffer[self], i->rect[self].x, i->rect[self].y))
+      if (gegl_buffer_scan_compatible (i->buffer[0], i->rect[0].x, i->rect[0].y,
+                                       i->buffer[self], i->rect[self].x, i->rect[self].y))
         {
           i->flags[self] |= GEGL_BUFFER_SCAN_COMPATIBLE;
           gegl_buffer_tile_iterator_init (&i->i[self], i->buffer[self], i->rect[self], ((i->flags[self] & GEGL_BUFFER_WRITE) != 0));
diff --git a/gegl/buffer/gegl-buffer-private.h b/gegl/buffer/gegl-buffer-private.h
index 5d4b8de..802af0b 100644
--- a/gegl/buffer/gegl-buffer-private.h
+++ b/gegl/buffer/gegl-buffer-private.h
@@ -168,12 +168,6 @@ struct _GeglTile
   gpointer         unlock_notify_data;
 };
 
-gboolean _gegl_buffer_scan_compatible (GeglBuffer *bufferA,
-                                       gint        xA,
-                                       gint        yA,
-                                       GeglBuffer *bufferB,
-                                       gint        xB,
-                                       gint        yB);
 
 #ifndef __GEGL_TILE_C
 #define gegl_tile_get_data(tile)  ((guchar*)((tile)->data))