[gegl] buffer: keep a list of tiles cache entries in handler

[Øyvind Kolås <ok src gnome org>]

commit 9a6091dccdf0be08bc6f8ee695345dcfde463755
Author: Øyvind Kolås <pippin gimp org>
Date:   Mon Jun 2 00:00:55 2014 +0200

    buffer: keep a list of tiles cache entries in handler
    
    The whole tile cache was being walked linearly on every buffer destruction to
    find the tiles a cache handler is responsible for. This made use of temporary
    buffers during processing slow down with a constant factor depending on how
    many tiles were in the cache.

 gegl/buffer/gegl-tile-handler-cache.c |   35 +++++++++-----------------------
 gegl/buffer/gegl-tile-handler-cache.h |    1 +
 2 files changed, 11 insertions(+), 25 deletions(-)
---
diff --git a/gegl/buffer/gegl-tile-handler-cache.c b/gegl/buffer/gegl-tile-handler-cache.c
index 07228b4..a1aa38a 100644
--- a/gegl/buffer/gegl-tile-handler-cache.c
+++ b/gegl/buffer/gegl-tile-handler-cache.c
@@ -113,29 +113,9 @@ gegl_tile_handler_cache_init (GeglTileHandlerCache *cache)
   gegl_tile_cache_init ();
 }
 
-typedef struct
-{
-  GeglTileHandlerCache *cache;
-  GSList               *free_list;
-} CacheReInitContext;
-
-static void
-gegl_tile_handler_cache_reinit_buffer_tiles (gpointer queue_item,
-                                             gpointer userdata)
-{
-  CacheReInitContext *ctx  = userdata;
-  CacheItem          *item = queue_item;
-
-  if (item->handler == ctx->cache)
-    {
-      ctx->free_list = g_slist_prepend (ctx->free_list, item);
-    }
-}
-
 static void
 gegl_tile_handler_cache_reinit (GeglTileHandlerCache *cache)
 {
-  CacheReInitContext    ctx = {cache, NULL};
   CacheItem            *item;
   GSList               *iter;
 
@@ -149,22 +129,24 @@ gegl_tile_handler_cache_reinit (GeglTileHandlerCache *cache)
     return;
 
   g_mutex_lock (&mutex);
-  g_queue_foreach (cache_queue, gegl_tile_handler_cache_reinit_buffer_tiles, &ctx);
-  for (iter = ctx.free_list; iter; iter = g_slist_next (iter))
+  {
+    for (iter = cache->items; iter; iter = cache->items)
     {
       item = iter->data;
       if (item->tile)
         {
           cache_total -= item->tile->size;
-          gegl_tile_mark_as_stored (item->tile); /* to avoid saving */
+          gegl_tile_mark_as_stored (item->tile); // to avoid saving 
           gegl_tile_unref (item->tile);
           cache->count--;
         }
       g_queue_unlink (cache_queue, &item->link);
+      cache->items = g_slist_remove (cache->items, item);
       g_hash_table_remove (cache_ht, item);
       g_slice_free (CacheItem, item);
     }
-  g_slist_free (ctx.free_list);
+  }
+
   g_mutex_unlock (&mutex);
 }
 
@@ -397,6 +379,7 @@ gegl_tile_handler_cache_trim (GeglTileHandlerCache *cache)
       GeglTile *tile = last_writable->tile;
       GeglTileStorage *storage = tile->tile_storage;
 
+      cache->items = g_slist_remove (cache->items, last_writable);
       g_hash_table_remove (cache_ht, last_writable);
       cache_total -= tile->size;
 
@@ -431,6 +414,7 @@ gegl_tile_handler_cache_invalidate (GeglTileHandlerCache *cache,
       gegl_tile_mark_as_stored (item->tile); /* to cheat it out of being stored */
       gegl_tile_unref (item->tile);
       g_queue_unlink (cache_queue, &item->link);
+      cache->items = g_slist_remove (cache->items, item);
       g_hash_table_remove (cache_ht, item);
       g_slice_free (CacheItem, item);
     }
@@ -452,6 +436,7 @@ gegl_tile_handler_cache_void (GeglTileHandlerCache *cache,
     {
       cache_total -= item->tile->size;
       g_queue_unlink (cache_queue, &item->link);
+      cache->items = g_slist_remove (cache->items, item);
       g_hash_table_remove (cache_ht, item);
       cache->count--;
     }
@@ -498,7 +483,7 @@ gegl_tile_handler_cache_insert (GeglTileHandlerCache *cache,
 
   cache->count ++;
 
-
+  cache->items = g_slist_prepend (cache->items, item);
   g_hash_table_insert (cache_ht, item, item);
 
   while (cache_total > gegl_config()->tile_cache_size)
diff --git a/gegl/buffer/gegl-tile-handler-cache.h b/gegl/buffer/gegl-tile-handler-cache.h
index ad80cfe..ef20169 100644
--- a/gegl/buffer/gegl-tile-handler-cache.h
+++ b/gegl/buffer/gegl-tile-handler-cache.h
@@ -40,6 +40,7 @@ struct _GeglTileHandlerCache
 {
   GeglTileHandler  parent_instance;
   GeglTileStorage *tile_storage;
+  GSList          *items;
   int              count; /* number of items held by cache */
 };