/**********************************************************
 * Copyright 2008-2009 VMware, Inc.  All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 **********************************************************/

#ifndef SVGA_SCREEN_CACHE_H_
#define SVGA_SCREEN_CACHE_H_


#include "svga_types.h"
#include "svga_reg.h"
#include "svga3d_reg.h"

#include "os/os_thread.h"

#include "util/u_double_list.h"


/* Guess the storage size of cached surfaces and try and keep it under
 * this amount:
 */ 
#define SVGA_HOST_SURFACE_CACHE_BYTES (16 * 1024 * 1024)

/* Maximum number of discrete surfaces in the cache:
 */
#define SVGA_HOST_SURFACE_CACHE_SIZE 1024

/* Number of hash buckets:
 */
#define SVGA_HOST_SURFACE_CACHE_BUCKETS 256


struct svga_winsys_surface;
struct svga_screen;

/**
 * Same as svga_winsys_screen::surface_create.
 */
struct svga_host_surface_cache_key
{
   SVGA3dSurfaceFlags flags;
   SVGA3dSurfaceFormat format;
   SVGA3dSize size;
   uint32_t numFaces:24;
   uint32_t numMipLevels:7;
   uint32_t cachable:1;         /* False if this is a shared surface */
};


struct svga_host_surface_cache_entry 
{
   /** 
    * Head for the LRU list, svga_host_surface_cache::unused, and
    * svga_host_surface_cache::empty
    */
   struct list_head head;
   
   /** Head for the bucket lists. */
   struct list_head bucket_head;

   struct svga_host_surface_cache_key key;
   struct svga_winsys_surface *handle;
   
   struct pipe_fence_handle *fence;
};


/**
 * Cache of the host surfaces.
 * 
 * A cache entry can be in the following stages:
 * 1. empty (entry->handle = NULL)
 * 2. holding a buffer in a validate list
 * 3. holding a flushed buffer (not in any validate list) with an active fence
 * 4. holding a flushed buffer with an expired fence
 * 
 * An entry progresses from 1 -> 2 -> 3 -> 4. When we need an entry to put a 
 * buffer into we preferencial take from 1, or from the least recentely used 
 * buffer from 3/4.
 */
struct svga_host_surface_cache 
{
   pipe_mutex mutex;
   
   /* Unused buffers are put in buckets to speed up lookups */
   struct list_head bucket[SVGA_HOST_SURFACE_CACHE_BUCKETS];
   
   /* Entries with unused buffers, ordered from most to least recently used 
    * (3 and 4) */
   struct list_head unused;
   
   /* Entries with buffers still in validate lists (2) */
   struct list_head validated;
   
   /** Empty entries (1) */
   struct list_head empty;

   /** The actual storage for the entries */
   struct svga_host_surface_cache_entry entries[SVGA_HOST_SURFACE_CACHE_SIZE];

   /** Sum of sizes of all surfaces (in bytes) */
   unsigned total_size;
};


void
svga_screen_cache_cleanup(struct svga_screen *svgascreen);

void
svga_screen_cache_flush(struct svga_screen *svgascreen,
                        struct pipe_fence_handle *fence);

enum pipe_error
svga_screen_cache_init(struct svga_screen *svgascreen);


struct svga_winsys_surface *
svga_screen_surface_create(struct svga_screen *svgascreen,
                           struct svga_host_surface_cache_key *key);

void
svga_screen_surface_destroy(struct svga_screen *svgascreen,
                            const struct svga_host_surface_cache_key *key,
                            struct svga_winsys_surface **handle);


#endif /* SVGA_SCREEN_CACHE_H_ */