/**************************************************************************
 * 
 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA
 * 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, sub license, 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * 
 **************************************************************************/

/**
 * \file
 * Batch buffer pool management.
 * 
 * \author José Fonseca <jrfonseca-at-tungstengraphics-dot-com>
 * \author Thomas Hellström <thomas-at-tungstengraphics-dot-com>
 */


#include <assert.h>
#include <stdlib.h>
#include <unistd.h>

#include "main/imports.h"
#include "glapi/glthread.h"
#include "linked_list.h"

#include "p_defines.h"

#include "pb_buffer.h"
#include "pb_bufmgr.h"


/**
 * Convenience macro (type safe).
 */
#define SUPER(__derived) (&(__derived)->base)


struct pool_buffer_manager
{
   struct buffer_manager base;
   
   _glthread_Mutex mutex;
   
   size_t bufSize;
   
   size_t numFree;
   size_t numTot;
   
   struct list_head free;
   
   struct pipe_buffer *buffer;
   void *map;
   
   struct pool_buffer *bufs;
};


static inline struct pool_buffer_manager *
pool_buffer_manager(struct buffer_manager *mgr)
{
   assert(mgr);
   return (struct pool_buffer_manager *)mgr;
}


struct pool_buffer
{
   struct pipe_buffer base;
   
   struct pool_buffer_manager *mgr;
   
   struct list_head head;
   
   size_t start;
};


static inline struct pool_buffer *
pool_buffer(struct pipe_buffer *buf)
{
   assert(buf);
   return (struct pool_buffer *)buf;
}


static void
pool_buffer_reference(struct pipe_buffer *buf)
{
   /* No-op */
}


static void
pool_buffer_release(struct pipe_buffer *buf)
{
   struct pool_buffer *pool_buf = pool_buffer(buf);
   struct pool_buffer_manager *pool = pool_buf->mgr;
   
   _glthread_LOCK_MUTEX(pool->mutex);
   LIST_ADD(&pool_buf->head, &pool->free);
   pool->numFree++;
   _glthread_UNLOCK_MUTEX(pool->mutex);
}


static void *
pool_buffer_map(struct pipe_buffer *buf, unsigned flags)
{
   struct pool_buffer *pool_buf = pool_buffer(buf);
   struct pool_buffer_manager *pool = pool_buf->mgr;
   void *map;

   _glthread_LOCK_MUTEX(pool->mutex);
   map = (unsigned char *) pool->map + pool_buf->start;
   _glthread_UNLOCK_MUTEX(pool->mutex);
   return map;
}


static void
pool_buffer_unmap(struct pipe_buffer *buf)
{
   /* No-op */
}


static void
pool_buffer_get_base_buffer(struct pipe_buffer *buf,
                            struct pipe_buffer **base_buf,
                            unsigned *offset)
{
   struct pool_buffer *pool_buf = pool_buffer(buf);
   struct pool_buffer_manager *pool = pool_buf->mgr;
   buffer_get_base_buffer(pool->buffer, base_buf, offset);
   *offset += pool_buf->start;
}


static const struct pipe_buffer_vtbl 
pool_buffer_vtbl = {
      pool_buffer_reference,
      pool_buffer_release,
      pool_buffer_map,
      pool_buffer_unmap,
      pool_buffer_get_base_buffer
};


static struct pipe_buffer *
pool_bufmgr_create_buffer(struct buffer_manager *mgr, size_t size)
{
   struct pool_buffer_manager *pool = pool_buffer_manager(mgr);
   struct pool_buffer *pool_buf;
   struct list_head *item;

   assert(size == pool->bufSize);
   
   _glthread_LOCK_MUTEX(pool->mutex);

   if (pool->numFree == 0) {
      _glthread_UNLOCK_MUTEX(pool->mutex);
      fprintf(stderr, "warning: out of fixed size buffer objects\n");
      return NULL;
   }

   item = pool->free.next;

   if (item == &pool->free) {
      _glthread_UNLOCK_MUTEX(pool->mutex);
      fprintf(stderr, "error: fixed size buffer pool corruption\n");
      return NULL;
   }

   LIST_DEL(item);
   --pool->numFree;

   _glthread_UNLOCK_MUTEX(pool->mutex);
   pool_buf = LIST_ENTRY(struct pool_buffer, item, head);
   return SUPER(pool_buf);
}


static void
pool_bufmgr_destroy(struct buffer_manager *mgr)
{
   struct pool_buffer_manager *pool = pool_buffer_manager(mgr);
   _glthread_LOCK_MUTEX(pool->mutex);

   free(pool->bufs);
   
   buffer_unmap(pool->buffer);
   buffer_release(pool->buffer);
   
   _glthread_UNLOCK_MUTEX(pool->mutex);
   
   free(mgr);
}


struct buffer_manager *
pool_bufmgr_create(struct buffer_manager *provider, 
                   size_t numBufs, 
                   size_t bufSize) 
{
   struct pool_buffer_manager *pool;
   struct pool_buffer *pool_buf;
   int i;

   pool = (struct pool_buffer_manager *)calloc(1, sizeof(*pool));
   if (!pool)
      return NULL;

   pool->base.destroy = pool_bufmgr_destroy;
   pool->base.create_buffer = pool_bufmgr_create_buffer;

   LIST_INITHEAD(&pool->free);

   pool->numTot = numBufs;
   pool->numFree = numBufs;
   pool->bufSize = bufSize;
   
   _glthread_INIT_MUTEX(pool->mutex);

   pool->buffer = provider->create_buffer(provider, numBufs*bufSize); 
   if (!pool->buffer)
      goto failure;

   pool->map = buffer_map(pool->buffer,
                          PIPE_BUFFER_FLAG_READ |
                          PIPE_BUFFER_FLAG_WRITE );
   if(!pool->map)
      goto failure;

   pool->bufs = (struct pool_buffer *) malloc(numBufs * sizeof(*pool->bufs));
   if (!pool->bufs)
      goto failure;

   pool_buf = pool->bufs;
   for (i = 0; i < numBufs; ++i) {
      pool_buf->base.vtbl = &pool_buffer_vtbl;
      pool_buf->mgr = pool;
      pool_buf->start = i * bufSize;
      LIST_ADDTAIL(&pool_buf->head, &pool->free);
      pool_buf++;
   }

   return SUPER(pool);
   
failure:
   if(pool->bufs)
      free(pool->bufs);
   if(pool->map)
      buffer_unmap(pool->buffer);
   if(pool->buffer)
      buffer_release(pool->buffer);
   if(pool)
      free(pool);
   return NULL;
}