/* EINA - EFL data type library
 * Copyright (C) 2008 Cedric Bail
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 this library;
 * if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef EINA_INLINE_MEMPOOL_X_
#define EINA_INLINE_MEMPOOL_X_

#include <string.h>

/* Memory Pool */
typedef struct _Eina_Mempool_Backend_ABI1 Eina_Mempool_Backend_ABI1;
typedef struct _Eina_Mempool_Backend_ABI2 Eina_Mempool_Backend_ABI2;

struct _Eina_Mempool_Backend
{
   /** Name of the mempool backend */
   const char *name;
   /** Function to initialize the backend. */
   void *(*init)(const char *context, const char *options, va_list args);
   /** Function to free memory back to the mempool. */
   void (*free)(void *data, void *element);
   /** Function to allocate memory from the mempool. */
   void *(*alloc)(void *data, unsigned int size);
   /** Function to change the size of a block of memory that is currently
    * allocated. */
   void *(*realloc)(void *data, void *element, unsigned int size);
   /** Function to trigger a garbage collection; can be NULL if the feature
    * isn't available in the backend. */
   void (*garbage_collect)(void *data);
   /** Report statistics on the content of the mempool; can be NULL if the
    * feature isn't available in the backend. */
   void (*statistics)(void *data);
   /** Function to destroy the backend, freeing memory back to the operating
    * system. */
   void (*shutdown)(void *data);
   /** Function to optimize the placement of objects in the mempool (it's
    * different from garbage_collect); can be NULL if the feature isn't
    * available in the backend.
    * @see Eina_Mempool_Repack_Cb */
   void (*repack)(void *data, Eina_Mempool_Repack_Cb cb, void *cb_data);
   /** Function to check is a valid element from a mempool.
    * @see eina_mempool_from
    */
   Eina_Bool (*from)(void *data, void *element);
   /** Function to get an Eina_Iterator that will walk every allocated element
    * in the pool.
    * @use eina_mempool_iterator_new
    */
   Eina_Iterator *(*iterator)(void *data);
   /** Function to allocate memory near already allocated memory.
    * @since 1.24
    * @use eina_mempool_malloc_near
    */
   void *(*alloc_near)(void *data, void *after, void *before, unsigned int size);
};

struct _Eina_Mempool_Backend_ABI1
{
   const char *name;
   void *(*init)(const char *context, const char *options, va_list args);
   void (*free)(void *data, void *element);
   void *(*alloc)(void *data, unsigned int size);
   void *(*realloc)(void *data, void *element, unsigned int size);
   void (*garbage_collect)(void *data);
   void (*statistics)(void *data);
   void (*shutdown)(void *data);
};

struct _Eina_Mempool_Backend_ABI2
{
   void (*repack)(void *data, Eina_Mempool_Repack_Cb cb, void *cb_data);
   Eina_Bool (*from)(void *data, void *element);
   Eina_Iterator *(*iterator)(void *data);
   void *(*alloc_near)(void *data, void *after, void *before, unsigned int size);
};

struct _Eina_Mempool
{
   Eina_Mempool_Backend_ABI1 backend;
   void *backend_data;
   Eina_Mempool_Backend_ABI2 *backend2;
};

static inline void *
eina_mempool_realloc(Eina_Mempool *mp, void *element, unsigned int size)
{
   return mp->backend.realloc(mp->backend_data, element, size);
}

static inline void *
eina_mempool_malloc(Eina_Mempool *mp, unsigned int size)
{
   return mp->backend.alloc(mp->backend_data, size);
}

static inline void *
eina_mempool_malloc_near(Eina_Mempool *mp, void *after, void *before, unsigned int size)
{
   if (mp->backend2 && mp->backend2->alloc_near && (!(after == NULL && before == NULL)))
     return mp->backend2->alloc_near(mp->backend_data, after, before, size);
   return mp->backend.alloc(mp->backend_data, size);
}

static inline void *
eina_mempool_calloc(Eina_Mempool *mp, unsigned int size)
{
   void *r = mp->backend.alloc(mp->backend_data, size);
   if (r) memset(r, 0, size);
   return r;
}

static inline void
eina_mempool_free(Eina_Mempool *mp, void *element)
{
   if (element) mp->backend.free(mp->backend_data, element);
}

static inline Eina_Bool
eina_mempool_from(Eina_Mempool *mp, void *element)
{
   if (!element) return EINA_FALSE;
   return mp->backend2->from(mp->backend_data, element);
}

static inline Eina_Iterator *
eina_mempool_iterator_new(Eina_Mempool *mp)
{
   if (!mp->backend2->iterator) return NULL;
   return mp->backend2->iterator(mp->backend_data);
}

static inline unsigned int
eina_mempool_alignof(unsigned int size)
{
   unsigned int align;

#if __WORDSIZE == 32
   if (size >= 8)
     {
        align = 8;
calc:
        return ((size / align) + (size % align ? 1 : 0)) * align;
     }
#else // __WORDSIZE == 64
   if (size >= 16)
     {
        align = 16;
calc:
        return ((size / align) + (size % align ? 1 : 0)) * align;
     }
   else if (size >= 8)
     {
        align = 8;
        goto calc;
     }
#endif
   else if (size >= 4)
     {
        align = 4;
        goto calc;
     }
   align = 2;
   goto calc;
}

#endif