/*
 * Copyright (c) 2007 Intel Corporation. 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 above copyright notice and this permission notice (including the
 * next paragraph) 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL PRECISION INSIGHT 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.
 */

#ifndef OBJECT_HEAP_H
#define OBJECT_HEAP_H

#include <pthread.h>

#define OBJECT_HEAP_OFFSET_MASK 0x7F000000
#define OBJECT_HEAP_ID_MASK     0x00FFFFFF

typedef struct object_base *object_base_p;
typedef struct object_heap *object_heap_p;

struct object_base {
    int id;
    int next_free;
};

struct object_heap {
    pthread_mutex_t mutex;
    int object_size;
    int id_offset;
    int next_free;
    int heap_size;
    int heap_increment;
    void **bucket;
    int num_buckets;
};

typedef int object_heap_iterator;

/*
 * Return 0 on success, -1 on error
 */
int
object_heap_init(object_heap_p heap, int object_size, int id_offset);

/*
 * Allocates an object
 * Returns the object ID on success, returns -1 on error
 */
int
object_heap_allocate(object_heap_p heap);

/*
 * Lookup an allocated object by object ID
 * Returns a pointer to the object on success, returns NULL on error
 */
object_base_p
object_heap_lookup(object_heap_p heap, int id);

/*
 * Iterate over all objects in the heap.
 * Returns a pointer to the first object on the heap, returns NULL if heap is empty.
 */
object_base_p
object_heap_first(object_heap_p heap, object_heap_iterator *iter);

/*
 * Iterate over all objects in the heap.
 * Returns a pointer to the next object on the heap, returns NULL if heap is empty.
 */
object_base_p
object_heap_next(object_heap_p heap, object_heap_iterator *iter);

/*
 * Frees an object
 */
void
object_heap_free(object_heap_p heap, object_base_p obj);

/*
 * Destroys a heap, the heap must be empty.
 */
void
object_heap_destroy(object_heap_p heap);

#endif /* OBJECT_HEAP_H */