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/*
* 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.
*/
#include "object_heap.h"
#include "assert.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define ASSERT assert
#define LAST_FREE -1
#define ALLOCATED -2
/*
* Expands the heap
* Return 0 on success, -1 on error
*/
static int object_heap_expand( object_heap_p heap )
{
int i;
void *new_heap_index;
int next_free;
int new_heap_size = heap->heap_size + heap->heap_increment;
new_heap_index = (void *) realloc( heap->heap_index, new_heap_size * heap->object_size );
if ( NULL == new_heap_index )
{
return -1; /* Out of memory */
}
memset(new_heap_index + heap->heap_size*heap->object_size, 0, heap->heap_increment * new_heap_size);
heap->heap_index = new_heap_index;
next_free = heap->next_free;
for(i = new_heap_size; i-- > heap->heap_size; )
{
object_base_p obj = (object_base_p) (heap->heap_index + i * heap->object_size);
obj->id = i + heap->id_offset;
obj->next_free = next_free;
next_free = i;
}
heap->next_free = next_free;
heap->heap_size = new_heap_size;
return 0; /* Success */
}
/*
* Return 0 on success, -1 on error
*/
int object_heap_init( object_heap_p heap, int object_size, int id_offset)
{
heap->object_size = object_size;
heap->id_offset = id_offset & OBJECT_HEAP_OFFSET_MASK;
heap->heap_size = 0;
heap->heap_increment = 16;
heap->heap_index = NULL;
heap->next_free = LAST_FREE;
return object_heap_expand(heap);
}
/*
* Allocates an object
* Returns the object ID on success, returns -1 on error
*/
int object_heap_allocate( object_heap_p heap )
{
object_base_p obj;
if ( LAST_FREE == heap->next_free )
{
if( -1 == object_heap_expand( heap ) )
{
return -1; /* Out of memory */
}
}
ASSERT( heap->next_free >= 0 );
obj = (object_base_p) (heap->heap_index + heap->next_free * heap->object_size);
heap->next_free = obj->next_free;
obj->next_free = ALLOCATED;
return obj->id;
}
/*
* Lookup an 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 )
{
object_base_p obj;
if ( (id < heap->id_offset) || (id > (heap->heap_size+heap->id_offset)) )
{
return NULL;
}
id &= OBJECT_HEAP_ID_MASK;
obj = (object_base_p) (heap->heap_index + id * heap->object_size);
/* Check if the object has in fact been allocated */
if ( obj->next_free != ALLOCATED )
{
return NULL;
}
return obj;
}
/*
* 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 )
{
*iter = -1;
return object_heap_next( heap, 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 )
{
object_base_p obj;
int i = *iter + 1;
while ( i < heap->heap_size)
{
obj = (object_base_p) (heap->heap_index + i * heap->object_size);
if (obj->next_free == ALLOCATED)
{
*iter = i;
return obj;
}
i++;
}
*iter = i;
return NULL;
}
/*
* Frees an object
*/
void object_heap_free( object_heap_p heap, object_base_p obj )
{
/* Don't complain about NULL pointers */
if (NULL != obj)
{
/* Check if the object has in fact been allocated */
ASSERT( obj->next_free == ALLOCATED );
obj->next_free = heap->next_free;
heap->next_free = obj->id & OBJECT_HEAP_ID_MASK;
}
}
/*
* Destroys a heap, the heap must be empty.
*/
void object_heap_destroy( object_heap_p heap )
{
object_base_p obj;
int i;
/* Check if heap is empty */
for (i = 0; i < heap->heap_size; i++)
{
/* Check if object is not still allocated */
obj = (object_base_p) (heap->heap_index + i * heap->object_size);
ASSERT( obj->next_free != ALLOCATED );
}
free(heap->heap_index);
heap->heap_size = 0;
heap->heap_index = NULL;
heap->next_free = LAST_FREE;
}
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