/*
* Copyright (c) 2009-2015 ZIH, TU Dresden, Federal Republic of Germany. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* 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.
*
*/
/*
* Abstract:
* This file contains a d-ary heap implementation.
* The default is a minimum heap, however the caller can overwrite
* the compare function for the keys of the heap.
*
*/
#if HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */
#include <stdlib.h>
#include <string.h>
#include <complib/cl_heap.h>
typedef struct _cl_heap_elem {
uint64_t key;
void *context;
} cl_heap_elem_t;
static int compare_keys(IN const void *p_key_1, IN const void *p_key_2)
{
uint64_t key1, key2;
CL_ASSERT(p_key_1);
CL_ASSERT(p_key_2);
key1 = *((uint64_t *) p_key_1);
key2 = *((uint64_t *) p_key_2);
return ((key1 < key2) ? -1 : ((key1 > key2) ? 1 : 0));
}
void cl_heap_construct(IN cl_heap_t * const p_heap)
{
CL_ASSERT(p_heap);
memset(p_heap, 0, sizeof(cl_heap_t));
p_heap->state = CL_UNINITIALIZED;
}
cl_status_t cl_heap_init(IN cl_heap_t * const p_heap, IN const size_t max_size,
IN const uint8_t d,
IN cl_pfn_heap_apply_index_update_t pfn_index_update,
IN cl_pfn_heap_compare_keys_t pfn_compare OPTIONAL)
{
CL_ASSERT(p_heap);
if (!cl_is_state_valid(p_heap->state))
cl_heap_construct(p_heap);
if (max_size <= 0 || !d || !pfn_index_update)
return (CL_INVALID_PARAMETER);
if (cl_is_heap_inited(p_heap))
cl_heap_destroy(p_heap);
p_heap->branching_factor = d;
p_heap->size = 0;
p_heap->capacity = max_size;
p_heap->pfn_index_update = pfn_index_update;
if (pfn_compare)
p_heap->pfn_compare = pfn_compare;
else
p_heap->pfn_compare = &compare_keys;
p_heap->element_array =
(cl_heap_elem_t *) malloc(max_size * sizeof(cl_heap_elem_t));
if (!p_heap->element_array)
return (CL_INSUFFICIENT_MEMORY);
memset(p_heap->element_array, 0, max_size * sizeof(cl_heap_elem_t));
p_heap->state = CL_INITIALIZED;
return (CL_SUCCESS);
}
void cl_heap_destroy(IN cl_heap_t * const p_heap)
{
CL_ASSERT(p_heap);
CL_ASSERT(cl_is_state_valid(p_heap->state));
if (p_heap->element_array)
free(p_heap->element_array);
cl_heap_construct(p_heap);
}
cl_status_t cl_heap_resize(IN cl_heap_t * const p_heap,
IN const size_t new_size)
{
cl_heap_elem_t *realloc_element_array = NULL;
CL_ASSERT(p_heap);
CL_ASSERT(cl_is_heap_inited(p_heap));
if (new_size <= 0 || new_size < p_heap->size)
return (CL_INVALID_PARAMETER);
if (new_size == p_heap->capacity)
return (CL_SUCCESS);
realloc_element_array =
(cl_heap_elem_t *) realloc(p_heap->element_array,
new_size * sizeof(cl_heap_elem_t));
if (!realloc_element_array)
return (CL_INSUFFICIENT_MEMORY);
p_heap->element_array = realloc_element_array;
memset(p_heap->element_array + p_heap->size, 0,
(new_size - p_heap->size) * sizeof(cl_heap_elem_t));
p_heap->capacity = new_size;
return (CL_SUCCESS);
}
static void heap_down(IN cl_heap_t * const p_heap, IN const size_t index)
{
int64_t first_child, swap_child, child, parent, d;
cl_heap_elem_t tmp = p_heap->element_array[index];
boolean_t swapped = FALSE;
d = (int64_t) p_heap->branching_factor;
parent = index;
while (parent * d + 1 < p_heap->size) {
swap_child = first_child = parent * d + 1;
/* find the min (or max) child among the children */
for (child = first_child + 1;
child < first_child + d && child < p_heap->size; child++)
if (p_heap->
pfn_compare(&(p_heap->element_array[child].key),
&(p_heap->element_array[swap_child].
key)) <= 0)
swap_child = child;
/* exchange parent and one child */
if (p_heap->
pfn_compare(&(tmp.key),
&(p_heap->element_array[swap_child].key)) > 0) {
p_heap->element_array[parent] =
p_heap->element_array[swap_child];
p_heap->pfn_index_update(p_heap->element_array[parent].
context, parent);
parent = swap_child;
swapped = TRUE;
} else
break;
}
/* move the original element down in the heap */
if (swapped) {
p_heap->element_array[parent] = tmp;
p_heap->pfn_index_update(p_heap->element_array[parent].context,
parent);
}
}
static void heap_up(IN cl_heap_t * const p_heap, IN const size_t index)
{
int64_t parent, child, swap_child = 0, d;
boolean_t swapped = FALSE;
if (!index)
return;
cl_heap_elem_t tmp = p_heap->element_array[index];
d = (int64_t) p_heap->branching_factor;
parent = index;
do {
child = parent;
parent = (child - 1) / d;
if (p_heap->
pfn_compare(&(tmp.key),
&(p_heap->element_array[parent].key)) < 0) {
/* move the parent down and notify the user context about the change */
p_heap->element_array[child] =
p_heap->element_array[parent];
p_heap->pfn_index_update(p_heap->element_array[child].
context, child);
swap_child = parent;
swapped = TRUE;
} else
break;
} while (parent > 0);
/* write original heap element to the correct position */
if (swapped) {
p_heap->element_array[swap_child] = tmp;
p_heap->pfn_index_update(p_heap->element_array[swap_child].
context, swap_child);
}
}
cl_status_t cl_heap_modify_key(IN cl_heap_t * const p_heap,
IN const uint64_t key, IN const size_t index)
{
uint64_t old_key;
int compare_result;
CL_ASSERT(p_heap);
CL_ASSERT(cl_is_heap_inited(p_heap));
if (index < 0 || index >= p_heap->size)
return (CL_INVALID_PARAMETER);
old_key = p_heap->element_array[index].key;
p_heap->element_array[index].key = key;
compare_result = p_heap->pfn_compare(&key, &old_key);
if (compare_result < 0)
heap_up(p_heap, index);
else if (compare_result > 0)
heap_down(p_heap, index);
return (CL_SUCCESS);
}
cl_status_t cl_heap_insert(IN cl_heap_t * const p_heap, IN const uint64_t key,
IN const void *const context)
{
CL_ASSERT(p_heap);
CL_ASSERT(cl_is_heap_inited(p_heap));
if (!context)
return (CL_INVALID_PARAMETER);
if (p_heap->size == p_heap->capacity)
return (CL_INSUFFICIENT_RESOURCES);
p_heap->element_array[p_heap->size].key = key;
p_heap->element_array[p_heap->size].context = (void *) context;
p_heap->pfn_index_update(context, p_heap->size);
heap_up(p_heap, p_heap->size++);
return (CL_SUCCESS);
}
void *cl_heap_delete(IN cl_heap_t * const p_heap, IN const size_t index)
{
int64_t parent, d;
int compare_result;
cl_heap_elem_t tmp;
CL_ASSERT(p_heap);
CL_ASSERT(cl_is_heap_inited(p_heap));
if (!p_heap->size)
return NULL;
if (index < 0 || index >= p_heap->size)
return NULL;
if (p_heap->size == 1)
return p_heap->element_array[--(p_heap->size)].context;
tmp = p_heap->element_array[--(p_heap->size)];
p_heap->element_array[p_heap->size] = p_heap->element_array[index];
p_heap->pfn_index_update(p_heap->element_array[p_heap->size].context,
p_heap->size);
p_heap->element_array[index] = tmp;
p_heap->pfn_index_update(p_heap->element_array[index].context, index);
if (0 == index)
heap_down(p_heap, index);
else {
d = (int64_t) p_heap->branching_factor;
parent = (index - 1) / d;
compare_result =
p_heap->pfn_compare(&(p_heap->element_array[parent].key),
&(p_heap->element_array[index].key));
/* if the parent is smaller than tmp (which we moved within
* the head), then we have to attempt a heap_down
*/
if (compare_result < 0)
heap_down(p_heap, index);
/* otherwise heap_up is needed to restore the heap property */
else if (compare_result > 0)
heap_up(p_heap, index);
}
return p_heap->element_array[p_heap->size].context;
}
void *cl_heap_extract_root(IN cl_heap_t * const p_heap)
{
return cl_heap_delete(p_heap, 0);
}
boolean_t cl_is_stored_in_heap(IN const cl_heap_t * const p_heap,
IN const void *const ctx, IN const size_t index)
{
CL_ASSERT(p_heap);
CL_ASSERT(cl_is_heap_inited(p_heap));
return ((index < 0 || index >= p_heap->size ||
p_heap->element_array[index].context != ctx) ? FALSE : TRUE);
}
boolean_t cl_verify_heap_property(IN const cl_heap_t * const p_heap)
{
int64_t first_child, child, parent, d;
CL_ASSERT(p_heap);
CL_ASSERT(cl_is_heap_inited(p_heap));
d = (int64_t) p_heap->branching_factor;
parent = 0;
while (parent < p_heap->size) {
first_child = parent * d + 1;
/* find the min (or max) child among the children */
for (child = first_child;
child < first_child + d && child < p_heap->size; child++)
if (p_heap->
pfn_compare(&(p_heap->element_array[parent].key),
&(p_heap->element_array[child].key)) >
0)
return FALSE;
parent++;
}
return TRUE;
}