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/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
#include "utils/s2n_set.h"
#include "utils/s2n_array.h"
#include "utils/s2n_blob.h"
#include "utils/s2n_mem.h"
#include "utils/s2n_result.h"
#include "utils/s2n_safety.h"
#define S2N_INITIAL_SET_SIZE 16
S2N_RESULT s2n_set_validate(const struct s2n_set *set)
{
RESULT_ENSURE_REF(set);
RESULT_GUARD(s2n_array_validate(set->data));
return S2N_RESULT_OK;
}
/* Sets "out" to the index at which the element should be inserted.
* Returns an error if the element already exists */
static S2N_RESULT s2n_set_binary_search(struct s2n_set *set, void *element, uint32_t *out)
{
RESULT_GUARD(s2n_set_validate(set));
RESULT_ENSURE(S2N_MEM_IS_READABLE(element, set->data->element_size), S2N_ERR_NULL);
RESULT_ENSURE_REF(out);
struct s2n_array *array = set->data;
int (*comparator)(const void *, const void *) = set->comparator;
uint32_t len = 0;
RESULT_GUARD(s2n_array_num_elements(array, &len));
if (len == 0) {
*out = 0;
return S2N_RESULT_OK;
}
/* Use 64 bit ints to avoid possibility of overflow */
int64_t low = 0;
int64_t top = len - 1;
while (low <= top) {
int64_t mid = low + ((top - low) / 2);
void *array_element = NULL;
RESULT_GUARD(s2n_array_get(array, mid, &array_element));
int m = comparator(array_element, element);
/* the element is already in the set */
if (m == 0) {
RESULT_BAIL(S2N_ERR_SET_DUPLICATE_VALUE);
}
if (m > 0) {
top = mid - 1;
} else {
low = mid + 1;
}
}
*out = low;
return S2N_RESULT_OK;
}
struct s2n_set *s2n_set_new(uint32_t element_size, int (*comparator)(const void *, const void *))
{
PTR_ENSURE_REF(comparator);
struct s2n_blob mem = { 0 };
PTR_GUARD_POSIX(s2n_alloc(&mem, sizeof(struct s2n_set)));
struct s2n_set *set = (void *) mem.data;
*set = (struct s2n_set){ .data = s2n_array_new(element_size), .comparator = comparator };
if (set->data == NULL) {
PTR_GUARD_POSIX(s2n_free(&mem));
return NULL;
}
return set;
}
S2N_RESULT s2n_set_add(struct s2n_set *set, void *element)
{
RESULT_GUARD(s2n_set_validate(set));
uint32_t idx = 0;
RESULT_GUARD(s2n_set_binary_search(set, element, &idx));
RESULT_GUARD(s2n_array_insert_and_copy(set->data, idx, element));
return S2N_RESULT_OK;
}
S2N_RESULT s2n_set_get(struct s2n_set *set, uint32_t idx, void **element)
{
RESULT_GUARD(s2n_set_validate(set));
RESULT_ENSURE_REF(element);
RESULT_GUARD(s2n_array_get(set->data, idx, element));
return S2N_RESULT_OK;
}
S2N_RESULT s2n_set_remove(struct s2n_set *set, uint32_t idx)
{
RESULT_GUARD(s2n_set_validate(set));
RESULT_GUARD(s2n_array_remove(set->data, idx));
return S2N_RESULT_OK;
}
S2N_RESULT s2n_set_free_p(struct s2n_set **pset)
{
RESULT_ENSURE_REF(pset);
struct s2n_set *set = *pset;
RESULT_ENSURE_REF(set);
RESULT_GUARD(s2n_array_free(set->data));
/* And finally the set object. */
RESULT_GUARD_POSIX(s2n_free_object((uint8_t **) pset, sizeof(struct s2n_set)));
return S2N_RESULT_OK;
}
S2N_RESULT s2n_set_free(struct s2n_set *set)
{
RESULT_ENSURE_REF(set);
return s2n_set_free_p(&set);
}
S2N_RESULT s2n_set_len(struct s2n_set *set, uint32_t *len)
{
RESULT_GUARD(s2n_set_validate(set));
RESULT_GUARD(s2n_array_num_elements(set->data, len));
return S2N_RESULT_OK;
}
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