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#include <stdbool.h> // bool
#include <stdint.h> // uint64_t
#include <stdlib.h> // bsearch(), qsort()
#include <string.h> // memcpy
#include <stdio.h> // debug
#include "sok.h"
#define UNUSED(a) ((void) (a))
#define GROW_SIZE (4096 / sizeof(uint64_t))
#define USE_QSORT 1
static int
u64_cmp(
const void * const ap,
const void * const bp
) {
const uint64_t a = *((uint64_t*) ap),
b = *((uint64_t*) bp);
return (a > b) ? -1 : ((a == b) ? 0 : 1);
}
static bool
sok_cache_grow(
sok_cache_t * const cache
) {
// calculate new capacity
const size_t new_capacity = cache->capacity + GROW_SIZE;
if (new_capacity < cache->capacity) {
return false;
}
// reallocate memory
uint64_t * const vals = realloc(cache->vals, new_capacity * sizeof(uint64_t));
if (!vals) {
return false;
}
// update data
cache->vals = vals;
cache->capacity = new_capacity;
// return success
return true;
}
static bool
sok_cache_has_hash(
const sok_cache_t * const cache,
const uint64_t hash
) {
#if 0
for (size_t i = 0; i < cache->num_vals; i++) {
if (cache->vals[i] == hash) {
return true;
}
}
// return failure
return false;
#else
return !!bsearch(
&hash,
cache->vals,
cache->num_vals,
sizeof(uint64_t),
u64_cmp
);
#endif /* 0 */
}
bool
sok_cache_has(
const sok_cache_t * const cache,
const sok_ctx_t * const ctx
) {
return sok_cache_has_hash(cache, sok_ctx_hash(ctx));
}
bool
sok_cache_add(
sok_cache_t * const cache,
const sok_ctx_t * const ctx
) {
/*
* // hash context
* const uint64_t hash = sok_ctx_hash(ctx);
*
* // check for duplicates
* if (sok_cache_has_hash(cache, hash)) {
* return false;
* }
*/
// check capacity
if (cache->num_vals >= cache->capacity) {
// grow cache
if (!sok_cache_grow(cache)) {
// return failure
return false;
}
}
// append hash
const uint64_t hash = sok_ctx_hash(ctx);
#if USE_QSORT
cache->vals[cache->num_vals] = hash;
cache->num_vals++;
// sort values
qsort(cache->vals, cache->num_vals, sizeof(uint64_t), u64_cmp);
#else
size_t i;
for (i = 0; cache->vals[i] < hash && i < cache->num_vals; i++);
if (i < cache->num_vals) {
if (cache->vals[i] == hash) {
return true;
}
// move remaining data
const size_t num_bytes = (cache->num_vals - i) * sizeof(uint64_t);
memmove(cache->vals + (i + 1), cache->vals + i, num_bytes);
// insert value
cache->vals[i] = hash;
cache->num_vals++;
} else {
// append value
cache->vals[cache->num_vals] = hash;
cache->num_vals++;
}
#endif /* USE_QSORT */
// return success
return true;
}
bool
sok_cache_init(
sok_cache_t * const cache,
const size_t capacity
) {
// alloc memory, check for error
uint64_t * const vals = malloc(capacity * sizeof(uint64_t));
if (!vals) {
// return failure
return false;
}
// populate cache
cache->vals = vals;
cache->num_vals = 0;
cache->capacity = capacity;
// return success
return true;
}
void
sok_cache_fini(
sok_cache_t * const cache
) {
if (cache->vals) {
// free memory
free(cache->vals);
cache->vals = NULL;
}
}
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