/* creates a new counting bloom filter from a given scaling bloom filter, with count and id */
counting_bloom_t *new_counting_bloom_from_scale(scaling_bloom_t *bloom)
{
int i;
long offset;
double error_rate;
counting_bloom_t *cur_bloom;
error_rate = bloom->error_rate * (pow(ERROR_TIGHTENING_RATIO, bloom->num_blooms + 1));
if ((bloom->blooms = (counting_bloom_t **)realloc(bloom->blooms, (bloom->num_blooms + 1) * sizeof(counting_bloom_t *))) == NULL) {
fprintf(stderr, "Error, could not realloc a new bloom filter\n");
return NULL;
}
cur_bloom = counting_bloom_init(bloom->capacity, error_rate, bloom->num_bytes);
bloom->blooms[bloom->num_blooms] = cur_bloom;
bloom->bitmap = bitmap_resize(bloom->bitmap, bloom->num_bytes, bloom->num_bytes + cur_bloom->num_bytes);
/* reset header pointer, as mmap may have moved */
bloom->header = (scaling_bloom_header_t *) bloom->bitmap->array;
/* Set the pointers for these header structs to the right location since mmap may have moved */
bloom->num_blooms++;
for (i = 0; i < bloom->num_blooms; i++) {
offset = bloom->blooms[i]->offset - sizeof(counting_bloom_header_t);
bloom->blooms[i]->header = (counting_bloom_header_t *) (bloom->bitmap->array + offset);
}
bloom->num_bytes += cur_bloom->num_bytes;
cur_bloom->bitmap = bloom->bitmap;
return cur_bloom;
}
/*
* Create a new bitmap, not full featured, simple to give
* us a means of interacting with the 4 bit counters.
*/
bitmap_t *new_bitmap(size_t bytes)
{
bitmap_t *bitmap;
if ((bitmap = (bitmap_t *)malloc(sizeof(bitmap_t))) == NULL) {
return NULL;
}
bitmap->bytes = bytes;
bitmap->array = NULL;
if ((bitmap = bitmap_resize(bitmap, 0, bytes)) == NULL) {
return NULL;
}
return bitmap;
}
void bitmap_copy(BITMAP *dest, BITMAP *src) {
bitmap_resize(dest, src->width, src->height);
memcpy(dest->buffer, src->buffer, src->stride * src->height);
}
