Files
scylla/utils/i_filter.cc
Avi Kivity fcb8d040e8 treewide: use Software Package Data Exchange (SPDX) license identifiers
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.

Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.

The changes we applied mechanically with a script, except to
licenses/README.md.

Closes #9937
2022-01-18 12:15:18 +01:00

41 lines
1.1 KiB
C++

/*
* Copyright (C) 2015-present ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#include "log.hh"
#include "bloom_filter.hh"
#include "bloom_calculations.hh"
#include <seastar/core/thread.hh>
namespace utils {
static logging::logger filterlog("bloom_filter");
filter_ptr i_filter::get_filter(int64_t num_elements, double max_false_pos_probability, filter_format fformat) {
assert(seastar::thread::running_in_thread());
if (max_false_pos_probability > 1.0) {
throw std::invalid_argument(format("Invalid probability {:f}: must be lower than 1.0", max_false_pos_probability));
}
if (max_false_pos_probability == 1.0) {
return std::make_unique<filter::always_present_filter>();
}
int buckets_per_element = bloom_calculations::max_buckets_per_element(num_elements);
auto spec = bloom_calculations::compute_bloom_spec(buckets_per_element, max_false_pos_probability);
return filter::create_filter(spec.K, num_elements, spec.buckets_per_element, fformat);
}
hashed_key make_hashed_key(bytes_view b) {
std::array<uint64_t, 2> h;
utils::murmur_hash::hash3_x64_128(b, 0, h);
return { h };
}
}