+/*
+ * Copyright 2015 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License 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.
+ */
+
+/***
+ * A benchmark comparing SparseByteSet to bitset<256> and bool[256].
+ */
+
+#include <bitset>
+#include <random>
+#include <vector>
+#include <gflags/gflags.h>
+#include <folly/Benchmark.h>
+#include <folly/Format.h>
+#include <folly/SparseByteSet.h>
+
+using namespace std;
+using namespace folly;
+
+namespace {
+
+// Interface-identical to SparseByteSet. So that we can do compile-time
+// polymorphism.
+class BitSetWrapper {
+ public:
+ inline bool add(uint8_t i) {
+ auto r = !contains(i);
+ if (r) {
+ rep_[i] = true;
+ }
+ return r;
+ }
+ inline bool contains(uint8_t i) {
+ return rep_[i];
+ }
+ private:
+ bitset<256> rep_;
+};
+class BoolArraySet {
+ public:
+ BoolArraySet() {
+ memset(rep_, 0, sizeof(rep_));
+ }
+ inline bool add(uint8_t i) {
+ auto r = !contains(i);
+ if (r) {
+ rep_[i] = true;
+ }
+ return r;
+ }
+ inline bool contains(uint8_t i) {
+ return rep_[i];
+ }
+ private:
+ bool rep_[256];
+};
+
+template <typename Coll>
+void rand_bench(int iters, size_t size_add, size_t size_contains) {
+ BenchmarkSuspender braces;
+ vector<uint8_t> seq_add;
+ vector<uint8_t> seq_contains;
+ mt19937 rng;
+ uniform_int_distribution<uint8_t> dist;
+ for (size_t i = 0; i < size_add; ++i) {
+ seq_add.push_back(dist(rng));
+ }
+ for (size_t i = 0; i < size_contains; ++i) {
+ seq_contains.push_back(dist(rng));
+ }
+ braces.dismissing([&] {
+ while (iters--) {
+ Coll coll;
+ for (auto b : seq_add) {
+ coll.add(b);
+ }
+ bool q {};
+ for (auto b : seq_contains) {
+ q ^= coll.contains(b);
+ }
+ doNotOptimizeAway(q);
+ }
+ });
+}
+
+void setup_rand_bench() {
+ vector<pair<size_t, size_t>> rand_bench_params = {
+ {4, 4},
+ {4, 16},
+ {4, 64},
+ {4, 256},
+ {16, 4},
+ {16, 16},
+ {16, 64},
+ {16, 256},
+ {64, 4},
+ {64, 16},
+ {64, 64},
+ {64, 256},
+ {256, 4},
+ {256, 16},
+ {256, 64},
+ {256, 256},
+ };
+ for (auto kvp : rand_bench_params) {
+ size_t size_add, size_contains;
+ tie(size_add, size_contains) = kvp;
+ addBenchmark(
+ __FILE__,
+ sformat("bitset_rand_bench({}, {})",
+ size_add, size_contains).c_str(),
+ [=](int iters) {
+ rand_bench<BitSetWrapper>(iters, size_add, size_contains);
+ return iters;
+ });
+ addBenchmark(
+ __FILE__,
+ sformat("\%bool_array_set_rand_bench({}, {})",
+ size_add, size_contains).c_str(),
+ [=](int iters) {
+ rand_bench<BoolArraySet>(iters, size_add, size_contains);
+ return iters;
+ });
+ addBenchmark(
+ __FILE__,
+ sformat("\%sparse_byte_set_rand_bench({}, {})",
+ size_add, size_contains).c_str(),
+ [=](int iters) {
+ rand_bench<SparseByteSet>(iters, size_add, size_contains);
+ return iters;
+ });
+ addBenchmark(
+ __FILE__,
+ "-",
+ [](int) { return 0; });
+ }
+}
+
+}
+
+int main(int argc, char** argv) {
+ google::ParseCommandLineFlags(&argc, &argv, true);
+ setup_rand_bench();
+ runBenchmarks();
+ return 0;
+}