// Copyright 2024 The Division Authors.

//

// 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

//

// https://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.

// Author dietoad@gmail.com && firedtoad@gmail.com

#include <array>

#include <benchmark/benchmark.h>

#include <fcntl.h>

#include <sys/socket.h>

#include <sys/uio.h>

#include <unistd.h>

#include <vector>

template <size_t N> static void BenchReadWrite(benchmark::State &state)

{

int fd[2];

socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0, fd);

char rBuff[N];

char wBuff[N];

for (auto _ : state)

{

for (size_t i = 0; i < N; i++)

{

int w = write(fd[0], wBuff, N);

int r = read(fd[1], rBuff, N);

benchmark::DoNotOptimize(w);

benchmark::DoNotOptimize(r);

}

}

close(fd[0]);

close(fd[1]);

}

BENCHMARK_TEMPLATE(BenchReadWrite, 16);

BENCHMARK_TEMPLATE(BenchReadWrite, 16);

template <size_t N> static void BenchReadWriteV(benchmark::State &state)

{

int fd[2];

socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0, fd);

struct iovec rVec[N];

struct iovec wVec[N];

std::vector<std::array<char, N>> rVecBuff(N);

std::vector<std::array<char, N>> wVecBuff(N);

for (size_t i = 0; i < N; i++)

{

rVec[i].iov_base = rVecBuff[i].data();

rVec[i].iov_len = rVecBuff[i].size();

wVec[i].iov_base = wVecBuff[i].data();

wVec[i].iov_len = wVecBuff[i].size();

}

for (auto _ : state)

{

int w = writev(fd[0], wVec, N);

int r = readv(fd[1], rVec, N);

benchmark::DoNotOptimize(w);

benchmark::DoNotOptimize(r);

}

close(fd[0]);

close(fd[1]);

}

BENCHMARK_TEMPLATE(BenchReadWriteV, 1);

BENCHMARK_TEMPLATE(BenchReadWriteV, 1);

int main(int argc, char **argv)

{

benchmark::Initialize(&argc, argv);

benchmark::RunSpecifiedBenchmarks();

return 0;

}