// Licensed to the LF AI & Data foundation under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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.

#include "common/FastMem.h"

#include <algorithm>
#include <array>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <vector>

#include <benchmark/benchmark.h>

namespace milvus::fastmem {
namespace {

constexpr size_t kBufferSize = 4096;

std::vector<uint8_t>
MakeBenchmarkSource() {
    std::vector<uint8_t> source(kBufferSize);
    for (size_t i = 0; i < source.size(); ++i) {
        source[i] = static_cast<uint8_t>((i * 131 + 17) & 0xFF);
    }
    return source;
}

void
StdMemcpyBenchmark(benchmark::State& state) {
    auto source = MakeBenchmarkSource();
    std::vector<uint8_t> destination(kBufferSize);
    auto size = static_cast<size_t>(state.range(0));
    for (auto _ : state) {
        std::memcpy(destination.data(), source.data(), size);
        benchmark::DoNotOptimize(destination.data());
        benchmark::DoNotOptimize(source.data());
        benchmark::ClobberMemory();
    }
    state.SetBytesProcessed(state.iterations() * static_cast<int64_t>(size));
}

void
FastMemcpyBenchmark(benchmark::State& state) {
    auto source = MakeBenchmarkSource();
    std::vector<uint8_t> destination(kBufferSize);
    auto size = static_cast<size_t>(state.range(0));
    for (auto _ : state) {
        FastMemcpy(destination.data(), source.data(), size);
        benchmark::DoNotOptimize(destination.data());
        benchmark::DoNotOptimize(source.data());
        benchmark::ClobberMemory();
    }
    state.SetBytesProcessed(state.iterations() * static_cast<int64_t>(size));
}

void
ApplyFastMemArgs(benchmark::internal::Benchmark* benchmark) {
    for (auto size : std::array<int64_t, 9>{1, 2, 4, 8, 16, 32, 64, 128, 256}) {
        benchmark->Arg(size);
    }
}

}  // namespace
}  // namespace milvus::fastmem

BENCHMARK(milvus::fastmem::StdMemcpyBenchmark)
    ->Apply(milvus::fastmem::ApplyFastMemArgs);
BENCHMARK(milvus::fastmem::FastMemcpyBenchmark)
    ->Apply(milvus::fastmem::ApplyFastMemArgs);

BENCHMARK_MAIN();
