fc8dc48020
git-subtree-dir: third_party/abseil_cpp git-subtree-mainline:ffb2ae54begit-subtree-split:768eb2ca28
106 lines
3.2 KiB
C++
106 lines
3.2 KiB
C++
// Copyright 2018 The Abseil Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "absl/strings/internal/ostringstream.h"
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#include <sstream>
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#include <string>
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#include "benchmark/benchmark.h"
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namespace {
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enum StringType {
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kNone,
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kStdString,
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};
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// Benchmarks for std::ostringstream.
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template <StringType kOutput>
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void BM_StdStream(benchmark::State& state) {
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const int num_writes = state.range(0);
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const int bytes_per_write = state.range(1);
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const std::string payload(bytes_per_write, 'x');
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for (auto _ : state) {
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std::ostringstream strm;
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benchmark::DoNotOptimize(strm);
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for (int i = 0; i != num_writes; ++i) {
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strm << payload;
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}
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switch (kOutput) {
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case kNone: {
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break;
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}
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case kStdString: {
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std::string s = strm.str();
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benchmark::DoNotOptimize(s);
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break;
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}
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}
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}
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}
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// Create the stream, optionally write to it, then destroy it.
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BENCHMARK_TEMPLATE(BM_StdStream, kNone)
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->ArgPair(0, 0)
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->ArgPair(1, 16) // 16 bytes is small enough for SSO
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->ArgPair(1, 256) // 256 bytes requires heap allocation
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->ArgPair(1024, 256);
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// Create the stream, write to it, get std::string out, then destroy.
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BENCHMARK_TEMPLATE(BM_StdStream, kStdString)
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->ArgPair(1, 16) // 16 bytes is small enough for SSO
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->ArgPair(1, 256) // 256 bytes requires heap allocation
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->ArgPair(1024, 256);
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// Benchmarks for OStringStream.
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template <StringType kOutput>
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void BM_CustomStream(benchmark::State& state) {
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const int num_writes = state.range(0);
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const int bytes_per_write = state.range(1);
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const std::string payload(bytes_per_write, 'x');
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for (auto _ : state) {
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std::string out;
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absl::strings_internal::OStringStream strm(&out);
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benchmark::DoNotOptimize(strm);
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for (int i = 0; i != num_writes; ++i) {
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strm << payload;
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}
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switch (kOutput) {
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case kNone: {
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break;
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}
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case kStdString: {
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std::string s = out;
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benchmark::DoNotOptimize(s);
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break;
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}
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}
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}
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}
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// Create the stream, optionally write to it, then destroy it.
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BENCHMARK_TEMPLATE(BM_CustomStream, kNone)
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->ArgPair(0, 0)
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->ArgPair(1, 16) // 16 bytes is small enough for SSO
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->ArgPair(1, 256) // 256 bytes requires heap allocation
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->ArgPair(1024, 256);
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// Create the stream, write to it, get std::string out, then destroy.
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// It's not useful in practice to extract std::string from OStringStream; we
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// measure it for completeness.
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BENCHMARK_TEMPLATE(BM_CustomStream, kStdString)
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->ArgPair(1, 16) // 16 bytes is small enough for SSO
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->ArgPair(1, 256) // 256 bytes requires heap allocation
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->ArgPair(1024, 256);
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} // namespace
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