/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* 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.
*/
#include <boost/algorithm/string.hpp>
#include <random>
#include <fmt/format.h>
#include <folly/Benchmark.h>
#include <folly/Format.h>
#include <folly/Random.h>
#include <folly/String.h>
using namespace folly;
using namespace std;
BENCHMARK(libc_tolower, iters) {
static const size_t kSize = 256;
// This array is static to keep the compiler from optimizing the
// entire function down to a no-op if it has an inlined impl of
// tolower and thus is able to tell that there are no side-effects.
// No side-effects + no writes to anything other than local variables
// + no return value = no need to run any of the code in the function.
// gcc, for example, makes that optimization with -O2.
static char input[kSize];
for (size_t i = 0; i < kSize; i++) {
input[i] = (char)(i & 0xff);
}
for (auto i = iters; i > 0; i--) {
for (size_t offset = 0; offset < kSize; offset++) {
input[offset] = tolower(input[offset]);
}
}
}
BENCHMARK(folly_toLowerAscii, iters) {
static const size_t kSize = 256;
static char input[kSize];
for (size_t i = 0; i < kSize; i++) {
input[i] = (char)(i & 0xff);
}
for (auto i = iters; i > 0; i--) {
folly::toLowerAscii(input, kSize);
}
}
// A simple benchmark that tests various output sizes for a simple
// input; the goal is to measure the output buffer resize code cost.
const size_t kAppendBufSize = 300000;
void stringPrintfOutputSize(int iters, int param) {
string buffer;
BENCHMARK_SUSPEND {
buffer.resize(param, 'x');
}
for (int64_t i = 0; i < iters; ++i) {
string s = stringPrintf("msg: %d, %d, %s", 10, 20, buffer.c_str());
}
}
// The first few of these tend to fit in the inline buffer, while the
// subsequent ones cross that limit, trigger a second vsnprintf, and
// exercise a different codepath.
BENCHMARK_PARAM(stringPrintfOutputSize, 1)
BENCHMARK_PARAM(stringPrintfOutputSize, 4)
BENCHMARK_PARAM(stringPrintfOutputSize, 16)
BENCHMARK_PARAM(stringPrintfOutputSize, 64)
BENCHMARK_PARAM(stringPrintfOutputSize, 256)
BENCHMARK_PARAM(stringPrintfOutputSize, 1024)
// Benchmark simple stringAppendf behavior to show a pathology Lovro
// reported (t5735468).
BENCHMARK(stringPrintfAppendfBenchmark, iters) {
for (size_t i = 0; i < iters; ++i) {
string s;
BENCHMARK_SUSPEND {
s.reserve(kAppendBufSize);
}
for (size_t j = 0; j < kAppendBufSize; ++j) {
stringAppendf(&s, "%d", 1);
}
DCHECK_EQ(s.size(), kAppendBufSize);
}
}
// A simple benchmark that tests various output sizes for a simple
// input; the goal is to measure the output buffer resize code cost.
// Intended for comparison with stringPrintf.
void fmtOutputSize(int iters, int param) {
string buffer;
BENCHMARK_SUSPEND {
buffer.resize(param, 'x');
}
for (int64_t i = 0; i < iters; ++i) {
string s = fmt::format("msg: {}, {}, {}", 10, 20, buffer);
}
}
// The first few of these tend to fit in the inline buffer, while the
// subsequent ones cross that limit, trigger a second vsnprintf, and
// exercise a different codepath.
BENCHMARK_PARAM(fmtOutputSize, 1)
BENCHMARK_PARAM(fmtOutputSize, 4)
BENCHMARK_PARAM(fmtOutputSize, 16)
BENCHMARK_PARAM(fmtOutputSize, 64)
BENCHMARK_PARAM(fmtOutputSize, 256)
BENCHMARK_PARAM(fmtOutputSize, 1024)
// Benchmark simple fmt append behavior; intended as a comparison
// against stringAppendf.
BENCHMARK(fmtAppendfBenchmark, iters) {
for (size_t i = 0; i < iters; ++i) {
fmt::memory_buffer buf;
for (size_t j = 0; j < kAppendBufSize; ++j) {
fmt::format_to(std::back_inserter(buf), "{}", 1);
}
string s = fmt::to_string(buf);
DCHECK_EQ(s.size(), kAppendBufSize);
}
}
// A simple benchmark that tests various output sizes for a simple
// input; the goal is to measure the output buffer resize code cost.
// Intended for comparison with stringPrintf and fmt.
void follyFmtOutputSize(int iters, int param) {
string buffer;
BENCHMARK_SUSPEND {
buffer.resize(param, 'x');
}
for (int64_t i = 0; i < iters; ++i) {
string s = sformat("msg: {}, {}, {}", 10, 20, buffer);
}
}
// The first few of these tend to fit in the inline buffer, while the
// subsequent ones cross that limit, trigger a second vsnprintf, and
// exercise a different codepath.
BENCHMARK_PARAM(follyFmtOutputSize, 1)
BENCHMARK_PARAM(follyFmtOutputSize, 4)
BENCHMARK_PARAM(follyFmtOutputSize, 16)
BENCHMARK_PARAM(follyFmtOutputSize, 64)
BENCHMARK_PARAM(follyFmtOutputSize, 256)
BENCHMARK_PARAM(follyFmtOutputSize, 1024)
namespace {
fbstring cbmString;
fbstring cbmEscapedString;
fbstring cEscapedString;
fbstring cUnescapedString;
const size_t kCBmStringLength = 64 << 10;
const uint32_t kCPrintablePercentage = 90;
fbstring uribmString;
fbstring uribmEscapedString;
fbstring uriEscapedString;
fbstring uriUnescapedString;
const size_t kURIBmStringLength = 256;
const uint32_t kURIPassThroughPercentage = 50;
fbstring hexlifyInput;
fbstring hexlifyOutput;
const size_t kHexlifyLength = 1024;
void initBenchmark() {
std::mt19937 rnd;
// C escape
std::uniform_int_distribution<uint32_t> printable(32, 126);
std::uniform_int_distribution<uint32_t> nonPrintable(0, 160);
std::uniform_int_distribution<uint32_t> percentage(0, 99);
cbmString.reserve(kCBmStringLength);
for (size_t i = 0; i < kCBmStringLength; ++i) {
unsigned char c;
if (percentage(rnd) < kCPrintablePercentage) {
c = printable(rnd);
} else {
c = nonPrintable(rnd);
// Generate characters in both non-printable ranges:
// 0..31 and 127..255
if (c >= 32) {
c += (126 - 32) + 1;
}
}
cbmString.push_back(c);
}
cbmEscapedString = cEscape<fbstring>(cbmString);
// URI escape
std::uniform_int_distribution<uint32_t> passthrough('a', 'z');
std::string encodeChars = " ?!\"',+[]";
std::uniform_int_distribution<uint32_t> encode(0, encodeChars.size() - 1);
uribmString.reserve(kURIBmStringLength);
for (size_t i = 0; i < kURIBmStringLength; ++i) {
unsigned char c;
if (percentage(rnd) < kURIPassThroughPercentage) {
c = passthrough(rnd);
} else {
c = encodeChars[encode(rnd)];
}
uribmString.push_back(c);
}
uribmEscapedString = uriEscape<fbstring>(uribmString);
// hexlify
hexlifyInput.resize(kHexlifyLength);
Random::secureRandom(&hexlifyInput[0], kHexlifyLength);
folly::hexlify(hexlifyInput, hexlifyOutput);
}
BENCHMARK(BM_cEscape, iters) {
while (iters--) {
cEscapedString = cEscape<fbstring>(cbmString);
doNotOptimizeAway(cEscapedString.size());
}
}
BENCHMARK(BM_cUnescape, iters) {
while (iters--) {
cUnescapedString = cUnescape<fbstring>(cbmEscapedString);
doNotOptimizeAway(cUnescapedString.size());
}
}
BENCHMARK(BM_uriEscape, iters) {
while (iters--) {
uriEscapedString = uriEscape<fbstring>(uribmString);
doNotOptimizeAway(uriEscapedString.size());
}
}
BENCHMARK(BM_uriUnescape, iters) {
while (iters--) {
uriUnescapedString = uriUnescape<fbstring>(uribmEscapedString);
doNotOptimizeAway(uriUnescapedString.size());
}
}
BENCHMARK(BM_unhexlify, iters) {
// iters/sec = bytes output per sec
std::string unhexed;
folly::StringPiece hex = hexlifyOutput;
for (; iters >= hex.size(); iters -= hex.size()) {
folly::unhexlify(hex, unhexed);
}
iters -= iters % 2; // round down to an even number of chars
hex = hex.subpiece(0, iters);
folly::unhexlify(hex, unhexed);
}
} // namespace
//////////////////////////////////////////////////////////////////////
BENCHMARK(splitOnSingleChar, iters) {
static const std::string line = "one:two:three:four";
for (size_t i = 0; i < iters << 4; ++i) {
std::vector<StringPiece> pieces;
folly::split(':', line, pieces);
}
}
BENCHMARK(splitOnSingleCharFixed, iters) {
static const std::string line = "one:two:three:four";
for (size_t i = 0; i < iters << 4; ++i) {
StringPiece a, b, c, d;
folly::split(':', line, a, b, c, d);
}
}
BENCHMARK(splitOnSingleCharFixedAllowExtra, iters) {
static const std::string line = "one:two:three:four";
for (size_t i = 0; i < iters << 4; ++i) {
StringPiece a, b, c, d;
folly::split<false>(':', line, a, b, c, d);
}
}
BENCHMARK(splitStr, iters) {
static const std::string line = "one-*-two-*-three-*-four";
for (size_t i = 0; i < iters << 4; ++i) {
std::vector<StringPiece> pieces;
folly::split("-*-", line, pieces);
}
}
BENCHMARK(splitStrFixed, iters) {
static const std::string line = "one-*-two-*-three-*-four";
for (size_t i = 0; i < iters << 4; ++i) {
StringPiece a, b, c, d;
folly::split("-*-", line, a, b, c, d);
}
}
BENCHMARK(boost_splitOnSingleChar, iters) {
static const std::string line = "one:two:three:four";
bool (*pred)(char) = [](char c) -> bool { return c == ':'; };
for (size_t i = 0; i < iters << 4; ++i) {
std::vector<boost::iterator_range<std::string::const_iterator>> pieces;
boost::split(pieces, line, pred);
}
}
BENCHMARK(joinCharStr, iters) {
static const std::vector<std::string> input = {
"one", "two", "three", "four", "five", "six", "seven"};
for (size_t i = 0; i < iters << 4; ++i) {
std::string output;
folly::join(':', input, output);
}
}
BENCHMARK(joinStrStr, iters) {
static const std::vector<std::string> input = {
"one", "two", "three", "four", "five", "six", "seven"};
for (size_t i = 0; i < iters << 4; ++i) {
std::string output;
folly::join(":", input, output);
}
}
BENCHMARK(joinInt, iters) {
static const auto input = {123, 456, 78910, 1112, 1314, 151, 61718};
for (size_t i = 0; i < iters << 4; ++i) {
std::string output;
folly::join(":", input, output);
}
}
int main(int argc, char** argv) {
gflags::ParseCommandLineFlags(&argc, &argv, true);
initBenchmark();
folly::runBenchmarks();
return 0;
}
/*
Results on x86_64:
============================================================================
folly/test/StringBenchmark.cpp relative time/iter iters/s
============================================================================
libc_tolower 773.30ns 1.29M
folly_toLowerAscii 65.04ns 15.38M
stringPrintfOutputSize(1) 224.67ns 4.45M
stringPrintfOutputSize(4) 231.53ns 4.32M
stringPrintfOutputSize(16) 286.54ns 3.49M
stringPrintfOutputSize(64) 305.47ns 3.27M
stringPrintfOutputSize(256) 1.48us 674.45K
stringPrintfOutputSize(1024) 5.89us 169.72K
stringPrintfAppendfBenchmark 34.43ms 29.04
BM_cEscape 461.51us 2.17K
BM_cUnescape 328.19us 3.05K
BM_uriEscape 4.36us 229.25K
BM_uriUnescape 2.22us 450.64K
splitOnSingleChar 1.46us 687.21K
splitOnSingleCharFixed 133.02ns 7.52M
splitOnSingleCharFixedAllowExtra 74.35ns 13.45M
splitStr 2.36us 424.00K
splitStrFixed 282.38ns 3.54M
boost_splitOnSingleChar 2.83us 353.12K
joinCharStr 2.65us 376.93K
joinStrStr 2.64us 378.09K
joinInt 3.89us 257.37K
============================================================================
*/
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