+// A simple benchmark that tests various output sizes for a simple
+// input; the goal is to measure the output buffer resize code cost.
+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 (unsigned int i = 0; i < iters; ++i) {
+ string s;
+ BENCHMARK_SUSPEND { s.reserve(300000); }
+ for (int j = 0; j < 300000; ++j) {
+ stringAppendf(&s, "%d", 1);
+ }
+ }
+}
+
+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;
+
+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);
+}
+
+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());
+ }
+}
+
+} // 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);
+ }
+}
+