Adding Google benchmarking library.

third_party/google_benchmark/test/output_test_helper.cc

Index: third_party/google_benchmark/test/output_test_helper.cc
diff --git a/third_party/google_benchmark/test/output_test_helper.cc b/third_party/google_benchmark/test/output_test_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..24746f6d27f9b9816526b3610bbc6d984eb73ab9
--- /dev/null
+++ b/third_party/google_benchmark/test/output_test_helper.cc
@@ -0,0 +1,423 @@
+#include <iostream>
+#include <map>
+#include <memory>
+#include <sstream>
+#include <cstring>
+
+#include "../src/check.h"  // NOTE: check.h is for internal use only!
+#include "../src/re.h"     // NOTE: re.h is for internal use only
+#include "output_test.h"
+#include "../src/benchmark_api_internal.h"
+
+// ========================================================================= //
+// ------------------------------ Internals -------------------------------- //
+// ========================================================================= //
+namespace internal {
+namespace {
+
+using TestCaseList = std::vector<TestCase>;
+
+// Use a vector because the order elements are added matters during iteration.
+// std::map/unordered_map don't guarantee that.
+// For example:
+//  SetSubstitutions({{"%HelloWorld", "Hello"}, {"%Hello", "Hi"}});
+//     Substitute("%HelloWorld") // Always expands to Hello.
+using SubMap = std::vector<std::pair<std::string, std::string>>;
+
+TestCaseList& GetTestCaseList(TestCaseID ID) {
+  // Uses function-local statics to ensure initialization occurs
+  // before first use.
+  static TestCaseList lists[TC_NumID];
+  return lists[ID];
+}
+
+SubMap& GetSubstitutions() {
+  // Don't use 'dec_re' from header because it may not yet be initialized.
+  static std::string safe_dec_re = "[0-9]*[.]?[0-9]+([eE][-+][0-9]+)?";
+  static SubMap map = {
+      {"%float", "[0-9]*[.]?[0-9]+([eE][-+][0-9]+)?"},
+      // human-readable float
+      {"%hrfloat", "[0-9]*[.]?[0-9]+([eE][-+][0-9]+)?[kMGTPEZYmunpfazy]?"},
+      {"%int", "[ ]*[0-9]+"},
+      {" %s ", "[ ]+"},
+      {"%time", "[ ]*[0-9]{1,5} ns"},
+      {"%console_report", "[ ]*[0-9]{1,5} ns [ ]*[0-9]{1,5} ns [ ]*[0-9]+"},
+      {"%console_us_report", "[ ]*[0-9] us [ ]*[0-9] us [ ]*[0-9]+"},
+      {"%csv_header",
+       "name,iterations,real_time,cpu_time,time_unit,bytes_per_second,"
+       "items_per_second,label,error_occurred,error_message"},
+      {"%csv_report", "[0-9]+," + safe_dec_re + "," + safe_dec_re + ",ns,,,,,"},
+      {"%csv_us_report", "[0-9]+," + safe_dec_re + "," + safe_dec_re + ",us,,,,,"},
+      {"%csv_bytes_report",
+       "[0-9]+," + safe_dec_re + "," + safe_dec_re + ",ns," + safe_dec_re + ",,,,"},
+      {"%csv_items_report",
+       "[0-9]+," + safe_dec_re + "," + safe_dec_re + ",ns,," + safe_dec_re + ",,,"},
+      {"%csv_bytes_items_report",
+       "[0-9]+," + safe_dec_re + "," + safe_dec_re + ",ns," + safe_dec_re +
+       "," + safe_dec_re + ",,,"},
+      {"%csv_label_report_begin", "[0-9]+," + safe_dec_re + "," + safe_dec_re + ",ns,,,"},
+      {"%csv_label_report_end", ",,"}};
+  return map;
+}
+
+std::string PerformSubstitutions(std::string source) {
+  SubMap const& subs = GetSubstitutions();
+  using SizeT = std::string::size_type;
+  for (auto const& KV : subs) {
+    SizeT pos;
+    SizeT next_start = 0;
+    while ((pos = source.find(KV.first, next_start)) != std::string::npos) {
+      next_start = pos + KV.second.size();
+      source.replace(pos, KV.first.size(), KV.second);
+    }
+  }
+  return source;
+}
+
+void CheckCase(std::stringstream& remaining_output, TestCase const& TC,
+               TestCaseList const& not_checks) {
+  std::string first_line;
+  bool on_first = true;
+  std::string line;
+  while (remaining_output.eof() == false) {
+    CHECK(remaining_output.good());
+    std::getline(remaining_output, line);
+    if (on_first) {
+      first_line = line;
+      on_first = false;
+    }
+    for (const auto& NC : not_checks) {
+      CHECK(!NC.regex->Match(line))
+          << "Unexpected match for line \"" << line << "\" for MR_Not regex \""
+          << NC.regex_str << "\""
+          << "\n    actual regex string \"" << TC.substituted_regex << "\""
+          << "\n    started matching near: " << first_line;
+    }
+    if (TC.regex->Match(line)) return;
+    CHECK(TC.match_rule != MR_Next)
+        << "Expected line \"" << line << "\" to match regex \"" << TC.regex_str
+        << "\""
+        << "\n    actual regex string \"" << TC.substituted_regex << "\""
+        << "\n    started matching near: " << first_line;
+  }
+  CHECK(remaining_output.eof() == false)
+      << "End of output reached before match for regex \"" << TC.regex_str
+      << "\" was found"
+      << "\n    actual regex string \"" << TC.substituted_regex << "\""
+      << "\n    started matching near: " << first_line;
+}
+
+void CheckCases(TestCaseList const& checks, std::stringstream& output) {
+  std::vector<TestCase> not_checks;
+  for (size_t i = 0; i < checks.size(); ++i) {
+    const auto& TC = checks[i];
+    if (TC.match_rule == MR_Not) {
+      not_checks.push_back(TC);
+      continue;
+    }
+    CheckCase(output, TC, not_checks);
+    not_checks.clear();
+  }
+}
+
+class TestReporter : public benchmark::BenchmarkReporter {
+ public:
+  TestReporter(std::vector<benchmark::BenchmarkReporter*> reps)
+      : reporters_(reps) {}
+
+  virtual bool ReportContext(const Context& context) {
+    bool last_ret = false;
+    bool first = true;
+    for (auto rep : reporters_) {
+      bool new_ret = rep->ReportContext(context);
+      CHECK(first || new_ret == last_ret)
+          << "Reports return different values for ReportContext";
+      first = false;
+      last_ret = new_ret;
+    }
+    (void)first;
+    return last_ret;
+  }
+
+  void ReportRuns(const std::vector<Run>& report) {
+    for (auto rep : reporters_) rep->ReportRuns(report);
+  }
+  void Finalize() {
+    for (auto rep : reporters_) rep->Finalize();
+  }
+
+ private:
+  std::vector<benchmark::BenchmarkReporter *> reporters_;
+};
+}
+
+}  // end namespace internal
+
+// ========================================================================= //
+// -------------------------- Results checking ----------------------------- //
+// ========================================================================= //
+
+namespace internal {
+
+// Utility class to manage subscribers for checking benchmark results.
+// It works by parsing the CSV output to read the results.
+class ResultsChecker {
+ public:
+
+  struct PatternAndFn : public TestCase { // reusing TestCase for its regexes
+    PatternAndFn(const std::string& rx, ResultsCheckFn fn_)
+    : TestCase(rx), fn(fn_) {}
+    ResultsCheckFn fn;
+  };
+
+  std::vector< PatternAndFn > check_patterns;
+  std::vector< Results > results;
+  std::vector< std::string > field_names;
+
+  void Add(const std::string& entry_pattern, ResultsCheckFn fn);
+
+  void CheckResults(std::stringstream& output);
+
+ private:
+
+  void SetHeader_(const std::string& csv_header);
+  void SetValues_(const std::string& entry_csv_line);
+
+  std::vector< std::string > SplitCsv_(const std::string& line);
+
+};
+
+// store the static ResultsChecker in a function to prevent initialization
+// order problems
+ResultsChecker& GetResultsChecker() {
+  static ResultsChecker rc;
+  return rc;
+}
+
+// add a results checker for a benchmark
+void ResultsChecker::Add(const std::string& entry_pattern, ResultsCheckFn fn) {
+  check_patterns.emplace_back(entry_pattern, fn);
+}
+
+// check the results of all subscribed benchmarks
+void ResultsChecker::CheckResults(std::stringstream& output) {
+  // first reset the stream to the start
+  {
+    auto start = std::ios::streampos(0);
+    // clear before calling tellg()
+    output.clear();
+    // seek to zero only when needed
+    if(output.tellg() > start) output.seekg(start);
+    // and just in case
+    output.clear();
+  }
+  // now go over every line and publish it to the ResultsChecker
+  std::string line;
+  bool on_first = true;
+  while (output.eof() == false) {
+    CHECK(output.good());
+    std::getline(output, line);
+    if (on_first) {
+      SetHeader_(line); // this is important
+      on_first = false;
+      continue;
+    }
+    SetValues_(line);
+  }
+  // finally we can call the subscribed check functions
+  for(const auto& p : check_patterns) {
+    VLOG(2) << "--------------------------------\n";
+    VLOG(2) << "checking for benchmarks matching " << p.regex_str << "...\n";
+    for(const auto& r : results) {
+      if(!p.regex->Match(r.name)) {
+        VLOG(2) << p.regex_str << " is not matched by " << r.name << "\n";
+        continue;
+      } else {
+        VLOG(2) << p.regex_str << " is matched by " << r.name << "\n";
+      }
+      VLOG(1) << "Checking results of " << r.name << ": ... \n";
+      p.fn(r);
+      VLOG(1) << "Checking results of " << r.name << ": OK.\n";
+    }
+  }
+}
+
+// prepare for the names in this header
+void ResultsChecker::SetHeader_(const std::string& csv_header) {
+  field_names = SplitCsv_(csv_header);
+}
+
+// set the values for a benchmark
+void ResultsChecker::SetValues_(const std::string& entry_csv_line) {
+  if(entry_csv_line.empty()) return; // some lines are empty
+  CHECK(!field_names.empty());
+  auto vals = SplitCsv_(entry_csv_line);
+  CHECK_EQ(vals.size(), field_names.size());
+  results.emplace_back(vals[0]); // vals[0] is the benchmark name
+  auto &entry = results.back();
+  for (size_t i = 1, e = vals.size(); i < e; ++i) {
+    entry.values[field_names[i]] = vals[i];
+  }
+}
+
+// a quick'n'dirty csv splitter (eliminating quotes)
+std::vector< std::string > ResultsChecker::SplitCsv_(const std::string& line) {
+  std::vector< std::string > out;
+  if(line.empty()) return out;
+  if(!field_names.empty()) out.reserve(field_names.size());
+  size_t prev = 0, pos = line.find_first_of(','), curr = pos;
+  while(pos != line.npos) {
+    CHECK(curr > 0);
+    if(line[prev] == '"') ++prev;
+    if(line[curr-1] == '"') --curr;
+    out.push_back(line.substr(prev, curr-prev));
+    prev = pos + 1;
+    pos = line.find_first_of(',', pos + 1);
+    curr = pos;
+  }
+  curr = line.size();
+  if(line[prev] == '"') ++prev;
+  if(line[curr-1] == '"') --curr;
+  out.push_back(line.substr(prev, curr-prev));
+  return out;
+}
+
+}  // end namespace internal
+
+size_t AddChecker(const char* bm_name, ResultsCheckFn fn)
+{
+  auto &rc = internal::GetResultsChecker();
+  rc.Add(bm_name, fn);
+  return rc.results.size();
+}
+
+int Results::NumThreads() const {
+  auto pos = name.find("/threads:");
+  if(pos == name.npos) return 1;
+  auto end = name.find('/', pos + 9);
+  std::stringstream ss;
+  ss << name.substr(pos + 9, end);
+  int num = 1;
+  ss >> num;
+  CHECK(!ss.fail());
+  return num;
+}
+
+double Results::GetTime(BenchmarkTime which) const {
+  CHECK(which == kCpuTime || which == kRealTime);
+  const char *which_str = which == kCpuTime ? "cpu_time" : "real_time";
+  double val = GetAs< double >(which_str);
+  auto unit = Get("time_unit");
+  CHECK(unit);
+  if(*unit == "ns") {
+    return val * 1.e-9;
+  } else if(*unit == "us") {
+    return val * 1.e-6;
+  } else if(*unit == "ms") {
+    return val * 1.e-3;
+  } else if(*unit == "s") {
+    return val;
+  } else {
+    CHECK(1 == 0) << "unknown time unit: " << *unit;
+    return 0;
+  }
+}
+
+// ========================================================================= //
+// -------------------------- Public API Definitions------------------------ //
+// ========================================================================= //
+
+TestCase::TestCase(std::string re, int rule)
+    : regex_str(std::move(re)),
+      match_rule(rule),
+      substituted_regex(internal::PerformSubstitutions(regex_str)),
+      regex(std::make_shared<benchmark::Regex>()) {
+  std::string err_str;
+  regex->Init(substituted_regex,& err_str);
+  CHECK(err_str.empty()) << "Could not construct regex \"" << substituted_regex
+                         << "\""
+                         << "\n    originally \"" << regex_str << "\""
+                         << "\n    got error: " << err_str;
+}
+
+int AddCases(TestCaseID ID, std::initializer_list<TestCase> il) {
+  auto& L = internal::GetTestCaseList(ID);
+  L.insert(L.end(), il);
+  return 0;
+}
+
+int SetSubstitutions(
+    std::initializer_list<std::pair<std::string, std::string>> il) {
+  auto& subs = internal::GetSubstitutions();
+  for (auto KV : il) {
+    bool exists = false;
+    KV.second = internal::PerformSubstitutions(KV.second);
+    for (auto& EKV : subs) {
+      if (EKV.first == KV.first) {
+        EKV.second = std::move(KV.second);
+        exists = true;
+        break;
+      }
+    }
+    if (!exists) subs.push_back(std::move(KV));
+  }
+  return 0;
+}
+
+void RunOutputTests(int argc, char* argv[]) {
+  using internal::GetTestCaseList;
+  benchmark::Initialize(&argc, argv);
+  auto options = benchmark::internal::GetOutputOptions(/*force_no_color*/true);
+  benchmark::ConsoleReporter CR(options);
+  benchmark::JSONReporter JR;
+  benchmark::CSVReporter CSVR;
+  struct ReporterTest {
+    const char* name;
+    std::vector<TestCase>& output_cases;
+    std::vector<TestCase>& error_cases;
+    benchmark::BenchmarkReporter& reporter;
+    std::stringstream out_stream;
+    std::stringstream err_stream;
+
+    ReporterTest(const char* n, std::vector<TestCase>& out_tc,
+                 std::vector<TestCase>& err_tc,
+                 benchmark::BenchmarkReporter& br)
+        : name(n), output_cases(out_tc), error_cases(err_tc), reporter(br) {
+      reporter.SetOutputStream(&out_stream);
+      reporter.SetErrorStream(&err_stream);
+    }
+  } TestCases[] = {
+      {"ConsoleReporter", GetTestCaseList(TC_ConsoleOut),
+       GetTestCaseList(TC_ConsoleErr), CR},
+      {"JSONReporter", GetTestCaseList(TC_JSONOut), GetTestCaseList(TC_JSONErr),
+       JR},
+      {"CSVReporter", GetTestCaseList(TC_CSVOut), GetTestCaseList(TC_CSVErr),
+       CSVR},
+  };
+
+  // Create the test reporter and run the benchmarks.
+  std::cout << "Running benchmarks...\n";
+  internal::TestReporter test_rep({&CR, &JR, &CSVR});
+  benchmark::RunSpecifiedBenchmarks(&test_rep);
+
+  for (auto& rep_test : TestCases) {
+    std::string msg = std::string("\nTesting ") + rep_test.name + " Output\n";
+    std::string banner(msg.size() - 1, '-');
+    std::cout << banner << msg << banner << "\n";
+
+    std::cerr << rep_test.err_stream.str();
+    std::cout << rep_test.out_stream.str();
+
+    internal::CheckCases(rep_test.error_cases, rep_test.err_stream);
+    internal::CheckCases(rep_test.output_cases, rep_test.out_stream);
+
+    std::cout << "\n";
+  }
+
+  // now that we know the output is as expected, we can dispatch
+  // the checks to subscribees.
+  auto &csv = TestCases[2];
+  // would use == but gcc spits a warning
+  CHECK(std::strcmp(csv.name, "CSVReporter") == 0);
+  internal::GetResultsChecker().CheckResults(csv.out_stream);
+}