Adding Google benchmarking library.

third_party/google_benchmark/test/output_test.h

Index: third_party/google_benchmark/test/output_test.h
diff --git a/third_party/google_benchmark/test/output_test.h b/third_party/google_benchmark/test/output_test.h
new file mode 100644
index 0000000000000000000000000000000000000000..897a13866baecbac465bb89dad04df1dcc92e910
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+++ b/third_party/google_benchmark/test/output_test.h
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+#ifndef TEST_OUTPUT_TEST_H
+#define TEST_OUTPUT_TEST_H
+
+#undef NDEBUG
+#include <initializer_list>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+#include <functional>
+#include <sstream>
+
+#include "../src/re.h"
+#include "benchmark/benchmark.h"
+
+#define CONCAT2(x, y) x##y
+#define CONCAT(x, y) CONCAT2(x, y)
+
+#define ADD_CASES(...) int CONCAT(dummy, __LINE__) = ::AddCases(__VA_ARGS__)
+
+#define SET_SUBSTITUTIONS(...) \
+  int CONCAT(dummy, __LINE__) = ::SetSubstitutions(__VA_ARGS__)
+
+enum MatchRules {
+  MR_Default,  // Skip non-matching lines until a match is found.
+  MR_Next,     // Match must occur on the next line.
+  MR_Not  // No line between the current position and the next match matches
+          // the regex
+};
+
+struct TestCase {
+  TestCase(std::string re, int rule = MR_Default);
+
+  std::string regex_str;
+  int match_rule;
+  std::string substituted_regex;
+  std::shared_ptr<benchmark::Regex> regex;
+};
+
+enum TestCaseID {
+  TC_ConsoleOut,
+  TC_ConsoleErr,
+  TC_JSONOut,
+  TC_JSONErr,
+  TC_CSVOut,
+  TC_CSVErr,
+
+  TC_NumID  // PRIVATE
+};
+
+// Add a list of test cases to be run against the output specified by
+// 'ID'
+int AddCases(TestCaseID ID, std::initializer_list<TestCase> il);
+
+// Add or set a list of substitutions to be performed on constructed regex's
+// See 'output_test_helper.cc' for a list of default substitutions.
+int SetSubstitutions(
+    std::initializer_list<std::pair<std::string, std::string>> il);
+
+// Run all output tests.
+void RunOutputTests(int argc, char* argv[]);
+
+// ========================================================================= //
+// ------------------------- Results checking ------------------------------ //
+// ========================================================================= //
+
+// Call this macro to register a benchmark for checking its results. This
+// should be all that's needed. It subscribes a function to check the (CSV)
+// results of a benchmark. This is done only after verifying that the output
+// strings are really as expected.
+// bm_name_pattern: a name or a regex pattern which will be matched against
+//                  all the benchmark names. Matching benchmarks
+//                  will be the subject of a call to checker_function
+// checker_function: should be of type ResultsCheckFn (see below)
+#define CHECK_BENCHMARK_RESULTS(bm_name_pattern, checker_function) \
+    size_t CONCAT(dummy, __LINE__) = AddChecker(bm_name_pattern, checker_function)
+
+struct Results;
+typedef std::function< void(Results const&) > ResultsCheckFn;
+
+size_t AddChecker(const char* bm_name_pattern, ResultsCheckFn fn);
+
+// Class holding the results of a benchmark.
+// It is passed in calls to checker functions.
+struct Results {
+
+  // the benchmark name
+  std::string name;
+  // the benchmark fields
+  std::map< std::string, std::string > values;
+
+  Results(const std::string& n) : name(n) {}
+
+  int NumThreads() const;
+
+  typedef enum { kCpuTime, kRealTime } BenchmarkTime;
+
+  // get cpu_time or real_time in seconds
+  double GetTime(BenchmarkTime which) const;
+
+  // get the real_time duration of the benchmark in seconds.
+  // it is better to use fuzzy float checks for this, as the float
+  // ASCII formatting is lossy.
+  double DurationRealTime() const {
+    return GetAs< double >("iterations") * GetTime(kRealTime);
+  }
+  // get the cpu_time duration of the benchmark in seconds
+  double DurationCPUTime() const {
+    return GetAs< double >("iterations") * GetTime(kCpuTime);
+  }
+
+  // get the string for a result by name, or nullptr if the name
+  // is not found
+  const std::string* Get(const char* entry_name) const {
+    auto it = values.find(entry_name);
+    if(it == values.end()) return nullptr;
+    return &it->second;
+  }
+
+  // get a result by name, parsed as a specific type.
+  // NOTE: for counters, use GetCounterAs instead.
+  template <class T>
+  T GetAs(const char* entry_name) const;
+
+  // counters are written as doubles, so they have to be read first
+  // as a double, and only then converted to the asked type.
+  template <class T>
+  T GetCounterAs(const char* entry_name) const {
+    double dval = GetAs< double >(entry_name);
+    T tval = static_cast< T >(dval);
+    return tval;
+  }
+};
+
+template <class T>
+T Results::GetAs(const char* entry_name) const {
+  auto *sv = Get(entry_name);
+  CHECK(sv != nullptr && !sv->empty());
+  std::stringstream ss;
+  ss << *sv;
+  T out;
+  ss >> out;
+  CHECK(!ss.fail());
+  return out;
+}
+
+//----------------------------------
+// Macros to help in result checking. Do not use them with arguments causing
+// side-effects.
+
+#define _CHECK_RESULT_VALUE(entry, getfn, var_type, var_name, relationship, value) \
+    CONCAT(CHECK_, relationship)                                        \
+    (entry.getfn< var_type >(var_name), (value)) << "\n"                \
+    << __FILE__ << ":" << __LINE__ << ": " << (entry).name << ":\n"     \
+    << __FILE__ << ":" << __LINE__ << ": "                              \
+    << "expected (" << #var_type << ")" << (var_name)                   \
+    << "=" << (entry).getfn< var_type >(var_name)                       \
+    << " to be " #relationship " to " << (value) << "\n"
+
+// check with tolerance. eps_factor is the tolerance window, which is
+// interpreted relative to value (eg, 0.1 means 10% of value).
+#define _CHECK_FLOAT_RESULT_VALUE(entry, getfn, var_type, var_name, relationship, value, eps_factor) \
+    CONCAT(CHECK_FLOAT_, relationship)                                  \
+    (entry.getfn< var_type >(var_name), (value), (eps_factor) * (value)) << "\n" \
+    << __FILE__ << ":" << __LINE__ << ": " << (entry).name << ":\n"     \
+    << __FILE__ << ":" << __LINE__ << ": "                              \
+    << "expected (" << #var_type << ")" << (var_name)                   \
+    << "=" << (entry).getfn< var_type >(var_name)                       \
+    << " to be " #relationship " to " << (value) << "\n"                \
+    << __FILE__ << ":" << __LINE__ << ": "                              \
+    << "with tolerance of " << (eps_factor) * (value)                   \
+    << " (" << (eps_factor)*100. << "%), "                              \
+    << "but delta was " << ((entry).getfn< var_type >(var_name) - (value)) \
+    << " (" << (((entry).getfn< var_type >(var_name) - (value))         \
+               /                                                        \
+               ((value) > 1.e-5 || value < -1.e-5 ? value : 1.e-5)*100.) \
+    << "%)"
+
+#define CHECK_RESULT_VALUE(entry, var_type, var_name, relationship, value) \
+    _CHECK_RESULT_VALUE(entry, GetAs, var_type, var_name, relationship, value)
+
+#define CHECK_COUNTER_VALUE(entry, var_type, var_name, relationship, value) \
+    _CHECK_RESULT_VALUE(entry, GetCounterAs, var_type, var_name, relationship, value)
+
+#define CHECK_FLOAT_RESULT_VALUE(entry, var_name, relationship, value, eps_factor) \
+    _CHECK_FLOAT_RESULT_VALUE(entry, GetAs, double, var_name, relationship, value, eps_factor)
+
+#define CHECK_FLOAT_COUNTER_VALUE(entry, var_name, relationship, value, eps_factor) \
+    _CHECK_FLOAT_RESULT_VALUE(entry, GetCounterAs, double, var_name, relationship, value, eps_factor)
+
+// ========================================================================= //
+// --------------------------- Misc Utilities ------------------------------ //
+// ========================================================================= //
+
+namespace {
+
+const char* const dec_re = "[0-9]*[.]?[0-9]+([eE][-+][0-9]+)?";
+
+}  //  end namespace
+
+#endif  // TEST_OUTPUT_TEST_H