Simple google3-compatible benchmarking.

Based on our open-source RE2 benchmarking code.

Includes benchmarks for a handful of <string.h> functions.

Change-Id: I30eb70d25dbf4ad5f2ca44976a8ce3b1ff7dad01
diff --git a/tests/benchmark.h b/tests/benchmark.h
new file mode 100644
index 0000000..70d4c63
--- /dev/null
+++ b/tests/benchmark.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * 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 <stdint.h>
+
+#include <vector>
+
+namespace testing {
+
+class Benchmark {
+ public:
+  Benchmark(const char* name, void (*fn)(int)) {
+    Register(name, fn, NULL);
+  }
+
+  Benchmark(const char* name, void (*fn_range)(int, int)) {
+    Register(name, NULL, fn_range);
+  }
+
+  Benchmark* Arg(int x);
+
+  bool ShouldRun(int argc, char* argv[]);
+  void Run();
+
+ private:
+  const char* name_;
+
+  void (*fn_)(int);
+  void (*fn_range_)(int, int);
+
+  std::vector<int> args_;
+
+  void Register(const char* name, void (*fn)(int), void (*fn_range)(int, int));
+  void RunRepeatedlyWithArg(int iterations, int arg);
+  void RunWithArg(int arg);
+};
+
+}  // namespace testing
+
+void SetBenchmarkBytesProcessed(int64_t);
+void StopBenchmarkTiming();
+void StartBenchmarkTiming();
+
+#define BENCHMARK(f) \
+    static ::testing::Benchmark* _benchmark_##f __attribute__((unused)) = \
+        (new ::testing::Benchmark(#f, f))