[Not for commit] Test performance impact if string validation checks whether it is utf8.

mojo/public/cpp/bindings/tests/bindings_perftest.cc

Index: mojo/public/cpp/bindings/tests/bindings_perftest.cc
diff --git a/mojo/public/cpp/bindings/tests/bindings_perftest.cc b/mojo/public/cpp/bindings/tests/bindings_perftest.cc
index 6a50de46f93bad397468017dbebec3627fed9dda..741a5e915fdb8c15aab4b5c352c2b778c55a207e 100644
--- a/mojo/public/cpp/bindings/tests/bindings_perftest.cc
+++ b/mojo/public/cpp/bindings/tests/bindings_perftest.cc
@@ -8,12 +8,14 @@
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/cpp/bindings/interface_endpoint_client.h"
 #include "mojo/public/cpp/bindings/lib/message_builder.h"
 #include "mojo/public/cpp/bindings/lib/multiplex_router.h"
+#include "mojo/public/cpp/bindings/lib/serialization.h"
 #include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/test_support/test_support.h"
 #include "mojo/public/cpp/test_support/test_utils.h"
@@ -280,5 +282,48 @@ TEST_F(MojoBindingsPerftest, MultiplexRouterDispatchCost) {
   }
 }
 
-}  // namespace
+void TestStringDeserializationInternal(bool utf8_check,
+                                       const std::string& input,
+                                       size_t iterations) {
+  auto data = mojo::internal::SerializeString(input);
+  std::string output;
+  for (size_t i = 0; i < 10; ++i) {
+    EXPECT_TRUE(mojo::internal::DeserializeString(utf8_check, data, &output));
+  }
+  EXPECT_EQ(input, output);
+
+  base::TimeTicks start_time = base::TimeTicks::Now();
+  for (size_t i = 0; i < iterations; ++i) {
+    EXPECT_TRUE(mojo::internal::DeserializeString(utf8_check, data, &output));
+  }
+  base::TimeTicks end_time = base::TimeTicks::Now();
+  base::TimeDelta duration = end_time - start_time;
+
+  test::LogPerfResult(utf8_check ? "DeserializeString_Utf8Check"
+                                 : "DeserializeString_NoUtf8Check",
+                      base::StringPrintf("%lu", input.size()).c_str(),
+                      iterations / duration.InSecondsF(), "times/second");
+}
+
+void TestStringDeserialization(const std::string& input, size_t iterations) {
+  TestStringDeserializationInternal(false, input, iterations);
+  TestStringDeserializationInternal(true, input, iterations);
+}
+
+std::string CreateASCIIString(size_t length) {
+  std::string result(length, 0);
+  for (size_t i = 0; i < length; ++i) {
+    result[i] = i % 128;
+  }
+  EXPECT_EQ(length, result.size());
+  return result;
+}
+
+TEST_F(MojoBindingsPerftest, String) {
+  TestStringDeserialization(CreateASCIIString(8), 10000000);
+  TestStringDeserialization(CreateASCIIString(128), 10000000);
+  TestStringDeserialization(CreateASCIIString(1024), 10000000);
+}
+
+}
 }  // namespace mojo