[NOT FOR LANDING] Benchmark to test performance

components/password_manager/core/browser/password_store_unittest.cc

Index: components/password_manager/core/browser/password_store_unittest.cc
diff --git a/components/password_manager/core/browser/password_store_unittest.cc b/components/password_manager/core/browser/password_store_unittest.cc
index 681d0421ef5b5cf854137a2712a6c78eac0b2b2f..4507775884faa5c71275ce3428cf33765ae65aad 100644
--- a/components/password_manager/core/browser/password_store_unittest.cc
+++ b/components/password_manager/core/browser/password_store_unittest.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <memory>
+
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/files/scoped_temp_dir.h"
@@ -210,4 +212,158 @@ TEST_F(PasswordStoreTest, StartSyncFlare) {
   base::MessageLoop::current()->RunUntilIdle();
 }
 
+template <typename FormMover>
+inline void MoveAllFormsOut(ScopedVector<autofill::PasswordForm>* forms,
+                            FormMover mover) {
+  for (auto* form_ptr : *forms) {
+    scoped_ptr<autofill::PasswordForm> form(form_ptr);
+    mover(form.Pass());
+  }
+  forms->weak_clear();
+}
+
+template <typename FormMover>
+inline void MoveAllFormsOutNoScopedPtr(
+    ScopedVector<autofill::PasswordForm>* forms,
+    FormMover mover) {
+  for (auto* form_ptr : *forms) {
+    mover(form_ptr);
+  }
+  forms->weak_clear();
+}
+
+TEST(Vabr, Vabr) {
+  // First, do one loop without measuring. This is a warm-up and
+  // should ensure that memory caches and similar things do not
+  // skew the results.
+  for (unsigned size_shift = 3; size_shift < 20; ++size_shift) {
+    const size_t size = 1 << size_shift;
+    std::vector<autofill::PasswordForm*> v(size, nullptr);
+    ScopedVector<autofill::PasswordForm> target;
+    {
+      ScopedVector<autofill::PasswordForm> source;
+      source.swap(v);  // Fill up the source.
+      // Do not let allocation mess up the timing.
+      target.reserve(source.size());
+
+      MoveAllFormsOut(&source,
+                      [&target](scoped_ptr<autofill::PasswordForm> form) {
+        target.push_back(form.release());
+      });
+    }
+  }
+  for (unsigned size_shift = 3; size_shift < 20; ++size_shift) {
+    const size_t size = 1 << size_shift;
+    std::vector<autofill::PasswordForm*> v(size, nullptr);
+    ScopedVector<autofill::PasswordForm> target;
+    base::TimeTicks t;
+    {
+      ScopedVector<autofill::PasswordForm> source;
+      source.swap(v);  // Fill up the source.
+      // Do not let allocation mess up the timing.
+      target.reserve(source.size());
+
+      t = base::TimeTicks::Now();
+      for (auto* form_ptr : source) {
+        target.push_back(form_ptr);
+      }
+      source.weak_clear();
+    }
+    base::TimeDelta elapsed = base::TimeTicks::Now() - t;
+
+    LOG(INFO) << "For size=" << size << ", inline, elapsed "
+              << elapsed.InMicroseconds() << "us";
+  }
+  for (unsigned size_shift = 3; size_shift < 20; ++size_shift) {
+    const size_t size = 1 << size_shift;
+    std::vector<autofill::PasswordForm*> v(size, nullptr);
+    ScopedVector<autofill::PasswordForm> target;
+    base::TimeTicks t;
+    {
+      ScopedVector<autofill::PasswordForm> source;
+      source.swap(v);  // Fill up the source.
+      // Do not let allocation mess up the timing.
+      target.reserve(source.size());
+
+      t = base::TimeTicks::Now();
+      MoveAllFormsOutNoScopedPtr(&source,
+                                 [&target](autofill::PasswordForm* form_ptr) {
+        scoped_ptr<autofill::PasswordForm> form(form_ptr);
+        target.push_back(form.release());
+      });
+    }
+    base::TimeDelta elapsed = base::TimeTicks::Now() - t;
+
+    LOG(INFO) << "For size=" << size << ", LAMBDAS+local scoped_ptr, elapsed "
+              << elapsed.InMicroseconds() << "us";
+  }
+  for (unsigned size_shift = 3; size_shift < 20; ++size_shift) {
+    const size_t size = 1 << size_shift;
+    std::vector<autofill::PasswordForm*> v(size, nullptr);
+    ScopedVector<autofill::PasswordForm> target;
+    base::TimeTicks t;
+    {
+      ScopedVector<autofill::PasswordForm> source;
+      source.swap(v);  // Fill up the source.
+      // Do not let allocation mess up the timing.
+      target.reserve(source.size());
+
+      t = base::TimeTicks::Now();
+      MoveAllFormsOutNoScopedPtr(
+          &source,
+          [&target](autofill::PasswordForm* form) { target.push_back(form); });
+    }
+    base::TimeDelta elapsed = base::TimeTicks::Now() - t;
+
+    LOG(INFO) << "For size=" << size << ", LAMBDAS+naked pointers, elapsed "
+              << elapsed.InMicroseconds() << "us";
+  }
+#if 0
+  for (unsigned size_shift = 3; size_shift < 20; ++size_shift) {
+    const size_t size = 1 << size_shift;
+    std::vector<autofill::PasswordForm*> v(size, nullptr);
+    ScopedVector<autofill::PasswordForm> target;
+    base::TimeTicks t;
+    {
+      ScopedVector<autofill::PasswordForm> source;
+      source.swap(v);  // Fill up the source.
+      // Do not let allocation mess up the timing.
+      target.reserve(source.size());
+
+      t = base::TimeTicks::Now();
+      MoveAllFormsOutNoScopedPtr(
+          &source, [&target](std::unique_ptr<autofill::PasswordForm> form) {
+            target.push_back(form.release());
+          });
+    }
+    base::TimeDelta elapsed = base::TimeTicks::Now() - t;
+
+    LOG(INFO) << "For size=" << size << ", LAMBDAS+unique_ptr, elapsed "
+              << elapsed.InMicroseconds() << "us";
+  }
+#endif
+  for (unsigned size_shift = 3; size_shift < 20; ++size_shift) {
+    const size_t size = 1 << size_shift;
+    std::vector<autofill::PasswordForm*> v(size, nullptr);
+    ScopedVector<autofill::PasswordForm> target;
+    base::TimeTicks t;
+    {
+      ScopedVector<autofill::PasswordForm> source;
+      source.swap(v);  // Fill up the source.
+      // Do not let allocation mess up the timing.
+      target.reserve(source.size());
+
+      t = base::TimeTicks::Now();
+      MoveAllFormsOut(&source,
+                      [&target](scoped_ptr<autofill::PasswordForm> form) {
+        target.push_back(form.release());
+      });
+    }
+    base::TimeDelta elapsed = base::TimeTicks::Now() - t;
+
+    LOG(INFO) << "For size=" << size << ", LAMBDAS+scoped_ptr, elapsed "
+              << elapsed.InMicroseconds() << "us";
+  }
+}
+
 }  // namespace password_manager