Adding performance tests for HQP that represent importance of optimising HistoryItemsForTerms method

components/omnibox/browser/history_quick_provider_performance_unittest.cc

Index: components/omnibox/browser/history_quick_provider_performance_unittest.cc
diff --git a/components/omnibox/browser/history_quick_provider_performance_unittest.cc b/components/omnibox/browser/history_quick_provider_performance_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a682703ea624a569711c87cdfb80ef6603c2b96c
--- /dev/null
+++ b/components/omnibox/browser/history_quick_provider_performance_unittest.cc
@@ -0,0 +1,213 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/omnibox/browser/history_quick_provider.h"
+
+#include <memory>
+#include <random>
+#include <string>
+
+#include "base/macros.h"
+#include "base/run_loop.h"
+#include "base/strings/utf_string_conversions.h"
+#include "components/history/core/browser/history_backend.h"
+#include "components/history/core/browser/history_database.h"
+#include "components/history/core/browser/history_service.h"
+#include "components/history/core/test/history_service_test_util.h"
+#include "components/omnibox/browser/fake_autocomplete_provider_client.h"
+#include "components/omnibox/browser/history_test_util.h"
+#include "components/omnibox/browser/in_memory_url_index_test_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/perf/perf_test.h"
+
+namespace history {
+
+namespace {
+
+// Not threadsafe.
+std::string GenerateFakeHashedString(size_t sym_count) {
+  static constexpr char kSyms[] =
+      "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789,/=+?#";
+  CR_DEFINE_STATIC_LOCAL(std::mt19937, engine, ());
+  std::uniform_int_distribution<size_t> index_distribution(
+      0, arraysize(kSyms) - 2 /* trailing \0 */);
+
+  std::string res;
+  res.reserve(sym_count);
+
+  std::generate_n(std::back_inserter(res), sym_count, [&index_distribution] {
+    return kSyms[index_distribution(engine)];
+  });
+
+  return res;
+}
+
+URLRow GeneratePopularURLRow() {
+  static constexpr char kPopularUrl[] =
+      "http://long.popular_url_with.many_variations/";
+
+  constexpr size_t kFakeHashLength = 10;
+  std::string fake_hash = GenerateFakeHashedString(kFakeHashLength);
+
+  URLRow row{GURL(kPopularUrl + fake_hash)};
+  EXPECT_TRUE(row.url().is_valid());
+  row.set_title(base::UTF8ToUTF16("Page " + fake_hash));
+  row.set_visit_count(1);
+  row.set_typed_count(1);
+  row.set_last_visit(base::Time::Now() - base::TimeDelta::FromDays(1));
+  return row;
+}
+
+using StringPieces = std::vector<base::StringPiece>;
+
+StringPieces AllPrefixes(const std::string& str) {
+  std::vector<base::StringPiece> res;
+  res.reserve(str.size());
+  for (auto char_it = str.begin(); char_it != str.end(); ++char_it)
+    res.push_back({str.begin(), char_it});
+  return res;
+}
+
+}  // namespace
+
+class HQPPerfTestOnePopularURL : public testing::Test {
+ protected:
+  HQPPerfTestOnePopularURL() = default;
+
+  void SetUp() override;
+  void TearDown() override;
+
+  // Populates history with variations of the same URL.
+  void PrepareData();
+
+  // Runs HQP on a banch of consecutive pieces of an input string and times
+  // them. Resulting timings printed in groups.
+  template <typename PieceIt>
+  void RunAllTests(PieceIt first, PieceIt last);
+
+  // Encapsulates calls to performance infrastructure.
+  void PrintMeasurements(const std::string& trace_name,
+                         const std::vector<base::TimeDelta>& measurements);
+
+  history::HistoryBackend* history_backend() {
+    return client_->GetHistoryService()->history_backend_.get();
+  }
+
+ private:
+  base::TimeDelta RunTest(const base::string16& text);
+
+  base::MessageLoop message_loop_;
+  std::unique_ptr<FakeAutocompleteProviderClient> client_;
+
+  scoped_refptr<HistoryQuickProvider> provider_;
+
+  DISALLOW_COPY_AND_ASSIGN(HQPPerfTestOnePopularURL);
+};
+
+void HQPPerfTestOnePopularURL::SetUp() {
+  if (base::ThreadTicks::IsSupported())
+    base::ThreadTicks::WaitUntilInitialized();
+  client_.reset(new FakeAutocompleteProviderClient());
+  ASSERT_TRUE(client_->GetHistoryService());
+  ASSERT_NO_FATAL_FAILURE(PrepareData());
+}
+
+void HQPPerfTestOnePopularURL::TearDown() {
+  provider_ = nullptr;
+  // The InMemoryURLIndex must be explicitly shut down or it will DCHECK() in
+  // its destructor.
+  client_->GetInMemoryURLIndex()->Shutdown();
+  client_->set_in_memory_url_index(nullptr);
+  // History index rebuild task is created from main thread during SetUp,
+  // performed on DB thread and must be deleted on main thread.
+  // Run main loop to process delete task, to prevent leaks.
+  base::RunLoop().RunUntilIdle();
+}
+
+void HQPPerfTestOnePopularURL::PrepareData() {
+  // Adding fake urls to db must be done before RebuildFromHistory(). This will
+  // ensure that the index is properly populated with data from the database.
+  constexpr size_t kSimilarUrlCount = 10000;
+  for (size_t i = 0; i < kSimilarUrlCount; ++i)
+    AddFakeURLToHistoryDB(history_backend()->db(), GeneratePopularURLRow());
+
+  InMemoryURLIndex* url_index = client_->GetInMemoryURLIndex();
+  url_index->RebuildFromHistory(
+      client_->GetHistoryService()->history_backend_->db());
+  BlockUntilInMemoryURLIndexIsRefreshed(url_index);
+
+  // History index refresh creates rebuilt tasks to run on history thread.
+  // Block here to make sure that all of them are complete.
+  history::BlockUntilHistoryProcessesPendingRequests(
+      client_->GetHistoryService());
+
+  provider_ = new HistoryQuickProvider(client_.get());
+}
+
+void HQPPerfTestOnePopularURL::PrintMeasurements(
+    const std::string& trace_name,
+    const std::vector<base::TimeDelta>& measurements) {
+  auto test_info = ::testing::UnitTest::GetInstance()->current_test_info();
+
+  std::string durations;
+  for (const auto& measurement : measurements)
+    durations += std::to_string(measurement.InMillisecondsRoundedUp()) + ',';
+
+  perf_test::PrintResultList(test_info->test_case_name(), test_info->name(),
+                             trace_name, durations, "ms", true);
+}
+
+base::TimeDelta HQPPerfTestOnePopularURL::RunTest(const base::string16& text) {
+  base::RunLoop().RunUntilIdle();
+  AutocompleteInput input(text, base::string16::npos, std::string(), GURL(),
+                          metrics::OmniboxEventProto::INVALID_SPEC, false,
+                          false, true, true, false, TestSchemeClassifier());
+
+  if (base::ThreadTicks::IsSupported()) {
+    base::ThreadTicks start = base::ThreadTicks::Now();
+    provider_->Start(input, false);
+    return base::ThreadTicks::Now() - start;
+  }
+
+  base::Time start = base::Time::Now();
+  provider_->Start(input, false);
+  return base::Time::Now() - start;
+}
+
+template <typename PieceIt>
+void HQPPerfTestOnePopularURL::RunAllTests(PieceIt first, PieceIt last) {
+  constexpr size_t kTestGroupSize = 5;
+  std::vector<base::TimeDelta> measurements;
+  measurements.reserve(kTestGroupSize);
+
+  for (PieceIt group_start = first; group_start != last;) {
+    PieceIt group_end = std::min(group_start + kTestGroupSize, last);
+
+    std::transform(group_start, group_end, std::back_inserter(measurements),
+                   [this](const base::StringPiece& prefix) {
+                     return RunTest(base::UTF8ToUTF16(prefix));
+                   });
+
+    PrintMeasurements(std::to_string(group_start->size()) + '-' +
+                          std::to_string((group_end - 1)->size()),
+                      measurements);
+
+    measurements.clear();
+    group_start = group_end;
+  }
+}
+
+TEST_F(HQPPerfTestOnePopularURL, Typing) {
+  std::string test_url = GeneratePopularURLRow().url().spec();
+  StringPieces prefixes = AllPrefixes(test_url);
+  RunAllTests(prefixes.begin(), prefixes.end());
+}
+
+TEST_F(HQPPerfTestOnePopularURL, Backspacing) {
+  std::string test_url = GeneratePopularURLRow().url().spec();
+  StringPieces prefixes = AllPrefixes(test_url);
+  RunAllTests(prefixes.rbegin(), prefixes.rend());
+}
+
+}  // namespace history