[translate] Add translate ranker model loader.

components/translate/core/browser/ranker_model_loader_unittest.cc

Index: components/translate/core/browser/ranker_model_loader_unittest.cc
diff --git a/components/translate/core/browser/ranker_model_loader_unittest.cc b/components/translate/core/browser/ranker_model_loader_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2433ef1a456aba911aa2d0e63fa6561c1e1b6ec4
--- /dev/null
+++ b/components/translate/core/browser/ranker_model_loader_unittest.cc
@@ -0,0 +1,374 @@
+// 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/translate/core/browser/ranker_model_loader.h"
+
+#include <deque>
+#include <initializer_list>
+#include <memory>
+#include <vector>
+
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "base/strings/stringprintf.h"
+#include "base/task_scheduler/post_task.h"
+#include "base/task_scheduler/task_scheduler.h"
+#include "base/test/scoped_feature_list.h"
+#include "base/test/scoped_task_scheduler.h"
+#include "base/test/test_simple_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "components/metrics/proto/translate_event.pb.h"
+#include "components/prefs/scoped_user_pref_update.h"
+#include "components/sync_preferences/testing_pref_service_syncable.h"
+#include "components/translate/core/browser/proto/ranker_model.pb.h"
+#include "components/translate/core/browser/proto/translate_ranker_model.pb.h"
+#include "components/translate/core/browser/ranker_model.h"
+#include "components/translate/core/browser/translate_download_manager.h"
+#include "components/translate/core/browser/translate_prefs.h"
+#include "net/url_request/test_url_fetcher_factory.h"
+#include "net/url_request/url_request_test_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+using base::TaskScheduler;
+using chrome_intelligence::RankerModel;
+using translate::RankerModelLoader;
+using translate::RankerModelStatus;
+using translate::TranslateDownloadManager;
+
+const char kInvalidModelData[] = "not a valid model";
+const int kInvalidModelSize = sizeof(kInvalidModelData) - 1;
+
+class RankerModelLoaderTest : public ::testing::Test {
+ protected:
+  RankerModelLoaderTest();
+
+  void SetUp() override;
+
+  void TearDown() override;
+
+  // Returns a copy of |model|.
+  static std::unique_ptr<RankerModel> Clone(const RankerModel& model);
+
+  // Returns true if |m1| and |m2| are identical.
+  static bool IsEqual(const RankerModel& m1, const RankerModel& m2);
+
+  // Returns true if |m1| and |m2| are identical modulo metadata.
+  static bool IsEquivalent(const RankerModel& m1, const RankerModel& m2);
+
+  // Helper method to drive the loader for |model_path| and |model_url|.
+  bool DoLoaderTest(const base::FilePath& model_path, const GURL& model_url);
+
+  // Initialize the "remote" model data used for testing.
+  void InitRemoteModels();
+
+  // Initialize the "local" model data used for testing.
+  void InitLocalModels();
+
+  // Helper method used by InitRemoteModels() and InitLocalModels().
+  void InitModel(const GURL& model_url,
+                 const base::Time& last_modified,
+                 const base::TimeDelta& cache_duration,
+                 RankerModel* model);
+
+  // Save |model| to |model_path|.  Used by InitRemoteModels() and
+  // InitLocalModels()
+  void SaveModel(const RankerModel& model, const base::FilePath& model_path);
+
+  // Implements RankerModelLoader's ValidateModelCallback interface.
+  RankerModelStatus ValidateModel(const RankerModel& model);
+
+  // Implements RankerModelLoader's OnModelAvailableCallback interface.
+  void OnModelAvailable(std::unique_ptr<RankerModel> model);
+
+  // Sets up the task scheduling/task-runner environment for each test.
+  base::test::ScopedTaskScheduler scoped_task_scheduler_;
+
+  // Override the default URL fetcher to return custom responses for tests.
+  net::FakeURLFetcherFactory url_fetcher_factory_;
+
+  // Temporary directory for model files.
+  base::ScopedTempDir scoped_temp_dir_;
+
+  // Cache and reset the application locale for each test.
+  std::string locale_;
+
+  // Used to initialize the translate download manager.
+  scoped_refptr<net::TestURLRequestContextGetter> request_context_;
+
+  // A queue of responses to return from Validate(). If empty, validate will
+  // return 'OK'.
+  std::deque<RankerModelStatus> validate_model_response_;
+
+  // A cached to remember the model validation calls.
+  std::vector<std::unique_ptr<RankerModel>> validated_models_;
+
+  // A cache to remember the OnModelAvailable calls.
+  std::vector<std::unique_ptr<RankerModel>> available_models_;
+
+  // Cached model file paths.
+  base::FilePath local_model_path_;
+  base::FilePath expired_model_path_;
+  base::FilePath invalid_model_path_;
+
+  // Model URLS.
+  GURL remote_model_url_;
+  GURL invalid_model_url_;
+  GURL failed_model_url_;
+
+  // Model Data.
+  RankerModel remote_model_;
+  RankerModel local_model_;
+  RankerModel expired_model_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RankerModelLoaderTest);
+};
+
+RankerModelLoaderTest::RankerModelLoaderTest()
+    : url_fetcher_factory_(nullptr) {}
+
+void RankerModelLoaderTest::SetUp() {
+  // Setup the translate download manager.
+  locale_ = TranslateDownloadManager::GetInstance()->application_locale();
+  request_context_ =
+      new net::TestURLRequestContextGetter(base::ThreadTaskRunnerHandle::Get());
+  TranslateDownloadManager::GetInstance()->set_application_locale("fr-CA");
+  TranslateDownloadManager::GetInstance()->set_request_context(
+      request_context_.get());
+
+  ASSERT_TRUE(scoped_temp_dir_.CreateUniqueTempDir());
+  const auto& temp_dir_path = scoped_temp_dir_.GetPath();
+
+  // Setup the model file paths.
+  local_model_path_ = temp_dir_path.AppendASCII("local_model.bin");
+  expired_model_path_ = temp_dir_path.AppendASCII("expired_model.bin");
+  invalid_model_path_ = temp_dir_path.AppendASCII("invalid_model.bin");
+
+  // Setup the model URLs.
+  remote_model_url_ = GURL("https://some.url.net/good.model.bin");
+  invalid_model_url_ = GURL("https://some.url.net/bad.model.bin");
+  failed_model_url_ = GURL("https://some.url.net/fail");
+
+  // Initialize the model data.
+  ASSERT_NO_FATAL_FAILURE(InitRemoteModels());
+  ASSERT_NO_FATAL_FAILURE(InitLocalModels());
+}
+
+void RankerModelLoaderTest::TearDown() {
+  base::RunLoop().RunUntilIdle();
+  TranslateDownloadManager::GetInstance()->set_application_locale(locale_);
+  TranslateDownloadManager::GetInstance()->set_request_context(nullptr);
+}
+
+// static
+std::unique_ptr<RankerModel> RankerModelLoaderTest::Clone(
+    const RankerModel& model) {
+  auto copy = base::MakeUnique<RankerModel>();
+  *copy->mutable_proto() = model.proto();
+  return copy;
+}
+
+// static
+bool RankerModelLoaderTest::IsEqual(const RankerModel& m1,
+                                    const RankerModel& m2) {
+  return m1.SerializeAsString() == m2.SerializeAsString();
+}
+
+// static
+bool RankerModelLoaderTest::IsEquivalent(const RankerModel& m1,
+                                         const RankerModel& m2) {
+  auto copy_m1 = Clone(m1);
+  copy_m1->mutable_proto()->mutable_metadata()->Clear();
+
+  auto copy_m2 = Clone(m2);
+  copy_m2->mutable_proto()->mutable_metadata()->Clear();
+
+  return IsEqual(*copy_m1, *copy_m2);
+}
+
+bool RankerModelLoaderTest::DoLoaderTest(const base::FilePath& model_path,
+                                         const GURL& model_url) {
+  auto loader = base::MakeUnique<RankerModelLoader>(
+      base::Bind(&RankerModelLoaderTest::ValidateModel, base::Unretained(this)),
+      base::Bind(&RankerModelLoaderTest::OnModelAvailable,
+                 base::Unretained(this)),
+      model_path, model_url, "RankerModelLoaderTest");
+
+  loader->Start();
+  base::RunLoop().RunUntilIdle();
+
+  return true;
+}
+
+void RankerModelLoaderTest::InitRemoteModels() {
+  InitModel(remote_model_url_, base::Time(), base::TimeDelta(), &remote_model_);
+  url_fetcher_factory_.SetFakeResponse(
+      remote_model_url_, remote_model_.SerializeAsString(), net::HTTP_OK,
+      net::URLRequestStatus::SUCCESS);
+  url_fetcher_factory_.SetFakeResponse(invalid_model_url_, kInvalidModelData,
+                                       net::HTTP_OK,
+                                       net::URLRequestStatus::SUCCESS);
+  url_fetcher_factory_.SetFakeResponse(failed_model_url_, "",
+                                       net::HTTP_INTERNAL_SERVER_ERROR,
+                                       net::URLRequestStatus::FAILED);
+}
+
+void RankerModelLoaderTest::InitLocalModels() {
+  InitModel(remote_model_url_, base::Time::Now(), base::TimeDelta::FromDays(30),
+            &local_model_);
+  InitModel(remote_model_url_,
+            base::Time::Now() - base::TimeDelta::FromDays(60),
+            base::TimeDelta::FromDays(30), &expired_model_);
+  SaveModel(local_model_, local_model_path_);
+  SaveModel(expired_model_, expired_model_path_);
+  ASSERT_EQ(base::WriteFile(invalid_model_path_, kInvalidModelData,
+                            kInvalidModelSize),
+            kInvalidModelSize);
+}
+
+void RankerModelLoaderTest::InitModel(const GURL& model_url,
+                                      const base::Time& last_modified,
+                                      const base::TimeDelta& cache_duration,
+                                      RankerModel* model) {
+  ASSERT_TRUE(model != nullptr);
+  model->mutable_proto()->Clear();
+
+  auto* metadata = model->mutable_proto()->mutable_metadata();
+  if (!model_url.is_empty())
+    metadata->set_source(model_url.spec());
+  if (!last_modified.is_null()) {
+    auto last_modified_sec = (last_modified - base::Time()).InSeconds();
+    metadata->set_last_modified_sec(last_modified_sec);
+  }
+  if (!cache_duration.is_zero())
+    metadata->set_cache_duration_sec(cache_duration.InSeconds());
+
+  auto* translate = model->mutable_proto()->mutable_translate();
+  translate->set_version(1);
+
+  auto* logit = translate->mutable_logistic_regression_model();
+  logit->set_bias(0.1f);
+  logit->set_accept_ratio_weight(0.2f);
+  logit->set_decline_ratio_weight(0.3f);
+  logit->set_ignore_ratio_weight(0.4f);
+}
+
+void RankerModelLoaderTest::SaveModel(const RankerModel& model,
+                                      const base::FilePath& model_path) {
+  std::string model_str = model.SerializeAsString();
+  ASSERT_EQ(base::WriteFile(model_path, model_str.data(), model_str.size()),
+            static_cast<int>(model_str.size()));
+}
+
+RankerModelStatus RankerModelLoaderTest::ValidateModel(
+    const RankerModel& model) {
+  validated_models_.push_back(Clone(model));
+  RankerModelStatus response = RankerModelStatus::OK;
+  if (!validate_model_response_.empty()) {
+    response = validate_model_response_.front();
+    validate_model_response_.pop_front();
+  }
+  return response;
+}
+
+void RankerModelLoaderTest::OnModelAvailable(
+    std::unique_ptr<RankerModel> model) {
+  available_models_.push_back(std::move(model));
+}
+
+}  // namespace
+
+TEST_F(RankerModelLoaderTest, NoLocalOrRemoteModel) {
+  ASSERT_TRUE(DoLoaderTest(base::FilePath(), GURL()));
+
+  EXPECT_EQ(0U, validated_models_.size());
+  EXPECT_EQ(0U, available_models_.size());
+}
+
+TEST_F(RankerModelLoaderTest, BadLocalAndRemoteModel) {
+  ASSERT_TRUE(DoLoaderTest(invalid_model_path_, invalid_model_url_));
+
+  EXPECT_EQ(0U, validated_models_.size());
+  EXPECT_EQ(0U, available_models_.size());
+}
+
+TEST_F(RankerModelLoaderTest, LoadFromFileOnly) {
+  EXPECT_TRUE(DoLoaderTest(local_model_path_, GURL()));
+
+  ASSERT_EQ(1U, validated_models_.size());
+  ASSERT_EQ(1U, available_models_.size());
+  EXPECT_TRUE(IsEqual(*validated_models_[0], local_model_));
+  EXPECT_TRUE(IsEqual(*available_models_[0], local_model_));
+}
+
+TEST_F(RankerModelLoaderTest, LoadFromFileSkipsDownload) {
+  ASSERT_TRUE(DoLoaderTest(local_model_path_, remote_model_url_));
+
+  ASSERT_EQ(1U, validated_models_.size());
+  ASSERT_EQ(1U, available_models_.size());
+  EXPECT_TRUE(IsEqual(*validated_models_[0], local_model_));
+  EXPECT_TRUE(IsEqual(*available_models_[0], local_model_));
+}
+
+TEST_F(RankerModelLoaderTest, LoadFromFileAndBadUrl) {
+  ASSERT_TRUE(DoLoaderTest(local_model_path_, invalid_model_url_));
+  ASSERT_EQ(1U, validated_models_.size());
+  ASSERT_EQ(1U, available_models_.size());
+  EXPECT_TRUE(IsEqual(*validated_models_[0], local_model_));
+  EXPECT_TRUE(IsEqual(*available_models_[0], local_model_));
+}
+
+TEST_F(RankerModelLoaderTest, LoadFromURLOnly) {
+  ASSERT_TRUE(DoLoaderTest(base::FilePath(), remote_model_url_));
+  ASSERT_EQ(1U, validated_models_.size());
+  ASSERT_EQ(1U, available_models_.size());
+  EXPECT_TRUE(IsEquivalent(*validated_models_[0], remote_model_));
+  EXPECT_TRUE(IsEquivalent(*available_models_[0], remote_model_));
+}
+
+TEST_F(RankerModelLoaderTest, LoadFromExpiredFileTriggersDownload) {
+  ASSERT_TRUE(DoLoaderTest(expired_model_path_, remote_model_url_));
+  ASSERT_EQ(2U, validated_models_.size());
+  ASSERT_EQ(2U, available_models_.size());
+  EXPECT_TRUE(IsEquivalent(*validated_models_[0], local_model_));
+  EXPECT_TRUE(IsEquivalent(*available_models_[0], local_model_));
+  EXPECT_TRUE(IsEquivalent(*validated_models_[1], remote_model_));
+  EXPECT_TRUE(IsEquivalent(*available_models_[1], remote_model_));
+}
+
+TEST_F(RankerModelLoaderTest, LoadFromBadFileTriggersDownload) {
+  ASSERT_TRUE(DoLoaderTest(invalid_model_path_, remote_model_url_));
+  ASSERT_EQ(1U, validated_models_.size());
+  ASSERT_EQ(1U, available_models_.size());
+  EXPECT_TRUE(IsEquivalent(*validated_models_[0], remote_model_));
+  EXPECT_TRUE(IsEquivalent(*available_models_[0], remote_model_));
+}
+
+TEST_F(RankerModelLoaderTest, IncompatibleCachedFileTriggersDownload) {
+  validate_model_response_.push_back(RankerModelStatus::INCOMPATIBLE);
+
+  ASSERT_TRUE(DoLoaderTest(local_model_path_, remote_model_url_));
+  ASSERT_EQ(2U, validated_models_.size());
+  ASSERT_EQ(1U, available_models_.size());
+  EXPECT_TRUE(IsEquivalent(*validated_models_[0], local_model_));
+  EXPECT_TRUE(IsEquivalent(*validated_models_[1], remote_model_));
+  EXPECT_TRUE(IsEquivalent(*available_models_[0], remote_model_));
+}
+
+TEST_F(RankerModelLoaderTest, IncompatibleDownloadedFileKeepsExpired) {
+  validate_model_response_.push_back(RankerModelStatus::OK);
+  validate_model_response_.push_back(RankerModelStatus::INCOMPATIBLE);
+
+  ASSERT_TRUE(DoLoaderTest(expired_model_path_, remote_model_url_));
+  ASSERT_EQ(2U, validated_models_.size());
+  ASSERT_EQ(1U, available_models_.size());
+  EXPECT_TRUE(IsEquivalent(*validated_models_[0], local_model_));
+  EXPECT_TRUE(IsEquivalent(*validated_models_[1], remote_model_));
+  EXPECT_TRUE(IsEquivalent(*available_models_[0], local_model_));
+}