Revert "[translate] Add translate ranker model loader."

components/translate/core/browser/translate_ranker_impl.cc

Index: components/translate/core/browser/translate_ranker_impl.cc
diff --git a/components/translate/core/browser/translate_ranker_impl.cc b/components/translate/core/browser/translate_ranker_impl.cc
deleted file mode 100644
index ed4a9b1f2df21957ae73d17330d31d48db803f2c..0000000000000000000000000000000000000000
--- a/components/translate/core/browser/translate_ranker_impl.cc
+++ /dev/null
@@ -1,282 +0,0 @@
-// 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/translate_ranker_impl.h"
-
-#include <cmath>
-
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/command_line.h"
-#include "base/files/file_path.h"
-#include "base/files/file_util.h"
-#include "base/memory/ptr_util.h"
-#include "base/metrics/histogram_macros.h"
-#include "base/profiler/scoped_tracker.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_util.h"
-#include "base/task_runner.h"
-#include "base/threading/thread_task_runner_handle.h"
-#include "components/metrics/proto/translate_event.pb.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 "components/translate/core/browser/translate_url_fetcher.h"
-#include "components/translate/core/common/translate_switches.h"
-#include "components/variations/variations_associated_data.h"
-#include "url/gurl.h"
-
-namespace translate {
-
-namespace {
-
-using chrome_intelligence::RankerModel;
-using chrome_intelligence::RankerModelProto;
-using chrome_intelligence::TranslateRankerModel;
-
-const double kTranslationOfferThreshold = 0.5;
-
-const char kTranslateRankerModelFileName[] = "Translate Ranker Model";
-const char kUmaPrefix[] = "Translate.Ranker";
-const char kUnknown[] = "UNKNOWN";
-
-double Sigmoid(double x) {
-  return 1.0 / (1.0 + exp(-x));
-}
-
-double SafeRatio(int numerator, int denominator) {
-  return denominator ? (numerator / static_cast<double>(denominator)) : 0.0;
-}
-
-double ScoreComponent(const google::protobuf::Map<std::string, float>& weights,
-                      const std::string& key) {
-  auto i = weights.find(base::ToLowerASCII(key));
-  if (i == weights.end())
-    i = weights.find(kUnknown);
-  return i == weights.end() ? 0.0 : i->second;
-}
-
-RankerModelStatus ValidateModel(const RankerModel& model) {
-  if (model.proto().model_case() != RankerModelProto::kTranslate)
-    return RankerModelStatus::VALIDATION_FAILED;
-
-  if (model.proto().translate().model_revision_case() !=
-      TranslateRankerModel::kLogisticRegressionModel) {
-    return RankerModelStatus::INCOMPATIBLE;
-  }
-
-  return RankerModelStatus::OK;
-}
-
-}  // namespace
-
-const base::Feature kTranslateRankerQuery{"TranslateRankerQuery",
-                                          base::FEATURE_DISABLED_BY_DEFAULT};
-
-const base::Feature kTranslateRankerEnforcement{
-    "TranslateRankerEnforcement", base::FEATURE_DISABLED_BY_DEFAULT};
-
-const base::Feature kTranslateRankerLogging{"TranslateRankerLogging",
-                                            base::FEATURE_DISABLED_BY_DEFAULT};
-
-TranslateRankerFeatures::TranslateRankerFeatures() {}
-
-TranslateRankerFeatures::TranslateRankerFeatures(int accepted,
-                                                 int denied,
-                                                 int ignored,
-                                                 const std::string& src,
-                                                 const std::string& dst,
-                                                 const std::string& cntry,
-                                                 const std::string& locale)
-    : accepted_count(accepted),
-      denied_count(denied),
-      ignored_count(ignored),
-      total_count(accepted_count + denied_count + ignored_count),
-      src_lang(src),
-      dst_lang(dst),
-      country(cntry),
-      app_locale(locale),
-      accepted_ratio(SafeRatio(accepted_count, total_count)),
-      denied_ratio(SafeRatio(denied_count, total_count)),
-      ignored_ratio(SafeRatio(ignored_count, total_count)) {}
-
-TranslateRankerFeatures::TranslateRankerFeatures(const TranslatePrefs& prefs,
-                                                 const std::string& src,
-                                                 const std::string& dst,
-                                                 const std::string& locale)
-    : TranslateRankerFeatures(prefs.GetTranslationAcceptedCount(src),
-                              prefs.GetTranslationDeniedCount(src),
-                              prefs.GetTranslationIgnoredCount(src),
-                              src,
-                              dst,
-                              prefs.GetCountry(),
-                              locale) {}
-
-TranslateRankerFeatures::~TranslateRankerFeatures() {}
-
-void TranslateRankerFeatures::WriteTo(std::ostream& stream) const {
-  stream << "src_lang='" << src_lang << "', "
-         << "dst_lang='" << dst_lang << "', "
-         << "country='" << country << "', "
-         << "app_locale='" << app_locale << "', "
-         << "accept_count=" << accepted_count << ", "
-         << "denied_count=" << denied_count << ", "
-         << "ignored_count=" << ignored_count << ", "
-         << "total_count=" << total_count << ", "
-         << "accept_ratio=" << accepted_ratio << ", "
-         << "decline_ratio=" << denied_ratio << ", "
-         << "ignore_ratio=" << ignored_ratio;
-}
-
-TranslateRankerImpl::TranslateRankerImpl(const base::FilePath& model_path,
-                                         const GURL& model_url)
-    : weak_ptr_factory_(this) {
-  model_loader_ = base::MakeUnique<RankerModelLoader>(
-      base::Bind(&ValidateModel),
-      base::Bind(&TranslateRankerImpl::OnModelAvailable,
-                 weak_ptr_factory_.GetWeakPtr()),
-      model_path, model_url, kUmaPrefix);
-  model_loader_->Start();
-}
-
-TranslateRankerImpl::~TranslateRankerImpl() {}
-
-// static
-base::FilePath TranslateRankerImpl::GetModelPath(
-    const base::FilePath& data_dir) {
-  if (data_dir.empty())
-    return base::FilePath();
-
-  // Otherwise, look for the file in data dir.
-  return data_dir.AppendASCII(kTranslateRankerModelFileName);
-}
-
-// static
-GURL TranslateRankerImpl::GetModelURL() {
-  // Allow override of the ranker model URL from the command line.
-  std::string raw_url;
-  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(switches::kTranslateRankerModelURL)) {
-    raw_url =
-        command_line->GetSwitchValueASCII(switches::kTranslateRankerModelURL);
-  } else {
-    // Otherwise take the ranker model URL from the ranker query variation.
-    raw_url = variations::GetVariationParamValueByFeature(
-        kTranslateRankerQuery, switches::kTranslateRankerModelURL);
-  }
-
-  DVLOG(3) << switches::kTranslateRankerModelURL << " = " << raw_url;
-
-  return GURL(raw_url);
-}
-
-bool TranslateRankerImpl::IsLoggingEnabled() {
-  return base::FeatureList::IsEnabled(kTranslateRankerLogging);
-}
-
-bool TranslateRankerImpl::IsQueryEnabled() {
-  return base::FeatureList::IsEnabled(kTranslateRankerQuery);
-}
-
-bool TranslateRankerImpl::IsEnforcementEnabled() {
-  return base::FeatureList::IsEnabled(kTranslateRankerEnforcement);
-}
-
-int TranslateRankerImpl::GetModelVersion() const {
-  return model_ ? model_->proto().translate().version() : 0;
-}
-
-bool TranslateRankerImpl::ShouldOfferTranslation(
-    const TranslatePrefs& translate_prefs,
-    const std::string& src_lang,
-    const std::string& dst_lang) {
-  DCHECK(sequence_checker_.CalledOnValidSequence());
-  // The ranker is a gate in the "show a translation prompt" flow. To retain
-  // the pre-existing functionality, it defaults to returning true in the
-  // absence of a model or if enforcement is disabled. As this is ranker is
-  // subsumed into a more general assist ranker, this default will go away
-  // (or become False).
-  const bool kDefaultResponse = true;
-
-  // If we don't have a model, request one and return the default.
-  if (model_ == nullptr) {
-    return kDefaultResponse;
-  }
-
-  SCOPED_UMA_HISTOGRAM_TIMER("Translate.Ranker.Timer.ShouldOfferTranslation");
-
-  // TODO(rogerm): Remove ScopedTracker below once crbug.com/646711 is closed.
-  tracked_objects::ScopedTracker tracking_profile(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "646711 translate::TranslateRankerImpl::ShouldOfferTranslation"));
-
-  TranslateRankerFeatures features(
-      translate_prefs, src_lang, dst_lang,
-      TranslateDownloadManager::GetInstance()->application_locale());
-
-  double score = CalculateScore(features);
-
-  DVLOG(2) << "TranslateRankerImpl::ShouldOfferTranslation: "
-           << "Score = " << score << ", Features=[" << features << "]";
-
-  bool result = (score >= kTranslationOfferThreshold);
-
-  UMA_HISTOGRAM_BOOLEAN("Translate.Ranker.QueryResult", result);
-
-  return result;
-}
-
-double TranslateRankerImpl::CalculateScore(
-    const TranslateRankerFeatures& features) {
-  DCHECK(sequence_checker_.CalledOnValidSequence());
-  SCOPED_UMA_HISTOGRAM_TIMER("Translate.Ranker.Timer.CalculateScore");
-  DCHECK(model_ != nullptr);
-  const TranslateRankerModel::LogisticRegressionModel& logit =
-      model_->proto().translate().logistic_regression_model();
-
-  double dot_product =
-      (features.accepted_count * logit.accept_count_weight()) +
-      (features.denied_count * logit.decline_count_weight()) +
-      (features.ignored_count * logit.ignore_count_weight()) +
-      (features.accepted_ratio * logit.accept_ratio_weight()) +
-      (features.denied_ratio * logit.decline_ratio_weight()) +
-      (features.ignored_ratio * logit.ignore_ratio_weight()) +
-      ScoreComponent(logit.source_language_weight(), features.src_lang) +
-      ScoreComponent(logit.dest_language_weight(), features.dst_lang) +
-      ScoreComponent(logit.country_weight(), features.country) +
-      ScoreComponent(logit.locale_weight(), features.app_locale);
-
-  return Sigmoid(dot_product + logit.bias());
-}
-
-void TranslateRankerImpl::FlushTranslateEvents(
-    std::vector<metrics::TranslateEventProto>* events) {
-  DCHECK(sequence_checker_.CalledOnValidSequence());
-  DVLOG(3) << "Flushing translate ranker events.";
-  events->swap(event_cache_);
-  event_cache_.clear();
-}
-
-void TranslateRankerImpl::AddTranslateEvent(
-    const metrics::TranslateEventProto& event) {
-  DCHECK(sequence_checker_.CalledOnValidSequence());
-  DVLOG(3) << "Adding translate ranker event.";
-  if (IsLoggingEnabled())
-    event_cache_.push_back(event);
-}
-
-void TranslateRankerImpl::OnModelAvailable(std::unique_ptr<RankerModel> model) {
-  DCHECK(sequence_checker_.CalledOnValidSequence());
-  model_ = std::move(model);
-}
-
-}  // namespace translate
-
-std::ostream& operator<<(std::ostream& stream,
-                         const translate::TranslateRankerFeatures& features) {
-  features.WriteTo(stream);
-  return stream;
-}