Index: components/translate/core/browser/ranker_model_loader.h |
diff --git a/components/translate/core/browser/ranker_model_loader.h b/components/translate/core/browser/ranker_model_loader.h |
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+// 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. |
+ |
+#ifndef COMPONENTS_TRANSLATE_CORE_BROWSER_RANKER_MODEL_LOADER_H_ |
+#define COMPONENTS_TRANSLATE_CORE_BROWSER_RANKER_MODEL_LOADER_H_ |
+ |
+#include <memory> |
+#include <string> |
+ |
+#include "base/files/file_path.h" |
+#include "base/memory/ref_counted.h" |
+#include "base/sequence_checker.h" |
+#include "base/threading/thread.h" |
+#include "components/translate/core/browser/proto/ranker_model.pb.h" |
+#include "url/gurl.h" |
+ |
+namespace chrome_intelligence { |
+class RankerModel; |
+} // namespace chrome_intelligence |
+ |
+namespace translate { |
+ |
+class TranslateURLFetcher; |
+ |
+// Enumeration denoting the outcome of an attempt to download the model. This |
+// must be kept in sync with the TranslateRankerModelStatus enum in |
+// histograms.xml |
+// TODO(rogerm): rename the enum in histograms.xml to be more generic |
+enum class RankerModelStatus { |
+ OK = 0, |
+ DOWNLOAD_THROTTLED = 1, |
+ DOWNLOAD_FAILED = 2, |
+ PARSE_FAILED = 3, |
+ VALIDATION_FAILED = 4, |
+ INCOMPATIBLE = 5, |
+ |
+ // Insert new values above this line. |
+ MAX |
+}; |
+ |
+// Interface exposed by a Model Loader's Observer. The observer must outlive |
+// the model loader. |
+class RankerModelObserver { |
+ public: |
+ virtual ~RankerModelObserver() = default; |
+ |
+ // The type of model the observer is willing/able to accept. Must be |
+ // thread-safe. |
+ virtual RankerModelStatus Validate( |
+ const chrome_intelligence::RankerModel& model) const = 0; |
+ |
+ // Called when a model having the expected model type and compatibility level |
+ // is loaded the model loader. This call will be executed by the task_runner |
+ // used by this observer. |
+ virtual void OnModelAvailable( |
+ std::unique_ptr<chrome_intelligence::RankerModel> model) = 0; |
+ |
+ protected: |
+ RankerModelObserver() = default; |
+ |
+ private: |
+ DISALLOW_COPY_AND_ASSIGN(RankerModelObserver); |
+}; |
+ |
+// If enabled, downloads a translate ranker model and uses it to determine |
+// whether the user should be given a translation prompt or not. |
+class RankerModelLoader { |
+ public: |
+ RankerModelLoader(RankerModelObserver* observer, |
+ const base::FilePath& model_path, |
+ const GURL& model_url, |
+ const std::string& uma_prefix); |
+ |
+ ~RankerModelLoader(); |
+ |
+ // Asynchronously initiates loading the model from the cache file path and URL |
+ // previously configured. |
+ void Start(); |
+ |
+ // Call this method periodically to notify the model loader the network might |
+ // be available. If a model download is pending, this will trigger (subject to |
+ // retry and frequency limits) a download attempt. |
+ void NotifyOfNetworkAvailability(); |
+ |
+ private: |
+ // The maximum number of model download attempts to make. Download may fail |
+ // due to server error or network availability issues. |
+ const int kMaxRetryOn5xx = 8; |
+ |
+ // The minimum duration, in minutes, between download attempts. |
+ const int kDownloadRefractoryPeriodMin = 3; |
+ |
+ // Log the result of loading a model to UMA. |
+ void ReportModelStatus(RankerModelStatus model_status); |
+ |
+ // Called to construct a model from the given |data|. |
+ std::unique_ptr<chrome_intelligence::RankerModel> Parse( |
+ const std::string& data); |
+ |
+ // Attempt to read the model from the path returns by T::GerModelPath() |
+ void LoadFromFile(); |
+ |
+ // Attempt to read the model from the URL returns by T::GetModelURL() |
+ void LoadFromURL(); |
+ |
+ // Called when the background task to download the model from |model_url_| |
+ // has completed. |
+ void OnDownloadComplete(int id, bool success, const std::string& data); |
+ |
+ // Transfer owhersnip of |model| to the |observer_|. |
+ void TransferModelToObserver( |
+ std::unique_ptr<chrome_intelligence::RankerModel> model); |
+ |
+ // The thread on which to perform background IO to read, download and |
+ // cache the model. |
+ base::Thread thread_; |
+ |
+ // Used to download model data from |model_url_|. |
+ // TODO(rogerm): Use net::URLFetcher directly? |
+ std::unique_ptr<TranslateURLFetcher> url_fetcher_; |
+ |
+ // The next time before which no new attempts to download the model should be |
+ // attempted. |
+ base::TimeTicks next_earliest_download_time_; |
+ |
+ // Tracks the last time of the last attempt to download a model. Used for UMA |
+ // reporting of download duration. |
+ base::TimeTicks download_start_time_; |
+ |
+ // A pointer to the observer for this model loader. The observer must outlive |
+ // the loader. |
+ RankerModelObserver* const observer_; // Weak. |
+ |
+ // The path at which the model is (or should be) cached. |
+ const base::FilePath model_path_; |
+ |
+ // The URL from which to download the model if the model is not in the cache |
+ // or the cached model is invalid/expired. |
+ const GURL model_url_; |
+ |
+ // This will prefix all UMA metrics generated by the model loader. |
+ const std::string uma_prefix_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(RankerModelLoader); |
+}; |
+ |
+} // namespace translate |
+ |
+#endif // COMPONENTS_TRANSLATE_CORE_BROWSER_RANKER_MODEL_LOADER_H_ |