OLD | NEW |
(Empty) | |
| 1 // Copyright 2016 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 #ifndef COMPONENTS_TRANSLATE_CORE_BROWSER_RANKER_MODEL_LOADER_H_ |
| 6 #define COMPONENTS_TRANSLATE_CORE_BROWSER_RANKER_MODEL_LOADER_H_ |
| 7 |
| 8 #include <memory> |
| 9 #include <string> |
| 10 |
| 11 #include "base/callback.h" |
| 12 #include "base/memory/ref_counted.h" |
| 13 #include "base/memory/weak_ptr.h" |
| 14 #include "base/sequence_checker.h" |
| 15 |
| 16 class GURL; |
| 17 |
| 18 namespace base { |
| 19 class FilePath; |
| 20 class SequencedTaskRunner; |
| 21 } // namespace base |
| 22 |
| 23 namespace chrome_intelligence { |
| 24 class RankerModel; |
| 25 } // namespace chrome_intelligence |
| 26 |
| 27 namespace translate { |
| 28 |
| 29 // Enumeration denoting the outcome of an attempt to download the model. This |
| 30 // must be kept in sync with the RankerModelStatus enum in histograms.xml |
| 31 enum class RankerModelStatus { |
| 32 OK = 0, |
| 33 DOWNLOAD_THROTTLED = 1, |
| 34 DOWNLOAD_FAILED = 2, |
| 35 PARSE_FAILED = 3, |
| 36 VALIDATION_FAILED = 4, |
| 37 INCOMPATIBLE = 5, |
| 38 |
| 39 // Insert new values above this line. |
| 40 MAX |
| 41 }; |
| 42 |
| 43 // If enabled, downloads a translate ranker model and uses it to determine |
| 44 // whether the user should be given a translation prompt or not. |
| 45 class RankerModelLoader { |
| 46 public: |
| 47 // Callback to validate a ranker model on behalf of the model loader client. |
| 48 // For example, the callback might validate that the model is compatible with |
| 49 // the features generated when ranking translation offerings. This callback |
| 50 // may be called on any sequence and must, therefore, be thread-safe. This |
| 51 // callback may be invoked after the RankerModelLoader has been destroyed |
| 52 // and must, therefore, only access memory that it can guarantee to be |
| 53 // valid. |
| 54 using ValidateModelCallback = base::Callback<RankerModelStatus( |
| 55 const chrome_intelligence::RankerModel& model)>; |
| 56 |
| 57 // Called to transfer ownership of a loaded model back to the model loader |
| 58 // client. This will be called on the sequence on which the model loader was |
| 59 // constructed. This callback may be invoked after the RankerModelLoader has |
| 60 // been destroyed and must, therefore, only access memory that it can |
| 61 // guarantee to be valid. |
| 62 using OnModelAvailableCallback = base::Callback<void( |
| 63 std::unique_ptr<chrome_intelligence::RankerModel> model)>; |
| 64 |
| 65 // |validate_model_callback| may be called on any sequence; it must be thread |
| 66 // safe. |
| 67 // |
| 68 // |on_model_available_callback| will be called on the sequence on which the |
| 69 // ranker model loader is constructed. |
| 70 // |
| 71 // |model_path| denotes the file path at which the model is cached. The loader |
| 72 // will attempt to load the model from this path first, falling back to the |
| 73 // |model_url| if the model cannot be loaded or has expired. Upon downloading |
| 74 // a fresh model from |model_url| the model will be persisted to |model_path| |
| 75 // for subsequent caching. |
| 76 // |
| 77 // |model_url| denotes the URL from which the model should be loaded, if it |
| 78 // has not already been cached at |model_path|. |
| 79 // |
| 80 // |uma_prefix| will be used as a prefix for the names of all UMA metrics |
| 81 // generated by this loader. |
| 82 RankerModelLoader(const ValidateModelCallback& validate_model_callback, |
| 83 const OnModelAvailableCallback& on_model_available_callback, |
| 84 const base::FilePath& model_path, |
| 85 const GURL& model_url, |
| 86 const std::string& uma_prefix); |
| 87 |
| 88 ~RankerModelLoader(); |
| 89 |
| 90 // Asynchronously initiates loading the model from the cache file path and URL |
| 91 // previously configured. |
| 92 void Start(); |
| 93 |
| 94 // Call this method periodically to notify the model loader the ranker is |
| 95 // actively in use. The user's engagement with the feature is used as a proxy |
| 96 // for network activity. If a model download is pending, this will trigger |
| 97 // (subject to retry and frequency limits) a model download attempt. |
| 98 void NotifyOfRankerActivity(); |
| 99 |
| 100 private: |
| 101 // The model loader backend to which the actual loading functionality is |
| 102 // delegated. |
| 103 class Backend; |
| 104 friend class Backend; |
| 105 |
| 106 // A enum to track the current loader state. |
| 107 enum class LoaderState { NOT_STARTED, RUNNING, FINISHED }; |
| 108 |
| 109 // Helper method to forward OnModelAvailable callbacks while noting whether |
| 110 // or not the loader has finished its work. |
| 111 void InternalOnModelAvailable( |
| 112 const OnModelAvailableCallback& callback, |
| 113 std::unique_ptr<chrome_intelligence::RankerModel> model, |
| 114 bool finished); |
| 115 |
| 116 // Validates that ranker model loader tasks are all performed on the same |
| 117 // sequence. |
| 118 base::SequenceChecker sequence_checker_; |
| 119 |
| 120 // The task runner on which backend tasks are performed. |
| 121 const scoped_refptr<base::SequencedTaskRunner> backend_task_runner_; |
| 122 |
| 123 // The model loader backend to which the actual loading functionality is |
| 124 // delegated. |backend_| may outlive its RankerModelLoader. When the |
| 125 // RankerModelLoader is destroyed, ownership of |backend_| is transferred |
| 126 // to a delete task posted |backend_task_runner_|. |
| 127 std::unique_ptr<Backend> backend_; |
| 128 |
| 129 // The current state of the loader. |
| 130 LoaderState state_ = LoaderState::NOT_STARTED; |
| 131 |
| 132 base::WeakPtrFactory<RankerModelLoader> weak_ptr_factory_; |
| 133 |
| 134 DISALLOW_COPY_AND_ASSIGN(RankerModelLoader); |
| 135 }; |
| 136 |
| 137 } // namespace translate |
| 138 |
| 139 #endif // COMPONENTS_TRANSLATE_CORE_BROWSER_RANKER_MODEL_LOADER_H_ |
OLD | NEW |