Modularize Compact Language Detector 2 (CLD2) data sources

components/translate/content/browser/data_file_browser_cld_data_provider.h

+// Copyright 2014 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_CONTENT_BROWSER_DATA_FILE_BROWSER_CLD_DATA_PROVIDER_H_
+#define COMPONENTS_TRANSLATE_CONTENT_BROWSER_DATA_FILE_BROWSER_CLD_DATA_PROVIDER_H_
+
+#include "base/files/file.h"
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "components/translate/content/browser/browser_cld_data_provider.h"
+
+namespace translate {
+
+class DataFileBrowserCldDataProvider : public BrowserCldDataProvider {
+ public:
+  explicit DataFileBrowserCldDataProvider(content::RenderViewHost*);
+  virtual ~DataFileBrowserCldDataProvider();
+  // BrowserCldDataProvider implementations:
+  virtual bool OnMessageReceived(const IPC::Message&) OVERRIDE;
+  virtual void OnCldDataRequest() OVERRIDE;
+  virtual void SendCldDataResponse() OVERRIDE;
+
+  // Sets the data file that this data provider will use to fulfill requests.
+  // This method does nothing if the specified path is equal to the path that
+  // is already configured. Otherwise, the specified path is cached and
+  // subsequent requests for data will attempt to load CLD data from the file
+  // at the specified path.
+  // This method is threadsafe.
+  static void SetCldDataFilePath(const base::FilePath& filePath);
+
+  // Returns the path most recently set by SetDataFilePath. The initial value
+  // prior to any such call is the empty path.
+  // This method is threadsafe.
+  static base::FilePath GetCldDataFilePath();
+
+ private:
+  void SendCldDataResponseInternal(const base::File*,
+                                   const uint64,
+                                   const uint64);
+  static void OnCldDataRequestInternal();
+
+  content::RenderViewHost* render_view_host_;
+  scoped_ptr<base::WeakPtrFactory<DataFileBrowserCldDataProvider> >
+      weak_pointer_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(DataFileBrowserCldDataProvider);
+};
+
+}  // namespace translate
+
+#endif  // COMPONENTS_TRANSLATE_CONTENT_BROWSER_DATA_FILE_BROWSER_CLD_DATA_PROVIDER_H_