SavedFilesServiceInterface in //extensions

extensions/browser/api/file_system/saved_files_service_interface.h

+// Copyright 2017 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 EXTENSIONS_BROWSER_API_FILE_SYSTEM_SAVED_FILES_SERVICE_INTERFACE_H_
+#define EXTENSIONS_BROWSER_API_FILE_SYSTEM_SAVED_FILES_SERVICE_INTERFACE_H_
+
+#include <string>
+
+#include "base/files/file_path.h"
+
+namespace extensions {
+
+struct SavedFileEntry;
+
+// Provides an LRU of saved file entries that persist across app reloads.
+class SavedFilesServiceInterface {
+ public:
+  virtual ~SavedFilesServiceInterface() {}
+
+  // Registers a file entry with the saved files service, making it eligible to
+  // be put into the queue. File entries that are in the retained files queue at
+  // object construction are automatically registered.
+  virtual void RegisterFileEntry(const std::string& extension_id,
+                                 const std::string& id,
+                                 const base::FilePath& file_path,
+                                 bool is_directory) = 0;
+
+  // If the file with |id| is not in the queue of files to be retained
+  // permanently, adds the file to the back of the queue, evicting the least
+  // recently used entry at the front of the queue if it is full. If it is
+  // already present, moves it to the back of the queue. The |id| must have been
+  // registered.
+  virtual void EnqueueFileEntry(const std::string& extension_id,
+                                const std::string& id) = 0;
+
+  // Returns whether the file entry with the given |id| has been registered.
+  virtual bool IsRegistered(const std::string& extension_id,
+                            const std::string& id) = 0;
+
+  // Gets a borrowed pointer to the file entry with the specified |id|. Returns
+  // nullptr if the file entry has not been registered.
+  virtual const SavedFileEntry* GetFileEntry(const std::string& extension_id,
+                                             const std::string& id) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_API_FILE_SYSTEM_SAVED_FILES_SERVICE_INTERFACE_H_