| // Copyright 2022 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_USER_NOTES_INTERFACES_USER_NOTE_METADATA_SNAPSHOT_H_ |
| #define COMPONENTS_USER_NOTES_INTERFACES_USER_NOTE_METADATA_SNAPSHOT_H_ |
| |
| #include <memory> |
| #include <string> |
| #include <unordered_map> |
| |
| #include "base/unguessable_token.h" |
| #include "url/gurl.h" |
| |
| namespace user_notes { |
| |
| class UserNoteMetadata; |
| |
| // In order to have GURL as a key in a hashmap, GURL hashing mechanism is |
| // needed. |
| struct GURLHash { |
| size_t operator()(const GURL& url) const { |
| return std::hash<std::string>()(url.spec()); |
| } |
| }; |
| |
| // A class that encapsulates an |
| // `unordered_map<GURL, unordered_map<ID, UserNoteMetadata>>`. This represents |
| // a snapshot of the note metadata contained in the database for a set of URLs. |
| // The first map is to group metadata by URL, which makes it easy to look up |
| // what notes are attached to that URL. The second map is for quick lookup of a |
| // note's metadata by its ID. Using this class makes code simpler and clearer |
| // than if using the raw type. |
| class UserNoteMetadataSnapshot { |
| public: |
| using IdToMetadataMap = std::unordered_map<base::UnguessableToken, |
| std::unique_ptr<UserNoteMetadata>, |
| base::UnguessableTokenHash>; |
| using UrlToIdToMetadataMap = |
| std::unordered_map<GURL, IdToMetadataMap, GURLHash>; |
| |
| UserNoteMetadataSnapshot(); |
| UserNoteMetadataSnapshot(UserNoteMetadataSnapshot&& other); |
| UserNoteMetadataSnapshot(const UserNoteMetadataSnapshot&) = delete; |
| UserNoteMetadataSnapshot& operator=(const UserNoteMetadataSnapshot&) = delete; |
| ~UserNoteMetadataSnapshot(); |
| |
| // Returns false if there's at least one entry in the snapshot, true |
| // otherwise. |
| bool IsEmpty(); |
| |
| // Adds a metadata entry to this class, based on the URL the note is attached |
| // to and its ID. |
| void AddEntry(const GURL& url, |
| const base::UnguessableToken& id, |
| std::unique_ptr<UserNoteMetadata> metadata); |
| |
| // Returns a raw pointer to the Note ID -> Metadata hash map for the given |
| // URL, or nullptr if the URL does not have any notes associated with it. |
| const IdToMetadataMap* GetMapForUrl(const GURL& url) const; |
| |
| private: |
| UrlToIdToMetadataMap url_map_; |
| }; |
| |
| } // namespace user_notes |
| |
| #endif // COMPONENTS_USER_NOTES_INTERFACES_USER_NOTE_METADATA_SNAPSHOT_H_ |