| // Copyright 2012 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_SYNC_SYNCABLE_READ_NODE_H_ |
| #define COMPONENTS_SYNC_SYNCABLE_READ_NODE_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <string> |
| |
| #include "base/compiler_specific.h" |
| #include "base/macros.h" |
| #include "components/sync/base/model_type.h" |
| #include "components/sync/syncable/base_node.h" |
| |
| namespace syncer { |
| |
| // ReadNode wraps a syncable::Entry to provide the functionality of a |
| // read-only BaseNode. |
| class ReadNode : public BaseNode { |
| public: |
| // Create an unpopulated ReadNode on the given transaction. Call some flavor |
| // of Init to populate the ReadNode with a database entry. |
| explicit ReadNode(const BaseTransaction* transaction); |
| ~ReadNode() override; |
| |
| // A client must use one (and only one) of the following Init variants to |
| // populate the node. |
| |
| // BaseNode implementation. |
| InitByLookupResult InitByIdLookup(int64_t id) override; |
| InitByLookupResult InitByClientTagLookup(ModelType model_type, |
| const std::string& tag) override; |
| |
| // There is always a root node, so this can't fail. The root node is |
| // never mutable, so root lookup is only possible on a ReadNode. |
| void InitByRootLookup(); |
| |
| // Returns the type root node, if it exists. This is usually created by the |
| // server during first sync. Eventually, we plan to remove support for it |
| // from the protocol and have the client create the node instead. |
| InitByLookupResult InitTypeRoot(ModelType type); |
| |
| // Returns a server-created and unique-server-tagged item. |
| // |
| // This functionality is only useful for bookmarks because only bookmarks |
| // have server-tagged items. All other server-tagged items are type root |
| // nodes, which should be looked up with InitTypeRoot(). |
| InitByLookupResult InitByTagLookupForBookmarks(const std::string& tag); |
| |
| // Returns transaction version of the last transaction where this node has |
| // been modified. |
| int64_t GetTransactionVersion() const; |
| |
| // Implementation of BaseNode's abstract virtual accessors. |
| const syncable::Entry* GetEntry() const override; |
| const BaseTransaction* GetTransaction() const override; |
| |
| protected: |
| ReadNode(); |
| |
| private: |
| void* operator new(size_t size); // Node is meant for stack use only. |
| |
| // The underlying syncable object which this class wraps. |
| syncable::Entry* entry_; |
| |
| // The sync API transaction that is the parent of this node. |
| const BaseTransaction* transaction_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ReadNode); |
| }; |
| |
| } // namespace syncer |
| |
| #endif // COMPONENTS_SYNC_SYNCABLE_READ_NODE_H_ |