Original patch by rlarocque@chromium.org at http://codereview.chromium.org/7633077/

chrome/browser/sync/internal_api/base_node.h

Index: chrome/browser/sync/internal_api/base_node.h
diff --git a/chrome/browser/sync/internal_api/base_node.h b/chrome/browser/sync/internal_api/base_node.h
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+// Copyright (c) 2011 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 CHROME_BROWSER_SYNC_INTERNAL_API_BASE_NODE_H_
+#define CHROME_BROWSER_SYNC_INTERNAL_API_BASE_NODE_H_
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/sync/protocol/sync.pb.h"
+#include "chrome/browser/sync/syncable/model_type.h"
+#include "googleurl/src/gurl.h"
+
+// Forward declarations of internal class types so that sync API objects
+// may have opaque pointers to these types.
+namespace base {
+class DictionaryValue;
+}
+
+namespace syncable {
+class BaseTransaction;
+class Entry;
+}
+
+namespace sync_pb {
+class AppSpecifics;
+class AutofillSpecifics;
+class AutofillProfileSpecifics;
+class BookmarkSpecifics;
+class EntitySpecifics;
+class ExtensionSpecifics;
+class SessionSpecifics;
+class NigoriSpecifics;
+class PreferenceSpecifics;
+class PasswordSpecificsData;
+class ThemeSpecifics;
+class TypedUrlSpecifics;
+}
+
+namespace sync_api {
+
+class BaseTransaction;
+
+// A valid BaseNode will never have an ID of zero.
+static const int64 kInvalidId = 0;
+
+// BaseNode wraps syncable::Entry, and corresponds to a single object's state.
+// This, like syncable::Entry, is intended for use on the stack.  A valid
+// transaction is necessary to create a BaseNode or any of its children.
+// Unlike syncable::Entry, a sync API BaseNode is identified primarily by its
+// int64 metahandle, which we call an ID here.
+class BaseNode {
+ public:
+  // All subclasses of BaseNode must provide a way to initialize themselves by
+  // doing an ID lookup.  Returns false on failure.  An invalid or deleted
+  // ID will result in failure.
+  virtual bool InitByIdLookup(int64 id) = 0;
+
+  // All subclasses of BaseNode must also provide a way to initialize themselves
+  // by doing a client tag lookup. Returns false on failure. A deleted node
+  // will return FALSE.
+  virtual bool InitByClientTagLookup(syncable::ModelType model_type,
+      const std::string& tag) = 0;
+
+  // Each object is identified by a 64-bit id (internally, the syncable
+  // metahandle).  These ids are strictly local handles.  They will persist
+  // on this client, but the same object on a different client may have a
+  // different ID value.
+  virtual int64 GetId() const;
+
+  // Returns the modification time of the object (in TimeTicks internal format).
+  int64 GetModificationTime() const;
+
+  // Nodes are hierarchically arranged into a single-rooted tree.
+  // InitByRootLookup on ReadNode allows access to the root. GetParentId is
+  // how you find a node's parent.
+  int64 GetParentId() const;
+
+  // Nodes are either folders or not.  This corresponds to the IS_DIR property
+  // of syncable::Entry.
+  bool GetIsFolder() const;
+
+  // Returns the title of the object.
+  // Uniqueness of the title is not enforced on siblings -- it is not an error
+  // for two children to share a title.
+  std::string GetTitle() const;
+
+  // Returns the model type of this object.  The model type is set at node
+  // creation time and is expected never to change.
+  syncable::ModelType GetModelType() const;
+
+  // Getter specific to the BOOKMARK datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == BOOKMARK.
+  const sync_pb::BookmarkSpecifics& GetBookmarkSpecifics() const;
+
+  // Legacy, bookmark-specific getter that wraps GetBookmarkSpecifics() above.
+  // Returns the URL of a bookmark object.
+  // TODO(ncarter): Remove this datatype-specific accessor.
+  GURL GetURL() const;
+
+  // Legacy, bookmark-specific getter that wraps GetBookmarkSpecifics() above.
+  // Fill in a vector with the byte data of this node's favicon.  Assumes
+  // that the node is a bookmark.
+  // Favicons are expected to be PNG images, and though no verification is
+  // done on the syncapi client of this, the server may reject favicon updates
+  // that are invalid for whatever reason.
+  // TODO(ncarter): Remove this datatype-specific accessor.
+  void GetFaviconBytes(std::vector<unsigned char>* output) const;
+
+  // Getter specific to the APPS datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == APPS.
+  const sync_pb::AppSpecifics& GetAppSpecifics() const;
+
+  // Getter specific to the AUTOFILL datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == AUTOFILL.
+  const sync_pb::AutofillSpecifics& GetAutofillSpecifics() const;
+
+  virtual const sync_pb::AutofillProfileSpecifics&
+      GetAutofillProfileSpecifics() const;
+
+  // Getter specific to the NIGORI datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == NIGORI.
+  const sync_pb::NigoriSpecifics& GetNigoriSpecifics() const;
+
+  // Getter specific to the PASSWORD datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == PASSWORD.
+  const sync_pb::PasswordSpecificsData& GetPasswordSpecifics() const;
+
+  // Getter specific to the PREFERENCE datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == PREFERENCE.
+  const sync_pb::PreferenceSpecifics& GetPreferenceSpecifics() const;
+
+  // Getter specific to the THEME datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == THEME.
+  const sync_pb::ThemeSpecifics& GetThemeSpecifics() const;
+
+  // Getter specific to the TYPED_URLS datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == TYPED_URLS.
+  const sync_pb::TypedUrlSpecifics& GetTypedUrlSpecifics() const;
+
+  // Getter specific to the EXTENSIONS datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == EXTENSIONS.
+  const sync_pb::ExtensionSpecifics& GetExtensionSpecifics() const;
+
+  // Getter specific to the SESSIONS datatype.  Returns protobuf
+  // data.  Can only be called if GetModelType() == SESSIONS.
+  const sync_pb::SessionSpecifics& GetSessionSpecifics() const;
+
+  const sync_pb::EntitySpecifics& GetEntitySpecifics() const;
+
+  // Returns the local external ID associated with the node.
+  int64 GetExternalId() const;
+
+  // Return the ID of the node immediately before this in the sibling order.
+  // For the first node in the ordering, return 0.
+  int64 GetPredecessorId() const;
+
+  // Return the ID of the node immediately after this in the sibling order.
+  // For the last node in the ordering, return 0.
+  virtual int64 GetSuccessorId() const;
+
+  // Return the ID of the first child of this node.  If this node has no
+  // children, return 0.
+  virtual int64 GetFirstChildId() const;
+
+  // These virtual accessors provide access to data members of derived classes.
+  virtual const syncable::Entry* GetEntry() const = 0;
+  virtual const BaseTransaction* GetTransaction() const = 0;
+
+  // Dumps a summary of node info into a DictionaryValue and returns it.
+  // Transfers ownership of the DictionaryValue to the caller.
+  base::DictionaryValue* GetSummaryAsValue() const;
+
+  // Dumps all node details into a DictionaryValue and returns it.
+  // Transfers ownership of the DictionaryValue to the caller.
+  base::DictionaryValue* GetDetailsAsValue() const;
+
+ protected:
+  BaseNode();
+  virtual ~BaseNode();
+  // The server has a size limit on client tags, so we generate a fixed length
+  // hash locally. This also ensures that ModelTypes have unique namespaces.
+  static std::string GenerateSyncableHash(syncable::ModelType model_type,
+      const std::string& client_tag);
+
+  // Determines whether part of the entry is encrypted, and if so attempts to
+  // decrypt it. Unless decryption is necessary and fails, this will always
+  // return |true|. If the contents are encrypted, the decrypted data will be
+  // stored in |unencrypted_data_|.
+  // This method is invoked once when the BaseNode is initialized.
+  bool DecryptIfNecessary();
+
+  // Returns the unencrypted specifics associated with |entry|. If |entry| was
+  // not encrypted, it directly returns |entry|'s EntitySpecifics. Otherwise,
+  // returns |unencrypted_data_|.
+  const sync_pb::EntitySpecifics& GetUnencryptedSpecifics(
+      const syncable::Entry* entry) const;
+
+  // Copy |specifics| into |unencrypted_data_|.
+  void SetUnencryptedSpecifics(const sync_pb::EntitySpecifics& specifics);
+
+ private:
+  void* operator new(size_t size);  // Node is meant for stack use only.
+
+  // A holder for the unencrypted data stored in an encrypted node.
+  sync_pb::EntitySpecifics unencrypted_data_;
+
+  // Same as |unencrypted_data_|, but for legacy password encryption.
+  scoped_ptr<sync_pb::PasswordSpecificsData> password_data_;
+
+  friend class SyncApiTest;
+  FRIEND_TEST_ALL_PREFIXES(SyncApiTest, GenerateSyncableHash);
+
+  DISALLOW_COPY_AND_ASSIGN(BaseNode);
+};
+
+}  // namespace sync_api
+
+#endif  // CHROME_BROWSER_SYNC_INTERNAL_API_BASE_NODE_H_