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// 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_BOOKMARKS_BROWSER_BOOKMARK_CODEC_H_
#define COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_CODEC_H_
#include <stdint.h>
#include <memory>
#include <set>
#include <string>
#include "base/hash/md5.h"
#include "base/macros.h"
#include "base/strings/string16.h"
#include "components/bookmarks/browser/bookmark_node.h"
namespace base {
class DictionaryValue;
class ListValue;
class Value;
}
namespace bookmarks {
class BookmarkModel;
// BookmarkCodec is responsible for encoding and decoding the BookmarkModel
// into JSON values. The encoded values are written to disk via the
// BookmarkStorage.
class BookmarkCodec {
public:
// Creates an instance of the codec. During decoding, if the IDs in the file
// are not unique, we will reassign IDs to make them unique. There are no
// guarantees on how the IDs are reassigned or about doing minimal
// reassignments to achieve uniqueness.
BookmarkCodec();
~BookmarkCodec();
// Encodes the model to a JSON value. It's up to the caller to delete the
// returned object. This is invoked to encode the contents of the bookmark bar
// model and is currently a convenience to invoking Encode that takes the
// bookmark bar node and other folder node.
std::unique_ptr<base::Value> Encode(BookmarkModel* model,
const std::string& sync_metadata_str);
// Encodes the bookmark bar and other folders returning the JSON value.
std::unique_ptr<base::Value> Encode(
const BookmarkNode* bookmark_bar_node,
const BookmarkNode* other_folder_node,
const BookmarkNode* mobile_folder_node,
const BookmarkNode::MetaInfoMap* model_meta_info_map,
int64_t sync_transaction_version,
const std::string& sync_metadata_str);
// Decodes the previously encoded value to the specified nodes as well as
// setting |max_node_id| to the greatest node id. Returns true on success,
// false otherwise. If there is an error (such as unexpected version) all
// children are removed from the bookmark bar and other folder nodes. On exit
// |max_node_id| is set to the max id of the nodes.
bool Decode(const base::Value& value,
BookmarkNode* bb_node,
BookmarkNode* other_folder_node,
BookmarkNode* mobile_folder_node,
int64_t* max_node_id,
std::string* sync_metadata_str);
// Returns the checksum computed during last encoding/decoding call.
const std::string& computed_checksum() const { return computed_checksum_; }
// Returns the checksum that's stored in the file. After a call to Encode,
// the computed and stored checksums are the same since the computed checksum
// is stored to the file. After a call to decode, the computed checksum can
// differ from the stored checksum if the file contents were changed by the
// user.
const std::string& stored_checksum() const { return stored_checksum_; }
// Return meta info of bookmark model root.
const BookmarkNode::MetaInfoMap& model_meta_info_map() const {
return model_meta_info_map_;
}
// Return the sync transaction version of the bookmark model root.
int64_t model_sync_transaction_version() const {
return model_sync_transaction_version_;
}
// Returns whether the IDs were reassigned during decoding. Always returns
// false after encoding.
bool ids_reassigned() const { return ids_reassigned_; }
// Returns whether the GUIDs were reassigned during decoding. Always returns
// false after encoding.
bool guids_reassigned() const { return guids_reassigned_; }
// Names of the various keys written to the Value.
static const char kRootsKey[];
static const char kRootFolderNameKey[];
static const char kOtherBookmarkFolderNameKey[];
static const char kMobileBookmarkFolderNameKey[];
static const char kVersionKey[];
static const char kChecksumKey[];
static const char kIdKey[];
static const char kTypeKey[];
static const char kNameKey[];
static const char kGuidKey[];
static const char kDateAddedKey[];
static const char kURLKey[];
static const char kDateModifiedKey[];
static const char kChildrenKey[];
static const char kMetaInfo[];
static const char kSyncTransactionVersion[];
// Allows the BookmarkClient to read and a write a string blob from the JSON
// file. That string captures the bookmarks sync metadata.
static const char kSyncMetadata[];
// Possible values for kTypeKey.
static const char kTypeURL[];
static const char kTypeFolder[];
private:
// Encodes node and all its children into a Value object and returns it.
std::unique_ptr<base::Value> EncodeNode(const BookmarkNode* node);
// Encodes the given meta info into a Value object and returns it.
std::unique_ptr<base::Value> EncodeMetaInfo(
const BookmarkNode::MetaInfoMap& meta_info_map);
// Helper to perform decoding.
bool DecodeHelper(BookmarkNode* bb_node,
BookmarkNode* other_folder_node,
BookmarkNode* mobile_folder_node,
const base::Value& value,
std::string* sync_metadata_str);
// Decodes the children of the specified node. Returns true on success.
bool DecodeChildren(const base::ListValue& child_value_list,
BookmarkNode* parent);
// Reassigns bookmark IDs for all nodes.
void ReassignIDs(BookmarkNode* bb_node,
BookmarkNode* other_node,
BookmarkNode* mobile_node);
// Helper to recursively reassign IDs.
void ReassignIDsHelper(BookmarkNode* node);
// Decodes the supplied node from the supplied value. Child nodes are
// created appropriately by way of DecodeChildren. If node is NULL a new
// node is created and added to parent (parent must then be non-NULL),
// otherwise node is used.
bool DecodeNode(const base::DictionaryValue& value,
BookmarkNode* parent,
BookmarkNode* node);
// Decodes the meta info from the supplied value. If the meta info contains
// a "sync.transaction_version" key, the value of that field will be stored
// in the sync_transaction_version variable, then deleted. This is for
// backward-compatibility reasons.
// meta_info_map and sync_transaction_version must not be NULL.
bool DecodeMetaInfo(const base::DictionaryValue& value,
BookmarkNode::MetaInfoMap* meta_info_map,
int64_t* sync_transaction_version);
// Decodes the meta info from the supplied sub-node dictionary. The values
// found will be inserted in meta_info_map with the given prefix added to the
// start of their keys.
void DecodeMetaInfoHelper(const base::DictionaryValue& dict,
const std::string& prefix,
BookmarkNode::MetaInfoMap* meta_info_map);
// Updates the check-sum with the given string.
void UpdateChecksum(const std::string& str);
void UpdateChecksum(const base::string16& str);
// Updates the check-sum with the given contents of URL/folder bookmark node.
// NOTE: These functions take in individual properties of a bookmark node
// instead of taking in a BookmarkNode for efficiency so that we don't convert
// various data-types to UTF16 strings multiple times - once for serializing
// and once for computing the check-sum.
// The url parameter should be a valid UTF8 string.
void UpdateChecksumWithUrlNode(const std::string& id,
const base::string16& title,
const std::string& url);
void UpdateChecksumWithFolderNode(const std::string& id,
const base::string16& title);
// Initializes/Finalizes the checksum.
void InitializeChecksum();
void FinalizeChecksum();
// Whether or not IDs were reassigned by the codec.
bool ids_reassigned_;
// Whether or not GUIDs were reassigned by the codec.
bool guids_reassigned_;
// Whether or not IDs are valid. This is initially true, but set to false
// if an id is missing or not unique.
bool ids_valid_;
// Contains the id of each of the nodes found in the file. Used to determine
// if we have duplicates.
std::set<int64_t> ids_;
// Contains the GUID of each of the nodes found in the file. Used to determine
// if we have duplicates.
std::set<std::string> guids_;
// MD5 context used to compute MD5 hash of all bookmark data.
base::MD5Context md5_context_;
// Checksums.
std::string computed_checksum_;
std::string stored_checksum_;
// Maximum ID assigned when decoding data.
int64_t maximum_id_;
// Meta info set on bookmark model root.
BookmarkNode::MetaInfoMap model_meta_info_map_;
// Sync transaction version set on bookmark model root.
int64_t model_sync_transaction_version_;
DISALLOW_COPY_AND_ASSIGN(BookmarkCodec);
};
} // namespace bookmarks
#endif // COMPONENTS_BOOKMARKS_BROWSER_BOOKMARK_CODEC_H_