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// Copyright 2016 the V8 project 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 V8_VALUE_SERIALIZER_H_
#define V8_VALUE_SERIALIZER_H_
#include <cstdint>
#include <vector>
#include "include/v8.h"
#include "src/base/compiler-specific.h"
#include "src/base/macros.h"
#include "src/identity-map.h"
#include "src/vector.h"
#include "src/zone.h"
namespace v8 {
namespace internal {
class HeapNumber;
class Isolate;
class JSDate;
class JSRegExp;
class JSValue;
class Object;
class Oddball;
class Smi;
enum class SerializationTag : uint8_t;
/**
* Writes V8 objects in a binary format that allows the objects to be cloned
* according to the HTML structured clone algorithm.
*
* Format is based on Blink's previous serialization logic.
*/
class ValueSerializer {
public:
explicit ValueSerializer(Isolate* isolate);
~ValueSerializer();
/*
* Writes out a header, which includes the format version.
*/
void WriteHeader();
/*
* Serializes a V8 object into the buffer.
*/
Maybe<bool> WriteObject(Handle<Object> object) WARN_UNUSED_RESULT;
/*
* Returns the stored data. This serializer should not be used once the buffer
* is released. The contents are undefined if a previous write has failed.
*/
std::vector<uint8_t> ReleaseBuffer() { return std::move(buffer_); }
private:
// Writing the wire format.
void WriteTag(SerializationTag tag);
template <typename T>
void WriteVarint(T value);
template <typename T>
void WriteZigZag(T value);
void WriteDouble(double value);
void WriteOneByteString(Vector<const uint8_t> chars);
void WriteTwoByteString(Vector<const uc16> chars);
uint8_t* ReserveRawBytes(size_t bytes);
// Writing V8 objects of various kinds.
void WriteOddball(Oddball* oddball);
void WriteSmi(Smi* smi);
void WriteHeapNumber(HeapNumber* number);
void WriteString(Handle<String> string);
Maybe<bool> WriteJSReceiver(Handle<JSReceiver> receiver) WARN_UNUSED_RESULT;
Maybe<bool> WriteJSObject(Handle<JSObject> object) WARN_UNUSED_RESULT;
Maybe<bool> WriteJSArray(Handle<JSArray> array) WARN_UNUSED_RESULT;
void WriteJSDate(JSDate* date);
Maybe<bool> WriteJSValue(Handle<JSValue> value) WARN_UNUSED_RESULT;
void WriteJSRegExp(JSRegExp* regexp);
/*
* Reads the specified keys from the object and writes key-value pairs to the
* buffer. Returns the number of keys actually written, which may be smaller
* if some keys are not own properties when accessed.
*/
Maybe<uint32_t> WriteJSObjectProperties(
Handle<JSObject> object, Handle<FixedArray> keys) WARN_UNUSED_RESULT;
Isolate* const isolate_;
std::vector<uint8_t> buffer_;
Zone zone_;
// To avoid extra lookups in the identity map, ID+1 is actually stored in the
// map (checking if the used identity is zero is the fast way of checking if
// the entry is new).
IdentityMap<uint32_t> id_map_;
uint32_t next_id_ = 0;
DISALLOW_COPY_AND_ASSIGN(ValueSerializer);
};
/*
* Deserializes values from data written with ValueSerializer, or a compatible
* implementation.
*/
class ValueDeserializer {
public:
ValueDeserializer(Isolate* isolate, Vector<const uint8_t> data);
~ValueDeserializer();
/*
* Runs version detection logic, which may fail if the format is invalid.
*/
Maybe<bool> ReadHeader() WARN_UNUSED_RESULT;
/*
* Deserializes a V8 object from the buffer.
*/
MaybeHandle<Object> ReadObject() WARN_UNUSED_RESULT;
/*
* Reads an object, consuming the entire buffer.
*
* This is required for the legacy "version 0" format, which did not allow
* reference deduplication, and instead relied on a "stack" model for
* deserializing, with the contents of objects and arrays provided first.
*/
MaybeHandle<Object> ReadObjectUsingEntireBufferForLegacyFormat()
WARN_UNUSED_RESULT;
private:
// Reading the wire format.
Maybe<SerializationTag> PeekTag() const WARN_UNUSED_RESULT;
void ConsumeTag(SerializationTag peeked_tag);
Maybe<SerializationTag> ReadTag() WARN_UNUSED_RESULT;
template <typename T>
Maybe<T> ReadVarint() WARN_UNUSED_RESULT;
template <typename T>
Maybe<T> ReadZigZag() WARN_UNUSED_RESULT;
Maybe<double> ReadDouble() WARN_UNUSED_RESULT;
Maybe<Vector<const uint8_t>> ReadRawBytes(int size) WARN_UNUSED_RESULT;
// Reading V8 objects of specific kinds.
// The tag is assumed to have already been read.
MaybeHandle<String> ReadUtf8String() WARN_UNUSED_RESULT;
MaybeHandle<String> ReadTwoByteString() WARN_UNUSED_RESULT;
MaybeHandle<JSObject> ReadJSObject() WARN_UNUSED_RESULT;
MaybeHandle<JSArray> ReadSparseJSArray() WARN_UNUSED_RESULT;
MaybeHandle<JSArray> ReadDenseJSArray() WARN_UNUSED_RESULT;
MaybeHandle<JSDate> ReadJSDate() WARN_UNUSED_RESULT;
MaybeHandle<JSValue> ReadJSValue(SerializationTag tag) WARN_UNUSED_RESULT;
MaybeHandle<JSRegExp> ReadJSRegExp() WARN_UNUSED_RESULT;
/*
* Reads key-value pairs into the object until the specified end tag is
* encountered. If successful, returns the number of properties read.
*/
Maybe<uint32_t> ReadJSObjectProperties(Handle<JSObject> object,
SerializationTag end_tag);
// Manipulating the map from IDs to reified objects.
bool HasObjectWithID(uint32_t id);
MaybeHandle<JSReceiver> GetObjectWithID(uint32_t id);
void AddObjectWithID(uint32_t id, Handle<JSReceiver> object);
Isolate* const isolate_;
const uint8_t* position_;
const uint8_t* const end_;
uint32_t version_ = 0;
Handle<SeededNumberDictionary> id_map_; // Always a global handle.
uint32_t next_id_ = 0;
DISALLOW_COPY_AND_ASSIGN(ValueDeserializer);
};
} // namespace internal
} // namespace v8
#endif // V8_VALUE_SERIALIZER_H_
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