Support delegating serialization of host objects.

src/value-serializer.h

 // 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>
 
@@ skipping 51 matching lines @@
   std::vector<uint8_t> ReleaseBuffer() { return std::move(buffer_); }
 
   /*
    * Marks an ArrayBuffer as havings its contents transferred out of band.
    * Pass the corresponding JSArrayBuffer in the deserializing context to
    * ValueDeserializer::TransferArrayBuffer.
    */
   void TransferArrayBuffer(uint32_t transfer_id,
                            Handle<JSArrayBuffer> array_buffer);
 
+  /*
+   * Publicly exposed wire format writing methods.
+   * These are intended for use within the delegate's WriteHostObject method.
+   */
+  void WriteUint32(uint32_t value);
+  void WriteUint64(uint64_t value);
+  void WriteRawBytes(const void* source, size_t length);
+
  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);
-  void WriteRawBytes(const void* source, size_t length);
   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> WriteJSObjectSlow(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);
   Maybe<bool> WriteJSMap(Handle<JSMap> map) WARN_UNUSED_RESULT;
   Maybe<bool> WriteJSSet(Handle<JSSet> map) WARN_UNUSED_RESULT;
   Maybe<bool> WriteJSArrayBuffer(JSArrayBuffer* array_buffer);
   Maybe<bool> WriteJSArrayBufferView(JSArrayBufferView* array_buffer);
+  Maybe<bool> WriteHostObject(Handle<JSObject> object) WARN_UNUSED_RESULT;
 
   /*
    * 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> WriteJSObjectPropertiesSlow(
       Handle<JSObject> object, Handle<FixedArray> keys) WARN_UNUSED_RESULT;
 
   /*
@@ skipping 20 matching lines @@
 
   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(Isolate* isolate, Vector<const uint8_t> data,
+                    v8::ValueDeserializer::Delegate* delegate);
   ~ValueDeserializer();
 
   /*
    * Runs version detection logic, which may fail if the format is invalid.
    */
   Maybe<bool> ReadHeader() WARN_UNUSED_RESULT;
 
   /*
    * Reads the underlying wire format version. Likely mostly to be useful to
    * legacy code reading old wire format versions. Must be called after
@@ skipping 16 matching lines @@
   MaybeHandle<Object> ReadObjectUsingEntireBufferForLegacyFormat()
       WARN_UNUSED_RESULT;
 
   /*
    * Accepts the array buffer corresponding to the one passed previously to
    * ValueSerializer::TransferArrayBuffer.
    */
   void TransferArrayBuffer(uint32_t transfer_id,
                            Handle<JSArrayBuffer> array_buffer);
 
+  /*
+   * Publicly exposed wire format writing methods.
+   * These are intended for use within the delegate's WriteHostObject method.
+   */
+  bool ReadUint32(uint32_t* value) WARN_UNUSED_RESULT;
+  bool ReadUint64(uint64_t* value) WARN_UNUSED_RESULT;
+  bool ReadRawBytes(size_t length, const void** data) 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;
@@ skipping 13 matching lines @@
   MaybeHandle<JSDate> ReadJSDate() WARN_UNUSED_RESULT;
   MaybeHandle<JSValue> ReadJSValue(SerializationTag tag) WARN_UNUSED_RESULT;
   MaybeHandle<JSRegExp> ReadJSRegExp() WARN_UNUSED_RESULT;
   MaybeHandle<JSMap> ReadJSMap() WARN_UNUSED_RESULT;
   MaybeHandle<JSSet> ReadJSSet() WARN_UNUSED_RESULT;
   MaybeHandle<JSArrayBuffer> ReadJSArrayBuffer() WARN_UNUSED_RESULT;
   MaybeHandle<JSArrayBuffer> ReadTransferredJSArrayBuffer(bool is_shared)
       WARN_UNUSED_RESULT;
   MaybeHandle<JSArrayBufferView> ReadJSArrayBufferView(
       Handle<JSArrayBuffer> buffer) WARN_UNUSED_RESULT;
+  MaybeHandle<JSObject> ReadHostObject() 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_;
+  v8::ValueDeserializer::Delegate* const delegate_;
   const uint8_t* position_;
   const uint8_t* const end_;
   uint32_t version_ = 0;
   uint32_t next_id_ = 0;
 
   // Always global handles.
   Handle<SeededNumberDictionary> id_map_;
   MaybeHandle<SeededNumberDictionary> array_buffer_transfer_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ValueDeserializer);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_VALUE_SERIALIZER_H_