WIP: Allow ValueSerializer clients to transfer long strings out of band.

include/v8.h

 // Copyright 2012 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.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 1694 matching lines @@
      * ValueDeserializer::TransferSharedArrayBuffer as |transfer_id|.
      *
      * If the object cannot be serialized, an
      * exception should be thrown and Nothing<uint32_t>() returned.
      */
     virtual Maybe<uint32_t> GetSharedArrayBufferId(
         Isolate* isolate, Local<SharedArrayBuffer> shared_array_buffer);
 
     virtual Maybe<uint32_t> GetWasmModuleTransferId(
         Isolate* isolate, Local<WasmCompiledModule> module);
+
+    /*
+     * Called when the ValueSerializer encounters a string at least as long as
+     * the value passed to |SetMinimumLongStringLength|. The embedder is
+     * expected to return an ID for the string.
+     */
+    virtual Maybe<uint32_t> GetLongStringId(Isolate* isolate,
+                                            Local<String> string);
+
     /*
      * Allocates memory for the buffer of at least the size provided. The actual
      * size (which may be greater or equal) is written to |actual_size|. If no
      * buffer has been allocated yet, nullptr will be provided.
      *
      * If the memory cannot be allocated, nullptr should be returned.
      * |actual_size| will be ignored. It is assumed that |old_buffer| is still
      * valid in this case and has not been modified.
      */
     virtual void* ReallocateBufferMemory(void* old_buffer, size_t size,
@@ skipping 53 matching lines @@
   /*
    * Indicate whether to treat ArrayBufferView objects as host objects,
    * i.e. pass them to Delegate::WriteHostObject. This should not be
    * called when no Delegate was passed.
    *
    * The default is not to treat ArrayBufferViews as host objects.
    */
   void SetTreatArrayBufferViewsAsHostObjects(bool mode);
 
   /*
+   * If a positive values is assigned, strings of at least this length will be
+   * passed to the delegate instead of serialized inline into the buffer.
+   * This option is recommended only if the delegate has a more efficient means
+   * of delivering those strings. By default, this feature is disabled.
+   */
+  void SetMinimumLongStringLength(int size);
+
+  /*
    * Write raw data in various common formats to the buffer.
    * Note that integer types are written in base-128 varint format, not with a
    * binary copy. For use during an override of Delegate::WriteHostObject.
    */
   void WriteUint32(uint32_t value);
   void WriteUint64(uint64_t value);
   void WriteDouble(double value);
   void WriteRawBytes(const void* source, size_t length);
 
  private:
@@ skipping 58 matching lines @@
 
   /*
    * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
    * The id is not necessarily in the same namespace as unshared ArrayBuffer
    * objects.
    */
   void TransferSharedArrayBuffer(uint32_t id,
                                  Local<SharedArrayBuffer> shared_array_buffer);
 
   /*
+   * Similar to TransferArrayBuffer, but for IDs obtained from
+   * |GetLongStringId|.
+   */
+  void TransferLongString(uint32_t id, Local<String> string);
+
+  /*
    * Must be called before ReadHeader to enable support for reading the legacy
    * wire format (i.e., which predates this being shipped).
    *
    * Don't use this unless you need to read data written by previous versions of
    * blink::ScriptValueSerializer.
    */
   void SetSupportsLegacyWireFormat(bool supports_legacy_wire_format);
 
   /*
    * Expect inline wasm in the data stream (rather than in-memory transfer)
@@ skipping 8011 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_