third_party/WebKit/Source/bindings/core/v8/SerializedScriptValue.h

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#ifndef SerializedScriptValue_h
#define SerializedScriptValue_h

#include "bindings/core/v8/ScriptValue.h"
#include "bindings/core/v8/Transferables.h"
#include "core/CoreExport.h"
#include "wtf/HashMap.h"
#include "wtf/ThreadSafeRefCounted.h"
#include "wtf/typed_arrays/ArrayBufferContents.h"
#include <memory>
#include <v8.h>

namespace blink {

class BlobDataHandle;
class Transferables;
class ExceptionState;
class StaticBitmapImage;
class WebBlobInfo;

typedef HashMap<String, RefPtr<BlobDataHandle>> BlobDataHandleMap;
typedef Vector<WebBlobInfo> WebBlobInfoArray;

class CORE_EXPORT SerializedScriptValue
    : public ThreadSafeRefCounted<SerializedScriptValue> {
 public:
  using ArrayBufferContentsArray = Vector<WTF::ArrayBufferContents, 1>;
  using ImageBitmapContentsArray = Vector<RefPtr<StaticBitmapImage>, 1>;

  // Increment this for each incompatible change to the wire format.
  // Version 2: Added StringUCharTag for UChar v8 strings.
  // Version 3: Switched to using uuids as blob data identifiers.
  // Version 4: Extended File serialization to be complete.
  // Version 5: Added CryptoKeyTag for Key objects.
  // Version 6: Added indexed serialization for File, Blob, and FileList.
  // Version 7: Extended File serialization with user visibility.
  // Version 8: File.lastModified in milliseconds (seconds-based in earlier
  //            versions.)
  // Version 9: Added Map and Set support.
  static const uint32_t wireFormatVersion = 9;

  // VarInt encoding constants.
  static const int varIntShift = 7;
  static const int varIntMask = (1 << varIntShift) - 1;

  static PassRefPtr<SerializedScriptValue> serialize(v8::Isolate*,
                                                     v8::Local<v8::Value>,
                                                     Transferables*,
                                                     WebBlobInfoArray*,
                                                     ExceptionState&);
  static PassRefPtr<SerializedScriptValue> serialize(const String&);
  static PassRefPtr<SerializedScriptValue> serializeAndSwallowExceptions(
      v8::Isolate*,
      v8::Local<v8::Value>);

  static PassRefPtr<SerializedScriptValue> create();
  static PassRefPtr<SerializedScriptValue> create(const String&);
  static PassRefPtr<SerializedScriptValue> create(const char* data,
                                                  size_t length);

  virtual ~SerializedScriptValue();

  static PassRefPtr<SerializedScriptValue> nullValue();

  String toWireString() const { return m_data; }
  void toWireBytes(Vector<char>&) const;

  // Deserializes the value (in the current context). Returns a null value in
  // case of failure.
  v8::Local<v8::Value> deserialize(MessagePortArray* = 0);
  v8::Local<v8::Value> deserialize(v8::Isolate*,
                                   MessagePortArray* = 0,
                                   const WebBlobInfoArray* = 0);

  // Helper function which pulls the values out of a JS sequence and into a
  // MessagePortArray.  Also validates the elements per sections 4.1.13 and
  // 4.1.15 of the WebIDL spec and section 8.3.3 of the HTML5 spec and generates
  // exceptions as appropriate.
  // Returns true if the array was filled, or false if the passed value was not
  // of an appropriate type.
  static bool extractTransferables(v8::Isolate*,
                                   v8::Local<v8::Value>,
                                   int,
                                   Transferables&,
                                   ExceptionState&);

  // Informs the V8 about external memory allocated and owned by this object.
  // Large values should contribute to GC counters to eventually trigger a GC,
  // otherwise flood of postMessage() can cause OOM.
  // Ok to invoke multiple times (only adds memory once).
  // The memory registration is revoked automatically in destructor.
  void registerMemoryAllocatedWithCurrentScriptContext();

  // Returns true if the value contains a transferable ArrayBuffer.
  bool containsTransferableArrayBuffer() const;

  String& data() { return m_data; }
  BlobDataHandleMap& blobDataHandles() { return m_blobDataHandles; }
  ArrayBufferContentsArray* getArrayBufferContentsArray() {
    return m_arrayBufferContentsArray.get();
  }
  ImageBitmapContentsArray* getImageBitmapContentsArray() {
    return m_imageBitmapContentsArray.get();
  }

 private:
  friend class ScriptValueSerializer;
  friend class V8ScriptValueSerializer;

  enum StringDataMode { StringValue, WireData };

  SerializedScriptValue();
  explicit SerializedScriptValue(const String& wireData);

  void setData(const String& data) { m_data = data; }
  void transferArrayBuffers(v8::Isolate*,
                            const ArrayBufferArray&,
                            ExceptionState&);
  void transferImageBitmaps(v8::Isolate*,
                            const ImageBitmapArray&,
                            ExceptionState&);
  void transferOffscreenCanvas(v8::Isolate*,
                               const OffscreenCanvasArray&,
                               ExceptionState&);

  String m_data;
  std::unique_ptr<ArrayBufferContentsArray> m_arrayBufferContentsArray;
  std::unique_ptr<ImageBitmapContentsArray> m_imageBitmapContentsArray;
  BlobDataHandleMap m_blobDataHandles;
  intptr_t m_externallyAllocatedMemory;
};

}  // namespace blink

#endif  // SerializedScriptValue_h