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// Copyright 2018 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 THIRD_PARTY_BLINK_RENDERER_CORE_STREAMS_TRANSFORM_STREAM_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_STREAMS_TRANSFORM_STREAM_H_
#include "base/macros.h"
#include "third_party/blink/renderer/bindings/core/v8/script_value.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/platform/bindings/script_wrappable.h"
#include "third_party/blink/renderer/platform/bindings/trace_wrapper_member.h"
#include "third_party/blink/renderer/platform/bindings/trace_wrapper_v8_reference.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/heap/heap.h"
#include "third_party/blink/renderer/platform/heap/member.h"
#include "v8/include/v8.h"
namespace blink {
class ExceptionState;
class ScriptState;
class ReadableStream;
class TransformStreamTransformer;
class Visitor;
class WritableStream;
// Creates and wraps a JavaScript TransformStream object with a transformation
// defined in C++. Provides access to the readable and writable streams.
//
// On-heap references to this class must always be via a TraceWrapperMember, and
// must always have an ancestor in the V8 heap, or the internal JavaScript
// objects owned by |readable_| and |writable_| will be lost.
//
// To ensure that the JS TransformStream is always referenced, this class uses
// two-stage construction. After calling the constructor, store the reference
// in a TraceWrapperMember before calling Init(). Init() must always be called
// before using the instance.
class CORE_EXPORT TransformStream final : public ScriptWrappable {
DEFINE_WRAPPERTYPEINFO();
public:
TransformStream();
// This constructor produces a TransformStream from an existing {readable,
// writable} pair. It cannot fail and does not require calling Init().
TransformStream(ReadableStream*, WritableStream*);
~TransformStream() override;
// |Create| functions internally call Init().
static TransformStream* Create(ScriptState*, ExceptionState&);
static TransformStream* Create(ScriptState*,
ScriptValue transformer,
ExceptionState&);
static TransformStream* Create(ScriptState*,
ScriptValue transformer,
ScriptValue writable_strategy,
ExceptionState&);
static TransformStream* Create(ScriptState*,
ScriptValue transformer,
ScriptValue writable_strategy,
ScriptValue readable_strategy,
ExceptionState&);
// If HadException is true on return, the object is invalid and should be
// destroyed.
void Init(TransformStreamTransformer*, ScriptState*, ExceptionState&);
// IDL attributes
ReadableStream* readable() const { return readable_; }
WritableStream* writable() const { return writable_; }
ReadableStream* Readable() const { return readable_; }
WritableStream* Writable() const { return writable_; }
void Trace(Visitor*) override;
private:
// These are class-scoped to avoid name clashes in jumbo builds.
class Algorithm;
class FlushAlgorithm;
class TransformAlgorithm;
bool InitInternal(ScriptState*,
v8::Local<v8::Object> stream,
ExceptionState&);
TraceWrapperMember<ReadableStream> readable_;
TraceWrapperMember<WritableStream> writable_;
DISALLOW_COPY_AND_ASSIGN(TransformStream);
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_CORE_STREAMS_TRANSFORM_STREAM_H_