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// Copyright (c) 2017-2022 Cloudflare, Inc.
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// Licensed under the Apache 2.0 license found in the LICENSE file or at:
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//     https://opensource.org/licenses/Apache-2.0
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#pragma once
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#include "readable.h"
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#include "writable.h"
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namespace workerd::api {
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// A TransformStream is a readable, writable pair in which whatever is written to the writable
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// side can be read from the readable side, possibly transformed into a different type of value.
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//
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// The original version of TransformStream in Workers was nothing more than an identity
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// passthrough that only handled byte data. No actual transformation of the value was performed.
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// The original version did not conform to the streams standard. That original version has been
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// migrated into the IdentityTransformStream class. If the
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// transformstream_enable_standard_constructor compatibility flag is not enabled, then
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// TransformStream is just an alias for IdentityTransformStream and continues to implement the
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// non-standard behavior. With the transformstream_enable_standard_constructor flag set, however,
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// the TransformStream implements standardized behavior.
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class TransformStream: public jsg::Object {
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 public:
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  explicit TransformStream(jsg::Ref<ReadableStream> readable, jsg::Ref<WritableStream> writable)
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      : readable(kj::mv(readable)),
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        writable(kj::mv(writable)) {}
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  static jsg::Ref<TransformStream> constructor(jsg::Lock& js,
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      jsg::Optional<Transformer> maybeTransformer,
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      jsg::Optional<StreamQueuingStrategy> maybeWritableStrategy,
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      jsg::Optional<StreamQueuingStrategy> maybeReadableStrategy);
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  jsg::Ref<ReadableStream> getReadable() {
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    return readable.addRef();
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  }
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  jsg::Ref<WritableStream> getWritable() {
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    return writable.addRef();
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  }
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  JSG_RESOURCE_TYPE(TransformStream, CompatibilityFlags::Reader flags) {
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    if (flags.getJsgPropertyOnPrototypeTemplate()) {
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      JSG_READONLY_PROTOTYPE_PROPERTY(readable, getReadable);
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      JSG_READONLY_PROTOTYPE_PROPERTY(writable, getWritable);
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      JSG_TS_OVERRIDE(<I = any, O = any> {
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        constructor(transformer?: Transformer<I, O>, writableStrategy?: QueuingStrategy<I>, readableStrategy?: QueuingStrategy<O>);
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        get readable(): ReadableStream<O>;
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        get writable(): WritableStream<I>;
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      });
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    } else {
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      JSG_READONLY_INSTANCE_PROPERTY(readable, getReadable);
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      JSG_READONLY_INSTANCE_PROPERTY(writable, getWritable);
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      JSG_TS_OVERRIDE(<I = any, O = any> {
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        constructor(transformer?: Transformer<I, O>, writableStrategy?: QueuingStrategy<I>, readableStrategy?: QueuingStrategy<O>);
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        readonly readable: ReadableStream<O>;
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        readonly writable: WritableStream<I>;
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      });
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    }
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  }
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  void visitForMemoryInfo(jsg::MemoryTracker& tracker) const {
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    tracker.trackField("readable", readable);
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    tracker.trackField("writable", writable);
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  }
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 private:
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  jsg::Ref<ReadableStream> readable;
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  jsg::Ref<WritableStream> writable;
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  void visitForGc(jsg::GcVisitor& visitor) {
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    visitor.visit(readable, writable);
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  }
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};
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}  // namespace workerd::api