Source/WebCore/bindings/js/ReadableStream.cpp

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#include "config.h"
#include "ReadableStream.h"

#include "Exception.h"
#include "ExceptionCode.h"
#include "JSDOMConvertSequences.h"
#include "JSReadableStreamSink.h"
#include "JSReadableStreamSource.h"
#include "WebCoreJSClientData.h"


namespace WebCore {
using namespace JSC;

ExceptionOr<Ref<ReadableStream>> ReadableStream::create(JSC::JSGlobalObject& lexicalGlobalObject, RefPtr<ReadableStreamSource>&& source)
{
    VM& vm = lexicalGlobalObject.vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    auto& clientData = *static_cast<JSVMClientData*>(vm.clientData);
    auto& globalObject = *JSC::jsCast<JSDOMGlobalObject*>(&lexicalGlobalObject);

    auto* constructor = JSC::asObject(globalObject.get(&lexicalGlobalObject, clientData.builtinNames().ReadableStreamPrivateName()));
    RETURN_IF_EXCEPTION(scope, Exception { ExistingExceptionError });

    auto constructData = getConstructData(vm, constructor);
    ASSERT(constructData.type != CallData::Type::None);

    MarkedArgumentBuffer args;
    args.append(source ? toJSNewlyCreated(&lexicalGlobalObject, &globalObject, source.releaseNonNull()) : JSC::jsUndefined());
    ASSERT(!args.hasOverflowed());

    JSObject* object = JSC::construct(&lexicalGlobalObject, constructor, constructData, args);
    ASSERT(!!scope.exception() == !object);
    RETURN_IF_EXCEPTION(scope, Exception { ExistingExceptionError });

    return create(globalObject, *jsCast<JSReadableStream*>(object));
}

static inline std::optional<JSC::JSValue> invokeReadableStreamFunction(JSC::JSGlobalObject& lexicalGlobalObject, const JSC::Identifier& identifier, JSC::JSValue thisValue, const JSC::MarkedArgumentBuffer& arguments)
{
    JSC::VM& vm = lexicalGlobalObject.vm();
    JSC::JSLockHolder lock(vm);

    auto function = lexicalGlobalObject.get(&lexicalGlobalObject, identifier);
    ASSERT(function.isCallable(vm));

    auto scope = DECLARE_CATCH_SCOPE(vm);
    auto callData = JSC::getCallData(vm, function);
    auto result = call(&lexicalGlobalObject, function, callData, thisValue, arguments);
    EXCEPTION_ASSERT(!scope.exception() || vm.hasPendingTerminationException());
    if (scope.exception())
        return { };
    return result;
}

void ReadableStream::pipeTo(ReadableStreamSink& sink)
{
    auto& lexicalGlobalObject = *m_globalObject;
    auto* clientData = static_cast<JSVMClientData*>(lexicalGlobalObject.vm().clientData);
    auto& privateName = clientData->builtinFunctions().readableStreamInternalsBuiltins().readableStreamPipeToPrivateName();

    MarkedArgumentBuffer arguments;
    arguments.append(readableStream());
    arguments.append(toJS(&lexicalGlobalObject, m_globalObject.get(), sink));
    ASSERT(!arguments.hasOverflowed());
    invokeReadableStreamFunction(lexicalGlobalObject, privateName, JSC::jsUndefined(), arguments);
}

std::optional<std::pair<Ref<ReadableStream>, Ref<ReadableStream>>> ReadableStream::tee()
{
    auto& lexicalGlobalObject = *m_globalObject;
    auto* clientData = static_cast<JSVMClientData*>(lexicalGlobalObject.vm().clientData);
    auto& privateName = clientData->builtinFunctions().readableStreamInternalsBuiltins().readableStreamTeePrivateName();

    MarkedArgumentBuffer arguments;
    arguments.append(readableStream());
    arguments.append(JSC::jsBoolean(true));
    ASSERT(!arguments.hasOverflowed());
    auto returnedValue = invokeReadableStreamFunction(lexicalGlobalObject, privateName, JSC::jsUndefined(), arguments);
    if (!returnedValue)
        return { };

    auto results = Detail::SequenceConverter<IDLInterface<ReadableStream>>::convert(lexicalGlobalObject, *returnedValue);

    ASSERT(results.size() == 2);
    return std::make_pair(results[0].releaseNonNull(), results[1].releaseNonNull());
}

void ReadableStream::lock()
{
    auto& lexicalGlobalObject = *m_globalObject;
    auto& vm = lexicalGlobalObject.vm();
    auto scope = DECLARE_CATCH_SCOPE(vm);

    auto& clientData = *static_cast<JSVMClientData*>(vm.clientData);

    auto* constructor = JSC::asObject(m_globalObject->get(&lexicalGlobalObject, clientData.builtinNames().ReadableStreamDefaultReaderPrivateName()));
    EXCEPTION_ASSERT(!scope.exception() || vm.hasPendingTerminationException());
    if (scope.exception())
        return;

    auto constructData = getConstructData(vm, constructor);
    ASSERT(constructData.type != CallData::Type::None);

    MarkedArgumentBuffer args;
    args.append(readableStream());
    ASSERT(!args.hasOverflowed());

    JSC::construct(&lexicalGlobalObject, constructor, constructData, args);
    EXCEPTION_ASSERT(!scope.exception() || vm.hasPendingTerminationException());
}

static inline bool checkReadableStream(JSDOMGlobalObject& globalObject, JSReadableStream* readableStream, JSC::JSValue function)
{
    auto& lexicalGlobalObject = globalObject;

    ASSERT(function);
    JSC::MarkedArgumentBuffer arguments;
    arguments.append(readableStream);
    ASSERT(!arguments.hasOverflowed());

    auto& vm = lexicalGlobalObject.vm();
    auto scope = DECLARE_CATCH_SCOPE(vm);
    auto callData = JSC::getCallData(vm, function);
    ASSERT(callData.type != JSC::CallData::Type::None);

    auto result = call(&lexicalGlobalObject, function, callData, JSC::jsUndefined(), arguments);
    EXCEPTION_ASSERT(!scope.exception() || vm.hasPendingTerminationException());

    return result.isTrue() || scope.exception();
}

bool ReadableStream::isLocked() const
{
    return checkReadableStream(*globalObject(), readableStream(), globalObject()->builtinInternalFunctions().readableStreamInternals().m_isReadableStreamLockedFunction.get());
}

bool ReadableStream::isDisturbed() const
{
    return checkReadableStream(*globalObject(), readableStream(), globalObject()->builtinInternalFunctions().readableStreamInternals().m_isReadableStreamDisturbedFunction.get());
}

bool ReadableStream::isDisturbed(JSGlobalObject& lexicalGlobalObject, JSValue value)
{
    auto& vm = lexicalGlobalObject.vm();
    auto& globalObject = *jsDynamicCast<JSDOMGlobalObject*>(vm, &lexicalGlobalObject);
    auto* readableStream = jsDynamicCast<JSReadableStream*>(vm, value);

    return checkReadableStream(globalObject, readableStream, globalObject.builtinInternalFunctions().readableStreamInternals().m_isReadableStreamDisturbedFunction.get());
}

}