XMLHttpRequestWorker.cpp

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this file,

 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "XMLHttpRequestWorker.h"

#include "nsIDOMEventListener.h"

#include "GeckoProfiler.h"

#include "jsfriendapi.h"

#include "js/ArrayBuffer.h"  // JS::Is{,Detached}ArrayBufferObject

#include "js/GCPolicyAPI.h"

#include "js/JSON.h"

#include "js/RootingAPI.h"  // JS::{Handle,Heap,PersistentRooted}

#include "js/TracingAPI.h"

#include "js/Value.h"  // JS::{Undefined,}Value

#include "mozilla/ArrayUtils.h"

#include "mozilla/HoldDropJSObjects.h"

#include "mozilla/dom/Exceptions.h"

#include "mozilla/dom/Event.h"

#include "mozilla/dom/File.h"

#include "mozilla/dom/FormData.h"

#include "mozilla/dom/ProgressEvent.h"

#include "mozilla/dom/SerializedStackHolder.h"

#include "mozilla/dom/StreamBlobImpl.h"

#include "mozilla/dom/StructuredCloneHolder.h"

#include "mozilla/dom/URLSearchParams.h"

#include "mozilla/dom/WorkerScope.h"

#include "mozilla/dom/WorkerRef.h"

#include "mozilla/dom/WorkerRunnable.h"

#include "mozilla/dom/XMLHttpRequestBinding.h"

#include "mozilla/Telemetry.h"

#include "nsComponentManagerUtils.h"

#include "nsContentUtils.h"

#include "nsJSUtils.h"

#include "nsThreadUtils.h"

#include "XMLHttpRequestMainThread.h"

#include "XMLHttpRequestUpload.h"

#include "mozilla/UniquePtr.h"

extern mozilla::LazyLogModule gXMLHttpRequestLog;

namespace mozilla::dom {

using EventType = XMLHttpRequest::EventType;

using Events = XMLHttpRequest::Events;

/**

 *  XMLHttpRequest in workers

 *  XHR in workers is implemented by proxying calls/events/etc between the

 *  worker thread and an XMLHttpRequest on the main thread.  The glue

 *  object here is the Proxy, which lives on both threads.  All other objects

 *  live on either the main thread (the XMLHttpRequest) or the worker thread

 *  (the worker and XHR private objects).

 *  The main thread XHR is always operated in async mode, even for sync XHR

 *  in workers.  Calls made on the worker thread are proxied to the main thread

 *  synchronously (meaning the worker thread is blocked until the call

 *  returns).  Each proxied call spins up a sync queue, which captures any

 *  synchronously dispatched events and ensures that they run synchronously

 *  on the worker as well.  Asynchronously dispatched events are posted to the

 *  worker thread to run asynchronously.  Some of the XHR state is mirrored on

 *  the worker thread to avoid needing a cross-thread call on every property

 *  access.

 *  The XHR private is stored in the private slot of the XHR JSObject on the

 *  worker thread.  It is destroyed when that JSObject is GCd.  The private

 *  roots its JSObject while network activity is in progress.  It also

 *  adds itself as a feature to the worker to give itself a chance to clean up

 *  if the worker goes away during an XHR call.  It is important that the

 *  rooting and feature registration (collectively called pinning) happens at

 *  the proper times.  If we pin for too long we can cause memory leaks or even

 *  shutdown hangs.  If we don't pin for long enough we introduce a GC hazard.

 *  The XHR is pinned from the time Send is called to roughly the time loadend

 *  is received.  There are some complications involved with Abort and XHR

 *  reuse.  We maintain a counter on the main thread of how many times Send was

 *  called on this XHR, and we decrement the counter every time we receive a

 *  loadend event.  When the counter reaches zero we dispatch a runnable to the

 *  worker thread to unpin the XHR.  We only decrement the counter if the

 *  dispatch was successful, because the worker may no longer be accepting

 *  regular runnables.  In the event that we reach Proxy::Teardown and there

 *  the outstanding Send count is still non-zero, we dispatch a control

 *  runnable which is guaranteed to run.

 *  NB: Some of this could probably be simplified now that we have the

 *  inner/outer channel ids.

*/

class Proxy final : public nsIDOMEventListener {

 public:

  // Read on multiple threads.

  WorkerPrivate* mWorkerPrivate;

  const ClientInfo mClientInfo;

  const Maybe<ServiceWorkerDescriptor> mController;

  // Only ever dereferenced and/or checked on the worker thread. Cleared

  // explicitly on the worker thread inside XMLHttpRequestWorker::ReleaseProxy.

  WeakPtr<XMLHttpRequestWorker> mXMLHttpRequestPrivate;

  // XHR Params:

  bool mMozAnon;

  bool mMozSystem;

  // Only touched on the main thread.

  RefPtr<XMLHttpRequestMainThread> mXHR;

  RefPtr<XMLHttpRequestUpload> mXHRUpload;

  nsCOMPtr<nsIEventTarget> mSyncLoopTarget;

  nsCOMPtr<nsIEventTarget> mSyncEventResponseTarget;

  uint32_t mInnerEventStreamId;

  uint32_t mInnerChannelId;

  uint32_t mOutstandingSendCount;

  // Only touched on the worker thread.

  uint32_t mOuterEventStreamId;

  uint32_t mOuterChannelId;

  uint32_t mOpenCount;

  uint64_t mLastLoaded;

  uint64_t mLastTotal;

  uint64_t mLastUploadLoaded;

  uint64_t mLastUploadTotal;

  nsresult mLastErrorDetailAtLoadend;

  bool mIsSyncXHR;

  bool mLastLengthComputable;

  bool mLastUploadLengthComputable;

  bool mSeenLoadStart;

  bool mSeenUploadLoadStart;

  bool mDispatchPrematureAbortEvent;

  bool mDispatchPrematureAbortEventToUpload;

  // Only touched on the main thread.

  bool mUploadEventListenersAttached;

  bool mMainThreadSeenLoadStart;

  bool mInOpen;

 public:

  Proxy(XMLHttpRequestWorker* aXHRPrivate, const ClientInfo& aClientInfo,

        const Maybe<ServiceWorkerDescriptor>& aController, bool aMozAnon,

        bool aMozSystem)

      : mWorkerPrivate(nullptr),

        mClientInfo(aClientInfo),

        mController(aController),

        mXMLHttpRequestPrivate(aXHRPrivate),

        mMozAnon(aMozAnon),

        mMozSystem(aMozSystem),

        mInnerEventStreamId(0),

        mInnerChannelId(0),

        mOutstandingSendCount(0),

        mOuterEventStreamId(0),

        mOuterChannelId(0),

        mOpenCount(0),

        mLastLoaded(0),

        mLastTotal(0),

        mLastUploadLoaded(0),

        mLastUploadTotal(0),

        mLastErrorDetailAtLoadend(NS_OK),

        mIsSyncXHR(false),

        mLastLengthComputable(false),

        mLastUploadLengthComputable(false),

        mSeenLoadStart(false),

        mSeenUploadLoadStart(false),

        mDispatchPrematureAbortEvent(false),

        mDispatchPrematureAbortEventToUpload(false),

        mUploadEventListenersAttached(false),

        mMainThreadSeenLoadStart(false),

        mInOpen(false) {}

  NS_DECL_THREADSAFE_ISUPPORTS

  NS_DECL_NSIDOMEVENTLISTENER

  bool Init();

  void Teardown();

  bool AddRemoveEventListeners(bool aUpload, bool aAdd);

  void Reset() {

    AssertIsOnMainThread();

    if (mUploadEventListenersAttached) {

      AddRemoveEventListeners(true, false);

  already_AddRefed<nsIEventTarget> GetEventTarget() {

    AssertIsOnMainThread();

    nsCOMPtr<nsIEventTarget> target =

        mSyncEventResponseTarget ? mSyncEventResponseTarget : mSyncLoopTarget;

    return target.forget();

#ifdef DEBUG

  void DebugStoreWorkerRef(RefPtr<StrongWorkerRef>& aWorkerRef) {

    MOZ_ASSERT(!NS_IsMainThread());

    MutexAutoLock lock(mXHR->mTSWorkerRefMutex);

    mXHR->mTSWorkerRef = new ThreadSafeWorkerRef(aWorkerRef);

  void DebugForgetWorkerRef() {

    MOZ_ASSERT(!NS_IsMainThread());

    MutexAutoLock lock(mXHR->mTSWorkerRefMutex);

    mXHR->mTSWorkerRef = nullptr;

#endif

 private:

  ~Proxy() {

    MOZ_ASSERT(!mXHR);

    MOZ_ASSERT(!mXHRUpload);

    MOZ_ASSERT(!mOutstandingSendCount);

};

class WorkerThreadProxySyncRunnable : public WorkerMainThreadRunnable {

 protected:

  RefPtr<Proxy> mProxy;

 private:

  // mErrorCode is set on the main thread by MainThreadRun and it's used at the

  // end of the Dispatch() to return the error code.

  nsresult mErrorCode;

 public:

  WorkerThreadProxySyncRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy)

      : WorkerMainThreadRunnable(aWorkerPrivate, "XHR"_ns),

        mProxy(aProxy),

        mErrorCode(NS_OK) {

    MOZ_ASSERT(aWorkerPrivate);

    MOZ_ASSERT(aProxy);

    aWorkerPrivate->AssertIsOnWorkerThread();

  void Dispatch(WorkerStatus aFailStatus, ErrorResult& aRv) {

    WorkerMainThreadRunnable::Dispatch(aFailStatus, aRv);

    if (NS_WARN_IF(aRv.Failed())) {

      return;

    if (NS_FAILED(mErrorCode)) {

      aRv.Throw(mErrorCode);

 protected:

  virtual ~WorkerThreadProxySyncRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) = 0;

 private:

  virtual bool MainThreadRun() override;

};

class SendRunnable final : public WorkerThreadProxySyncRunnable {

  RefPtr<BlobImpl> mBlobImpl;

  nsCOMPtr<nsIEventTarget> mSyncLoopTarget;

  bool mHasUploadListeners;

 public:

  SendRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

               BlobImpl* aBlobImpl)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy),

        mBlobImpl(aBlobImpl),

        mHasUploadListeners(false) {}

  void SetHaveUploadListeners(bool aHasUploadListeners) {

    mHasUploadListeners = aHasUploadListeners;

  void SetSyncLoopTarget(nsIEventTarget* aSyncLoopTarget) {

    mSyncLoopTarget = aSyncLoopTarget;

 private:

  ~SendRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override;

};

namespace {

class MainThreadProxyRunnable : public MainThreadWorkerSyncRunnable {

 protected:

  RefPtr<Proxy> mProxy;

  MainThreadProxyRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                          const char* aName = "MainThreadProxyRunnable")

      : MainThreadWorkerSyncRunnable(aProxy->GetEventTarget(), aName),

        mProxy(aProxy) {

    MOZ_ASSERT(aProxy);

  virtual ~MainThreadProxyRunnable() = default;

};

class AsyncTeardownRunnable final : public Runnable {

  RefPtr<Proxy> mProxy;

 public:

  explicit AsyncTeardownRunnable(Proxy* aProxy)

      : Runnable("dom::AsyncTeardownRunnable"), mProxy(aProxy) {

    MOZ_ASSERT(aProxy);

 private:

  ~AsyncTeardownRunnable() = default;

  NS_IMETHOD

  Run() override {

    AssertIsOnMainThread();

    mProxy->Teardown();

    mProxy = nullptr;

    return NS_OK;

};

class LoadStartDetectionRunnable final : public Runnable,

                                         public nsIDOMEventListener {

  WorkerPrivate* mWorkerPrivate;

  RefPtr<Proxy> mProxy;

  RefPtr<XMLHttpRequest> mXHR;

  uint32_t mChannelId;

  bool mReceivedLoadStart;

  class ProxyCompleteRunnable final : public MainThreadProxyRunnable {

    uint32_t mChannelId;

   public:

    ProxyCompleteRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                          uint32_t aChannelId)

        : MainThreadProxyRunnable(aWorkerPrivate, aProxy,

                                  "ProxyCompleteRunnable"),

          mChannelId(aChannelId) {}

   private:

    ~ProxyCompleteRunnable() = default;

    virtual bool WorkerRun(JSContext* aCx,

                           WorkerPrivate* aWorkerPrivate) override {

      if (mChannelId != mProxy->mOuterChannelId) {

        // Threads raced, this event is now obsolete.

        return true;

      if (mSyncLoopTarget) {

        aWorkerPrivate->StopSyncLoop(mSyncLoopTarget, NS_OK);

      XMLHttpRequestWorker* xhrw = mProxy->mXMLHttpRequestPrivate.get();

      if (xhrw && xhrw->SendInProgress()) {

        xhrw->Unpin();

      return true;

    nsresult Cancel() override { return Run(); }

};

 public:

  explicit LoadStartDetectionRunnable(Proxy* aProxy)

      : Runnable("dom::LoadStartDetectionRunnable"),

        mWorkerPrivate(aProxy->mWorkerPrivate),

        mProxy(aProxy),

        mXHR(aProxy->mXHR),

        mChannelId(mProxy->mInnerChannelId),

        mReceivedLoadStart(false) {

    AssertIsOnMainThread();

  NS_DECL_ISUPPORTS_INHERITED

  NS_DECL_NSIRUNNABLE

  NS_DECL_NSIDOMEVENTLISTENER

  bool RegisterAndDispatch() {

    AssertIsOnMainThread();

    if (NS_FAILED(

            mXHR->AddEventListener(Events::loadstart, this, false, false))) {

      NS_WARNING("Failed to add event listener!");

      return false;

    return NS_SUCCEEDED(mWorkerPrivate->DispatchToMainThread(this));

 private:

  ~LoadStartDetectionRunnable() { AssertIsOnMainThread(); }

};

class EventRunnable final : public MainThreadProxyRunnable {

  const EventType& mType;

  UniquePtr<XMLHttpRequestWorker::ResponseData> mResponseData;

  nsString mResponseURL;

  nsCString mStatusText;

  uint64_t mLoaded;

  uint64_t mTotal;

  uint32_t mEventStreamId;

  uint32_t mStatus;

  uint16_t mReadyState;

  bool mUploadEvent;

  bool mProgressEvent;

  bool mLengthComputable;

  nsresult mStatusResult;

  nsresult mErrorDetail;

  // mScopeObj is used in PreDispatch only.  We init it in our constructor, and

  // reset() in PreDispatch, to ensure that it's not still linked into the

  // runtime once we go off-thread.

  JS::PersistentRooted<JSObject*> mScopeObj;

 public:

  EventRunnable(Proxy* aProxy, bool aUploadEvent, const EventType& aType,

                bool aLengthComputable, uint64_t aLoaded, uint64_t aTotal,

                JS::Handle<JSObject*> aScopeObj)

      : MainThreadProxyRunnable(aProxy->mWorkerPrivate, aProxy,

                                "EventRunnable"),

        mType(aType),

        mResponseData(new XMLHttpRequestWorker::ResponseData()),

        mLoaded(aLoaded),

        mTotal(aTotal),

        mEventStreamId(aProxy->mInnerEventStreamId),

        mStatus(0),

        mReadyState(0),

        mUploadEvent(aUploadEvent),

        mProgressEvent(true),

        mLengthComputable(aLengthComputable),

        mStatusResult(NS_OK),

        mErrorDetail(NS_OK),

        mScopeObj(RootingCx(), aScopeObj) {}

  EventRunnable(Proxy* aProxy, bool aUploadEvent, const EventType& aType,

                JS::Handle<JSObject*> aScopeObj)

      : MainThreadProxyRunnable(aProxy->mWorkerPrivate, aProxy,

                                "EventRunnable"),

        mType(aType),

        mResponseData(new XMLHttpRequestWorker::ResponseData()),

        mLoaded(0),

        mTotal(0),

        mEventStreamId(aProxy->mInnerEventStreamId),

        mStatus(0),

        mReadyState(0),

        mUploadEvent(aUploadEvent),

        mProgressEvent(false),

        mLengthComputable(0),

        mStatusResult(NS_OK),

        mErrorDetail(NS_OK),

        mScopeObj(RootingCx(), aScopeObj) {}

 private:

  ~EventRunnable() = default;

  bool PreDispatch(WorkerPrivate* /* unused */) final;

  bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override;

};

class SyncTeardownRunnable final : public WorkerThreadProxySyncRunnable {

 public:

  SyncTeardownRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy) {}

 private:

  ~SyncTeardownRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    mProxy->Teardown();

    MOZ_ASSERT(!mProxy->mSyncLoopTarget);

};

class SetBackgroundRequestRunnable final

    : public WorkerThreadProxySyncRunnable {

  bool mValue;

 public:

  SetBackgroundRequestRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                               bool aValue)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy), mValue(aValue) {}

 private:

  ~SetBackgroundRequestRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    // XXXedgar, do we intend to ignore the errors?

    mProxy->mXHR->SetMozBackgroundRequest(mValue, aRv);

};

class SetWithCredentialsRunnable final : public WorkerThreadProxySyncRunnable {

  bool mValue;

 public:

  SetWithCredentialsRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                             bool aValue)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy), mValue(aValue) {}

 private:

  ~SetWithCredentialsRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    mProxy->mXHR->SetWithCredentials(mValue, aRv);

};

class SetResponseTypeRunnable final : public WorkerThreadProxySyncRunnable {

  XMLHttpRequestResponseType mResponseType;

 public:

  SetResponseTypeRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                          XMLHttpRequestResponseType aResponseType)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy),

        mResponseType(aResponseType) {}

  XMLHttpRequestResponseType ResponseType() { return mResponseType; }

 private:

  ~SetResponseTypeRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    mProxy->mXHR->SetResponseTypeRaw(mResponseType);

    mResponseType = mProxy->mXHR->ResponseType();

};

class SetTimeoutRunnable final : public WorkerThreadProxySyncRunnable {

  uint32_t mTimeout;

 public:

  SetTimeoutRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                     uint32_t aTimeout)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy),

        mTimeout(aTimeout) {}

 private:

  ~SetTimeoutRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    mProxy->mXHR->SetTimeout(mTimeout, aRv);

};

class AbortRunnable final : public WorkerThreadProxySyncRunnable {

 public:

  AbortRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy) {}

 private:

  ~AbortRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override;

};

class GetAllResponseHeadersRunnable final

    : public WorkerThreadProxySyncRunnable {

  nsCString& mResponseHeaders;

 public:

  GetAllResponseHeadersRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                                nsCString& aResponseHeaders)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy),

        mResponseHeaders(aResponseHeaders) {}

 private:

  ~GetAllResponseHeadersRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    mProxy->mXHR->GetAllResponseHeaders(mResponseHeaders, aRv);

};

class GetResponseHeaderRunnable final : public WorkerThreadProxySyncRunnable {

  const nsCString mHeader;

  nsCString& mValue;

 public:

  GetResponseHeaderRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                            const nsACString& aHeader, nsCString& aValue)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy),

        mHeader(aHeader),

        mValue(aValue) {}

 private:

  ~GetResponseHeaderRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    mProxy->mXHR->GetResponseHeader(mHeader, mValue, aRv);

};

class OpenRunnable final : public WorkerThreadProxySyncRunnable {

  nsCString mMethod;

  nsString mURL;

  Optional<nsAString> mUser;

  nsString mUserStr;

  Optional<nsAString> mPassword;

  nsString mPasswordStr;

  bool mBackgroundRequest;

  bool mWithCredentials;

  uint32_t mTimeout;

  XMLHttpRequestResponseType mResponseType;

  const nsString mMimeTypeOverride;

  // Remember the worker thread's stack when the XHR was opened, so that it can

  // be passed on to the net monitor.

  UniquePtr<SerializedStackHolder> mOriginStack;

  // Remember the worker thread's stack when the XHR was opened for profiling

  // purposes.

  UniquePtr<ProfileChunkedBuffer> mSource;

 public:

  OpenRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

               const nsACString& aMethod, const nsAString& aURL,

               const Optional<nsAString>& aUser,

               const Optional<nsAString>& aPassword, bool aBackgroundRequest,

               bool aWithCredentials, uint32_t aTimeout,

               XMLHttpRequestResponseType aResponseType,

               const nsString& aMimeTypeOverride,

               UniquePtr<SerializedStackHolder> aOriginStack,

               UniquePtr<ProfileChunkedBuffer> aSource = nullptr)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy),

        mMethod(aMethod),

        mURL(aURL),

        mBackgroundRequest(aBackgroundRequest),

        mWithCredentials(aWithCredentials),

        mTimeout(aTimeout),

        mResponseType(aResponseType),

        mMimeTypeOverride(aMimeTypeOverride),

        mOriginStack(std::move(aOriginStack)),

        mSource(std::move(aSource)) {

    if (aUser.WasPassed()) {

      mUserStr = aUser.Value();

      mUser = &mUserStr;

    if (aPassword.WasPassed()) {

      mPasswordStr = aPassword.Value();

      mPassword = &mPasswordStr;

 private:

  ~OpenRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    WorkerPrivate* oldWorker = mProxy->mWorkerPrivate;

    mProxy->mWorkerPrivate = mWorkerPrivate;

    MainThreadRunInternal(aRv);

    mProxy->mWorkerPrivate = oldWorker;

  void MainThreadRunInternal(ErrorResult& aRv);

};

class SetRequestHeaderRunnable final : public WorkerThreadProxySyncRunnable {

  nsCString mHeader;

  nsCString mValue;

 public:

  SetRequestHeaderRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                           const nsACString& aHeader, const nsACString& aValue)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy),

        mHeader(aHeader),

        mValue(aValue) {}

 private:

  ~SetRequestHeaderRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    mProxy->mXHR->SetRequestHeader(mHeader, mValue, aRv);

};

class OverrideMimeTypeRunnable final : public WorkerThreadProxySyncRunnable {

  nsString mMimeType;

 public:

  OverrideMimeTypeRunnable(WorkerPrivate* aWorkerPrivate, Proxy* aProxy,

                           const nsAString& aMimeType)

      : WorkerThreadProxySyncRunnable(aWorkerPrivate, aProxy),

        mMimeType(aMimeType) {}

 private:

  ~OverrideMimeTypeRunnable() = default;

  virtual void RunOnMainThread(ErrorResult& aRv) override {

    mProxy->mXHR->OverrideMimeType(mMimeType, aRv);

};

class AutoUnpinXHR {

  XMLHttpRequestWorker* mXMLHttpRequestPrivate;

 public:

  explicit AutoUnpinXHR(XMLHttpRequestWorker* aXMLHttpRequestPrivate)

      : mXMLHttpRequestPrivate(aXMLHttpRequestPrivate) {

    MOZ_ASSERT(aXMLHttpRequestPrivate);

  ~AutoUnpinXHR() {

    if (mXMLHttpRequestPrivate) {

      mXMLHttpRequestPrivate->Unpin();

  void Clear() { mXMLHttpRequestPrivate = nullptr; }

};

}  // namespace

bool Proxy::Init() {

  AssertIsOnMainThread();

  MOZ_ASSERT(mWorkerPrivate);

  if (mXHR) {

    return true;

  nsPIDOMWindowInner* ownerWindow = mWorkerPrivate->GetWindow();

  if (ownerWindow && !ownerWindow->IsCurrentInnerWindow()) {

    NS_WARNING("Window has navigated, cannot create XHR here.");

    return false;

  mXHR = new XMLHttpRequestMainThread(ownerWindow ? ownerWindow->AsGlobal()

                                                  : nullptr);

  mXHR->Construct(mWorkerPrivate->GetPrincipal(),

                  mWorkerPrivate->CookieJarSettings(), true,

                  mWorkerPrivate->GetBaseURI(), mWorkerPrivate->GetLoadGroup(),

                  mWorkerPrivate->GetPerformanceStorage(),

                  mWorkerPrivate->CSPEventListener());

  mXHR->SetParameters(mMozAnon, mMozSystem);

  mXHR->SetClientInfoAndController(mClientInfo, mController);

  ErrorResult rv;

  mXHRUpload = mXHR->GetUpload(rv);

  if (NS_WARN_IF(rv.Failed())) {

    mXHR = nullptr;

    return false;

  if (!AddRemoveEventListeners(false, true)) {

    mXHR = nullptr;

    mXHRUpload = nullptr;

    return false;

  return true;

void Proxy::Teardown() {

  AssertIsOnMainThread();

  if (mXHR) {

    Reset();

    // NB: We are intentionally dropping events coming from xhr.abort on the

    // floor.

    AddRemoveEventListeners(false, false);

    ErrorResult rv;

    mXHR->Abort(rv);

    if (NS_WARN_IF(rv.Failed())) {

      rv.SuppressException();

    if (mOutstandingSendCount) {

      if (mSyncLoopTarget) {

        // We have an unclosed sync loop.  Fix that now.

        RefPtr<MainThreadStopSyncLoopRunnable> runnable =

            new MainThreadStopSyncLoopRunnable(std::move(mSyncLoopTarget),

                                               NS_ERROR_FAILURE);

        MOZ_ALWAYS_TRUE(runnable->Dispatch(mWorkerPrivate));

      mOutstandingSendCount = 0;

    mWorkerPrivate = nullptr;

    mXHRUpload = nullptr;

    mXHR = nullptr;

  MOZ_ASSERT(!mWorkerPrivate);

  MOZ_ASSERT(!mSyncLoopTarget);

  // If there are rare edge cases left that violate our invariants

  // just ensure that they won't harm us too much.

  mWorkerPrivate = nullptr;

  mSyncLoopTarget = nullptr;

bool Proxy::AddRemoveEventListeners(bool aUpload, bool aAdd) {

  AssertIsOnMainThread();

  NS_ASSERTION(!aUpload || (mUploadEventListenersAttached && !aAdd) ||

                   (!mUploadEventListenersAttached && aAdd),

               "Messed up logic for upload listeners!");

  RefPtr<DOMEventTargetHelper> targetHelper =

      aUpload ? static_cast<XMLHttpRequestUpload*>(mXHRUpload.get())

              : static_cast<XMLHttpRequestEventTarget*>(mXHR.get());

  MOZ_ASSERT(targetHelper, "This should never fail!");

  for (const EventType* type : Events::All) {

    if (aUpload && *type == Events::readystatechange) {

      continue;

    if (aAdd) {

      if (NS_FAILED(targetHelper->AddEventListener(*type, this, false))) {

        return false;

    } else {

      targetHelper->RemoveEventListener(*type, this, false);

  if (aUpload) {

    mUploadEventListenersAttached = aAdd;

  return true;

NS_IMPL_ISUPPORTS(Proxy, nsIDOMEventListener)

NS_IMETHODIMP

Proxy::HandleEvent(Event* aEvent) {

  AssertIsOnMainThread();

  // EventRunnable::WorkerRun will bail out if mXMLHttpRequestWorker is null,

  // so we do not need to prevent the dispatch from the main thread such that

  // we do not need to touch it off-worker-thread.

  if (!mWorkerPrivate) {

    NS_ERROR("Shouldn't get here!");

    return NS_OK;

  nsAutoString _type;

  aEvent->GetType(_type);

  const EventType* typePtr = Events::Find(_type);

  MOZ_DIAGNOSTIC_ASSERT(typePtr, "Shouldn't get non-XMLHttpRequest events");

  const EventType& type = *typePtr;

  bool isUploadTarget = mXHR != aEvent->GetTarget();

  ProgressEvent* progressEvent = aEvent->AsProgressEvent();

  if (mInOpen && type == Events::readystatechange) {

    if (mXHR->ReadyState() == 1) {

      mInnerEventStreamId++;

    AutoJSAPI jsapi;

    JSObject* junkScope = xpc::UnprivilegedJunkScope(fallible);

    if (!junkScope || !jsapi.Init(junkScope)) {

      return NS_ERROR_FAILURE;

    JSContext* cx = jsapi.cx();

    JS::Rooted<JS::Value> value(cx);

    if (!GetOrCreateDOMReflectorNoWrap(cx, mXHR, &value)) {

      return NS_ERROR_FAILURE;

    JS::Rooted<JSObject*> scope(cx, &value.toObject());

    RefPtr<EventRunnable> runnable;

    if (progressEvent) {

      if (!mIsSyncXHR || type != Events::progress) {

        runnable = new EventRunnable(

            this, isUploadTarget, type, progressEvent->LengthComputable(),

            progressEvent->Loaded(), progressEvent->Total(), scope);

    } else {

      runnable = new EventRunnable(this, isUploadTarget, type, scope);

    if (runnable) {

      runnable->Dispatch(mWorkerPrivate);

  if (!isUploadTarget) {

    if (type == Events::loadstart) {

      mMainThreadSeenLoadStart = true;

    } else if (mMainThreadSeenLoadStart && type == Events::loadend) {

      mMainThreadSeenLoadStart = false;

      RefPtr<LoadStartDetectionRunnable> runnable =

          new LoadStartDetectionRunnable(this);

      if (!runnable->RegisterAndDispatch()) {

        NS_WARNING("Failed to dispatch LoadStartDetectionRunnable!");

  return NS_OK;

NS_IMPL_ISUPPORTS_INHERITED(LoadStartDetectionRunnable, Runnable,

                            nsIDOMEventListener)

NS_IMETHODIMP

LoadStartDetectionRunnable::Run() {

  AssertIsOnMainThread();

  mXHR->RemoveEventListener(Events::loadstart, this, false);

  if (!mReceivedLoadStart) {

    if (mProxy->mOutstandingSendCount > 1) {

      mProxy->mOutstandingSendCount--;

    } else if (mProxy->mOutstandingSendCount == 1) {

      mProxy->Reset();

      RefPtr<ProxyCompleteRunnable> runnable =

          new ProxyCompleteRunnable(mWorkerPrivate, mProxy, mChannelId);

      if (runnable->Dispatch(mWorkerPrivate)) {

        mProxy->mWorkerPrivate = nullptr;

        mProxy->mSyncLoopTarget = nullptr;

        mProxy->mOutstandingSendCount--;

  mProxy = nullptr;

  mXHR = nullptr;

  return NS_OK;

NS_IMETHODIMP

LoadStartDetectionRunnable::HandleEvent(Event* aEvent) {

  AssertIsOnMainThread();

#ifdef DEBUG

    nsAutoString type;

    aEvent->GetType(type);

    MOZ_ASSERT(type == Events::loadstart);

#endif

  mReceivedLoadStart = true;

  return NS_OK;

bool EventRunnable::PreDispatch(WorkerPrivate* /* unused */) {

  AssertIsOnMainThread();

  AutoJSAPI jsapi;

  DebugOnly<bool> ok = jsapi.Init(xpc::NativeGlobal(mScopeObj));

  MOZ_ASSERT(ok);

  JSContext* cx = jsapi.cx();

  // Now keep the mScopeObj alive for the duration

  JS::Rooted<JSObject*> scopeObj(cx, mScopeObj);

  // And reset mScopeObj now, before we have a chance to run its destructor on

  // some background thread.

  mScopeObj.reset();

  RefPtr<XMLHttpRequestMainThread>& xhr = mProxy->mXHR;

  MOZ_ASSERT(xhr);

  ErrorResult rv;

  XMLHttpRequestResponseType type = xhr->ResponseType();

  // We want to take the result data only if this is available.

  if (mType == Events::readystatechange) {

    switch (type) {

      case XMLHttpRequestResponseType::_empty:

      case XMLHttpRequestResponseType::Text: {

        xhr->GetResponseText(mResponseData->mResponseText, rv);

        mResponseData->mResponseResult = rv.StealNSResult();

        break;

      case XMLHttpRequestResponseType::Blob: {

        mResponseData->mResponseBlobImpl = xhr->GetResponseBlobImpl();

        break;

      case XMLHttpRequestResponseType::Arraybuffer: {

        mResponseData->mResponseArrayBufferBuilder =

            xhr->GetResponseArrayBufferBuilder();

        break;

      case XMLHttpRequestResponseType::Json: {

        mResponseData->mResponseResult =

            xhr->GetResponseTextForJSON(mResponseData->mResponseJSON);

        break;

      default:

        MOZ_ASSERT_UNREACHABLE("Invalid response type");

        return false;

  mStatus = xhr->GetStatus(rv);

  mStatusResult = rv.StealNSResult();

  mErrorDetail = xhr->ErrorDetail();

  xhr->GetStatusText(mStatusText, rv);

  MOZ_ASSERT(!rv.Failed());

  mReadyState = xhr->ReadyState();

  xhr->GetResponseURL(mResponseURL);

  return true;

bool EventRunnable::WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) {

  if (mEventStreamId != mProxy->mOuterEventStreamId) {

    // Threads raced, this event is now obsolete.

    return true;

  if (!mProxy->mXMLHttpRequestPrivate) {

    // Object was finalized, bail.

    return true;

  if (mType == Events::loadend) {

    mProxy->mLastErrorDetailAtLoadend = mErrorDetail;

  if (mType == Events::loadstart) {

    if (mUploadEvent) {

      mProxy->mSeenUploadLoadStart = true;

    } else {

      mProxy->mSeenLoadStart = true;

  } else if (mType == Events::loadend) {

    if (mUploadEvent) {

      mProxy->mSeenUploadLoadStart = false;

      if (mProxy->mDispatchPrematureAbortEventToUpload) {

        // We've already dispatched premature abort events.

        return true;

    } else {

      mProxy->mSeenLoadStart = false;

      if (mProxy->mDispatchPrematureAbortEvent) {

        // We've already dispatched premature abort events.

        return true;

  } else if (mType == Events::abort) {

    if ((mUploadEvent && mProxy->mDispatchPrematureAbortEventToUpload) ||

        (!mUploadEvent && mProxy->mDispatchPrematureAbortEvent)) {

      // We've already dispatched premature abort events.

      return true;

  if (mProgressEvent) {

    // Cache these for premature abort events.

    if (mUploadEvent) {

      mProxy->mLastUploadLengthComputable = mLengthComputable;

      mProxy->mLastUploadLoaded = mLoaded;

      mProxy->mLastUploadTotal = mTotal;

    } else {

      mProxy->mLastLengthComputable = mLengthComputable;

      mProxy->mLastLoaded = mLoaded;

      mProxy->mLastTotal = mTotal;

  UniquePtr<XMLHttpRequestWorker::StateData> state(

      new XMLHttpRequestWorker::StateData());

  state->mStatusResult = mStatusResult;

  state->mStatus = mStatus;

  state->mStatusText = mStatusText;

  state->mReadyState = mReadyState;

  state->mResponseURL = mResponseURL;

  XMLHttpRequestWorker* xhr = mProxy->mXMLHttpRequestPrivate;

  xhr->UpdateState(std::move(state), mType == Events::readystatechange

                                         ? std::move(mResponseData)

                                         : nullptr);

  if (mUploadEvent && !xhr->GetUploadObjectNoCreate()) {

    return true;

  XMLHttpRequestEventTarget* target;

  if (mUploadEvent) {

    target = xhr->GetUploadObjectNoCreate();

  } else {

    target = xhr;

  MOZ_ASSERT(target);

  RefPtr<Event> event;

  if (mProgressEvent) {

    ProgressEventInit init;

    init.mBubbles = false;

    init.mCancelable = false;

    init.mLengthComputable = mLengthComputable;

    init.mLoaded = mLoaded;

    init.mTotal = mTotal;

    event = ProgressEvent::Constructor(target, mType, init);

  } else {

    event = NS_NewDOMEvent(target, nullptr, nullptr);

    if (event) {

      event->InitEvent(mType, false, false);

  if (!event) {

    return false;

  event->SetTrusted(true);

  if (MOZ_LOG_TEST(gXMLHttpRequestLog, LogLevel::Debug)) {

    nsAutoString type;

    event->GetType(type);

    MOZ_LOG(gXMLHttpRequestLog, LogLevel::Debug,

            ("%p firing %s event (%u,%u,%" PRIu64 ",%" PRIu64 ")",

             mProxy->mXHR.get(), NS_ConvertUTF16toUTF8(type).get(),

             mUploadEvent, mLengthComputable, mLoaded, mTotal));

  target->DispatchEvent(*event);

  return true;

bool WorkerThreadProxySyncRunnable::MainThreadRun() {

  AssertIsOnMainThread();

  nsCOMPtr<nsIEventTarget> tempTarget = mSyncLoopTarget;

  mProxy->mSyncEventResponseTarget.swap(tempTarget);

  ErrorResult rv;

  RunOnMainThread(rv);

  mErrorCode = rv.StealNSResult();

  mProxy->mSyncEventResponseTarget.swap(tempTarget);

  return true;

void AbortRunnable::RunOnMainThread(ErrorResult& aRv) {

  mProxy->mInnerEventStreamId++;

  WorkerPrivate* oldWorker = mProxy->mWorkerPrivate;

  mProxy->mWorkerPrivate = mWorkerPrivate;

  mProxy->mXHR->Abort(aRv);

  mProxy->mWorkerPrivate = oldWorker;

  mProxy->Reset();

void OpenRunnable::MainThreadRunInternal(ErrorResult& aRv) {

  if (!mProxy->Init()) {

    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

    return;

  if (mBackgroundRequest) {

    mProxy->mXHR->SetMozBackgroundRequestExternal(mBackgroundRequest, aRv);

    if (aRv.Failed()) {

      return;

  if (mOriginStack) {

    mProxy->mXHR->SetOriginStack(std::move(mOriginStack));

  if (mWithCredentials) {

    mProxy->mXHR->SetWithCredentials(mWithCredentials, aRv);

    if (NS_WARN_IF(aRv.Failed())) {

      return;

  if (mTimeout) {

    mProxy->mXHR->SetTimeout(mTimeout, aRv);

    if (NS_WARN_IF(aRv.Failed())) {

      return;

  if (!mMimeTypeOverride.IsVoid()) {

    mProxy->mXHR->OverrideMimeType(mMimeTypeOverride, aRv);

    if (NS_WARN_IF(aRv.Failed())) {

      return;

  MOZ_ASSERT(!mProxy->mInOpen);

  mProxy->mInOpen = true;

  mProxy->mXHR->Open(

      mMethod, mURL, true, mUser.WasPassed() ? mUser.Value() : VoidString(),

      mPassword.WasPassed() ? mPassword.Value() : VoidString(), aRv);

  MOZ_ASSERT(mProxy->mInOpen);

  mProxy->mInOpen = false;

  if (NS_WARN_IF(aRv.Failed())) {

    return;

  if (mSource) {

    mProxy->mXHR->SetSource(std::move(mSource));

  mProxy->mXHR->SetResponseType(mResponseType, aRv);

void SendRunnable::RunOnMainThread(ErrorResult& aRv) {

  // Before we change any state let's check if we can send.

  if (!mProxy->mXHR->CanSend(aRv)) {

    return;

  Nullable<

      DocumentOrBlobOrArrayBufferViewOrArrayBufferOrFormDataOrURLSearchParamsOrUSVString>

      payload;

  if (!mBlobImpl) {

    payload.SetNull();

  } else {

    JS::Rooted<JSObject*> globalObject(RootingCx(),

                                       xpc::UnprivilegedJunkScope(fallible));

    if (NS_WARN_IF(!globalObject)) {

      aRv.Throw(NS_ERROR_FAILURE);

      return;

    nsCOMPtr<nsIGlobalObject> parent = xpc::NativeGlobal(globalObject);

    if (NS_WARN_IF(!parent)) {

      aRv.Throw(NS_ERROR_FAILURE);

      return;

    RefPtr<Blob> blob = Blob::Create(parent, mBlobImpl);

    MOZ_ASSERT(blob);

    DocumentOrBlobOrArrayBufferViewOrArrayBufferOrFormDataOrURLSearchParamsOrUSVString&

        ref = payload.SetValue();

    ref.SetAsBlob() = blob;

  // Send() has been already called, reset the proxy.

  if (mProxy->mWorkerPrivate) {

    mProxy->Reset();

  mProxy->mWorkerPrivate = mWorkerPrivate;

  MOZ_ASSERT(!mProxy->mSyncLoopTarget);

  mProxy->mSyncLoopTarget.swap(mSyncLoopTarget);

  if (mHasUploadListeners) {

    // Send() can be called more than once before failure,

    // so don't attach the upload listeners more than once.

    if (!mProxy->mUploadEventListenersAttached &&

        !mProxy->AddRemoveEventListeners(true, true)) {

      MOZ_ASSERT(false, "This should never fail!");

  mProxy->mInnerChannelId++;

  mProxy->mXHR->Send(payload, aRv);

  if (!aRv.Failed()) {

    mProxy->mOutstandingSendCount++;

    if (!mHasUploadListeners) {

      // Send() can be called more than once before failure,

      // so don't attach the upload listeners more than once.

      if (!mProxy->mUploadEventListenersAttached &&

          !mProxy->AddRemoveEventListeners(true, true)) {

        MOZ_ASSERT(false, "This should never fail!");

  } else {

    // In case of failure we just break the sync loop

    mProxy->mSyncLoopTarget = nullptr;

    mSyncLoopTarget = nullptr;

XMLHttpRequestWorker::XMLHttpRequestWorker(WorkerPrivate* aWorkerPrivate,

                                           nsIGlobalObject* aGlobalObject)

    : XMLHttpRequest(aGlobalObject),

      mWorkerPrivate(aWorkerPrivate),

      mResponseType(XMLHttpRequestResponseType::_empty),

      mStateData(new StateData()),

      mResponseData(new ResponseData()),

      mResponseArrayBufferValue(nullptr),

      mResponseJSONValue(JS::UndefinedValue()),

      mTimeout(0),

      mBackgroundRequest(false),

      mWithCredentials(false),

      mCanceled(false),

      mFlagSendActive(false),

      mMozAnon(false),

      mMozSystem(false),

      mMimeTypeOverride(VoidString()) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  mozilla::HoldJSObjects(this);

XMLHttpRequestWorker::~XMLHttpRequestWorker() {

  mWorkerPrivate->AssertIsOnWorkerThread();

  ReleaseProxy(XHRIsGoingAway);

  MOZ_ASSERT(!mWorkerRef);

  mozilla::DropJSObjects(this);

NS_IMPL_ADDREF_INHERITED(XMLHttpRequestWorker, XMLHttpRequestEventTarget)

NS_IMPL_RELEASE_INHERITED(XMLHttpRequestWorker, XMLHttpRequestEventTarget)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(XMLHttpRequestWorker)

NS_INTERFACE_MAP_END_INHERITING(XMLHttpRequestEventTarget)

NS_IMPL_CYCLE_COLLECTION_CLASS(XMLHttpRequestWorker)

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(XMLHttpRequestWorker,

                                                  XMLHttpRequestEventTarget)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mUpload)

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResponseBlob)

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(XMLHttpRequestWorker,

                                                XMLHttpRequestEventTarget)

  tmp->ReleaseProxy(XHRIsGoingAway);

  NS_IMPL_CYCLE_COLLECTION_UNLINK(mUpload)

  tmp->mResponseData = nullptr;

  tmp->mResponseBlob = nullptr;

  tmp->mResponseArrayBufferValue = nullptr;

  tmp->mResponseJSONValue.setUndefined();

NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(XMLHttpRequestWorker,

                                               XMLHttpRequestEventTarget)

  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mResponseArrayBufferValue)

  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mResponseJSONValue)

NS_IMPL_CYCLE_COLLECTION_TRACE_END

/* static */

already_AddRefed<XMLHttpRequest> XMLHttpRequestWorker::Construct(

    const GlobalObject& aGlobal, const MozXMLHttpRequestParameters& aParams,

    ErrorResult& aRv) {

  JSContext* cx = aGlobal.Context();

  WorkerPrivate* workerPrivate = GetWorkerPrivateFromContext(cx);

  MOZ_ASSERT(workerPrivate);

  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());

  if (NS_WARN_IF(!global)) {

    aRv.Throw(NS_ERROR_FAILURE);

    return nullptr;

  RefPtr<XMLHttpRequestWorker> xhr =

      new XMLHttpRequestWorker(workerPrivate, global);

  if (workerPrivate->XHRParamsAllowed()) {

    if (aParams.mMozSystem) {

      xhr->mMozAnon = true;

    } else {

      xhr->mMozAnon =

          aParams.mMozAnon.WasPassed() ? aParams.mMozAnon.Value() : false;

    xhr->mMozSystem = aParams.mMozSystem;

  return xhr.forget();

void XMLHttpRequestWorker::ReleaseProxy(ReleaseType aType) {

  // Can't assert that we're on the worker thread here because mWorkerPrivate

  // may be gone.

  if (mProxy) {

    if (aType == XHRIsGoingAway) {

      // Coming here means the XHR was GC'd, so we can't be pinned.

      MOZ_ASSERT(!mProxy->mXMLHttpRequestPrivate ||

                 !mProxy->mXMLHttpRequestPrivate->mPinnedSelfRef);

      // We need to clear our weak pointer on the worker thread, let's do it now

      // before doing it implicitly in the Proxy dtor on the wrong thread.

      mProxy->mXMLHttpRequestPrivate = nullptr;

      // We're in a GC finalizer, so we can't do a sync call here (and we don't

      // need to).

      RefPtr<AsyncTeardownRunnable> runnable =

          new AsyncTeardownRunnable(mProxy);

      mProxy = nullptr;

      if (NS_FAILED(mWorkerPrivate->DispatchToMainThread(runnable.forget()))) {

        NS_ERROR("Failed to dispatch teardown runnable!");

    } else {

      // This isn't necessary if the worker is going away or the XHR is going

      // away.

      if (aType == Default) {

        // Don't let any more events run.

        mProxy->mOuterEventStreamId++;

      // Ensure we are unpinned before we clear the weak reference.

      RefPtr<XMLHttpRequestWorker> self = this;

      if (mPinnedSelfRef) {

        Unpin();

      mProxy->mXMLHttpRequestPrivate = nullptr;

      // We need to make a sync call here.

      RefPtr<SyncTeardownRunnable> runnable =

          new SyncTeardownRunnable(mWorkerPrivate, mProxy);

      mProxy = nullptr;

      IgnoredErrorResult forAssertionsOnly;

      // This runnable _must_ be executed.

      runnable->Dispatch(Dead, forAssertionsOnly);

      MOZ_DIAGNOSTIC_ASSERT(!forAssertionsOnly.Failed());

void XMLHttpRequestWorker::MaybePin(ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mWorkerRef) {

    return;

  RefPtr<XMLHttpRequestWorker> self = this;

  mWorkerRef =

      StrongWorkerRef::Create(mWorkerPrivate, "XMLHttpRequestWorker", [self]() {

        if (!self->mCanceled) {

          self->mCanceled = true;

          self->ReleaseProxy(WorkerIsGoingAway);

});

  if (NS_WARN_IF(!mWorkerRef)) {

    aRv.Throw(NS_ERROR_FAILURE);

    return;

  mPinnedSelfRef = this;

#ifdef DEBUG

  mProxy->DebugStoreWorkerRef(mWorkerRef);

#endif

void XMLHttpRequestWorker::MaybeDispatchPrematureAbortEvents(ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  MOZ_ASSERT(mProxy);

  // Only send readystatechange event when state changed.

  bool isStateChanged = false;

  if ((mStateData->mReadyState == 1 && mStateData->mFlagSend) ||

      mStateData->mReadyState == 2 || mStateData->mReadyState == 3) {

    isStateChanged = true;

    mStateData->mReadyState = 4;

  if (mProxy->mSeenUploadLoadStart) {

    MOZ_ASSERT(mUpload);

    FireEvent(mUpload, Events::abort, true, aRv);

    if (aRv.Failed()) {

      return;

    FireEvent(mUpload, Events::loadend, true, aRv);

    if (aRv.Failed()) {

      return;

    // Similarly to null check in ::Open, mProxy may have been cleared here.

    if (!mProxy) {

      aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

      return;

    mProxy->mSeenUploadLoadStart = false;

    mProxy->mDispatchPrematureAbortEventToUpload = true;

  if (mProxy->mSeenLoadStart) {

    if (isStateChanged) {

      FireEvent(this, Events::readystatechange, false, aRv);

      if (aRv.Failed()) {

        return;

    FireEvent(this, Events::abort, false, aRv);

    if (aRv.Failed()) {

      return;

    FireEvent(this, Events::loadend, false, aRv);

    if (aRv.Failed()) {

      return;

    // Similarly to null check in ::Open, mProxy may have been cleared here.

    if (!mProxy) {

      aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

      return;

    mProxy->mSeenLoadStart = false;

    mProxy->mDispatchPrematureAbortEvent = true;

void XMLHttpRequestWorker::FireEvent(EventTarget* aTarget,

                                     const EventType& aEventType,

                                     bool aUploadTarget, ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  MOZ_ASSERT(aTarget);

  if (!mProxy) {

    aRv.Throw(NS_ERROR_FAILURE);

    return;

  RefPtr<Event> event;

  if (aEventType == Events::readystatechange) {

    event = NS_NewDOMEvent(aTarget, nullptr, nullptr);

    event->InitEvent(aEventType, false, false);

  } else {

    if (mProxy->mIsSyncXHR && aEventType == Events::progress) {

      return;

    ProgressEventInit init;

    init.mBubbles = false;

    init.mCancelable = false;

    if (aUploadTarget) {

      init.mLengthComputable = mProxy->mLastUploadLengthComputable;

      init.mLoaded = mProxy->mLastUploadLoaded;

      init.mTotal = mProxy->mLastUploadTotal;

    } else {

      init.mLengthComputable = mProxy->mLastLengthComputable;

      init.mLoaded = mProxy->mLastLoaded;

      init.mTotal = mProxy->mLastTotal;

    event = ProgressEvent::Constructor(aTarget, aEventType, init);

  if (!event) {

    aRv.Throw(NS_ERROR_FAILURE);

    return;

  event->SetTrusted(true);

  MOZ_LOG(gXMLHttpRequestLog, LogLevel::Debug,

          ("%p firing %s pre-abort event (%u,%u,%" PRIu64 ",%" PRIu64, this,

           aEventType.cStr, aUploadTarget,

           aUploadTarget ? mProxy->mLastUploadLengthComputable

                         : mProxy->mLastLengthComputable,

           aUploadTarget ? mProxy->mLastUploadLoaded : mProxy->mLastLoaded,

           aUploadTarget ? mProxy->mLastUploadTotal : mProxy->mLastTotal));

  aTarget->DispatchEvent(*event);

void XMLHttpRequestWorker::Unpin() {

  mWorkerPrivate->AssertIsOnWorkerThread();

  MOZ_ASSERT(mWorkerRef, "Mismatched calls to Unpin!");

#ifdef DEBUG

  if (mProxy) {

    // The proxy will be gone if WorkerIsGoingAway

    mProxy->DebugForgetWorkerRef();

#endif

  mWorkerRef = nullptr;

  mPinnedSelfRef = nullptr;

void XMLHttpRequestWorker::SendInternal(const BodyExtractorBase* aBody,

                                        ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  // We don't really need to keep the same body-type when we proxy the send()

  // call to the main-thread XHR. Let's extract the nsIInputStream from the

  // aBody and let's wrap it into a StreamBlobImpl.

  RefPtr<BlobImpl> blobImpl;

  if (aBody) {

    nsAutoCString charset;

    nsAutoCString defaultContentType;

    nsCOMPtr<nsIInputStream> uploadStream;

    uint64_t size_u64;

    aRv = aBody->GetAsStream(getter_AddRefs(uploadStream), &size_u64,

                             defaultContentType, charset);

    if (NS_WARN_IF(aRv.Failed())) {

      return;

    blobImpl = StreamBlobImpl::Create(uploadStream.forget(),

                                      NS_ConvertUTF8toUTF16(defaultContentType),

                                      size_u64, u"StreamBlobImpl"_ns);

    MOZ_ASSERT(blobImpl);

  RefPtr<SendRunnable> sendRunnable =

      new SendRunnable(mWorkerPrivate, mProxy, blobImpl);

  // No send() calls when open is running.

  if (mProxy->mOpenCount) {

    aRv.Throw(NS_ERROR_FAILURE);

    return;

  bool hasUploadListeners = mUpload ? mUpload->HasListeners() : false;

  MaybePin(aRv);

  if (aRv.Failed()) {

    return;

  RefPtr<XMLHttpRequestWorker> selfRef = this;

  AutoUnpinXHR autoUnpin(this);

  Maybe<AutoSyncLoopHolder> autoSyncLoop;

  nsCOMPtr<nsISerialEventTarget> syncLoopTarget;

  bool isSyncXHR = mProxy->mIsSyncXHR;

  if (isSyncXHR) {

    autoSyncLoop.emplace(mWorkerPrivate, Canceling);

    syncLoopTarget = autoSyncLoop->GetSerialEventTarget();

    if (!syncLoopTarget) {

      aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

      return;

  mProxy->mOuterChannelId++;

  mProxy->mDispatchPrematureAbortEvent = false;

  mProxy->mDispatchPrematureAbortEventToUpload = false;

  sendRunnable->SetSyncLoopTarget(syncLoopTarget);

  sendRunnable->SetHaveUploadListeners(hasUploadListeners);

  mStateData->mFlagSend = true;

  sendRunnable->Dispatch(Canceling, aRv);

  if (aRv.Failed()) {

    // Dispatch() may have spun the event loop and we may have already unrooted.

    // If so we don't want autoUnpin to try again.

    if (!mWorkerRef) {

      autoUnpin.Clear();

    return;

  if (!isSyncXHR) {

    autoUnpin.Clear();

    MOZ_ASSERT(!autoSyncLoop);

    return;

  autoUnpin.Clear();

  bool succeeded = NS_SUCCEEDED(autoSyncLoop->Run());

  mStateData->mFlagSend = false;

  // Throw appropriately If a sync XHR failed per spec's RequestErrorSteps

  if (isSyncXHR && mProxy) {

    nsresult error = mProxy->mLastErrorDetailAtLoadend;

    if (error == NS_ERROR_DOM_ABORT_ERR) {

      MOZ_LOG(gXMLHttpRequestLog, LogLevel::Info,

              ("%p throwing NS_ERROR_DOM_ABORT_ERR", this));

      aRv.Throw(error);

      return;

    if (error == NS_ERROR_DOM_TIMEOUT_ERR) {

      MOZ_LOG(gXMLHttpRequestLog, LogLevel::Info,

              ("%p throwing NS_ERROR_DOM_TIMEOUT_ERR", this));

      aRv.Throw(error);

      return;

    if (error == NS_ERROR_DOM_NETWORK_ERR ||

        NS_ERROR_GET_MODULE(error) == NS_ERROR_MODULE_NETWORK) {

      MOZ_LOG(gXMLHttpRequestLog, LogLevel::Info,

              ("%p throwing NS_ERROR_DOM_NETWORK_ERR (0x%" PRIx32 ")", this,

               static_cast<uint32_t>(error)));

      aRv.Throw(NS_ERROR_DOM_NETWORK_ERR);

      return;

  // Don't clobber an existing exception that we may have thrown on aRv

  // already... though can there really be one?  In any case, it seems to me

  // that this autoSyncLoop->Run() can never fail, since the StopSyncLoop call

  // for it will come from ProxyCompleteRunnable and that always passes true for

  // the second arg.

  if (!succeeded && !aRv.Failed()) {

    MOZ_LOG(gXMLHttpRequestLog, LogLevel::Debug,

            ("%p SendInternal failed; throwing NS_ERROR_FAILURE", this));

    aRv.Throw(NS_ERROR_FAILURE);

void XMLHttpRequestWorker::Open(const nsACString& aMethod,

                                const nsAString& aUrl, bool aAsync,

                                const Optional<nsAString>& aUser,

                                const Optional<nsAString>& aPassword,

                                ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  MOZ_LOG(gXMLHttpRequestLog, LogLevel::Debug,

          ("%p Open(%s,%s,%d)", this, nsAutoCString(aMethod).get(),

           NS_ConvertUTF16toUTF8(aUrl).get(), aAsync));

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  bool alsoOverrideMimeType = false;

  if (mProxy) {

    MaybeDispatchPrematureAbortEvents(aRv);

    if (aRv.Failed()) {

      return;

  } else {

    Maybe<ClientInfo> clientInfo(

        mWorkerPrivate->GlobalScope()->GetClientInfo());

    if (clientInfo.isNothing()) {

      aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

      return;

    mProxy = new Proxy(this, clientInfo.ref(),

                       mWorkerPrivate->GlobalScope()->GetController(), mMozAnon,

                       mMozSystem);

    alsoOverrideMimeType = true;

  mProxy->mOuterEventStreamId++;

  UniquePtr<SerializedStackHolder> stack;

  if (mWorkerPrivate->IsWatchedByDevTools()) {

    if (JSContext* cx = nsContentUtils::GetCurrentJSContext()) {

      stack = GetCurrentStackForNetMonitor(cx);

  RefPtr<OpenRunnable> runnable = new OpenRunnable(

      mWorkerPrivate, mProxy, aMethod, aUrl, aUser, aPassword,

      mBackgroundRequest, mWithCredentials, mTimeout, mResponseType,

      alsoOverrideMimeType ? mMimeTypeOverride : VoidString(), std::move(stack),

      profiler_capture_backtrace());

  ++mProxy->mOpenCount;

  runnable->Dispatch(Canceling, aRv);

  if (aRv.Failed()) {

    if (mProxy && !--mProxy->mOpenCount) {

      ReleaseProxy();

    return;

  // We have been released in one of the nested Open() calls.

  if (!mProxy) {

    aRv.Throw(NS_ERROR_FAILURE);

    return;

  --mProxy->mOpenCount;

  mProxy->mIsSyncXHR = !aAsync;

void XMLHttpRequestWorker::SetRequestHeader(const nsACString& aHeader,

                                            const nsACString& aValue,

                                            ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  if (!mProxy) {

    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

    return;

  RefPtr<SetRequestHeaderRunnable> runnable =

      new SetRequestHeaderRunnable(mWorkerPrivate, mProxy, aHeader, aValue);

  runnable->Dispatch(Canceling, aRv);

void XMLHttpRequestWorker::SetTimeout(uint32_t aTimeout, ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  mTimeout = aTimeout;

  if (!mProxy) {

    // Open might not have been called yet, in which case we'll handle the

    // timeout in OpenRunnable.

    return;

  RefPtr<SetTimeoutRunnable> runnable =

      new SetTimeoutRunnable(mWorkerPrivate, mProxy, aTimeout);

  runnable->Dispatch(Canceling, aRv);

void XMLHttpRequestWorker::SetWithCredentials(bool aWithCredentials,

                                              ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  mWithCredentials = aWithCredentials;

  if (!mProxy) {

    // Open might not have been called yet, in which case we'll handle the

    // credentials in OpenRunnable.

    return;

  RefPtr<SetWithCredentialsRunnable> runnable =

      new SetWithCredentialsRunnable(mWorkerPrivate, mProxy, aWithCredentials);

  runnable->Dispatch(Canceling, aRv);

void XMLHttpRequestWorker::SetMozBackgroundRequest(bool aBackgroundRequest,

                                                   ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  mBackgroundRequest = aBackgroundRequest;

  if (!mProxy) {

    // Open might not have been called yet, in which case we'll handle the

    // background request in OpenRunnable.

    return;

  RefPtr<SetBackgroundRequestRunnable> runnable =

      new SetBackgroundRequestRunnable(mWorkerPrivate, mProxy,

                                       aBackgroundRequest);

  runnable->Dispatch(Canceling, aRv);

XMLHttpRequestUpload* XMLHttpRequestWorker::GetUpload(ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return nullptr;

  if (!mUpload) {

    mUpload = new XMLHttpRequestUpload(this);

  return mUpload;

void XMLHttpRequestWorker::Send(

    const Nullable<

        DocumentOrBlobOrArrayBufferViewOrArrayBufferOrFormDataOrURLSearchParamsOrUSVString>&

        aData,

    ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mFlagSendActive) {

    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_XHR_HAS_INVALID_CONTEXT);

    return;

  mFlagSendActive = true;

  auto clearRecursionFlag = MakeScopeExit([&]() {

    // No one else should have touched this flag.

    MOZ_ASSERT(mFlagSendActive);

    mFlagSendActive = false;

});

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  if (mStateData->mReadyState != XMLHttpRequest_Binding::OPENED) {

    aRv.ThrowInvalidStateError("XMLHttpRequest state must be OPENED.");

    return;

  if (!mProxy || !mProxy->mXMLHttpRequestPrivate || mStateData->mFlagSend) {

    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

    return;

  if (aData.IsNull()) {

    SendInternal(nullptr, aRv);

    return;

  if (aData.Value().IsDocument()) {

    MOZ_ASSERT_UNREACHABLE("Documents are not exposed to workers.");

    aRv.Throw(NS_ERROR_FAILURE);

    return;

  if (aData.Value().IsBlob()) {

    BodyExtractor<const Blob> body(&aData.Value().GetAsBlob());

    SendInternal(&body, aRv);

    return;

  if (aData.Value().IsArrayBuffer()) {

    BodyExtractor<const ArrayBuffer> body(&aData.Value().GetAsArrayBuffer());

    SendInternal(&body, aRv);

    return;

  if (aData.Value().IsArrayBufferView()) {

    BodyExtractor<const ArrayBufferView> body(

        &aData.Value().GetAsArrayBufferView());

    SendInternal(&body, aRv);

    return;

  if (aData.Value().IsFormData()) {

    BodyExtractor<const FormData> body(&aData.Value().GetAsFormData());

    SendInternal(&body, aRv);

    return;

  if (aData.Value().IsURLSearchParams()) {

    BodyExtractor<const URLSearchParams> body(

        &aData.Value().GetAsURLSearchParams());

    SendInternal(&body, aRv);

    return;

  if (aData.Value().IsUSVString()) {

    BodyExtractor<const nsAString> body(&aData.Value().GetAsUSVString());

    SendInternal(&body, aRv);

    return;

void XMLHttpRequestWorker::Abort(ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  if (!mProxy) {

    return;

  // Set our status to 0 and statusText to "" if we

  // will be aborting an ongoing fetch, so the upcoming

  // abort events we dispatch have the correct info.

  if ((mStateData->mReadyState == XMLHttpRequest_Binding::OPENED &&

       mStateData->mFlagSend) ||

      mStateData->mReadyState == XMLHttpRequest_Binding::HEADERS_RECEIVED ||

      mStateData->mReadyState == XMLHttpRequest_Binding::LOADING ||

      mStateData->mReadyState == XMLHttpRequest_Binding::DONE) {

    mStateData->mStatus = 0;

    mStateData->mStatusText.Truncate();

  MaybeDispatchPrematureAbortEvents(aRv);

  if (aRv.Failed()) {

    return;

  if (mStateData->mReadyState == 4) {

    // No one did anything to us while we fired abort events, so reset our state

    // to "unsent"

    mStateData->mReadyState = 0;

  mProxy->mOuterEventStreamId++;

  RefPtr<AbortRunnable> runnable = new AbortRunnable(mWorkerPrivate, mProxy);

  runnable->Dispatch(Canceling, aRv);

void XMLHttpRequestWorker::GetResponseHeader(const nsACString& aHeader,

                                             nsACString& aResponseHeader,

                                             ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  if (!mProxy) {

    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

    return;

  nsCString responseHeader;

  RefPtr<GetResponseHeaderRunnable> runnable = new GetResponseHeaderRunnable(

      mWorkerPrivate, mProxy, aHeader, responseHeader);

  runnable->Dispatch(Canceling, aRv);

  if (aRv.Failed()) {

    return;

  aResponseHeader = responseHeader;

void XMLHttpRequestWorker::GetAllResponseHeaders(nsACString& aResponseHeaders,

                                                 ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  if (!mProxy) {

    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

    return;

  nsCString responseHeaders;

  RefPtr<GetAllResponseHeadersRunnable> runnable =

      new GetAllResponseHeadersRunnable(mWorkerPrivate, mProxy,

                                        responseHeaders);

  runnable->Dispatch(Canceling, aRv);

  if (aRv.Failed()) {

    return;

  aResponseHeaders = responseHeaders;

void XMLHttpRequestWorker::OverrideMimeType(const nsAString& aMimeType,

                                            ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  if (mCanceled) {

    aRv.ThrowUncatchableException();

    return;

  // We're supposed to throw if the state is LOADING or DONE.

  if (mStateData->mReadyState == XMLHttpRequest_Binding::LOADING ||

      mStateData->mReadyState == XMLHttpRequest_Binding::DONE) {

    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);

    return;

  mMimeTypeOverride = aMimeType;

  if (mProxy) {

    RefPtr<OverrideMimeTypeRunnable> runnable =

        new OverrideMimeTypeRunnable(mWorkerPrivate, mProxy, aMimeType);

    runnable->Dispatch(Canceling, aRv);

void XMLHttpRequestWorker::SetResponseType(

    XMLHttpRequestResponseType aResponseType, ErrorResult& aRv) {

  mWorkerPrivate->AssertIsOnWorkerThread();

  // "document" is fine for the main thread but not for a worker. Short-circuit

  // that here.

  if (aResponseType == XMLHttpRequestResponseType::Document) {

    return;

  if (!mProxy) {

    // Open() has not been called yet. We store the responseType and we will use

    // it later in Open().

    mResponseType = aResponseType;

    return;

  if (mStateData->mReadyState == XMLHttpRequest_Binding::LOADING ||

      mStateData->mReadyState == XMLHttpRequest_Binding::DONE) {

    aRv.ThrowInvalidStateError(

        "Cannot set 'responseType' property on XMLHttpRequest after 'send()' "

        "(when its state is LOADING or DONE).");

    return;

  RefPtr<SetResponseTypeRunnable> runnable =

      new SetResponseTypeRunnable(mWorkerPrivate, mProxy, aResponseType);

  runnable->Dispatch(Canceling, aRv);

  if (aRv.Failed()) {

    return;

  mResponseType = runnable->ResponseType();

void XMLHttpRequestWorker::GetResponse(JSContext* aCx,

                                       JS::MutableHandle<JS::Value> aResponse,

                                       ErrorResult& aRv) {

  if (NS_FAILED(mResponseData->mResponseResult)) {

    aRv.Throw(mResponseData->mResponseResult);

    return;

  switch (mResponseType) {

    case XMLHttpRequestResponseType::_empty:

    case XMLHttpRequestResponseType::Text: {

      JSString* str;

      if (mResponseData->mResponseText.IsEmpty()) {

        aResponse.set(JS_GetEmptyStringValue(aCx));

        return;

      str = mResponseData->mResponseText.GetAsJSStringCopy(aCx);

      if (!str) {

        aRv.Throw(NS_ERROR_OUT_OF_MEMORY);

        return;

      aResponse.setString(str);

      return;

    case XMLHttpRequestResponseType::Arraybuffer: {

      if (!mResponseData->mResponseArrayBufferBuilder) {

        aResponse.setNull();

        return;

      if (!mResponseArrayBufferValue) {

        mResponseArrayBufferValue =

            mResponseData->mResponseArrayBufferBuilder->TakeArrayBuffer(aCx);

        if (!mResponseArrayBufferValue) {

          aRv.Throw(NS_ERROR_OUT_OF_MEMORY);

          return;

      aResponse.setObject(*mResponseArrayBufferValue);

      return;

    case XMLHttpRequestResponseType::Blob: {

      if (!mResponseData->mResponseBlobImpl) {

        aResponse.setNull();

        return;

      if (!mResponseBlob) {

        mResponseBlob =

            Blob::Create(GetOwnerGlobal(), mResponseData->mResponseBlobImpl);

      if (!mResponseBlob ||

          !GetOrCreateDOMReflector(aCx, mResponseBlob, aResponse)) {

        aResponse.setNull();

      return;

    case XMLHttpRequestResponseType::Json: {

      if (mResponseData->mResponseJSON.IsVoid()) {

        aResponse.setNull();

        return;

      if (mResponseJSONValue.isUndefined()) {

        // The Unicode converter has already zapped the BOM if there was one

        JS::Rooted<JS::Value> value(aCx);

        if (!JS_ParseJSON(aCx, mResponseData->mResponseJSON.BeginReading(),

                          mResponseData->mResponseJSON.Length(), &value)) {

          JS_ClearPendingException(aCx);

          mResponseJSONValue.setNull();

        } else {

          mResponseJSONValue = value;

        mResponseData->mResponseJSON.Truncate();

      aResponse.set(mResponseJSONValue);

      return;

    default:

      MOZ_ASSERT_UNREACHABLE("Invalid type");

      aResponse.setNull();

      return;

void XMLHttpRequestWorker::GetResponseText(DOMString& aResponseText,

                                           ErrorResult& aRv) {

  MOZ_DIAGNOSTIC_ASSERT(mResponseData);

  if (mResponseType != XMLHttpRequestResponseType::_empty &&

      mResponseType != XMLHttpRequestResponseType::Text) {

    aRv.ThrowInvalidStateError(

        "responseText is only available if responseType is '' or 'text'.");

    return;

  if (!mResponseData->mResponseText.GetAsString(aResponseText)) {

    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);

    return;

void XMLHttpRequestWorker::UpdateState(

    UniquePtr<StateData>&& aStateData,

    UniquePtr<ResponseData>&& aResponseData) {

  mStateData = std::move(aStateData);

  UniquePtr<ResponseData> responseData = std::move(aResponseData);

  if (responseData) {

    ResetResponseData();

    mResponseData = std::move(responseData);

  XMLHttpRequest_Binding::ClearCachedResponseTextValue(this);

void XMLHttpRequestWorker::ResetResponseData() {

  mResponseBlob = nullptr;

  mResponseArrayBufferValue = nullptr;

  mResponseJSONValue.setUndefined();

}  // namespace mozilla::dom