gecko-dev/dom/xhr/XMLHttpRequestMainThread.h

/* -*- 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/. */

#ifndef mozilla_dom_XMLHttpRequestMainThread_h
#define mozilla_dom_XMLHttpRequestMainThread_h

#include <bitset>
#include "nsISupportsUtils.h"
#include "nsIURI.h"
#include "mozilla/dom/Document.h"
#include "nsIStreamListener.h"
#include "nsIChannelEventSink.h"
#include "nsIAsyncVerifyRedirectCallback.h"
#include "nsIDOMEventListener.h"
#include "nsIInterfaceRequestor.h"
#include "nsIHttpHeaderVisitor.h"
#include "nsIProgressEventSink.h"
#include "nsJSUtils.h"
#include "nsTArray.h"
#include "nsITimer.h"
#include "nsIPrincipal.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsISizeOfEventTarget.h"
#include "nsIInputStream.h"
#include "nsIContentSecurityPolicy.h"
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/DOMEventTargetHelper.h"
#include "mozilla/Maybe.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/NotNull.h"
#include "mozilla/dom/MutableBlobStorage.h"
#include "mozilla/dom/BodyExtractor.h"
#include "mozilla/dom/ClientInfo.h"
#include "mozilla/dom/TypedArray.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/FormData.h"
#include "mozilla/dom/MimeType.h"
#include "mozilla/dom/PerformanceStorage.h"
#include "mozilla/dom/ServiceWorkerDescriptor.h"
#include "mozilla/dom/URLSearchParams.h"
#include "mozilla/dom/XMLHttpRequest.h"
#include "mozilla/dom/XMLHttpRequestBinding.h"
#include "mozilla/dom/XMLHttpRequestEventTarget.h"
#include "mozilla/dom/XMLHttpRequestString.h"
#include "mozilla/Encoding.h"

#ifdef Status
/* Xlib headers insist on this for some reason... Nuke it because
   it'll override our member name */
typedef Status __StatusTmp;
#  undef Status
typedef __StatusTmp Status;
#endif

class nsIHttpChannel;
class nsIJARChannel;
class nsILoadGroup;

namespace mozilla {
class ProfileChunkedBuffer;

namespace dom {

class DOMString;
class XMLHttpRequestUpload;
class SerializedStackHolder;
struct OriginAttributesDictionary;

// A helper for building up an ArrayBuffer object's data
// before creating the ArrayBuffer itself.  Will do doubling
// based reallocation, up to an optional maximum growth given.
//
// When all the data has been appended, call GetArrayBuffer,
// passing in the JSContext* for which the ArrayBuffer object
// is to be created.  This also implicitly resets the builder.
class ArrayBufferBuilder {
 public:
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ArrayBufferBuilder);

  ArrayBufferBuilder();

  // Will truncate if aNewCap is < Length().
  bool SetCapacity(uint32_t aNewCap);

  // Append aDataLen bytes from data to the current buffer.  If we
  // need to grow the buffer, grow by doubling the size up to a
  // maximum of aMaxGrowth (if given).  If aDataLen is greater than
  // what the new capacity would end up as, then grow by aDataLen.
  //
  // The data parameter must not overlap with anything beyond the
  // builder's current valid contents [0..length)
  bool Append(const uint8_t* aNewData, uint32_t aDataLen,
              uint32_t aMaxGrowth = 0);

  uint32_t Length();
  uint32_t Capacity();

  JSObject* TakeArrayBuffer(JSContext* aCx);

  // Memory mapping to starting position of file(aFile) in the zip
  // package(aJarFile).
  //
  // The file in the zip package has to be uncompressed and the starting
  // position of the file must be aligned according to array buffer settings
  // in JS engine.
  nsresult MapToFileInPackage(const nsCString& aFile, nsIFile* aJarFile);

 private:
  ~ArrayBufferBuilder();

  ArrayBufferBuilder(const ArrayBufferBuilder&) = delete;
  ArrayBufferBuilder& operator=(const ArrayBufferBuilder&) = delete;
  ArrayBufferBuilder& operator=(const ArrayBufferBuilder&&) = delete;

  bool SetCapacityInternal(uint32_t aNewCap, const MutexAutoLock& aProofOfLock)
      MOZ_REQUIRES(mMutex);

  static bool AreOverlappingRegions(const uint8_t* aStart1, uint32_t aLength1,
                                    const uint8_t* aStart2, uint32_t aLength2);

  Mutex mMutex;

  // All of these are protected by mMutex.
  uint8_t* mDataPtr MOZ_GUARDED_BY(mMutex);
  uint32_t mCapacity MOZ_GUARDED_BY(mMutex);
  uint32_t mLength MOZ_GUARDED_BY(mMutex);
  void* mMapPtr MOZ_GUARDED_BY(mMutex);

  // This is used in assertions only.
  bool mNeutered;
};

class nsXMLHttpRequestXPCOMifier;

class RequestHeaders {
  struct RequestHeader {
    nsCString mName;
    nsCString mValue;
  };
  nsTArray<RequestHeader> mHeaders;
  RequestHeader* Find(const nsACString& aName);

 public:
  class CharsetIterator {
    bool mValid;
    int32_t mCurPos, mCurLen, mCutoff;
    nsACString& mSource;

   public:
    explicit CharsetIterator(nsACString& aSource);
    bool Equals(const nsACString& aOther,
                const nsCStringComparator& aCmp) const;
    void Replace(const nsACString& aReplacement);
    bool Next();
  };

  bool IsEmpty() const;
  bool Has(const char* aName);
  bool Has(const nsACString& aName);
  void Get(const char* aName, nsACString& aValue);
  void Get(const nsACString& aName, nsACString& aValue);
  void Set(const char* aName, const nsACString& aValue);
  void Set(const nsACString& aName, const nsACString& aValue);
  void MergeOrSet(const char* aName, const nsACString& aValue);
  void MergeOrSet(const nsACString& aName, const nsACString& aValue);
  void Clear();
  void ApplyToChannel(nsIHttpChannel* aChannel, bool aStripRequestBodyHeader,
                      bool aStripAuth) const;
  void GetCORSUnsafeHeaders(nsTArray<nsCString>& aArray) const;
};

class nsXHRParseEndListener;
class XMLHttpRequestDoneNotifier;

// Make sure that any non-DOM interfaces added here are also added to
// nsXMLHttpRequestXPCOMifier.
class XMLHttpRequestMainThread final : public XMLHttpRequest,
                                       public nsIStreamListener,
                                       public nsIChannelEventSink,
                                       public nsIProgressEventSink,
                                       public nsIInterfaceRequestor,
                                       public nsITimerCallback,
                                       public nsISizeOfEventTarget,
                                       public nsINamed,
                                       public MutableBlobStorageCallback {
  friend class nsXHRParseEndListener;
  friend class nsXMLHttpRequestXPCOMifier;
  friend class XMLHttpRequestDoneNotifier;

 public:
  enum class ProgressEventType : uint8_t {
    loadstart,
    progress,
    error,
    abort,
    timeout,
    load,
    loadend,
    ENUM_MAX
  };

  // Make sure that any additions done to ErrorType enum are also mirrored in
  // XHR_ERROR_TYPE enum of TelemetrySend.sys.mjs.
  enum class ErrorType : uint16_t {
    eOK,
    eRequest,
    eUnreachable,
    eChannelOpen,
    eRedirect,
    eTerminated,
    ENUM_MAX
  };

  explicit XMLHttpRequestMainThread(nsIGlobalObject* aGlobalObject);

  void Construct(nsIPrincipal* aPrincipal,
                 nsICookieJarSettings* aCookieJarSettings, bool aForWorker,
                 nsIURI* aBaseURI = nullptr, nsILoadGroup* aLoadGroup = nullptr,
                 PerformanceStorage* aPerformanceStorage = nullptr,
                 nsICSPEventListener* aCSPEventListener = nullptr);

  void InitParameters(bool aAnon, bool aSystem);

  void SetParameters(bool aAnon, bool aSystem) {
    mIsAnon = aAnon || aSystem;
    mIsSystem = aSystem;
  }

  void SetClientInfoAndController(
      const ClientInfo& aClientInfo,
      const Maybe<ServiceWorkerDescriptor>& aController);

  NS_DECL_ISUPPORTS_INHERITED

  // nsIStreamListener
  NS_DECL_NSISTREAMLISTENER

  // nsIRequestObserver
  NS_DECL_NSIREQUESTOBSERVER

  // nsIChannelEventSink
  NS_DECL_NSICHANNELEVENTSINK

  // nsIProgressEventSink
  NS_DECL_NSIPROGRESSEVENTSINK

  // nsIInterfaceRequestor
  NS_DECL_NSIINTERFACEREQUESTOR

  // nsITimerCallback
  NS_DECL_NSITIMERCALLBACK

  // nsINamed
  NS_DECL_NSINAMED

  // nsISizeOfEventTarget
  virtual size_t SizeOfEventTargetIncludingThis(
      MallocSizeOf aMallocSizeOf) const override;

  // states
  virtual uint16_t ReadyState() const override;

  // request
  nsresult CreateChannel();
  nsresult InitiateFetch(already_AddRefed<nsIInputStream> aUploadStream,
                         int64_t aUploadLength, nsACString& aUploadContentType);

  virtual void Open(const nsACString& aMethod, const nsAString& aUrl,
                    ErrorResult& aRv) override;

  virtual void Open(const nsACString& aMethod, const nsAString& aUrl,
                    bool aAsync, const nsAString& aUsername,
                    const nsAString& aPassword, ErrorResult& aRv) override;

  void Open(const nsACString& aMethod, const nsACString& aUrl, bool aAsync,
            const nsAString& aUsername, const nsAString& aPassword,
            ErrorResult& aRv);

  virtual void SetRequestHeader(const nsACString& aName,
                                const nsACString& aValue,
                                ErrorResult& aRv) override;

  virtual uint32_t Timeout() const override { return mTimeoutMilliseconds; }

  virtual void SetTimeout(uint32_t aTimeout, ErrorResult& aRv) override;

  virtual bool WithCredentials() const override;

  virtual void SetWithCredentials(bool aWithCredentials,
                                  ErrorResult& aRv) override;

  virtual XMLHttpRequestUpload* GetUpload(ErrorResult& aRv) override;

 private:
  virtual ~XMLHttpRequestMainThread();

  nsresult MaybeSilentSendFailure(nsresult aRv);
  void SendInternal(const BodyExtractorBase* aBody,
                    bool aBodyIsDocumentOrString, ErrorResult& aRv);

  bool IsCrossSiteCORSRequest() const;
  bool IsDeniedCrossSiteCORSRequest();

  void ResumeTimeout();

  void MaybeLowerChannelPriority();

 public:
  bool CanSend(ErrorResult& aRv);

  virtual void Send(
      const Nullable<
          DocumentOrBlobOrArrayBufferViewOrArrayBufferOrFormDataOrURLSearchParamsOrUSVString>&
          aData,
      ErrorResult& aRv) override;

  virtual void SendInputStream(nsIInputStream* aInputStream,
                               ErrorResult& aRv) override {
    if (!CanSend(aRv)) {
      return;
    }
    BodyExtractor<nsIInputStream> body(aInputStream);
    SendInternal(&body, false, aRv);
  }

  void RequestErrorSteps(const ProgressEventType aEventType,
                         const nsresult aOptionalException, ErrorResult& aRv);

  void Abort() {
    IgnoredErrorResult rv;
    AbortInternal(rv);
    MOZ_ASSERT(!rv.Failed());
  }

  virtual void Abort(ErrorResult& aRv) override;

  // response
  virtual void GetResponseURL(nsAString& aUrl) override;

  virtual uint32_t GetStatus(ErrorResult& aRv) override;

  virtual void GetStatusText(nsACString& aStatusText,
                             ErrorResult& aRv) override;

  virtual void GetResponseHeader(const nsACString& aHeader, nsACString& aResult,
                                 ErrorResult& aRv) override;

  void GetResponseHeader(const nsAString& aHeader, nsAString& aResult,
                         ErrorResult& aRv) {
    nsAutoCString result;
    GetResponseHeader(NS_ConvertUTF16toUTF8(aHeader), result, aRv);
    if (result.IsVoid()) {
      aResult.SetIsVoid(true);
    } else {
      // The result value should be inflated:
      CopyASCIItoUTF16(result, aResult);
    }
  }

  virtual void GetAllResponseHeaders(nsACString& aResponseHeaders,
                                     ErrorResult& aRv) override;

  bool IsSafeHeader(const nsACString& aHeaderName,
                    NotNull<nsIHttpChannel*> aHttpChannel) const;

  virtual void OverrideMimeType(const nsAString& aMimeType,
                                ErrorResult& aRv) override;

  virtual XMLHttpRequestResponseType ResponseType() const override {
    return XMLHttpRequestResponseType(mResponseType);
  }

  virtual void SetResponseType(XMLHttpRequestResponseType aType,
                               ErrorResult& aRv) override;

  void SetResponseTypeRaw(XMLHttpRequestResponseType aType) {
    mResponseType = aType;
  }

  virtual void GetResponse(JSContext* aCx,
                           JS::MutableHandle<JS::Value> aResponse,
                           ErrorResult& aRv) override;

  virtual void GetResponseText(DOMString& aResponseText,
                               ErrorResult& aRv) override;

  // GetResponse* for workers:
  already_AddRefed<BlobImpl> GetResponseBlobImpl();
  already_AddRefed<ArrayBufferBuilder> GetResponseArrayBufferBuilder();
  nsresult GetResponseTextForJSON(nsAString& aString);
  void GetResponseText(XMLHttpRequestStringSnapshot& aSnapshot,
                       ErrorResult& aRv);

  virtual Document* GetResponseXML(ErrorResult& aRv) override;

  virtual bool MozBackgroundRequest() const override;

  void SetMozBackgroundRequestExternal(bool aMozBackgroundRequest,
                                       ErrorResult& aRv);

  virtual void SetMozBackgroundRequest(bool aMozBackgroundRequest,
                                       ErrorResult& aRv) override;

  void SetOriginStack(UniquePtr<SerializedStackHolder> aOriginStack);

  void SetSource(UniquePtr<ProfileChunkedBuffer> aSource);

  virtual uint16_t ErrorCode() const override {
    return static_cast<uint16_t>(mErrorLoad);
  }

  virtual bool MozAnon() const override;

  virtual bool MozSystem() const override;

  virtual nsIChannel* GetChannel() const override { return mChannel; }

  // We need a GetInterface callable from JS for chrome JS
  virtual void GetInterface(JSContext* aCx, JS::Handle<JS::Value> aIID,
                            JS::MutableHandle<JS::Value> aRetval,
                            ErrorResult& aRv) override;

  // This fires a trusted readystatechange event, which is not cancelable and
  // doesn't bubble.
  nsresult FireReadystatechangeEvent();
  void DispatchProgressEvent(DOMEventTargetHelper* aTarget,
                             const ProgressEventType aType, int64_t aLoaded,
                             int64_t aTotal);

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(
      XMLHttpRequestMainThread, XMLHttpRequest)
  virtual bool IsCertainlyAliveForCC() const override;

  bool AllowUploadProgress();

  virtual void DisconnectFromOwner() override;

  static void SetDontWarnAboutSyncXHR(bool aVal) {
    sDontWarnAboutSyncXHR = aVal;
  }
  static bool DontWarnAboutSyncXHR() { return sDontWarnAboutSyncXHR; }

  virtual void SetOriginAttributes(
      const mozilla::dom::OriginAttributesDictionary& aAttrs) override;

  void BlobStoreCompleted(MutableBlobStorage* aBlobStorage, BlobImpl* aBlobImpl,
                          nsresult aResult) override;

  void LocalFileToBlobCompleted(BlobImpl* aBlobImpl);

 protected:
  nsresult DetectCharset();
  nsresult AppendToResponseText(Span<const uint8_t> aBuffer,
                                bool aLast = false);
  static nsresult StreamReaderFunc(nsIInputStream* in, void* closure,
                                   const char* fromRawSegment,
                                   uint32_t toOffset, uint32_t count,
                                   uint32_t* writeCount);
  nsresult CreateResponseParsedJSON(JSContext* aCx);
  // Change the state of the object with this. The broadcast argument
  // determines if the onreadystatechange listener should be called.
  nsresult ChangeState(uint16_t aState, bool aBroadcast = true);
  already_AddRefed<nsILoadGroup> GetLoadGroup() const;

  // Finds a preload for this XHR.  If it is found it's removed from the preload
  // table of the document and marked as used.  The called doesn't need to do
  // any more comparative checks.
  already_AddRefed<PreloaderBase> FindPreload();
  // If no or unknown mime type is set on the channel this method ensures it's
  // set to "text/xml".
  void EnsureChannelContentType();

  already_AddRefed<nsIHttpChannel> GetCurrentHttpChannel();
  already_AddRefed<nsIJARChannel> GetCurrentJARChannel();

  void TruncateResponseText();

  bool IsSystemXHR() const;
  bool InUploadPhase() const;

  void OnBodyParseEnd();
  void ChangeStateToDone(bool aWasSync);
  void ChangeStateToDoneInternal();

  void StartProgressEventTimer();
  void StopProgressEventTimer();

  void MaybeCreateBlobStorage();

  nsresult OnRedirectVerifyCallback(nsresult result, bool stripAuth = false);

  nsIEventTarget* GetTimerEventTarget();

  nsresult DispatchToMainThread(already_AddRefed<nsIRunnable> aRunnable);

  void DispatchOrStoreEvent(DOMEventTargetHelper* aTarget, Event* aEvent);

  already_AddRefed<nsXMLHttpRequestXPCOMifier> EnsureXPCOMifier();

  void SuspendEventDispatching();
  void ResumeEventDispatching();

  void AbortInternal(ErrorResult& aRv);

  struct PendingEvent {
    RefPtr<DOMEventTargetHelper> mTarget;
    RefPtr<Event> mEvent;
  };

  nsTArray<PendingEvent> mPendingEvents;

  nsCOMPtr<nsISupports> mContext;
  nsCOMPtr<nsIPrincipal> mPrincipal;
  nsCOMPtr<nsIChannel> mChannel;
  nsCString mRequestMethod;
  nsCOMPtr<nsIURI> mRequestURL;
  RefPtr<Document> mResponseXML;

  nsCOMPtr<nsIStreamListener> mXMLParserStreamListener;

  nsCOMPtr<nsICookieJarSettings> mCookieJarSettings;

  RefPtr<PerformanceStorage> mPerformanceStorage;
  nsCOMPtr<nsICSPEventListener> mCSPEventListener;

  // used to implement getAllResponseHeaders()
  class nsHeaderVisitor : public nsIHttpHeaderVisitor {
    struct HeaderEntry final {
      nsCString mName;
      nsCString mValue;

      HeaderEntry(const nsACString& aName, const nsACString& aValue)
          : mName(aName), mValue(aValue) {}

      bool operator==(const HeaderEntry& aOther) const {
        return mName == aOther.mName;
      }

      bool operator<(const HeaderEntry& aOther) const {
        uint32_t selfLen = mName.Length();
        uint32_t otherLen = aOther.mName.Length();
        uint32_t min = XPCOM_MIN(selfLen, otherLen);
        for (uint32_t i = 0; i < min; ++i) {
          unsigned char self = mName[i];
          unsigned char other = aOther.mName[i];
          MOZ_ASSERT(!(self >= 'A' && self <= 'Z'));
          MOZ_ASSERT(!(other >= 'A' && other <= 'Z'));
          if (self == other) {
            continue;
          }
          if (self >= 'a' && self <= 'z') {
            self -= 0x20;
          }
          if (other >= 'a' && other <= 'z') {
            other -= 0x20;
          }
          return self < other;
        }
        return selfLen < otherLen;
      }
    };

   public:
    NS_DECL_ISUPPORTS
    NS_DECL_NSIHTTPHEADERVISITOR
    nsHeaderVisitor(const XMLHttpRequestMainThread& aXMLHttpRequest,
                    NotNull<nsIHttpChannel*> aHttpChannel);
    const nsACString& Headers() {
      for (uint32_t i = 0; i < mHeaderList.Length(); i++) {
        HeaderEntry& header = mHeaderList.ElementAt(i);

        mHeaders.Append(header.mName);
        mHeaders.AppendLiteral(": ");
        mHeaders.Append(header.mValue);
        mHeaders.AppendLiteral("\r\n");
      }
      return mHeaders;
    }

   private:
    virtual ~nsHeaderVisitor();

    nsTArray<HeaderEntry> mHeaderList;
    nsCString mHeaders;
    const XMLHttpRequestMainThread& mXHR;
    NotNull<nsCOMPtr<nsIHttpChannel>> mHttpChannel;
  };

  // The bytes of our response body. Only used for DEFAULT, ARRAYBUFFER and
  // BLOB responseTypes
  nsCString mResponseBody;

  // The text version of our response body. This is incrementally decoded into
  // as we receive network data. However for the DEFAULT responseType we
  // lazily decode into this from mResponseBody only when .responseText is
  // accessed.
  // Only used for DEFAULT and TEXT responseTypes.
  XMLHttpRequestString mResponseText;

  // For DEFAULT responseType we use this to keep track of how far we've
  // lazily decoded from mResponseBody to mResponseText
  uint32_t mResponseBodyDecodedPos;

  // Decoder used for decoding into mResponseText
  // Only used for DEFAULT, TEXT and JSON responseTypes.
  // In cases where we've only received half a surrogate, the decoder itself
  // carries the state to remember this. Next time we receive more data we
  // simply feed the new data into the decoder which will handle the second
  // part of the surrogate.
  mozilla::UniquePtr<mozilla::Decoder> mDecoder;

  void MatchCharsetAndDecoderToResponseDocument();

  XMLHttpRequestResponseType mResponseType;

  RefPtr<BlobImpl> mResponseBlobImpl;

  // This is the cached blob-response, created only at the first GetResponse()
  // call.
  RefPtr<Blob> mResponseBlob;

  // We stream data to mBlobStorage when response type is "blob".
  RefPtr<MutableBlobStorage> mBlobStorage;

  nsString mOverrideMimeType;

  /**
   * The notification callbacks the channel had when Send() was
   * called.  We want to forward things here as needed.
   */
  nsCOMPtr<nsIInterfaceRequestor> mNotificationCallbacks;
  /**
   * Sink interfaces that we implement that mNotificationCallbacks may
   * want to also be notified for.  These are inited lazily if we're
   * asked for the relevant interface.
   */
  nsCOMPtr<nsIChannelEventSink> mChannelEventSink;
  nsCOMPtr<nsIProgressEventSink> mProgressEventSink;

  nsCOMPtr<nsIURI> mBaseURI;
  nsCOMPtr<nsILoadGroup> mLoadGroup;

  Maybe<ClientInfo> mClientInfo;
  Maybe<ServiceWorkerDescriptor> mController;

  uint16_t mState;

  // If true, this object is used by the worker's XMLHttpRequest.
  bool mForWorker;

  bool mFlagSynchronous;
  bool mFlagAborted;
  bool mFlagParseBody;
  bool mFlagSyncLooping;
  bool mFlagBackgroundRequest;
  bool mFlagHadUploadListenersOnSend;
  bool mFlagACwithCredentials;
  bool mFlagTimedOut;
  bool mFlagDeleted;

  // The XHR2 spec's send() flag. Set when the XHR begins uploading, until it
  // finishes downloading (or an error/abort has occurred during either phase).
  // Used to guard against the user trying to alter headers/etc when it's too
  // late, and ensure the XHR only handles one in-flight request at once.
  bool mFlagSend;

  RefPtr<XMLHttpRequestUpload> mUpload;
  int64_t mUploadTransferred;
  int64_t mUploadTotal;
  bool mUploadComplete;
  bool mProgressSinceLastProgressEvent;

  // Timeout support
  PRTime mRequestSentTime;
  uint32_t mTimeoutMilliseconds;
  nsCOMPtr<nsITimer> mTimeoutTimer;
  void StartTimeoutTimer();
  void HandleTimeoutCallback();

  nsCOMPtr<nsIRunnable> mResumeTimeoutRunnable;

  nsCOMPtr<nsITimer> mSyncTimeoutTimer;

  enum SyncTimeoutType { eErrorOrExpired, eTimerStarted, eNoTimerNeeded };

  SyncTimeoutType MaybeStartSyncTimeoutTimer();
  void HandleSyncTimeoutTimer();
  void CancelSyncTimeoutTimer();

  ErrorType mErrorLoad;
  bool mErrorParsingXML;
  bool mWaitingForOnStopRequest;
  bool mProgressTimerIsActive;
  bool mIsHtml;
  bool mWarnAboutSyncHtml;
  int64_t mLoadTotal;  // -1 if not known.
  // Number of HTTP message body bytes received so far. This quantity is
  // in the same units as Content-Length and mLoadTotal, and hence counts
  // compressed bytes when the channel has gzip Content-Encoding. If the
  // channel does not have Content-Encoding, this will be the same as
  // mDataReceived except between the OnProgress that changes mLoadTransferred
  // and the corresponding OnDataAvailable (which changes mDataReceived).
  // Ordering of OnProgress and OnDataAvailable is undefined.
  int64_t mLoadTransferred;
  nsCOMPtr<nsITimer> mProgressNotifier;
  void HandleProgressTimerCallback();

  bool mIsSystem;
  bool mIsAnon;

  /**
   * Close the XMLHttpRequest's channels.
   */
  void CloseRequest();

  void TerminateOngoingFetch();

  /**
   * Close the XMLHttpRequest's channels and dispatch appropriate progress
   * events.
   *
   * @param aType The progress event type.
   */
  void CloseRequestWithError(const ProgressEventType aType);

  nsCOMPtr<nsIAsyncVerifyRedirectCallback> mRedirectCallback;
  nsCOMPtr<nsIChannel> mNewRedirectChannel;

  JS::Heap<JS::Value> mResultJSON;

  RefPtr<ArrayBufferBuilder> mArrayBufferBuilder;
  JS::Heap<JSObject*> mResultArrayBuffer;
  bool mIsMappedArrayBuffer;

  void ResetResponse();

  bool ShouldBlockAuthPrompt();

  RequestHeaders mAuthorRequestHeaders;

  // Helper object to manage our XPCOM scriptability bits
  nsXMLHttpRequestXPCOMifier* mXPCOMifier;

  // When this is set to true, the event dispatching is suspended. This is
  // useful to change the correct state when XHR is working sync.
  bool mEventDispatchingSuspended;

  // True iff mDecoder has processed the end of the stream.
  // Used in lazy decoding to distinguish between having
  // processed all the bytes but not the EOF and having
  // processed all the bytes and the EOF.
  bool mEofDecoded;

  // This flag will be set in `Send()` when we successfully reuse a "fetch"
  // preload to satisfy this XHR.
  bool mFromPreload = false;

  // Our parse-end listener, if we are parsing.
  RefPtr<nsXHRParseEndListener> mParseEndListener;

  XMLHttpRequestDoneNotifier* mDelayedDoneNotifier;
  void DisconnectDoneNotifier();

  // Any stack information for the point the XHR was opened. This is deleted
  // after the XHR is opened, to avoid retaining references to the worker.
  UniquePtr<SerializedStackHolder> mOriginStack;

  static bool sDontWarnAboutSyncXHR;
};

class MOZ_STACK_CLASS AutoDontWarnAboutSyncXHR {
 public:
  AutoDontWarnAboutSyncXHR()
      : mOldVal(XMLHttpRequestMainThread::DontWarnAboutSyncXHR()) {
    XMLHttpRequestMainThread::SetDontWarnAboutSyncXHR(true);
  }

  ~AutoDontWarnAboutSyncXHR() {
    XMLHttpRequestMainThread::SetDontWarnAboutSyncXHR(mOldVal);
  }

 private:
  bool mOldVal;
};

// A shim class designed to expose the non-DOM interfaces of
// XMLHttpRequest via XPCOM stuff.
class nsXMLHttpRequestXPCOMifier final : public nsIStreamListener,
                                         public nsIChannelEventSink,
                                         public nsIAsyncVerifyRedirectCallback,
                                         public nsIProgressEventSink,
                                         public nsIInterfaceRequestor,
                                         public nsITimerCallback,
                                         public nsINamed {
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsXMLHttpRequestXPCOMifier,
                                           nsIStreamListener)

  explicit nsXMLHttpRequestXPCOMifier(XMLHttpRequestMainThread* aXHR)
      : mXHR(aXHR) {}

 private:
  ~nsXMLHttpRequestXPCOMifier() {
    if (mXHR) {
      mXHR->mXPCOMifier = nullptr;
    }
  }

 public:
  NS_FORWARD_NSISTREAMLISTENER(mXHR->)
  NS_FORWARD_NSIREQUESTOBSERVER(mXHR->)
  NS_FORWARD_NSICHANNELEVENTSINK(mXHR->)
  NS_FORWARD_NSIASYNCVERIFYREDIRECTCALLBACK(mXHR->)
  NS_FORWARD_NSIPROGRESSEVENTSINK(mXHR->)
  NS_FORWARD_NSITIMERCALLBACK(mXHR->)
  NS_FORWARD_NSINAMED(mXHR->)

  NS_DECL_NSIINTERFACEREQUESTOR

 private:
  RefPtr<XMLHttpRequestMainThread> mXHR;
};

class XMLHttpRequestDoneNotifier : public Runnable {
 public:
  explicit XMLHttpRequestDoneNotifier(XMLHttpRequestMainThread* aXHR)
      : Runnable("XMLHttpRequestDoneNotifier"), mXHR(aXHR) {}

  NS_IMETHOD Run() override {
    if (mXHR) {
      RefPtr<XMLHttpRequestMainThread> xhr = mXHR;
      // ChangeStateToDoneInternal ends up calling Disconnect();
      xhr->ChangeStateToDoneInternal();
      MOZ_ASSERT(!mXHR);
    }
    return NS_OK;
  }

  void Disconnect() { mXHR = nullptr; }

 private:
  RefPtr<XMLHttpRequestMainThread> mXHR;
};

class nsXHRParseEndListener : public nsIDOMEventListener {
 public:
  NS_DECL_ISUPPORTS
  NS_IMETHOD HandleEvent(Event* event) override {
    if (mXHR) {
      mXHR->OnBodyParseEnd();
    }
    mXHR = nullptr;
    return NS_OK;
  }

  explicit nsXHRParseEndListener(XMLHttpRequestMainThread* aXHR) : mXHR(aXHR) {}

  void SetIsStale() { mXHR = nullptr; }

 private:
  virtual ~nsXHRParseEndListener() = default;

  XMLHttpRequestMainThread* mXHR;
};

}  // namespace dom
}  // namespace mozilla

#endif  // mozilla_dom_XMLHttpRequestMainThread_h