dom/base/DOMRequest.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "DOMRequest.h"
   8
   9 #include "DOMException.h"
  10 #include "nsThreadUtils.h"
  11 #include "mozilla/HoldDropJSObjects.h"
  12 #include "mozilla/ErrorResult.h"
  13 #include "mozilla/dom/Event.h"
  14 #include "mozilla/dom/Promise.h"
  15 #include "mozilla/dom/ScriptSettings.h"
  16 #include "jsfriendapi.h"
  17 #include "nsContentUtils.h"
  18
  19 using mozilla::dom::AnyCallback;
  20 using mozilla::dom::AutoJSAPI;
  21 using mozilla::dom::DOMException;
  22 using mozilla::dom::DOMRequest;
  23 using mozilla::dom::DOMRequestService;
  24 using mozilla::dom::Promise;
  25 using mozilla::dom::RootingCx;
  26
  27 DOMRequest::DOMRequest(nsPIDOMWindowInner* aWindow)
  28     : DOMEventTargetHelper(aWindow),
  29       mResult(JS::UndefinedValue()),
  30       mDone(false) {}
  31
  32 DOMRequest::DOMRequest(nsIGlobalObject* aGlobal)
  33     : DOMEventTargetHelper(aGlobal),
  34       mResult(JS::UndefinedValue()),
  35       mDone(false) {}
  36
  37 DOMRequest::~DOMRequest() {
  38   mResult.setUndefined();
  39   mozilla::DropJSObjects(this);
  40 }
  41
  42 NS_IMPL_CYCLE_COLLECTION_CLASS(DOMRequest)
  43
  44 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(DOMRequest,
  45                                                   DOMEventTargetHelper)
  46   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mError)
  47   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPromise)
  48 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  49
  50 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(DOMRequest,
  51                                                 DOMEventTargetHelper)
  52   NS_IMPL_CYCLE_COLLECTION_UNLINK(mError)
  53   NS_IMPL_CYCLE_COLLECTION_UNLINK(mPromise)
  54   tmp->mResult.setUndefined();
  55 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  56
  57 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(DOMRequest, DOMEventTargetHelper)
  58   // Don't need NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER because
  59   // DOMEventTargetHelper does it for us.
  60   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mResult)
  61 NS_IMPL_CYCLE_COLLECTION_TRACE_END
  62
  63 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMRequest)
  64 NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
  65
  66 NS_IMPL_ADDREF_INHERITED(DOMRequest, DOMEventTargetHelper)
  67 NS_IMPL_RELEASE_INHERITED(DOMRequest, DOMEventTargetHelper)
  68
  69 /* virtual */
  70 JSObject* DOMRequest::WrapObject(JSContext* aCx,
  71                                  JS::Handle<JSObject*> aGivenProto) {
  72   return DOMRequest_Binding::Wrap(aCx, this, aGivenProto);
  73 }
  74
  75 void DOMRequest::FireSuccess(JS::Handle<JS::Value> aResult) {
  76   NS_ASSERTION(!mDone, "mDone shouldn't have been set to true already!");
  77   NS_ASSERTION(!mError, "mError shouldn't have been set!");
  78   NS_ASSERTION(mResult.isUndefined(), "mResult shouldn't have been set!");
  79
  80   mDone = true;
  81   if (aResult.isGCThing()) {
  82     RootResultVal();
  83   }
  84   mResult = aResult;
  85
  86   FireEvent(u"success"_ns, false, false);
  87
  88   if (mPromise) {
  89     mPromise->MaybeResolve(mResult);
  90   }
  91 }
  92
  93 void DOMRequest::FireError(const nsAString& aError) {
  94   NS_ASSERTION(!mDone, "mDone shouldn't have been set to true already!");
  95   NS_ASSERTION(!mError, "mError shouldn't have been set!");
  96   NS_ASSERTION(mResult.isUndefined(), "mResult shouldn't have been set!");
  97
  98   mDone = true;
  99   // XXX Error code chosen arbitrarily
 100   mError = DOMException::Create(NS_ERROR_DOM_UNKNOWN_ERR,
 101                                 NS_ConvertUTF16toUTF8(aError));
 102
 103   FireEvent(u"error"_ns, true, true);
 104
 105   if (mPromise) {
 106     mPromise->MaybeRejectBrokenly(mError);
 107   }
 108 }
 109
 110 void DOMRequest::FireError(nsresult aError) {
 111   NS_ASSERTION(!mDone, "mDone shouldn't have been set to true already!");
 112   NS_ASSERTION(!mError, "mError shouldn't have been set!");
 113   NS_ASSERTION(mResult.isUndefined(), "mResult shouldn't have been set!");
 114
 115   mDone = true;
 116   mError = DOMException::Create(aError);
 117
 118   FireEvent(u"error"_ns, true, true);
 119
 120   if (mPromise) {
 121     mPromise->MaybeRejectBrokenly(mError);
 122   }
 123 }
 124
 125 void DOMRequest::FireDetailedError(DOMException& aError) {
 126   NS_ASSERTION(!mDone, "mDone shouldn't have been set to true already!");
 127   NS_ASSERTION(!mError, "mError shouldn't have been set!");
 128   NS_ASSERTION(mResult.isUndefined(), "mResult shouldn't have been set!");
 129
 130   mDone = true;
 131   mError = &aError;
 132
 133   FireEvent(u"error"_ns, true, true);
 134
 135   if (mPromise) {
 136     mPromise->MaybeRejectBrokenly(mError);
 137   }
 138 }
 139
 140 void DOMRequest::FireEvent(const nsAString& aType, bool aBubble,
 141                            bool aCancelable) {
 142   if (NS_FAILED(CheckCurrentGlobalCorrectness())) {
 143     return;
 144   }
 145
 146   RefPtr<Event> event = NS_NewDOMEvent(this, nullptr, nullptr);
 147   event->InitEvent(aType, aBubble, aCancelable);
 148   event->SetTrusted(true);
 149
 150   DispatchEvent(*event);
 151 }
 152
 153 void DOMRequest::RootResultVal() { mozilla::HoldJSObjects(this); }
 154
 155 void DOMRequest::Then(JSContext* aCx, AnyCallback* aResolveCallback,
 156                       AnyCallback* aRejectCallback,
 157                       JS::MutableHandle<JS::Value> aRetval,
 158                       mozilla::ErrorResult& aRv) {
 159   if (!mPromise) {
 160     mPromise = Promise::Create(DOMEventTargetHelper::GetParentObject(), aRv);
 161     if (aRv.Failed()) {
 162       return;
 163     }
 164     if (mDone) {
 165       // Since we create mPromise lazily, it's possible that the DOMRequest
 166       // object has already fired its success/error event.  In that case we
 167       // should manually resolve/reject mPromise here.  mPromise will take care
 168       // of calling the callbacks on |promise| as needed.
 169       if (mError) {
 170         mPromise->MaybeRejectBrokenly(mError);
 171       } else {
 172         mPromise->MaybeResolve(mResult);
 173       }
 174     }
 175   }
 176
 177   // Just use the global of the Promise itself as the callee global.
 178   JS::Rooted<JSObject*> global(aCx, mPromise->PromiseObj());
 179   global = JS::GetNonCCWObjectGlobal(global);
 180   mPromise->Then(aCx, global, aResolveCallback, aRejectCallback, aRetval, aRv);
 181 }
 182
 183 NS_IMPL_ISUPPORTS(DOMRequestService, nsIDOMRequestService)
 184
 185 NS_IMETHODIMP
 186 DOMRequestService::CreateRequest(mozIDOMWindow* aWindow,
 187                                  DOMRequest** aRequest) {
 188   MOZ_ASSERT(NS_IsMainThread());
 189   NS_ENSURE_STATE(aWindow);
 190   auto* win = nsPIDOMWindowInner::From(aWindow);
 191   RefPtr<DOMRequest> req = new DOMRequest(win);
 192   req.forget(aRequest);
 193
 194   return NS_OK;
 195 }
 196
 197 NS_IMETHODIMP
 198 DOMRequestService::FireSuccess(DOMRequest* aRequest,
 199                                JS::Handle<JS::Value> aResult) {
 200   NS_ENSURE_STATE(aRequest);
 201   aRequest->FireSuccess(aResult);
 202
 203   return NS_OK;
 204 }
 205
 206 NS_IMETHODIMP
 207 DOMRequestService::FireError(DOMRequest* aRequest, const nsAString& aError) {
 208   NS_ENSURE_STATE(aRequest);
 209   aRequest->FireError(aError);
 210
 211   return NS_OK;
 212 }
 213
 214 class FireSuccessAsyncTask : public mozilla::Runnable {
 215   FireSuccessAsyncTask(DOMRequest* aRequest, const JS::Value& aResult)
 216       : mozilla::Runnable("FireSuccessAsyncTask"),
 217         mReq(aRequest),
 218         mResult(RootingCx(), aResult) {}
 219
 220  public:
 221   // Due to the fact that initialization can fail during shutdown (since we
 222   // can't fetch a js context), set up an initiatization function to make sure
 223   // we can return the failure appropriately
 224   static nsresult Dispatch(DOMRequest* aRequest, const JS::Value& aResult) {
 225     RefPtr<FireSuccessAsyncTask> asyncTask =
 226         new FireSuccessAsyncTask(aRequest, aResult);
 227     MOZ_ALWAYS_SUCCEEDS(NS_DispatchToCurrentThread(asyncTask));
 228     return NS_OK;
 229   }
 230
 231   NS_IMETHOD
 232   Run() override {
 233     mReq->FireSuccess(
 234         JS::Handle<JS::Value>::fromMarkedLocation(mResult.address()));
 235     return NS_OK;
 236   }
 237
 238  private:
 239   RefPtr<DOMRequest> mReq;
 240   JS::PersistentRooted<JS::Value> mResult;
 241 };
 242
 243 class FireErrorAsyncTask : public mozilla::Runnable {
 244  public:
 245   FireErrorAsyncTask(DOMRequest* aRequest, const nsAString& aError)
 246       : mozilla::Runnable("FireErrorAsyncTask"),
 247         mReq(aRequest),
 248         mError(aError) {}
 249
 250   NS_IMETHOD
 251   Run() override {
 252     mReq->FireError(mError);
 253     return NS_OK;
 254   }
 255
 256  private:
 257   RefPtr<DOMRequest> mReq;
 258   nsString mError;
 259 };
 260
 261 NS_IMETHODIMP
 262 DOMRequestService::FireSuccessAsync(DOMRequest* aRequest,
 263                                     JS::Handle<JS::Value> aResult) {
 264   NS_ENSURE_STATE(aRequest);
 265   return FireSuccessAsyncTask::Dispatch(aRequest, aResult);
 266 }
 267
 268 NS_IMETHODIMP
 269 DOMRequestService::FireErrorAsync(DOMRequest* aRequest,
 270                                   const nsAString& aError) {
 271   NS_ENSURE_STATE(aRequest);
 272   nsCOMPtr<nsIRunnable> asyncTask = new FireErrorAsyncTask(aRequest, aError);
 273   MOZ_ALWAYS_SUCCEEDS(NS_DispatchToCurrentThread(asyncTask));
 274   return NS_OK;
 275 }