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