dom/streams/ReadableStreamBYOBRequest.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   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
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/dom/ReadableStreamBYOBRequest.h"
   8
   9 #include "mozilla/dom/ByteStreamHelpers.h"
  10 #include "js/ArrayBuffer.h"
  11 #include "js/TypeDecls.h"
  12 #include "mozilla/dom/ReadableByteStreamController.h"
  13 #include "mozilla/dom/ReadableStream.h"
  14 #include "mozilla/dom/ReadableStreamBYOBRequestBinding.h"
  15 #include "js/experimental/TypedData.h"
  16 #include "mozilla/dom/ReadableStreamController.h"
  17 #include "nsCOMPtr.h"
  18 #include "nsIGlobalObject.h"
  19 #include "nsWrapperCache.h"
  20
  21 namespace mozilla::dom {
  22
  23 using namespace streams_abstract;
  24
  25 ReadableStreamBYOBRequest::ReadableStreamBYOBRequest(nsIGlobalObject* aGlobal)
  26     : mGlobal(aGlobal) {
  27   mozilla::HoldJSObjects(this);
  28 }
  29
  30 ReadableStreamBYOBRequest::~ReadableStreamBYOBRequest() {
  31   mozilla::DropJSObjects(this);
  32 }
  33
  34 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_WITH_JS_MEMBERS(ReadableStreamBYOBRequest,
  35                                                       (mGlobal, mController),
  36                                                       (mView))
  37
  38 NS_IMPL_CYCLE_COLLECTING_ADDREF(ReadableStreamBYOBRequest)
  39 NS_IMPL_CYCLE_COLLECTING_RELEASE(ReadableStreamBYOBRequest)
  40
  41 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ReadableStreamBYOBRequest)
  42   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  43   NS_INTERFACE_MAP_ENTRY(nsISupports)
  44 NS_INTERFACE_MAP_END
  45
  46 JSObject* ReadableStreamBYOBRequest::WrapObject(
  47     JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
  48   return ReadableStreamBYOBRequest_Binding::Wrap(aCx, this, aGivenProto);
  49 }
  50
  51 // https://streams.spec.whatwg.org/#rs-byob-request-view
  52 void ReadableStreamBYOBRequest::GetView(
  53     JSContext* cx, JS::MutableHandle<JSObject*> aRetVal) const {
  54   // Step 1.
  55   aRetVal.set(mView);
  56 }
  57
  58 // https://streams.spec.whatwg.org/#rs-byob-request-respond
  59 void ReadableStreamBYOBRequest::Respond(JSContext* aCx, uint64_t bytesWritten,
  60                                         ErrorResult& aRv) {
  61   // Step 1.
  62   if (!mController) {
  63     aRv.ThrowTypeError("Undefined Controller");
  64     return;
  65   }
  66
  67   // Step 2.
  68   bool isSharedMemory;
  69   JS::Rooted<JSObject*> view(aCx, mView);
  70   JS::Rooted<JSObject*> arrayBuffer(
  71       aCx, JS_GetArrayBufferViewBuffer(aCx, view, &isSharedMemory));
  72   if (!arrayBuffer) {
  73     aRv.StealExceptionFromJSContext(aCx);
  74     return;
  75   }
  76
  77   if (JS::IsDetachedArrayBufferObject(arrayBuffer)) {
  78     aRv.ThrowTypeError("View of Detached buffer");
  79     return;
  80   }
  81
  82   // Step 3.
  83   MOZ_ASSERT(JS_GetArrayBufferViewByteLength(view) > 0);
  84
  85   // Step 4.
  86   MOZ_ASSERT(JS::GetArrayBufferByteLength(arrayBuffer) > 0);
  87
  88   // Step 5.
  89   RefPtr<ReadableByteStreamController> controller(mController);
  90   ReadableByteStreamControllerRespond(aCx, controller, bytesWritten, aRv);
  91 }
  92
  93 // https://streams.spec.whatwg.org/#rs-byob-request-respond-with-new-view
  94 void ReadableStreamBYOBRequest::RespondWithNewView(JSContext* aCx,
  95                                                    const ArrayBufferView& view,
  96                                                    ErrorResult& aRv) {
  97   // Step 1.
  98   if (!mController) {
  99     aRv.ThrowTypeError("Undefined Controller");
 100     return;
 101   }
 102
 103   // Step 2.
 104   bool isSharedMemory;
 105   JS::Rooted<JSObject*> rootedViewObj(aCx, view.Obj());
 106   JS::Rooted<JSObject*> viewedArrayBuffer(
 107       aCx, JS_GetArrayBufferViewBuffer(aCx, rootedViewObj, &isSharedMemory));
 108   if (!viewedArrayBuffer) {
 109     aRv.StealExceptionFromJSContext(aCx);
 110     return;
 111   }
 112
 113   if (JS::IsDetachedArrayBufferObject(viewedArrayBuffer)) {
 114     aRv.ThrowTypeError("View of Detached Array Buffer");
 115     return;
 116   }
 117
 118   // Step 3.
 119   RefPtr<ReadableByteStreamController> controller(mController);
 120   ReadableByteStreamControllerRespondWithNewView(aCx, controller, rootedViewObj,
 121                                                  aRv);
 122 }
 123
 124 void ReadableStreamBYOBRequest::SetController(
 125     ReadableByteStreamController* aController) {
 126   mController = aController;
 127 }
 128
 129 }  // namespace mozilla::dom