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 ReadableStreamBYOBRequest::ReadableStreamBYOBRequest(nsIGlobalObject* aGlobal)
  24     : mGlobal(aGlobal) {
  25   mozilla::HoldJSObjects(this);
  26 }
  27
  28 ReadableStreamBYOBRequest::~ReadableStreamBYOBRequest() {
  29   mozilla::DropJSObjects(this);
  30 }
  31
  32 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_WITH_JS_MEMBERS(ReadableStreamBYOBRequest,
  33                                                       (mGlobal, mController),
  34                                                       (mView))
  35
  36 NS_IMPL_CYCLE_COLLECTING_ADDREF(ReadableStreamBYOBRequest)
  37 NS_IMPL_CYCLE_COLLECTING_RELEASE(ReadableStreamBYOBRequest)
  38
  39 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ReadableStreamBYOBRequest)
  40   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  41   NS_INTERFACE_MAP_ENTRY(nsISupports)
  42 NS_INTERFACE_MAP_END
  43
  44 JSObject* ReadableStreamBYOBRequest::WrapObject(
  45     JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
  46   return ReadableStreamBYOBRequest_Binding::Wrap(aCx, this, aGivenProto);
  47 }
  48
  49 // https://streams.spec.whatwg.org/#rs-byob-request-view
  50 void ReadableStreamBYOBRequest::GetView(
  51     JSContext* cx, JS::MutableHandle<JSObject*> aRetVal) const {
  52   // Step 1.
  53   aRetVal.set(mView);
  54 }
  55
  56 // https://streams.spec.whatwg.org/#rs-byob-request-respond
  57 void ReadableStreamBYOBRequest::Respond(JSContext* aCx, uint64_t bytesWritten,
  58                                         ErrorResult& aRv) {
  59   // Step 1.
  60   if (!mController) {
  61     aRv.ThrowTypeError("Undefined Controller");
  62     return;
  63   }
  64
  65   // Step 2.
  66   bool isSharedMemory;
  67   JS::Rooted<JSObject*> view(aCx, mView);
  68   JS::Rooted<JSObject*> arrayBuffer(
  69       aCx, JS_GetArrayBufferViewBuffer(aCx, view, &isSharedMemory));
  70   if (!arrayBuffer) {
  71     aRv.StealExceptionFromJSContext(aCx);
  72     return;
  73   }
  74
  75   if (JS::IsDetachedArrayBufferObject(arrayBuffer)) {
  76     aRv.ThrowTypeError("View of Detached buffer");
  77     return;
  78   }
  79
  80   // Step 3.
  81   MOZ_ASSERT(JS_GetArrayBufferViewByteLength(view) > 0);
  82
  83   // Step 4.
  84   MOZ_ASSERT(JS::GetArrayBufferByteLength(arrayBuffer) > 0);
  85
  86   // Step 5.
  87   RefPtr<ReadableByteStreamController> controller(mController);
  88   ReadableByteStreamControllerRespond(aCx, controller, bytesWritten, aRv);
  89 }
  90
  91 // https://streams.spec.whatwg.org/#rs-byob-request-respond-with-new-view
  92 void ReadableStreamBYOBRequest::RespondWithNewView(JSContext* aCx,
  93                                                    const ArrayBufferView& view,
  94                                                    ErrorResult& aRv) {
  95   // Step 1.
  96   if (!mController) {
  97     aRv.ThrowTypeError("Undefined Controller");
  98     return;
  99   }
 100
 101   // Step 2.
 102   bool isSharedMemory;
 103   JS::Rooted<JSObject*> rootedViewObj(aCx, view.Obj());
 104   JS::Rooted<JSObject*> viewedArrayBuffer(
 105       aCx, JS_GetArrayBufferViewBuffer(aCx, rootedViewObj, &isSharedMemory));
 106   if (!viewedArrayBuffer) {
 107     aRv.StealExceptionFromJSContext(aCx);
 108     return;
 109   }
 110
 111   if (JS::IsDetachedArrayBufferObject(viewedArrayBuffer)) {
 112     aRv.ThrowTypeError("View of Detatched Array Buffer");
 113     return;
 114   }
 115
 116   // Step 3.
 117   RefPtr<ReadableByteStreamController> controller(mController);
 118   ReadableByteStreamControllerRespondWithNewView(aCx, controller, rootedViewObj,
 119                                                  aRv);
 120 }
 121
 122 void ReadableStreamBYOBRequest::SetController(
 123     ReadableByteStreamController* aController) {
 124   mController = aController;
 125 }
 126
 127 }  // namespace mozilla::dom