tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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TeeState.cpp (3044B)

      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 "TeeState.h"
      8 
      9 #include "ReadableStreamTee.h"
     10 #include "js/Value.h"
     11 #include "mozilla/HoldDropJSObjects.h"
     12 #include "mozilla/dom/Promise.h"
     13 #include "mozilla/dom/ReadableStream.h"
     14 
     15 namespace mozilla::dom {
     16 
     17 using namespace streams_abstract;
     18 
     19 NS_IMPL_CYCLE_COLLECTION_WITH_JS_MEMBERS(TeeState,
     20                                         (mStream, mReader, mBranch1, mBranch2,
     21                                          mCancelPromise),
     22                                         (mReason1, mReason2))
     23 NS_IMPL_CYCLE_COLLECTING_ADDREF(TeeState)
     24 NS_IMPL_CYCLE_COLLECTING_RELEASE(TeeState)
     25 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TeeState)
     26  NS_INTERFACE_MAP_ENTRY(nsISupports)
     27 NS_INTERFACE_MAP_END
     28 
     29 TeeState::TeeState(ReadableStream* aStream, bool aCloneForBranch2)
     30    : mStream(aStream),
     31      mReason1(JS::NullValue()),
     32      mReason2(JS::NullValue()),
     33      mCloneForBranch2(aCloneForBranch2) {
     34  mozilla::HoldJSObjects(this);
     35  MOZ_RELEASE_ASSERT(!aCloneForBranch2,
     36                     "cloneForBranch2 path is not implemented.");
     37 }
     38 
     39 already_AddRefed<TeeState> TeeState::Create(ReadableStream* aStream,
     40                                            bool aCloneForBranch2,
     41                                            ErrorResult& aRv) {
     42  RefPtr<TeeState> teeState = new TeeState(aStream, aCloneForBranch2);
     43 
     44  RefPtr<ReadableStreamDefaultReader> reader =
     45      AcquireReadableStreamDefaultReader(teeState->GetStream(), aRv);
     46  if (aRv.Failed()) {
     47    return nullptr;
     48  }
     49  teeState->SetReader(reader);
     50 
     51  RefPtr<Promise> promise =
     52      Promise::CreateInfallible(teeState->GetStream()->GetParentObject());
     53  teeState->SetCancelPromise(promise);
     54 
     55  return teeState.forget();
     56 }
     57 
     58 // https://streams.spec.whatwg.org/#abstract-opdef-readablestreamdefaulttee
     59 // Pull Algorithm Steps:
     60 void TeeState::PullCallback(JSContext* aCx, nsIGlobalObject* aGlobal,
     61                            ErrorResult& aRv) {
     62  // Step 13.1: If reading is true,
     63  if (Reading()) {
     64    // Step 13.1.1: Set readAgain to true.
     65    SetReadAgain(true);
     66 
     67    // Step 13.1.2: Return a promise resolved with undefined.
     68    // (The caller will create it if necessary)
     69    return;
     70  }
     71 
     72  // Step 13.2: Set reading to true.
     73  SetReading(true);
     74 
     75  // Step 13.3: Let readRequest be a read request with the following items:
     76  RefPtr<ReadRequest> readRequest =
     77      new ReadableStreamDefaultTeeReadRequest(this);
     78 
     79  // Step 13.4: Perform ! ReadableStreamDefaultReaderRead(reader, readRequest).
     80  RefPtr<ReadableStreamGenericReader> reader = GetReader();
     81  ReadableStreamDefaultReaderRead(aCx, reader, readRequest, aRv);
     82 
     83  // Step 13.5: Return a promise resolved with undefined.
     84  // (The caller will create it if necessary)
     85 }
     86 
     87 }  // namespace mozilla::dom