dom/streams/StreamUtils.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "StreamUtils.h"
   6
   7 #include <cmath>
   8 #include "mozilla/dom/QueuingStrategyBinding.h"
   9
  10 namespace mozilla::dom {
  11
  12 // Streams Spec: 7.4
  13 // https://streams.spec.whatwg.org/#validate-and-normalize-high-water-mark
  14 double ExtractHighWaterMark(const QueuingStrategy& aStrategy,
  15                             double aDefaultHWM, mozilla::ErrorResult& aRv) {
  16   // Step 1.
  17   if (!aStrategy.mHighWaterMark.WasPassed()) {
  18     return aDefaultHWM;
  19   }
  20
  21   // Step 2.
  22   double highWaterMark = aStrategy.mHighWaterMark.Value();
  23
  24   // Step 3.
  25   if (std::isnan(highWaterMark) || highWaterMark < 0) {
  26     aRv.ThrowRangeError("Invalid highWaterMark");
  27     return 0.0;
  28   }
  29
  30   // Step 4.
  31   return highWaterMark;
  32 }
  33
  34 }  // namespace mozilla::dom