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-rw-r--r--dom/streams/ByteLengthQueuingStrategy.cpp100
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diff --git a/dom/streams/ByteLengthQueuingStrategy.cpp b/dom/streams/ByteLengthQueuingStrategy.cpp
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/ByteLengthQueuingStrategy.h"
+#include "mozilla/dom/FunctionBinding.h"
+#include "mozilla/dom/QueuingStrategyBinding.h"
+#include "nsCOMPtr.h"
+#include "nsISupports.h"
+
+#include "js/TypeDecls.h"
+#include "js/PropertyAndElement.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_INHERITED(ByteLengthQueuingStrategy,
+ BaseQueuingStrategy)
+NS_IMPL_ADDREF_INHERITED(ByteLengthQueuingStrategy, BaseQueuingStrategy)
+NS_IMPL_RELEASE_INHERITED(ByteLengthQueuingStrategy, BaseQueuingStrategy)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ByteLengthQueuingStrategy)
+ NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+NS_INTERFACE_MAP_END_INHERITING(BaseQueuingStrategy)
+
+/* static */
+already_AddRefed<ByteLengthQueuingStrategy>
+ByteLengthQueuingStrategy::Constructor(const GlobalObject& aGlobal,
+ const QueuingStrategyInit& aInit) {
+ RefPtr<ByteLengthQueuingStrategy> strategy = new ByteLengthQueuingStrategy(
+ aGlobal.GetAsSupports(), aInit.mHighWaterMark);
+ return strategy.forget();
+}
+
+JSObject* ByteLengthQueuingStrategy::WrapObject(
+ JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
+ return ByteLengthQueuingStrategy_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+static bool ByteLengthQueuingStrategySize(JSContext* cx, unsigned argc,
+ JS::Value* vp) {
+ // https://streams.spec.whatwg.org/#blqs-internal-slots
+ JS::CallArgs args = CallArgsFromVp(argc, vp);
+
+ // Step 1: Return ? GetV(chunk, "byteLength").
+ JS::Rooted<JSObject*> chunkObj(cx, JS::ToObject(cx, args.get(0)));
+ if (!chunkObj) {
+ return false;
+ }
+
+ return JS_GetProperty(cx, chunkObj, "byteLength", args.rval());
+}
+
+// https://streams.spec.whatwg.org/#blqs-size
+already_AddRefed<Function> ByteLengthQueuingStrategy::GetSize(
+ ErrorResult& aRv) {
+ // Step 1. Return this's relevant global object's ByteLength queuing strategy
+ // size function.
+ if (RefPtr<Function> fun =
+ mGlobal->GetByteLengthQueuingStrategySizeFunction()) {
+ return fun.forget();
+ }
+
+ // Note: Instead of eagerly allocating a size function for every global object
+ // we do it lazily once in this getter.
+ // After this point the steps refer to:
+ // https://streams.spec.whatwg.org/#byte-length-queuing-strategy-size-function
+
+ AutoJSAPI jsapi;
+ if (!jsapi.Init(mGlobal)) {
+ aRv.ThrowUnknownError("Internal error");
+ return nullptr;
+ }
+ JSContext* cx = jsapi.cx();
+
+ // Step 1. Let steps be the following steps, given chunk
+ // Note: See ByteLengthQueuingStrategySize instead.
+
+ // Step 2. Let F be !CreateBuiltinFunction(steps, 1, "size", « »,
+ // globalObject’s relevant Realm).
+ JS::Rooted<JSFunction*> sizeFunction(
+ cx, JS_NewFunction(cx, ByteLengthQueuingStrategySize, 1, 0, "size"));
+ if (!sizeFunction) {
+ aRv.StealExceptionFromJSContext(cx);
+ return nullptr;
+ }
+
+ // Step 3. Set globalObject’s byte length queuing strategy size function to
+ // a Function that represents a reference to F,
+ // with callback context equal to globalObject’s relevant settings object.
+ JS::Rooted<JSObject*> funObj(cx, JS_GetFunctionObject(sizeFunction));
+ JS::Rooted<JSObject*> global(cx, mGlobal->GetGlobalJSObject());
+ RefPtr<Function> function = new Function(cx, funObj, global, mGlobal);
+ mGlobal->SetByteLengthQueuingStrategySizeFunction(function);
+
+ return function.forget();
+}
+
+} // namespace mozilla::dom