1 files changed, 107 insertions, 0 deletions
diff --git a/dom/streams/UnderlyingSinkCallbackHelpers.cpp b/dom/streams/UnderlyingSinkCallbackHelpers.cpp
new file mode 100644
index 0000000000..1a1acea7dc
--- /dev/null
+++ b/dom/streams/UnderlyingSinkCallbackHelpers.cpp
@@ -0,0 +1,107 @@
+/* -*- 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/UnderlyingSinkCallbackHelpers.h"
+
+using namespace mozilla::dom;
+
+NS_IMPL_CYCLE_COLLECTION(UnderlyingSinkAlgorithmsBase)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(UnderlyingSinkAlgorithmsBase)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(UnderlyingSinkAlgorithmsBase)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(UnderlyingSinkAlgorithmsBase)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED_WITH_JS_MEMBERS(
+    UnderlyingSinkAlgorithms, UnderlyingSinkAlgorithmsBase,
+    (mGlobal, mStartCallback, mWriteCallback, mCloseCallback, mAbortCallback),
+    (mUnderlyingSink))
+NS_IMPL_ADDREF_INHERITED(UnderlyingSinkAlgorithms, UnderlyingSinkAlgorithmsBase)
+NS_IMPL_RELEASE_INHERITED(UnderlyingSinkAlgorithms,
+                          UnderlyingSinkAlgorithmsBase)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(UnderlyingSinkAlgorithms)
+NS_INTERFACE_MAP_END_INHERITING(UnderlyingSinkAlgorithmsBase)
+
+// https://streams.spec.whatwg.org/#set-up-writable-stream-default-controller-from-underlying-sink
+void UnderlyingSinkAlgorithms::StartCallback(
+    JSContext* aCx, WritableStreamDefaultController& aController,
+    JS::MutableHandle<JS::Value> aRetVal, ErrorResult& aRv) {
+  if (!mStartCallback) {
+    // Step 2: Let startAlgorithm be an algorithm that returns undefined.
+    aRetVal.setUndefined();
+    return;
+  }
+
+  // Step 6: If underlyingSinkDict["start"] exists, then set startAlgorithm to
+  // an algorithm which returns the result of invoking
+  // underlyingSinkDict["start"] with argument list « controller » and callback
+  // this value underlyingSink.
+  JS::Rooted<JSObject*> thisObj(aCx, mUnderlyingSink);
+  return mStartCallback->Call(thisObj, aController, aRetVal, aRv,
+                              "UnderlyingSink.start",
+                              CallbackFunction::eRethrowExceptions);
+}
+
+// https://streams.spec.whatwg.org/#set-up-writable-stream-default-controller-from-underlying-sink
+already_AddRefed<Promise> UnderlyingSinkAlgorithms::WriteCallback(
+    JSContext* aCx, JS::Handle<JS::Value> aChunk,
+    WritableStreamDefaultController& aController, ErrorResult& aRv) {
+  if (!mWriteCallback) {
+    // Step 3: Let writeAlgorithm be an algorithm that returns a promise
+    // resolved with undefined.
+    return Promise::CreateResolvedWithUndefined(mGlobal, aRv);
+  }
+
+  // Step 7: If underlyingSinkDict["write"] exists, then set writeAlgorithm to
+  // an algorithm which takes an argument chunk and returns the result of
+  // invoking underlyingSinkDict["write"] with argument list « chunk, controller
+  // » and callback this value underlyingSink.
+  JS::Rooted<JSObject*> thisObj(aCx, mUnderlyingSink);
+  RefPtr<Promise> promise = mWriteCallback->Call(
+      thisObj, aChunk, aController, aRv, "UnderlyingSink.write",
+      CallbackFunction::eRethrowExceptions);
+  return promise.forget();
+}
+
+// https://streams.spec.whatwg.org/#set-up-writable-stream-default-controller-from-underlying-sink
+already_AddRefed<Promise> UnderlyingSinkAlgorithms::CloseCallback(
+    JSContext* aCx, ErrorResult& aRv) {
+  if (!mCloseCallback) {
+    // Step 4: Let closeAlgorithm be an algorithm that returns a promise
+    // resolved with undefined.
+    return Promise::CreateResolvedWithUndefined(mGlobal, aRv);
+  }
+
+  // Step 8: If underlyingSinkDict["close"] exists, then set closeAlgorithm to
+  // an algorithm which returns the result of invoking
+  // underlyingSinkDict["close"] with argument list «» and callback this value
+  // underlyingSink.
+  JS::Rooted<JSObject*> thisObj(aCx, mUnderlyingSink);
+  RefPtr<Promise> promise =
+      mCloseCallback->Call(thisObj, aRv, "UnderlyingSink.close",
+                           CallbackFunction::eRethrowExceptions);
+  return promise.forget();
+}
+
+// https://streams.spec.whatwg.org/#set-up-writable-stream-default-controller-from-underlying-sink
+already_AddRefed<Promise> UnderlyingSinkAlgorithms::AbortCallback(
+    JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
+    ErrorResult& aRv) {
+  if (!mAbortCallback) {
+    // Step 5: Let abortAlgorithm be an algorithm that returns a promise
+    // resolved with undefined.
+    return Promise::CreateResolvedWithUndefined(mGlobal, aRv);
+  }
+
+  // Step 9: Let abortAlgorithm be an algorithm that returns a promise resolved
+  // with undefined.
+  JS::Rooted<JSObject*> thisObj(aCx, mUnderlyingSink);
+  RefPtr<Promise> promise =
+      mAbortCallback->Call(thisObj, aReason, aRv, "UnderlyingSink.abort",
+                           CallbackFunction::eRethrowExceptions);
+
+  return promise.forget();
+}