1 files changed, 87 insertions, 0 deletions
diff --git a/dom/streams/TeeState.cpp b/dom/streams/TeeState.cpp
new file mode 100644
index 0000000000..8600ea1205
--- /dev/null
+++ b/dom/streams/TeeState.cpp
@@ -0,0 +1,87 @@
+/* -*- 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 "TeeState.h"
+
+#include "ReadableStreamTee.h"
+#include "js/Value.h"
+#include "mozilla/HoldDropJSObjects.h"
+#include "mozilla/dom/ReadableStream.h"
+#include "mozilla/dom/Promise.h"
+
+namespace mozilla::dom {
+
+using namespace streams_abstract;
+
+NS_IMPL_CYCLE_COLLECTION_WITH_JS_MEMBERS(TeeState,
+                                         (mStream, mReader, mBranch1, mBranch2,
+                                          mCancelPromise),
+                                         (mReason1, mReason2))
+NS_IMPL_CYCLE_COLLECTING_ADDREF(TeeState)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(TeeState)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TeeState)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+TeeState::TeeState(ReadableStream* aStream, bool aCloneForBranch2)
+    : mStream(aStream),
+      mReason1(JS::NullValue()),
+      mReason2(JS::NullValue()),
+      mCloneForBranch2(aCloneForBranch2) {
+  mozilla::HoldJSObjects(this);
+  MOZ_RELEASE_ASSERT(!aCloneForBranch2,
+                     "cloneForBranch2 path is not implemented.");
+}
+
+already_AddRefed<TeeState> TeeState::Create(ReadableStream* aStream,
+                                            bool aCloneForBranch2,
+                                            ErrorResult& aRv) {
+  RefPtr<TeeState> teeState = new TeeState(aStream, aCloneForBranch2);
+
+  RefPtr<ReadableStreamDefaultReader> reader =
+      AcquireReadableStreamDefaultReader(teeState->GetStream(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+  teeState->SetReader(reader);
+
+  RefPtr<Promise> promise =
+      Promise::CreateInfallible(teeState->GetStream()->GetParentObject());
+  teeState->SetCancelPromise(promise);
+
+  return teeState.forget();
+}
+
+// https://streams.spec.whatwg.org/#abstract-opdef-readablestreamdefaulttee
+// Pull Algorithm Steps:
+void TeeState::PullCallback(JSContext* aCx, nsIGlobalObject* aGlobal,
+                            ErrorResult& aRv) {
+  // Step 13.1: If reading is true,
+  if (Reading()) {
+    // Step 13.1.1: Set readAgain to true.
+    SetReadAgain(true);
+
+    // Step 13.1.2: Return a promise resolved with undefined.
+    // (The caller will create it if necessary)
+    return;
+  }
+
+  // Step 13.2: Set reading to true.
+  SetReading(true);
+
+  // Step 13.3: Let readRequest be a read request with the following items:
+  RefPtr<ReadRequest> readRequest =
+      new ReadableStreamDefaultTeeReadRequest(this);
+
+  // Step 13.4: Perform ! ReadableStreamDefaultReaderRead(reader, readRequest).
+  RefPtr<ReadableStreamGenericReader> reader = GetReader();
+  ReadableStreamDefaultReaderRead(aCx, reader, readRequest, aRv);
+
+  // Step 13.5: Return a promise resolved with undefined.
+  // (The caller will create it if necessary)
+}
+
+}  // namespace mozilla::dom