1 files changed, 94 insertions, 0 deletions
diff --git a/dom/fetch/FetchStreamReader.h b/dom/fetch/FetchStreamReader.h
new file mode 100644
index 0000000000..65d94d8cb0
--- /dev/null
+++ b/dom/fetch/FetchStreamReader.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef mozilla_dom_FetchStreamReader_h
+#define mozilla_dom_FetchStreamReader_h
+
+#include "js/RootingAPI.h"
+#include "js/TypeDecls.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/dom/FetchBinding.h"
+#include "mozilla/dom/PromiseNativeHandler.h"
+#include "nsIAsyncOutputStream.h"
+#include "nsIGlobalObject.h"
+
+namespace mozilla::dom {
+
+class ReadableStream;
+class ReadableStreamDefaultReader;
+class StrongWorkerRef;
+
+class FetchStreamReader final : public nsIOutputStreamCallback {
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(
+      FetchStreamReader, nsIOutputStreamCallback)
+  NS_DECL_NSIOUTPUTSTREAMCALLBACK
+
+  // This creates a nsIInputStream able to retrieve data from the ReadableStream
+  // object. The reading starts when StartConsuming() is called.
+  static nsresult Create(JSContext* aCx, nsIGlobalObject* aGlobal,
+                         FetchStreamReader** aStreamReader,
+                         nsIInputStream** aInputStream);
+
+  MOZ_CAN_RUN_SCRIPT
+  void ChunkSteps(JSContext* aCx, JS::Handle<JS::Value> aChunk,
+                  ErrorResult& aRv);
+  MOZ_CAN_RUN_SCRIPT
+  void CloseSteps(JSContext* aCx, ErrorResult& aRv);
+  MOZ_CAN_RUN_SCRIPT
+  void ErrorSteps(JSContext* aCx, JS::Handle<JS::Value> aError,
+                  ErrorResult& aRv);
+
+  // Idempotently close the output stream and null out all state. If aCx is
+  // provided, the reader will also be canceled.  aStatus must be a DOM error
+  // as understood by DOMException because it will be provided as the
+  // cancellation reason.
+  //
+  // This is a script boundary minimize annotation changes required while
+  // we figure out how to handle some more tricky annotation cases (for
+  // example, the destructor of this class. Tracking under Bug 1750656)
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY
+  void CloseAndRelease(JSContext* aCx, nsresult aStatus);
+
+  void StartConsuming(JSContext* aCx, ReadableStream* aStream,
+                      ErrorResult& aRv);
+
+ private:
+  explicit FetchStreamReader(nsIGlobalObject* aGlobal);
+  ~FetchStreamReader();
+
+  nsresult WriteBuffer();
+
+  // Attempt to copy data from mBuffer into mPipeOut. Returns `true` if data was
+  // written, and AsyncWait callbacks or FetchReadRequest calls have been set up
+  // to write more data in the future, and `false` otherwise.
+  MOZ_CAN_RUN_SCRIPT
+  bool Process(JSContext* aCx);
+
+  void ReportErrorToConsole(JSContext* aCx, JS::Handle<JS::Value> aValue);
+
+  nsCOMPtr<nsIGlobalObject> mGlobal;
+  nsCOMPtr<nsIEventTarget> mOwningEventTarget;
+
+  nsCOMPtr<nsIAsyncOutputStream> mPipeOut;
+
+  RefPtr<StrongWorkerRef> mWorkerRef;
+  RefPtr<StrongWorkerRef> mAsyncWaitWorkerRef;
+
+  RefPtr<ReadableStreamDefaultReader> mReader;
+
+  nsTArray<uint8_t> mBuffer;
+  uint32_t mBufferRemaining = 0;
+  uint32_t mBufferOffset = 0;
+
+  bool mHasOutstandingReadRequest = false;
+  bool mStreamClosed = false;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_FetchStreamReader_h