1 files changed, 205 insertions, 0 deletions
diff --git a/dom/base/BodyStream.h b/dom/base/BodyStream.h
new file mode 100644
index 0000000000..bb627ff9be
--- /dev/null
+++ b/dom/base/BodyStream.h
@@ -0,0 +1,205 @@
+/* -*- 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_BodyStream_h
+#define mozilla_dom_BodyStream_h
+
+#include "jsapi.h"
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/dom/ByteStreamHelpers.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "nsIAsyncInputStream.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsIObserver.h"
+#include "nsISupportsImpl.h"
+#include "nsNetCID.h"
+#include "nsWeakReference.h"
+#include "mozilla/Mutex.h"
+
+class nsIGlobalObject;
+
+class nsIInputStream;
+
+namespace mozilla {
+class ErrorResult;
+
+namespace dom {
+
+class BodyStream;
+class StrongWorkerRef;
+class ReadableStream;
+class ReadableStreamController;
+
+class BodyStreamUnderlyingSourceAlgorithms;
+
+class BodyStreamHolder : public nsISupports {
+  friend class BodyStream;
+  friend class BodyStreamUnderlyingSourceAlgorithms;
+  friend class BodyStreamUnderlyingSourceErrorCallbackHelper;
+
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS(BodyStreamHolder)
+
+  BodyStreamHolder();
+
+  virtual void NullifyStream() = 0;
+
+  virtual void MarkAsRead() = 0;
+
+  virtual void SetReadableStreamBody(ReadableStream* aBody) = 0;
+  virtual ReadableStream* GetReadableStreamBody() = 0;
+
+ protected:
+  virtual ~BodyStreamHolder() = default;
+
+ private:
+  void StoreBodyStream(BodyStream* aBodyStream);
+  already_AddRefed<BodyStream> TakeBodyStream() {
+    MOZ_ASSERT_IF(mStreamCreated, mBodyStream);
+    return mBodyStream.forget();
+  }
+  BodyStream* GetBodyStream() { return mBodyStream; }
+
+  RefPtr<BodyStream> mBodyStream;
+
+#ifdef DEBUG
+  bool mStreamCreated = false;
+#endif
+};
+
+class BodyStream final : public nsIInputStreamCallback,
+                         public nsIObserver,
+                         public nsSupportsWeakReference,
+                         public SingleWriterLockOwner {
+  friend class BodyStreamHolder;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+  NS_DECL_NSIOBSERVER
+
+  // This method creates a JS ReadableStream object and it assigns it to the
+  // aStreamHolder calling SetReadableStreamBody().
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY
+  static void Create(JSContext* aCx, BodyStreamHolder* aStreamHolder,
+                     nsIGlobalObject* aGlobal, nsIInputStream* aInputStream,
+                     ErrorResult& aRv);
+
+  void Close();
+
+  bool OnWritingThread() const override {
+#ifdef MOZ_THREAD_SAFETY_OWNERSHIP_CHECKS_SUPPORTED
+    return _mOwningThread.IsCurrentThread();
+#else
+    return true;
+#endif
+  }
+
+  static nsresult RetrieveInputStream(BodyStreamHolder* aStream,
+                                      nsIInputStream** aInputStream);
+
+ private:
+  BodyStream(nsIGlobalObject* aGlobal, BodyStreamHolder* aStreamHolder,
+             nsIInputStream* aInputStream);
+  ~BodyStream() = default;
+
+#ifdef DEBUG
+  void AssertIsOnOwningThread() const;
+#else
+  void AssertIsOnOwningThread() const {}
+#endif
+
+ public:
+  // Pull Callback
+  already_AddRefed<Promise> PullCallback(JSContext* aCx,
+                                         ReadableStreamController& aController,
+                                         ErrorResult& aRv);
+
+  void CloseInputAndReleaseObjects();
+
+ private:
+  // Fills a buffer with bytes from the stream.
+  void WriteIntoReadRequestBuffer(JSContext* aCx, ReadableStream* aStream,
+                                  JS::Handle<JSObject*> aBuffer,
+                                  uint32_t aLength, uint32_t* aByteWritten);
+
+  // This is a script boundary until Bug 1750605 is resolved and allows us
+  // to replace this with MOZ_CAN_RUN_SCRIPT.
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY void EnqueueChunkWithSizeIntoStream(
+      JSContext* aCx, ReadableStream* aStream, uint64_t bytes,
+      ErrorResult& aRv);
+
+  void ErrorPropagation(JSContext* aCx,
+                        const MutexSingleWriterAutoLock& aProofOfLock,
+                        ReadableStream* aStream, nsresult aError)
+      MOZ_REQUIRES(mMutex);
+
+  // TODO: convert this to MOZ_CAN_RUN_SCRIPT (bug 1750605)
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY void CloseAndReleaseObjects(
+      JSContext* aCx, const MutexSingleWriterAutoLock& aProofOfLock,
+      ReadableStream* aStream) MOZ_REQUIRES(mMutex);
+
+  class WorkerShutdown;
+
+  void ReleaseObjects(const MutexSingleWriterAutoLock& aProofOfLock)
+      MOZ_REQUIRES(mMutex);
+
+  void ReleaseObjects();
+
+  // Common methods
+
+  enum State {
+    // This is the beginning state before any reading operation.
+    eInitializing,
+
+    // RequestDataCallback has not been called yet. We haven't started to read
+    // data from the stream yet.
+    eWaiting,
+
+    // We are reading data in a separate I/O thread.
+    eReading,
+
+    // We are ready to write something in the JS Buffer.
+    eWriting,
+
+    // After a writing, we want to check if the stream is closed. After the
+    // check, we go back to eWaiting. If a reading request happens in the
+    // meantime, we move to eReading state.
+    eChecking,
+
+    // Operation completed.
+    eClosed,
+  };
+
+  // We need a mutex because JS engine can release BodyStream on a non-owning
+  // thread. We must be sure that the releasing of resources doesn't trigger
+  // race conditions.
+  MutexSingleWriter mMutex;
+
+  // Protected by mutex.
+  State mState MOZ_GUARDED_BY(mMutex);  // all writes are from the owning thread
+
+  // mGlobal is set on creation, and isn't modified off the owning thread.
+  // It isn't set to nullptr until ReleaseObjects() runs.
+  nsCOMPtr<nsIGlobalObject> mGlobal;
+  RefPtr<BodyStreamHolder> mStreamHolder MOZ_GUARDED_BY(mMutex);
+  nsCOMPtr<nsIEventTarget> mOwningEventTarget;
+
+  // This is the original inputStream received during the CTOR. It will be
+  // converted into an nsIAsyncInputStream and stored into mInputStream at the
+  // first use.
+  nsCOMPtr<nsIInputStream> mOriginalInputStream;
+  nsCOMPtr<nsIAsyncInputStream> mInputStream;
+
+  RefPtr<StrongWorkerRef> mWorkerRef;
+  RefPtr<StrongWorkerRef> mAsyncWaitWorkerRef;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_BodyStream_h