1 files changed, 123 insertions, 0 deletions
diff --git a/dom/file/ipc/RemoteLazyInputStream.h b/dom/file/ipc/RemoteLazyInputStream.h
new file mode 100644
index 0000000000..c36f63f4ab
--- /dev/null
+++ b/dom/file/ipc/RemoteLazyInputStream.h
@@ -0,0 +1,123 @@
+/* -*- 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_RemoteLazyInputStream_h
+#define mozilla_RemoteLazyInputStream_h
+
+#include "mozilla/Mutex.h"
+#include "mozIRemoteLazyInputStream.h"
+#include "nsIAsyncInputStream.h"
+#include "nsICloneableInputStream.h"
+#include "nsIFileStreams.h"
+#include "nsIIPCSerializableInputStream.h"
+#include "nsIInputStreamLength.h"
+#include "nsCOMPtr.h"
+
+namespace mozilla {
+
+class RemoteLazyInputStreamChild;
+
+class RemoteLazyInputStream final : public nsIAsyncInputStream,
+                                    public nsIInputStreamCallback,
+                                    public nsICloneableInputStreamWithRange,
+                                    public nsIIPCSerializableInputStream,
+                                    public nsIAsyncFileMetadata,
+                                    public nsIInputStreamLength,
+                                    public nsIAsyncInputStreamLength,
+                                    public mozIRemoteLazyInputStream {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+  NS_DECL_NSICLONEABLEINPUTSTREAM
+  NS_DECL_NSICLONEABLEINPUTSTREAMWITHRANGE
+  NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
+  NS_DECL_NSIFILEMETADATA
+  NS_DECL_NSIASYNCFILEMETADATA
+  NS_DECL_NSIINPUTSTREAMLENGTH
+  NS_DECL_NSIASYNCINPUTSTREAMLENGTH
+
+  explicit RemoteLazyInputStream(RemoteLazyInputStreamChild* aActor);
+
+  void StreamReady(already_AddRefed<nsIInputStream> aInputStream);
+
+  void LengthReady(int64_t aLength);
+
+  // mozIRemoteLazyInputStream
+  NS_IMETHOD_(nsIInputStream*) GetInternalStream() override {
+    if (mRemoteStream) {
+      return mRemoteStream;
+    }
+
+    if (mAsyncRemoteStream) {
+      return mAsyncRemoteStream;
+    }
+
+    return nullptr;
+  }
+
+ private:
+  ~RemoteLazyInputStream();
+
+  nsresult EnsureAsyncRemoteStream(const MutexAutoLock& aProofOfLock);
+
+  void InitWithExistingRange(uint64_t aStart, uint64_t aLength,
+                             const MutexAutoLock& aProofOfLock);
+
+  RefPtr<RemoteLazyInputStreamChild> mActor;
+
+  // This is the list of possible states.
+  enum {
+    // The initial state. Only ::Available() can be used without receiving an
+    // error. The available size is known by the actor.
+    eInit,
+
+    // AsyncWait() has been called for the first time. SendStreamNeeded() has
+    // been called and we are waiting for the 'real' inputStream.
+    ePending,
+
+    // When the child receives the stream from the parent, we move to this
+    // state. The received stream is stored in mRemoteStream. From now on, any
+    // method call will be forwared to mRemoteStream.
+    eRunning,
+
+    // If Close() or CloseWithStatus() is called, we move to this state.
+    // mRemoveStream is released and any method will return
+    // NS_BASE_STREAM_CLOSED.
+    eClosed,
+  } mState;
+
+  uint64_t mStart;
+  uint64_t mLength;
+
+  // Set to true if the stream is used via Read/ReadSegments or Close.
+  bool mConsumed;
+
+  nsCOMPtr<nsIInputStream> mRemoteStream;
+  nsCOMPtr<nsIAsyncInputStream> mAsyncRemoteStream;
+
+  // These 2 values are set only if mState is ePending.
+  nsCOMPtr<nsIInputStreamCallback> mInputStreamCallback;
+  nsCOMPtr<nsIEventTarget> mInputStreamCallbackEventTarget;
+
+  // These 2 values are set only if mState is ePending.
+  nsCOMPtr<nsIFileMetadataCallback> mFileMetadataCallback;
+  nsCOMPtr<nsIEventTarget> mFileMetadataCallbackEventTarget;
+
+  // These 2 values are set only when nsIAsyncInputStreamLength::asyncWait() is
+  // called.
+  nsCOMPtr<nsIInputStreamLengthCallback> mLengthCallback;
+  nsCOMPtr<nsIEventTarget> mLengthCallbackEventTarget;
+
+  // Any member of this class is protected by mutex because touched on
+  // multiple threads.
+  Mutex mMutex;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_RemoteLazyInputStream_h