/* -*- 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_ipc_IPCBlobInputStream_h

#define mozilla_dom_ipc_IPCBlobInputStream_h

#include "mozilla/Mutex.h"

#include "nsIAsyncInputStream.h"

#include "nsICloneableInputStream.h"

#include "nsIFileStreams.h"

#include "nsIIPCSerializableInputStream.h"

#include "nsIInputStreamLength.h"

#include "nsCOMPtr.h"

namespace mozilla {

namespace dom {

class IPCBlobInputStreamChild;

#define IPCBLOBINPUTSTREAM_IID \

  { 0xbcfa38fc, 0x8b7f, 0x4d79, \

    { 0xbe, 0x3a, 0x1e, 0x7b, 0xbe, 0x52, 0x38, 0xcd } }

class nsIIPCBlobInputStream : public nsISupports

{

public:

  NS_DECLARE_STATIC_IID_ACCESSOR(IPCBLOBINPUTSTREAM_IID)

  virtual nsIInputStream*

  GetInternalStream() const = 0;

};

NS_DEFINE_STATIC_IID_ACCESSOR(nsIIPCBlobInputStream,

                              IPCBLOBINPUTSTREAM_IID)

class IPCBlobInputStream final : public nsIAsyncInputStream

                               , public nsIInputStreamCallback

                               , public nsICloneableInputStreamWithRange

                               , public nsIIPCSerializableInputStream

                               , public nsIAsyncFileMetadata

                               , public nsIInputStreamLength

                               , public nsIAsyncInputStreamLength

                               , public nsIIPCBlobInputStream

{

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 IPCBlobInputStream(IPCBlobInputStreamChild* aActor);

  void

  StreamReady(already_AddRefed<nsIInputStream> aInputStream);

  void

  LengthReady(int64_t aLength);

  // nsIIPCBlobInputStream

  nsIInputStream*

  GetInternalStream() const override

  {

    if (mRemoteStream) {

     return mRemoteStream;

    }

    if (mAsyncRemoteStream) {

      return mAsyncRemoteStream;

    }

    return nullptr;

  }

private:

  ~IPCBlobInputStream();

  nsresult

  EnsureAsyncRemoteStream(const MutexAutoLock& aProofOfLock);

  void

  InitWithExistingRange(uint64_t aStart, uint64_t aLength,

                        const MutexAutoLock& aProofOfLock);

  RefPtr<IPCBlobInputStreamChild> 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 dom

} // namespace mozilla

#endif // mozilla_dom_ipc_IPCBlobInputStream_h