/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 nsInputStreamPump_h__
#define nsInputStreamPump_h__

#include "nsIInputStreamPump.h"
#include "nsIAsyncInputStream.h"
#include "nsIThreadRetargetableRequest.h"
#include "nsCOMPtr.h"
#include "mozilla/Attributes.h"
#include "mozilla/RecursiveMutex.h"

class nsIInputStream;
class nsILoadGroup;
class nsIStreamListener;

class nsInputStreamPump final : public nsIInputStreamPump,
                                public nsIInputStreamCallback,
                                public nsIThreadRetargetableRequest {
  ~nsInputStreamPump() = default;

 public:
  typedef mozilla::RecursiveMutexAutoLock RecursiveMutexAutoLock;
  typedef mozilla::RecursiveMutexAutoUnlock RecursiveMutexAutoUnlock;
  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIREQUEST
  NS_DECL_NSIINPUTSTREAMPUMP
  NS_DECL_NSIINPUTSTREAMCALLBACK
  NS_DECL_NSITHREADRETARGETABLEREQUEST

  nsInputStreamPump();

  static nsresult Create(nsInputStreamPump **result, nsIInputStream *stream,
                         uint32_t segsize = 0, uint32_t segcount = 0,
                         bool closeWhenDone = false,
                         nsIEventTarget *mainThreadTarget = nullptr);

  typedef void (*PeekSegmentFun)(void *closure, const uint8_t *buf,
                                 uint32_t bufLen);
  /**
   * Peek into the first chunk of data that's in the stream. Note that this
   * method will not call the callback when there is no data in the stream.
   * The callback will be called at most once.
   *
   * The data from the stream will not be consumed, i.e. the pump's listener
   * can still read all the data.
   *
   * Do not call before asyncRead. Do not call after onStopRequest.
   */
  nsresult PeekStream(PeekSegmentFun callback, void *closure);

  /**
   * Dispatched (to the main thread) by OnStateStop if it's called off main
   * thread. Updates mState based on return value of OnStateStop.
   */
  nsresult CallOnStateStop();

 protected:
  enum { STATE_IDLE, STATE_START, STATE_TRANSFER, STATE_STOP };

  nsresult EnsureWaiting();
  uint32_t OnStateStart();
  uint32_t OnStateTransfer();
  uint32_t OnStateStop();
  nsresult CreateBufferedStreamIfNeeded();

  uint32_t mState;
  nsCOMPtr<nsILoadGroup> mLoadGroup;
  nsCOMPtr<nsIStreamListener> mListener;
  nsCOMPtr<nsIEventTarget> mTargetThread;
  nsCOMPtr<nsIEventTarget> mLabeledMainThreadTarget;
  nsCOMPtr<nsIInputStream> mStream;
  nsCOMPtr<nsIAsyncInputStream> mAsyncStream;
  uint64_t mStreamOffset;
  uint64_t mStreamLength;
  uint32_t mSegSize;
  uint32_t mSegCount;
  nsresult mStatus;
  uint32_t mSuspendCount;
  uint32_t mLoadFlags;
  bool mIsPending;
  // True while in OnInputStreamReady, calling OnStateStart, OnStateTransfer
  // and OnStateStop. Used to prevent calls to AsyncWait during callbacks.
  bool mProcessingCallbacks;
  // True if waiting on the "input stream ready" callback.
  bool mWaitingForInputStreamReady;
  bool mCloseWhenDone;
  bool mRetargeting;
  bool mAsyncStreamIsBuffered;
  // Protects state/member var accesses across multiple threads.
  mozilla::RecursiveMutex mMutex;
};

#endif  // !nsInputStreamChannel_h__