netwerk/base/nsStreamListenerWrapper.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   3  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef nsStreamListenerWrapper_h__
   6 #define nsStreamListenerWrapper_h__
   7
   8 #include "nsCOMPtr.h"
   9 #include "nsIRequest.h"
  10 #include "nsIStreamListener.h"
  11 #include "nsIThreadRetargetableStreamListener.h"
  12 #include "nsIMultiPartChannel.h"
  13 #include "mozilla/Attributes.h"
  14
  15 namespace mozilla {
  16 namespace net {
  17
  18 // Wrapper class to make replacement of nsHttpChannel's listener
  19 // from JavaScript possible. It is workaround for bug 433711 and 682305.
  20 class nsStreamListenerWrapper final
  21     : public nsIMultiPartChannelListener,
  22       public nsIThreadRetargetableStreamListener {
  23  public:
  24   explicit nsStreamListenerWrapper(nsIStreamListener* listener)
  25       : mListener(listener) {
  26     MOZ_ASSERT(mListener, "no stream listener specified");
  27   }
  28
  29   NS_DECL_THREADSAFE_ISUPPORTS
  30   NS_FORWARD_SAFE_NSISTREAMLISTENER(mListener)
  31   NS_DECL_NSIMULTIPARTCHANNELLISTENER
  32   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
  33
  34   //  Don't use NS_FORWARD_NSIREQUESTOBSERVER(mListener->) here, because we need
  35   //  to release mListener in OnStopRequest, and IDL-generated function doesn't.
  36   NS_IMETHOD OnStartRequest(nsIRequest* aRequest) override {
  37     // OnStartRequest can come after OnStopRequest in certain cases (multipart
  38     // listeners)
  39     nsCOMPtr<nsIMultiPartChannel> multiPartChannel =
  40         do_QueryInterface(aRequest);
  41     if (multiPartChannel) {
  42       mIsMulti = true;
  43     }
  44     return mListener->OnStartRequest(aRequest);
  45   }
  46   NS_IMETHOD OnStopRequest(nsIRequest* aRequest,
  47                            nsresult aStatusCode) override {
  48     nsresult rv = mListener->OnStopRequest(aRequest, aStatusCode);
  49     if (!mIsMulti) {
  50       // Multipart channels can call OnStartRequest again
  51       mListener = nullptr;
  52     }
  53     return rv;
  54   }
  55
  56  private:
  57   bool mIsMulti{false};
  58   ~nsStreamListenerWrapper() = default;
  59   nsCOMPtr<nsIStreamListener> mListener;
  60 };
  61
  62 }  // namespace net
  63 }  // namespace mozilla
  64
  65 #endif  // nsStreamListenerWrapper_h__