netwerk/base/MemoryDownloader.h

   1 /* -*- Mode: C++; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_net_MemoryDownloader_h__
   7 #define mozilla_net_MemoryDownloader_h__
   8
   9 #include "mozilla/UniquePtr.h"
  10 #include "nsCOMPtr.h"
  11 #include "nsIStreamListener.h"
  12 #include "nsTArray.h"
  13
  14 /**
  15  * mozilla::net::MemoryDownloader
  16  *
  17  * This class is similar to nsIDownloader, but stores the downloaded
  18  * stream in memory instead of a file.  Ownership of the temporary
  19  * memory is transferred to the observer when download is complete;
  20  * there is no need to retain a reference to the downloader.
  21  */
  22
  23 namespace mozilla {
  24 namespace net {
  25
  26 class MemoryDownloader final : public nsIStreamListener {
  27  public:
  28   NS_DECL_ISUPPORTS
  29   NS_DECL_NSIREQUESTOBSERVER
  30   NS_DECL_NSISTREAMLISTENER
  31
  32   using Data = mozilla::UniquePtr<FallibleTArray<uint8_t>>;
  33
  34   class IObserver : public nsISupports {
  35    public:
  36     // Note: aData may be null if (and only if) aStatus indicates failure.
  37     virtual void OnDownloadComplete(MemoryDownloader* aDownloader,
  38                                     nsIRequest* aRequest, nsresult aStatus,
  39                                     Data aData) = 0;
  40   };
  41
  42   explicit MemoryDownloader(IObserver* aObserver);
  43
  44  private:
  45   virtual ~MemoryDownloader() = default;
  46
  47   static nsresult ConsumeData(nsIInputStream* in, void* closure,
  48                               const char* fromRawSegment, uint32_t toOffset,
  49                               uint32_t count, uint32_t* writeCount);
  50
  51   RefPtr<IObserver> mObserver;
  52   Data mData;
  53   nsresult mStatus;
  54 };
  55
  56 }  // namespace net
  57 }  // namespace mozilla
  58
  59 #endif  // mozilla_net_MemoryDownloader_h__