dom/media/mediacontrol/FetchImageHelper.cpp

   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
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "FetchImageHelper.h"
   6
   7 #include "mozilla/gfx/2D.h"
   8 #include "mozilla/Logging.h"
   9 #include "mozilla/NullPrincipal.h"
  10 #include "nsIChannel.h"
  11 #include "nsNetUtil.h"
  12
  13 mozilla::LazyLogModule gFetchImageLog("FetchImageHelper");
  14
  15 #undef LOG
  16 #define LOG(msg, ...)                      \
  17   MOZ_LOG(gFetchImageLog, LogLevel::Debug, \
  18           ("FetchImageHelper=%p, " msg, this, ##__VA_ARGS__))
  19
  20 using namespace mozilla::gfx;
  21
  22 namespace mozilla::dom {
  23
  24 FetchImageHelper::FetchImageHelper(const MediaImage& aImage)
  25     : mSrc(aImage.mSrc) {}
  26
  27 FetchImageHelper::~FetchImageHelper() { AbortFetchingImage(); }
  28
  29 RefPtr<ImagePromise> FetchImageHelper::FetchImage() {
  30   MOZ_ASSERT(NS_IsMainThread());
  31   if (IsFetchingImage()) {
  32     return mPromise.Ensure(__func__);
  33   }
  34
  35   LOG("Start fetching image from %s", NS_ConvertUTF16toUTF8(mSrc).get());
  36   nsCOMPtr<nsIURI> uri;
  37   if (NS_FAILED(NS_NewURI(getter_AddRefs(uri), mSrc))) {
  38     LOG("Failed to create URI");
  39     return ImagePromise::CreateAndReject(false, __func__);
  40   }
  41
  42   MOZ_ASSERT(!mListener);
  43   mListener = new ImageFetchListener();
  44   if (NS_FAILED(mListener->FetchDecodedImageFromURI(uri, this))) {
  45     LOG("Failed to decode image from async channel");
  46     return ImagePromise::CreateAndReject(false, __func__);
  47   }
  48   return mPromise.Ensure(__func__);
  49 }
  50
  51 void FetchImageHelper::AbortFetchingImage() {
  52   MOZ_ASSERT(NS_IsMainThread());
  53   LOG("AbortFetchingImage");
  54   mPromise.RejectIfExists(false, __func__);
  55   ClearListenerIfNeeded();
  56 }
  57
  58 void FetchImageHelper::ClearListenerIfNeeded() {
  59   if (mListener) {
  60     mListener->Clear();
  61     mListener = nullptr;
  62   }
  63 }
  64
  65 bool FetchImageHelper::IsFetchingImage() const {
  66   MOZ_ASSERT(NS_IsMainThread());
  67   return !mPromise.IsEmpty() && mListener;
  68 }
  69
  70 void FetchImageHelper::HandleFetchSuccess(imgIContainer* aImage) {
  71   MOZ_ASSERT(aImage);
  72   MOZ_ASSERT(NS_IsMainThread());
  73   MOZ_ASSERT(IsFetchingImage());
  74   LOG("Finished fetching image");
  75   mPromise.Resolve(aImage, __func__);
  76   ClearListenerIfNeeded();
  77 }
  78
  79 void FetchImageHelper::HandleFetchFail() {
  80   MOZ_ASSERT(NS_IsMainThread());
  81   MOZ_ASSERT(IsFetchingImage());
  82   LOG("Reject the promise because of fetching failed");
  83   mPromise.RejectIfExists(false, __func__);
  84   ClearListenerIfNeeded();
  85 }
  86
  87 /**
  88  * Implementation for FetchImageHelper::ImageFetchListener
  89  */
  90 NS_IMPL_ISUPPORTS(FetchImageHelper::ImageFetchListener, imgIContainerCallback)
  91
  92 FetchImageHelper::ImageFetchListener::~ImageFetchListener() {
  93   MOZ_ASSERT(NS_IsMainThread());
  94   MOZ_ASSERT(!mHelper, "Cancel() should be called before desturction!");
  95 }
  96
  97 nsresult FetchImageHelper::ImageFetchListener::FetchDecodedImageFromURI(
  98     nsIURI* aURI, FetchImageHelper* aHelper) {
  99   MOZ_ASSERT(!mHelper && !mChannel,
 100              "Should call Clear() berfore running another fetching process!");
 101   RefPtr<nsIPrincipal> nullPrincipal =
 102       NullPrincipal::CreateWithoutOriginAttributes();
 103   nsCOMPtr<nsIChannel> channel;
 104   nsresult rv =
 105       NS_NewChannel(getter_AddRefs(channel), aURI, nullPrincipal,
 106                     nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
 107                     nsIContentPolicy::TYPE_INTERNAL_IMAGE, nullptr, nullptr,
 108                     nullptr, nullptr, nsIRequest::LOAD_ANONYMOUS);
 109   if (NS_FAILED(rv)) {
 110     return rv;
 111   }
 112
 113   nsCOMPtr<imgITools> imgTools = do_GetService("@mozilla.org/image/tools;1");
 114   if (!imgTools) {
 115     return NS_ERROR_FAILURE;
 116   }
 117
 118   rv = imgTools->DecodeImageFromChannelAsync(aURI, channel, this, nullptr);
 119   if (NS_FAILED(rv)) {
 120     return NS_ERROR_FAILURE;
 121   }
 122   MOZ_ASSERT(aHelper);
 123   mHelper = aHelper;
 124   mChannel = channel;
 125   return NS_OK;
 126 }
 127
 128 void FetchImageHelper::ImageFetchListener::Clear() {
 129   MOZ_ASSERT(NS_IsMainThread());
 130   if (mChannel) {
 131     mChannel->CancelWithReason(
 132         NS_BINDING_ABORTED, "FetchImageHelper::ImageFetchListener::Clear"_ns);
 133     mChannel = nullptr;
 134   }
 135   mHelper = nullptr;
 136 }
 137
 138 bool FetchImageHelper::ImageFetchListener::IsFetchingImage() const {
 139   MOZ_ASSERT(NS_IsMainThread());
 140   return mHelper ? mHelper->IsFetchingImage() : false;
 141 }
 142
 143 NS_IMETHODIMP FetchImageHelper::ImageFetchListener::OnImageReady(
 144     imgIContainer* aImage, nsresult aStatus) {
 145   MOZ_ASSERT(NS_IsMainThread());
 146   if (!IsFetchingImage()) {
 147     return NS_OK;
 148   }
 149   // We have received image, so we don't need the channel anymore.
 150   mChannel = nullptr;
 151
 152   MOZ_ASSERT(mHelper);
 153   if (NS_FAILED(aStatus) || !aImage) {
 154     mHelper->HandleFetchFail();
 155     Clear();
 156     return aStatus;
 157   }
 158
 159   mHelper->HandleFetchSuccess(aImage);
 160
 161   return NS_OK;
 162 }
 163
 164 }  // namespace mozilla::dom