/* -*- 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/. */ /** * An interface for tasks which can execute on the ImageLib DecodePool, and * various implementations. */ #ifndef mozilla_image_IDecodingTask_h #define mozilla_image_IDecodingTask_h #include "mozilla/NotNull.h" #include "mozilla/RefPtr.h" #include "imgFrame.h" #include "SourceBuffer.h" namespace mozilla { namespace image { class Decoder; class RasterImage; /// A priority hint that DecodePool can use when scheduling an IDecodingTask. enum class TaskPriority : uint8_t { eLow, eHigh }; /** * An interface for tasks which can execute on the ImageLib DecodePool. */ class IDecodingTask : public IResumable { public: /// Run the task. virtual void Run() = 0; /// @return true if, given the option, this task prefers to run synchronously. virtual bool ShouldPreferSyncRun() const = 0; /// @return a priority hint that DecodePool can use when scheduling this task. virtual TaskPriority Priority() const = 0; /// A default implementation of IResumable which resubmits the task to the /// DecodePool. Subclasses can override this if they need different behavior. void Resume() override; protected: /// Notify @aImage of @aDecoder's progress. static void NotifyProgress(NotNull<RasterImage*> aImage, NotNull<Decoder*> aDecoder); /// Notify @aImage that @aDecoder has finished. static void NotifyDecodeComplete(NotNull<RasterImage*> aImage, NotNull<Decoder*> aDecoder); virtual ~IDecodingTask() { } }; /** * An IDecodingTask implementation for metadata decodes of images. */ class MetadataDecodingTask final : public IDecodingTask { public: NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MetadataDecodingTask, override) explicit MetadataDecodingTask(NotNull<Decoder*> aDecoder); void Run() override; // Metadata decodes are very fast (since they only need to examine an image's // header) so there's no reason to refuse to run them synchronously if the // caller will allow us to. bool ShouldPreferSyncRun() const override { return true; } // Metadata decodes run at the highest priority because they block layout and // page load. TaskPriority Priority() const override { return TaskPriority::eHigh; } private: virtual ~MetadataDecodingTask() { } /// Mutex protecting access to mDecoder. Mutex mMutex; NotNull<RefPtr<Decoder>> mDecoder; }; /** * An IDecodingTask implementation for anonymous decoders - that is, decoders * with no associated Image object. */ class AnonymousDecodingTask final : public IDecodingTask { public: NS_INLINE_DECL_THREADSAFE_REFCOUNTING(AnonymousDecodingTask, override) explicit AnonymousDecodingTask(NotNull<Decoder*> aDecoder); void Run() override; bool ShouldPreferSyncRun() const override { return true; } TaskPriority Priority() const override { return TaskPriority::eLow; } // Anonymous decoders normally get all their data at once. We have tests where // they don't; in these situations, the test re-runs them manually. So no // matter what, we don't want to resume by posting a task to the DecodePool. void Resume() override { } private: virtual ~AnonymousDecodingTask() { } NotNull<RefPtr<Decoder>> mDecoder; }; } // namespace image } // namespace mozilla #endif // mozilla_image_IDecodingTask_h