spiderweb/image/DecodedSurfaceProvider.h

90 строки
2.6 KiB
C++

/* -*- 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 ISurfaceProvider implemented for single-frame decoded surfaces.
*/
#ifndef mozilla_image_DecodedSurfaceProvider_h
#define mozilla_image_DecodedSurfaceProvider_h
#include "IDecodingTask.h"
#include "ISurfaceProvider.h"
#include "SurfaceCache.h"
namespace mozilla {
namespace image {
/**
* An ISurfaceProvider that manages the decoding of a single-frame image and
* stores the resulting surface.
*/
class DecodedSurfaceProvider final
: public ISurfaceProvider
, public IDecodingTask
{
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(DecodedSurfaceProvider, override)
DecodedSurfaceProvider(NotNull<RasterImage*> aImage,
const SurfaceKey& aSurfaceKey,
NotNull<Decoder*> aDecoder);
//////////////////////////////////////////////////////////////////////////////
// ISurfaceProvider implementation.
//////////////////////////////////////////////////////////////////////////////
public:
bool IsFinished() const override;
size_t LogicalSizeInBytes() const override;
protected:
DrawableFrameRef DrawableRef(size_t aFrame) override;
bool IsLocked() const override { return bool(mLockRef); }
void SetLocked(bool aLocked) override;
//////////////////////////////////////////////////////////////////////////////
// IDecodingTask implementation.
//////////////////////////////////////////////////////////////////////////////
public:
void Run() override;
bool ShouldPreferSyncRun() const override;
// Full decodes are low priority compared to metadata decodes because they
// don't block layout or page load.
TaskPriority Priority() const override { return TaskPriority::eLow; }
private:
virtual ~DecodedSurfaceProvider();
void DropImageReference();
void CheckForNewSurface();
void FinishDecoding();
/// The image associated with our decoder. Dropped after decoding.
RefPtr<RasterImage> mImage;
/// Mutex protecting access to mDecoder.
Mutex mMutex;
/// The decoder that will generate our surface. Dropped after decoding.
RefPtr<Decoder> mDecoder;
/// Our surface. Initially null until it's generated by the decoder.
RefPtr<imgFrame> mSurface;
/// A drawable reference to our service; used for locking.
DrawableFrameRef mLockRef;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_DecodedSurfaceProvider_h