import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

image/DecodedSurfaceProvider.h

@@ -0,0 +1,89 @@
+/* -*- 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