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// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CC_TILES_DECODED_IMAGE_TRACKER_H_
#define CC_TILES_DECODED_IMAGE_TRACKER_H_
#include <utility>
#include <vector>
#include "base/bind.h"
#include "base/time/tick_clock.h"
#include "base/time/time.h"
#include "cc/cc_export.h"
#include "cc/tiles/image_controller.h"
namespace cc {
// This class is the main interface for the rest of the system to request
// decodes. It is responsible for keeping the decodes locked for a number of
// frames, specified as |kNumFramesToLock| in the implementation file.
//
// Note that it is safe to replace ImageController's cache without doing
// anything special with this class, since it retains only ids to the decode
// requests. When defunct ids are then used to try and unlock the image, they
// are silently ignored.
class CC_EXPORT DecodedImageTracker {
public:
explicit DecodedImageTracker(
ImageController* controller,
scoped_refptr<base::SequencedTaskRunner> task_runner);
DecodedImageTracker(const DecodedImageTracker&) = delete;
~DecodedImageTracker();
DecodedImageTracker& operator=(const DecodedImageTracker&) = delete;
// Request that the given image be decoded. This issues a callback upon
// completion. The callback takes a bool indicating whether the decode was
// successful or not.
void QueueImageDecode(const PaintImage& image,
const gfx::ColorSpace& target_color_space,
base::OnceCallback<void(bool)> callback);
// Unlock all locked images - used to respond to memory pressure or
// application background.
void UnlockAllImages();
// Notifies the tracker that images have been used, allowing it to
// unlock them.
void OnImagesUsedInDraw(const std::vector<DrawImage>& draw_images);
void SetTickClockForTesting(const base::TickClock* tick_clock) {
tick_clock_ = tick_clock;
}
// Test only functions:
size_t NumLockedImagesForTesting() const { return locked_images_.size(); }
private:
friend class DecodedImageTrackerTest;
void ImageDecodeFinished(base::OnceCallback<void(bool)> callback,
PaintImage::Id image_id,
ImageController::ImageDecodeRequestId request_id,
ImageController::ImageDecodeResult result);
void OnTimeoutImages();
void EnqueueTimeout();
ImageController* image_controller_;
// Helper class tracking a locked image decode. Automatically releases the
// lock using the provided DecodedImageTracker* on destruction.
class ImageLock {
public:
ImageLock(DecodedImageTracker* tracker,
ImageController::ImageDecodeRequestId request_id,
base::TimeTicks lock_time);
ImageLock(const ImageLock&) = delete;
~ImageLock();
ImageLock& operator=(const ImageLock&) = delete;
base::TimeTicks lock_time() const { return lock_time_; }
private:
DecodedImageTracker* tracker_;
ImageController::ImageDecodeRequestId request_id_;
base::TimeTicks lock_time_;
};
base::flat_map<PaintImage::Id, std::unique_ptr<ImageLock>> locked_images_;
bool timeout_pending_ = false;
scoped_refptr<base::SequencedTaskRunner> task_runner_;
// Defaults to base::TimeTicks::Now(), but overrideable for testing.
const base::TickClock* tick_clock_;
base::WeakPtrFactory<DecodedImageTracker> weak_ptr_factory_{this};
};
} // namespace cc
#endif // CC_TILES_DECODED_IMAGE_TRACKER_H_