// Copyright (c) 2008, Rodrigo Braz Monteiro, Fredrik Mellbin
// All rights reserved.
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/// @file video_provider_cache.h
/// @see video_provider_cache.cpp
/// @ingroup video_input
///

#include <boost/container/list.hpp>

#include "include/aegisub/video_provider.h"

#include <libaegisub/scoped_ptr.h>

struct CachedFrame;

/// @class VideoProviderCache
/// @brief A wrapper around a video provider which provides LRU caching
class VideoProviderCache : public VideoProvider {
	/// The source provider to get frames from
	agi::scoped_ptr<VideoProvider> master;

	/// @brief Maximum size of the cache in bytes
	///
	/// Note that this is a soft limit. The cache stops allocating new frames
	/// once it has exceeded the limit, but it never tries to shrink
	const size_t max_cache_size;

	/// Cache of video frames with the most recently used ones at the front
	boost::container::list<CachedFrame> cache;

public:
	VideoProviderCache(VideoProvider *master);
	~VideoProviderCache();

	const AegiVideoFrame GetFrame(int n);

	int GetFrameCount() const             { return master->GetFrameCount(); }
	int GetWidth() const                  { return master->GetWidth(); }
	int GetHeight() const                 { return master->GetHeight(); }
	double GetDAR() const                 { return master->GetDAR(); }
	agi::vfr::Framerate GetFPS() const    { return master->GetFPS(); }
	std::vector<int> GetKeyFrames() const { return master->GetKeyFrames(); }
	std::string GetWarning() const        { return master->GetWarning(); }
	std::string GetDecoderName() const    { return master->GetDecoderName(); }
	std::string GetColorSpace() const     { return master->GetColorSpace(); }
};