This class is a disk-based cache manager for Frame objects. More...

#include <CacheDisk.h>

Inheritance diagram for openshot::CacheDisk:

Collaboration diagram for openshot::CacheDisk:

Public Member Functions
void	Add (std::shared_ptr< openshot::Frame > frame)
	Add a Frame to the cache. More...

	CacheDisk (std::string cache_path, std::string format, float quality, float scale)
	Default constructor, no max bytes. More...

	CacheDisk (std::string cache_path, std::string format, float quality, float scale, int64_t max_bytes)
	Constructor that sets the max bytes to cache. More...

void	Clear ()
	Clear the cache of all frames. More...

bool	Contains (int64_t frame_number)
	Check if frame is already contained in cache. More...

int64_t	Count ()
	Count the frames in the queue. More...

int64_t	GetBytes ()
	Gets the maximum bytes value. More...

std::shared_ptr< openshot::Frame >	GetFrame (int64_t frame_number)
	Get a frame from the cache. More...

std::vector< std::shared_ptr< openshot::Frame > >	GetFrames ()
	Get an array of all Frames. More...

std::shared_ptr< openshot::Frame >	GetSmallestFrame ()
	Get the smallest frame number. More...

std::string	Json ()
	Generate JSON string of this object. More...

Json::Value	JsonValue ()
	Generate Json::Value for this object. More...

void	MoveToFront (int64_t frame_number)
	Move frame to front of queue (so it lasts longer) More...

void	Remove (int64_t frame_number)
	Remove a specific frame. More...

void	Remove (int64_t start_frame_number, int64_t end_frame_number)
	Remove a range of frames. More...

void	SetJson (const std::string value)
	Load JSON string into this object. More...

void	SetJsonValue (const Json::Value root)
	Load Json::Value into this object. More...

	~CacheDisk ()

Public Member Functions inherited from openshot::CacheBase
	CacheBase ()
	Default constructor, no max bytes. More...

	CacheBase (int64_t max_bytes)
	Constructor that sets the max bytes to cache. More...

int64_t	GetMaxBytes ()
	Gets the maximum bytes value. More...

void	SetMaxBytes (int64_t number_of_bytes)
	Set maximum bytes to a different amount. More...

void	SetMaxBytesFromInfo (int64_t number_of_frames, int width, int height, int sample_rate, int channels)
	Set maximum bytes to a different amount based on a ReaderInfo struct. More...

virtual	~CacheBase ()=default

Additional Inherited Members
Protected Member Functions inherited from openshot::CacheBase
void	CalculateRanges ()
	Calculate ranges of frames. More...

Protected Attributes inherited from openshot::CacheBase
std::string	cache_type
	This is a friendly type name of the derived cache instance. More...

std::recursive_mutex *	cacheMutex
	Mutex for multiple threads. More...

std::map< int64_t, int64_t >	frame_ranges
	This map holds the ranges of frames, useful for quickly displaying the contents of the cache. More...

std::string	json_ranges
	JSON ranges of frame numbers. More...

int64_t	max_bytes
	This is the max number of bytes to cache (0 = no limit) More...

bool	needs_range_processing
	Something has changed, and the range data needs to be re-calculated. More...

std::vector< int64_t >	ordered_frame_numbers
	Ordered list of frame numbers used by cache. More...

int64_t	range_version
	The version of the JSON range data (incremented with each change) More...

Detailed Description

This class is a disk-based cache manager for Frame objects.

It is used by the Timeline class, if enabled, to cache video and audio frames to disk, to cut down on CPU and memory utilization. This will thrash a user's disk, but save their memory and CPU. It's a trade off that sometimes makes perfect sense. You can also set the max number of bytes to cache.

Definition at line 30 of file CacheDisk.h.

Constructor & Destructor Documentation

◆ CacheDisk() [1/2]

CacheDisk::CacheDisk	(	std::string	cache_path,
		std::string	format,
		float	quality,
		float	scale
	)

Default constructor, no max bytes.

Parameters

cache_path	The folder path of the cache directory (empty string = /tmp/preview-cache/)
format	The image format for disk caching (ppm, jpg, png)
quality	The quality of the image (1.0=highest quality/slowest speed, 0.0=worst quality/fastest speed)
scale	The scale factor for the preview images (1.0 = original size, 0.5=half size, 0.25=quarter size, etc...)

Definition at line 26 of file CacheDisk.cpp.

◆ CacheDisk() [2/2]

CacheDisk::CacheDisk	(	std::string	cache_path,
		std::string	format,
		float	quality,
		float	scale,
		int64_t	max_bytes
	)

Constructor that sets the max bytes to cache.

Parameters

cache_path	The folder path of the cache directory (empty string = /tmp/preview-cache/)
format	The image format for disk caching (ppm, jpg, png)
quality	The quality of the image (1.0=highest quality/slowest speed, 0.0=worst quality/fastest speed)
scale	The scale factor for the preview images (1.0 = original size, 0.5=half size, 0.25=quarter size, etc...)
max_bytes	The maximum bytes to allow in the cache. Once exceeded, the cache will purge the oldest frames.

Definition at line 42 of file CacheDisk.cpp.

◆ ~CacheDisk()

CacheDisk::~CacheDisk ( )

Definition at line 79 of file CacheDisk.cpp.

Member Function Documentation

◆ Add()

void CacheDisk::Add ( std::shared_ptr< openshot::Frame > frame )

virtual

Add a Frame to the cache.

Parameters

frame The openshot::Frame object needing to be cached.

Implements openshot::CacheBase.

Definition at line 88 of file CacheDisk.cpp.

◆ Clear()

void CacheDisk::Clear ( )

virtual

Clear the cache of all frames.

Implements openshot::CacheBase.

Definition at line 363 of file CacheDisk.cpp.

Referenced by SetJsonValue(), and ~CacheDisk().

◆ Contains()

bool CacheDisk::Contains ( int64_t frame_number )

virtual

Check if frame is already contained in cache.

Parameters

frame_number The frame number to be checked

Implements openshot::CacheBase.

Definition at line 147 of file CacheDisk.cpp.

◆ Count()

int64_t CacheDisk::Count ( )

virtual

Count the frames in the queue.

Implements openshot::CacheBase.

Definition at line 386 of file CacheDisk.cpp.

◆ GetBytes()

int64_t CacheDisk::GetBytes ( )

virtual

Gets the maximum bytes value.

Implements openshot::CacheBase.

Definition at line 266 of file CacheDisk.cpp.

◆ GetFrame()

std::shared_ptr< Frame > CacheDisk::GetFrame ( int64_t frame_number )

virtual

Get a frame from the cache.

Parameters

frame_number The frame number of the cached frame

Implements openshot::CacheBase.

Definition at line 156 of file CacheDisk.cpp.

Referenced by GetFrames(), and GetSmallestFrame().

◆ GetFrames()

std::vector< std::shared_ptr< openshot::Frame > > CacheDisk::GetFrames ( )

virtual

Get an array of all Frames.

Implements openshot::CacheBase.

Definition at line 226 of file CacheDisk.cpp.

◆ GetSmallestFrame()

std::shared_ptr< Frame > CacheDisk::GetSmallestFrame ( )

virtual

Get the smallest frame number.

Implements openshot::CacheBase.

Definition at line 243 of file CacheDisk.cpp.

◆ Json()

std::string CacheDisk::Json ( )

virtual

Generate JSON string of this object.

Implements openshot::CacheBase.

Definition at line 416 of file CacheDisk.cpp.

◆ JsonValue()

Json::Value CacheDisk::JsonValue ( )

virtual

Generate Json::Value for this object.

Implements openshot::CacheBase.

Definition at line 423 of file CacheDisk.cpp.

Referenced by Json().

◆ MoveToFront()

void CacheDisk::MoveToFront ( int64_t frame_number )

Move frame to front of queue (so it lasts longer)

Parameters

frame_number The frame number of the cached frame

Definition at line 337 of file CacheDisk.cpp.

Referenced by Add().

◆ Remove() [1/2]

void CacheDisk::Remove ( int64_t frame_number )

virtual

Remove a specific frame.

Parameters

frame_number The frame number of the cached frame

Implements openshot::CacheBase.

Definition at line 282 of file CacheDisk.cpp.

◆ Remove() [2/2]

void CacheDisk::Remove	(	int64_t	start_frame_number,
		int64_t	end_frame_number
	)

virtual

Remove a range of frames.

Parameters

start_frame_number	The starting frame number of the cached frame
end_frame_number	The ending frame number of the cached frame

Implements openshot::CacheBase.

Definition at line 288 of file CacheDisk.cpp.

◆ SetJson()

void CacheDisk::SetJson ( const std::string value )

virtual

Load JSON string into this object.

Implements openshot::CacheBase.

Definition at line 450 of file CacheDisk.cpp.

◆ SetJsonValue()

void CacheDisk::SetJsonValue ( const Json::Value root )

virtual

Load Json::Value into this object.

Implements openshot::CacheBase.

Definition at line 467 of file CacheDisk.cpp.

Referenced by SetJson().

The documentation for this class was generated from the following files:

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ CacheDisk() [1/2]

◆ CacheDisk() [2/2]

◆ ~CacheDisk()

Member Function Documentation

◆ Add()

◆ Clear()

◆ Contains()

◆ Count()

◆ GetBytes()

◆ GetFrame()

◆ GetFrames()

◆ GetSmallestFrame()

◆ Json()

◆ JsonValue()

◆ MoveToFront()

◆ Remove() [1/2]

◆ Remove() [2/2]

◆ SetJson()

◆ SetJsonValue()