Caching - Revision history

Kris: layout

2012-01-06T07:44:39Z

layout

← Older revision		Revision as of 07:44, 6 January 2012
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	~~= Caching =~~

	This page is for notes in the discussion on adding caching to Inkscape for a performance boost. It started from a note on caching an item's bounding box (end of Aug 2011).		This page is for notes in the discussion on adding caching to Inkscape for a performance boost. It started from a note on caching an item's bounding box (end of Aug 2011).

Marko: /* Cache class */ shorter

2012-01-06T04:39:21Z

Cache class: shorter

← Older revision		Revision as of 04:39, 6 January 2012
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	// Advantages:		// Advantages:
	// - client code shorter and thus simpler to read		// - client code shorter and thus simpler to read
	// - Avoid ~~unnecessary repetition~~ of ~~the same pattern~~		// - Avoid duplication of code
	~~// anywhere a client needs to get something from the cache~~

Marko at 04:20, 6 January 2012

2012-01-06T04:20:32Z

← Older revision		Revision as of 04:20, 6 January 2012
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	cache.addValue("bbox", bbox);		cache.addValue("bbox", bbox);
	}		}

			Or maybe:

			Geom::Rect bbox = cache.get("bbox", ...); // string key + factory callback
			// cache.get looks for the key-value mapping and decides what to return
			// Advantages:
			// - client code shorter and thus simpler to read
			// - Avoid unnecessary repetition of the same pattern
			// anywhere a client needs to get something from the cache

Johanengelen: /* Cache class */

2011-09-01T20:59:50Z

Cache class

← Older revision		Revision as of 20:59, 1 September 2011
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	A Cache object class that can be added to objects that need a cache. Each object then has its own cache, so no clashing of itemnames in the cache etc.		A Cache object class that can be added to objects that need a cache. Each object then has its own cache, so no clashing of itemnames in the cache etc.
	The item's cache object can be publicly accessible for some classes, and is private in other classes, right?		The item's cache object can be publicly accessible for some classes, and is private in other classes, right?
			All Cache objects should somehow be monitored for memory use, such that things can be invalidated/removed when Inkscape needs the memory somewhere else.

	How about these methods:		How about these methods:
	* addValue( string key, any value )		* addValue( string key, any value )
	** adds an item to the cache, could be any type of data (?)		** adds an item to the cache, could be any type of data (?)
			* bool contains( string key )
			** returns true iff the key is found valid in the cache.
	* retrieve( string key )		* retrieve( string key )
	** returns optional value. Must work out how to return "no value found".		** returns optional value. Must work out how to return "no value found".

Johanengelen: /* What to cache */

2011-09-01T20:57:42Z

What to cache

← Older revision		Revision as of 20:57, 1 September 2011
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	* SPItem bounding box		* SPItem bounding box
	** should invalidate on probably all changes? We could also consider storing a relative bounding box, which stays valid after a translation has been applied. ~~I guess~~ 90% of the time items are merely translated, and not really changed		** should invalidate on probably all changes? We could also consider storing a relative bounding box, which stays valid after a translation has been applied. This only works with transforms that scale or translate, not with rotations or shearing. Probably 90% of the time items are merely translated, and not really changed.
	* SPItem snap points		* SPItem snap points
	** should invalidate on all changes of the item, but also on changing snap preferences		** should invalidate on all changes of the item, but also on changing snap preferences

Johanengelen: /* Cache class */

2011-09-01T20:56:30Z

Cache class

← Older revision		Revision as of 20:56, 1 September 2011
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	* invalidate( string key )		* invalidate( string key )
	** invalidates named entry, or all entries when string is NULL or "all" ?		** invalidates named entry, or all entries when string is NULL or "all" ?

			Code example:

			Geom::Rect bbox;
			if (cache.contains("bbox")) {
			bbox = cache.retrieve("bbox");
			} else {
			bbox = calcbbox(...);
			cache.addValue("bbox", bbox);
			}

Dvlierop: /* What to cache */

2011-08-31T21:02:41Z

What to cache

← Older revision		Revision as of 21:02, 31 August 2011
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	* SPItem bounding box		* SPItem bounding box
	** should invalidate on probably all changes		** should invalidate on probably all changes? We could also consider storing a relative bounding box, which stays valid after a translation has been applied. I guess 90% of the time items are merely translated, and not really changed
			* SPItem snap points
			** should invalidate on all changes of the item, but also on changing snap preferences
	* SPShape conversion to SBasis (2geom path data)		* SPShape conversion to SBasis (2geom path data)
			** should invalidate on path data and transform change
			* SPShape intersections from a path with itself
	** should invalidate on path data and transform change		** should invalidate on path data and transform change
	* SPLPEItem, LPE intermediate data (related to the input path, this requires some architectural changes in LPE code)		* SPLPEItem, LPE intermediate data (related to the input path, this requires some architectural changes in LPE code)

Johanengelen: create discussion page on caching

2011-08-31T18:10:23Z

create discussion page on caching

New page

= Caching =

This page is for notes in the discussion on adding caching to Inkscape for a performance boost. It started from a note on caching an item's bounding box (end of Aug 2011).

== What to cache ==
(please write down which object type the data should belong to)

* SPItem bounding box
** should invalidate on probably all changes
* SPShape conversion to SBasis (2geom path data)
** should invalidate on path data and transform change
* SPLPEItem, LPE intermediate data (related to the input path, this requires some architectural changes in LPE code)
** invalidates on path data change
* LivePathEffect::Parameter
** intermediate results, like arc-length-reparametrisation for LPE-Bend
** LivePathEffect::PathParam already caches the conversion to pwd2

Perhaps it is best to start implementing this by invalidating the full cache for an object if any change on it is detected?

== Cache class ==

A Cache object class that can be added to objects that need a cache. Each object then has its own cache, so no clashing of itemnames in the cache etc.
The item's cache object can be publicly accessible for some classes, and is private in other classes, right?

How about these methods:
* addValue( string key, any value )
** adds an item to the cache, could be any type of data (?)
* retrieve( string key )
** returns optional value. Must work out how to return "no value found".
* invalidate( string key )
** invalidates named entry, or all entries when string is NULL or "all" ?