interface ICacheCallback in Tinman.Core.Caching

Callback interface used by ICache implementations.

interface	ICacheCallback	with	<in TId>
		base of	DataCache

Remarks

An ICacheCallback object is responsible for loading cache pages when they are requested for the first time and unloading existing cache pages when they are evicted from the cache.

Page loading can also be performed by the code that calls Fetch, after analysing the return value.

Methods

CachePageChoose

When a cache page needs to be (re-)used, this method is called for each candidate until an invocation returns true.

method	CachePageChoose (int32 pageIndex, bool partially)
type	bool
params	pageIndex		The cache page index.
	partially		Going to do partial load of cache page (see Partial)?
returns			true if the cache page will be reused, false if not.

CachePageData

Performs writing and/or reading of cache page data.

method	CachePageData (int32 pageIndex, int32 write, TId writeId, int32 read, TId readId)
params	pageIndex		The cache page index.
	write		Depicts how to write cache page data: <0: Do not write cache page data. 0: Unload partial page (no longer present in the cache). 1: Unload full page (no longer present in the cache). 2: Flush partial page (still present in the cache). 3: Flush full page (still present in the cache).
	writeId		The cache page ID currently loaded in pageIndex iff write is greater than or equal to 0.
	read		Depicts how to load the cache page: <0: Do not load the page. 0: Load partial page (overwrite given cache page) 1: Load full page (overwrite given cache page) 2: Finish loading of partial page (complete given cache page)
	readId		The cache page ID to load into pageIndex iff read is greater than or equal to 0.

Remarks:

Writing must always be done first, following by cache page reading.