cache.md

Kopytko Framework: Cache

CacheFacade operates in global scope. It stores items in the global scope. Renderable nodes can't be cached (types of Group node).

CacheFacade interface:

• read(keyData as Object, scopeName = "" as String) - returns data associated with given key. The key can be string or AA.
• write(keyData as Object, data as Object, options = {} as Object) - writes data to given key.
• clearScope(scopeName as String) - removes all items from the given scope
• clearStaleItems(scopeName = "" as String) - removes items from the scope when caching policy allows to do that.

There are two types of caching policies:

• ExhaustibleCachingPolicy - the policy allows to retrieve cached items only once.
• ExpirableCachingPolicy - the timestamp (as seconds) controls lifetime of cached items.

Stale items are not removed automatically when expired.

ExhaustibleCachingPolicy example:

cache = CacheFacade()
cache.write("myKey", { myData: true }, { isSingleUse: true })
cachedItem = cache.read("myKey") ' Retrieves data.
cachedItem = cache.read("myKey") ' The data is not retrieved anymore

ExpirableCachingPolicy example:

cache = CacheFacade()
cache.write("myKey", { myData: true }, { expirationTimestamp: 120 })
cachedItem = cache.read("myKey") ' Retrieves data.
' More than 120 seconds passed
cachedItem = cache.read("myKey") ' The data is not retrieved anymore

Caching mechanism allows to store the same keys in different scopes.