CustomDataSetContext.GetFromCache Method
Retrieves a cached object from the Carmenta Engine global cache.
GetFromCache(System.UInt64 key)
Retrieves a cached object from the Carmenta Engine global cache.Syntax
public EngineObject GetFromCache (
System.UInt64 key
)Parameters
A 64-bit integer identifying the cached object.
Return Value
the cached object, or null.
Remarks
This method, together with AddToCache, gives a custom dataset access to the Carmenta Engine global cache mechanism. This is typically much easier to use than writing your own caching mechanism in your dataset, and it also works very well together with the caches used by other Carmenta Engine datasets.
To use the cache, you need to designate a unique 64-bit integer identifier for each object you want to cache. The identifiers must only be unique within each instance of a dataset.
Whenever you need an object that could be potentially be cached, you typically first check if it is already in the cache, using this method. If the object is found, you don't have to do anything else. If it isn't, you need to create the object like you normally would, and then call the AddToCache method to add it to the cache. The next time you need the same object, you can retrieve it directly from the cache, unless it has been evicted due to the cache getting full.
Adding objects to the global cache is only supported for a limited number of types. Currently, the only supported types are Feature and Visualizer subclasses. Trying to add any other type of object will throw an exception.
Platforms
Windows, Linux, Android