Utilities for cache population

A Provider is the owner of one or more CachingAgents.

A CatsModule configures the various components needed to schedule execution of each CachingAgent for each Provider. new CatsModule.Builder().build(aProvider) comes configured with reasonable defaults for in-memory caching and refreshing on a fixed interval. The CatsModule.getView() returns a Cache that provides read access to the data populated by the CachingAgents

To gain insight into the execution of the CachingAgents, one or more ExecutionInstrumentation can be provided which will receive callbacks around the start, completion, or failure of each CachingAgent.loadData()

CacheData stored in the Cache is classified by a type and identified by an id (for example type: application, id: myapp). CacheData has attributes - facts about the item such as an application owner's email address, as well as relationships - references to other items in the cache.

A CachingAgent belongs to a Provider and is identified by its CachingAgent.agentType. The CacheResult returned by the CachingAgent contains CacheData for all the CachingAgent.providedDataTypes. A CachingAgent can be either an AgentDataType.Authority.AUTHORITATIVE source of data, or an AgentDataType.Authority.INFORMATIVE source of data. An AUTHORITATIVE source of data means the agent knows that it has the complete set of data for a particular type. For example an agent that cached Amazon AutoScalingGroups by performing describeAutoScalingGroup would authoritatively know the set AutoScalingGroups because it sees them all, but only informatively know about LoadBalancers or Instances because it only sees those associated with an AutoScalingGroup.