com.netflix.hollow.api.objects.delegate

Interface HollowRecordDelegate

All Known Subinterfaces:

BooleanDelegate, DoubleDelegate, FloatDelegate, HollowCachedDelegate, HollowListDelegate<T>, HollowMapDelegate<K,V>, HollowObjectDelegate, HollowSetDelegate<T>, IntegerDelegate, LongDelegate, StringDelegate

All Known Implementing Classes:

BooleanDelegateCachedImpl, BooleanDelegateLookupImpl, DoubleDelegateCachedImpl, DoubleDelegateLookupImpl, FloatDelegateCachedImpl, FloatDelegateLookupImpl, HollowListCachedDelegate, HollowListLookupDelegate, HollowMapCachedDelegate, HollowMapLookupDelegate, HollowObjectAbstractDelegate, HollowObjectGenericDelegate, HollowSetCachedDelegate, HollowSetLookupDelegate, IntegerDelegateCachedImpl, IntegerDelegateLookupImpl, LongDelegateCachedImpl, LongDelegateLookupImpl, StringDelegateCachedImpl, StringDelegateLookupImpl

public interface HollowRecordDelegate

A HollowRecordDelegate is used by a generated Hollow Objects API to access data from the data model.

Two flavors of delegate currently exist -- lookup and cached.

The lookup delegate reads directly from a HollowDataAccess. The cached delegate will copy the data from a HollowDataAccess, then read from the copy of the data. The intention is that the cached delegate has the performance profile of a POJO, while the lookup delegate imposes the minor performance penalty incurred by reading directly from Hollow.

The performance penalty of a lookup delegate is minor enough that it doesn't usually matter except in the tightest of loops. If a type exists which has a low cardinality but is accessed disproportionately frequently, then it may be a good candidate to be represented with a cached delegate.