Package org.opendaylight.yangtools.yang.data.util

Class LeafInterner

java.lang.Object

org.opendaylight.yangtools.yang.data.util.LeafInterner

@Beta
public final class LeafInterner
extends Object

Utility class for sharing instances of LeafNodes which have low cardinality-- e.g. those which hold boolean or enumeration values. Instances containing attributes are not interned.

Such objects have cardinality which is capped at the product of QNAMES * TYPE_CARDINALITY, where QNAMES is the total number of different QNames where the type is used and TYPE_CARDINALITY is the number of possible values for the type. Boolean has cardinality of 2, enumerations have cardinality equal to the number of enum statements.

The theory here is that we tend to have a large number (100K+) of entries in a few places, which could end up hogging the heap retained via the DataTree with duplicate objects (same QName, same value, different object). Using this utility, such objects will end up reusing the same object, preventing this overhead.

Method Summary

Modifier and Type	Method	Description
static <T extends LeafNode<?>> @NonNull Optional<Interner<T>>	forSchema(@Nullable LeafSchemaNode schema)	Return a LeafInterner for a particular schema.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

forSchema

public static <T extends LeafNode<?>>
@NonNull Optional<Interner<T>> forSchema(@Nullable LeafSchemaNode schema)

Return a LeafInterner for a particular schema. Interner instances must not be reused for leaves of different types, otherwise they may produce unexpected results.

Parameters:

schema - The leaf node's schema

Returns:

An interner instance, if applicable