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

Class LeafsetEntryInterner

java.lang.Object

org.opendaylight.yangtools.yang.data.util.LeafsetEntryInterner

@Beta
public final class LeafsetEntryInterner
extends Object

Utility class for sharing instances of LeafSetEntryNodes 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 @Nullable LeafsetEntryInterner	forSchema(@Nullable LeafListSchemaNode schema)	Return a LeafsetEntryInterner for a particular schema.
<T extends LeafSetEntryNode<?>> @NonNull T	intern(@NonNull T sample)

Methods inherited from class java.lang.Object

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

Method Detail

intern

public <T extends LeafSetEntryNode<?>> @NonNull T intern(@NonNull T sample)

forSchema

public static @Nullable LeafsetEntryInterner forSchema(@Nullable LeafListSchemaNode schema)

Return a LeafsetEntryInterner for a particular schema. Interner instances must be used only for leafset entries for that particular schema, otherwise they may produce unexpected results.

Parameters:

schema - Schema of the parent leaf set

Returns:

An interner instance, or null if the leafset's type should not be interned.