org.opendaylight.yangtools.yang.data.util.LeafsetEntryInterner Maven / Gradle / Ivy
/*
* Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.yang.data.util;
import com.google.common.annotations.Beta;
import com.google.common.collect.Interner;
import com.google.common.collect.Interners;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
import org.opendaylight.yangtools.yang.model.api.LeafListSchemaNode;
import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.BooleanTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.EnumTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.IdentityrefTypeDefinition;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Utility class for sharing instances of {@link LeafSetEntryNode}s 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.
*/
@Beta
public final class LeafsetEntryInterner {
private static final Logger LOG = LoggerFactory.getLogger(LeafsetEntryInterner.class);
private static final LeafsetEntryInterner INSTANCE = new LeafsetEntryInterner();
private static final Interner