bgp/parser-spi/src/main/java/org/opendaylight/protocol/bgp/parser/spi/pojo/AbstractFamilyRegistry.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.protocol.bgp.parser.spi.pojo;
   9
  10 import java.util.Map;
  11 import java.util.concurrent.ConcurrentHashMap;
  12
  13 import org.opendaylight.protocol.concepts.AbstractRegistration;
  14
  15 import com.google.common.base.Preconditions;
  16
  17 abstract class AbstractFamilyRegistry<CLASS, NUMBER> {
  18         private final Map<Class<? extends CLASS>, NUMBER> classToNumber = new ConcurrentHashMap<>();
  19         private final Map<NUMBER, Class<? extends CLASS>> numberToClass = new ConcurrentHashMap<>();
  20
  21         protected synchronized AutoCloseable registerFamily(final Class<? extends CLASS> clazz, final NUMBER number) {
  22                 Preconditions.checkNotNull(clazz);
  23
  24                 final Class<?> c = numberToClass.get(number);
  25                 Preconditions.checkState(c == null, "Number " + number + " already registered to " + c);
  26
  27                 final NUMBER n = classToNumber.get(clazz);
  28                 Preconditions.checkState(n == null, "Class " + clazz + " already registered to " + n);
  29
  30                 numberToClass.put(number, clazz);
  31                 classToNumber.put(clazz, number);
  32
  33                 final Object lock = this;
  34                 return new AbstractRegistration() {
  35
  36                         @Override
  37                         protected void removeRegistration() {
  38                                 synchronized (lock) {
  39                                         classToNumber.remove(clazz);
  40                                         numberToClass.remove(number);
  41                                 }
  42                         }
  43                 };
  44         }
  45
  46         protected Class<? extends CLASS> classForFamily(final NUMBER number) {
  47                 return numberToClass.get(number);
  48         }
  49
  50         protected NUMBER numberForClass(final Class<? extends CLASS> clazz) {
  51                 return classToNumber.get(clazz);
  52         }
  53 }