yang/yang-model-util/src/main/java/org/opendaylight/yangtools/yang/model/repo/util/InMemorySchemaSourceCache.java

   1 /*
   2  * Copyright (c) 2014 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.yangtools.yang.model.repo.util;
   9
  10 import com.google.common.annotations.Beta;
  11 import com.google.common.base.FinalizablePhantomReference;
  12 import com.google.common.base.FinalizableReferenceQueue;
  13 import com.google.common.cache.Cache;
  14 import com.google.common.cache.CacheBuilder;
  15 import com.google.common.util.concurrent.Futures;
  16 import com.google.common.util.concurrent.ListenableFuture;
  17 import java.util.ArrayList;
  18 import java.util.Collections;
  19 import java.util.List;
  20 import java.util.concurrent.TimeUnit;
  21 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  22 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  23 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  24 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource.Costs;
  25 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  26 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  27
  28 @Beta
  29 public class InMemorySchemaSourceCache<T extends SchemaSourceRepresentation> extends AbstractSchemaSourceCache<T>
  30         implements AutoCloseable {
  31     private final List<FinalizablePhantomReference<T>> regs = Collections.synchronizedList(new ArrayList<>());
  32     private final FinalizableReferenceQueue queue = new FinalizableReferenceQueue();
  33     private final Cache<SourceIdentifier, T> cache;
  34
  35     protected InMemorySchemaSourceCache(final SchemaSourceRegistry consumer, final Class<T> representation,
  36             final CacheBuilder<Object, Object> builder) {
  37         super(consumer, representation, Costs.IMMEDIATE);
  38         cache = builder.build();
  39     }
  40
  41     public static <R extends SchemaSourceRepresentation> InMemorySchemaSourceCache<R> createSoftCache(
  42             final SchemaSourceRegistry consumer, final Class<R> representation) {
  43         return new InMemorySchemaSourceCache<>(consumer, representation, CacheBuilder.newBuilder().softValues());
  44     }
  45
  46     public static <R extends SchemaSourceRepresentation> InMemorySchemaSourceCache<R> createSoftCache(
  47             final SchemaSourceRegistry consumer, final Class<R> representation, final long lifetime,
  48             final TimeUnit units) {
  49         return new InMemorySchemaSourceCache<>(consumer, representation, CacheBuilder.newBuilder().softValues()
  50                 .expireAfterAccess(lifetime, units));
  51     }
  52
  53     @Override
  54     public ListenableFuture<? extends T> getSource(final SourceIdentifier sourceIdentifier) {
  55         final T present = cache.getIfPresent(sourceIdentifier);
  56         if (present != null) {
  57             return Futures.immediateFuture(present);
  58         }
  59
  60         return Futures.immediateFailedFuture(new MissingSchemaSourceException("Source not found", sourceIdentifier));
  61     }
  62
  63     @Override
  64     protected void offer(final T source) {
  65         final T present = cache.getIfPresent(source.getIdentifier());
  66         if (present == null) {
  67             cache.put(source.getIdentifier(), source);
  68
  69             final SchemaSourceRegistration<T> reg = register(source.getIdentifier());
  70             final FinalizablePhantomReference<T> ref = new FinalizablePhantomReference<T>(source, queue) {
  71                 @Override
  72                 public void finalizeReferent() {
  73                     reg.close();
  74                     regs.remove(this);
  75                 }
  76             };
  77
  78             regs.add(ref);
  79         }
  80     }
  81
  82     @Override
  83     public void close() {
  84         while (!regs.isEmpty()) {
  85             final FinalizablePhantomReference<?> ref = regs.get(0);
  86             ref.finalizeReferent();
  87         }
  88
  89         cache.invalidateAll();
  90         queue.close();
  91     }
  92 }