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.CheckedFuture;
  16 import com.google.common.util.concurrent.Futures;
  17 import java.util.ArrayList;
  18 import java.util.Collections;
  19 import java.util.List;
  20 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  21 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceException;
  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> implements AutoCloseable {
  30     private final List<FinalizablePhantomReference<T>> regs = Collections.synchronizedList(new ArrayList<FinalizablePhantomReference<T>>());
  31     private final FinalizableReferenceQueue queue = new FinalizableReferenceQueue();
  32     private final Cache<SourceIdentifier, T> cache;
  33
  34     protected InMemorySchemaSourceCache(final SchemaSourceRegistry consumer, final Class<T> representation, final CacheBuilder<Object, Object> builder) {
  35         super(consumer, representation, Costs.IMMEDIATE);
  36         cache = builder.build();
  37     }
  38
  39     public static <R extends SchemaSourceRepresentation> InMemorySchemaSourceCache<R> createSoftCache(final SchemaSourceRegistry consumer, final Class<R> representation) {
  40         return new InMemorySchemaSourceCache<>(consumer, representation, CacheBuilder.newBuilder().softValues());
  41     }
  42
  43     @Override
  44     public CheckedFuture<? extends T, SchemaSourceException> getSource(final SourceIdentifier sourceIdentifier) {
  45         final T present = cache.getIfPresent(sourceIdentifier);
  46         if (present != null) {
  47             return Futures.immediateCheckedFuture(present);
  48         }
  49
  50         return Futures.<T, SchemaSourceException>immediateFailedCheckedFuture(new MissingSchemaSourceException("Source not found", sourceIdentifier));
  51     }
  52
  53     @Override
  54     protected void offer(final T source) {
  55         final T present = cache.getIfPresent(source.getIdentifier());
  56         if (present == null) {
  57             cache.put(source.getIdentifier(), source);
  58
  59             final SchemaSourceRegistration<T> reg = register(source.getIdentifier());
  60             final FinalizablePhantomReference<T> ref = new FinalizablePhantomReference<T>(source, queue) {
  61                 @Override
  62                 public void finalizeReferent() {
  63                     reg.close();
  64                     regs.remove(this);
  65                 }
  66             };
  67
  68             regs.add(ref);
  69         }
  70     }
  71
  72     @Override
  73     public void close() {
  74         while (!regs.isEmpty()) {
  75             final FinalizablePhantomReference<?> ref = regs.get(0);
  76             ref.finalizeReferent();
  77         }
  78
  79         cache.invalidateAll();
  80         queue.close();
  81     }
  82 }