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 java.util.concurrent.TimeUnit;
  21 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  22 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceException;
  23 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  24 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  25 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource.Costs;
  26 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  27 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  28
  29 @Beta
  30 public class InMemorySchemaSourceCache<T extends SchemaSourceRepresentation> extends AbstractSchemaSourceCache<T>
  31         implements AutoCloseable {
  32     private final List<FinalizablePhantomReference<T>> regs = Collections.synchronizedList(new ArrayList<>());
  33     private final FinalizableReferenceQueue queue = new FinalizableReferenceQueue();
  34     private final Cache<SourceIdentifier, T> cache;
  35
  36     protected InMemorySchemaSourceCache(final SchemaSourceRegistry consumer, final Class<T> representation,
  37             final CacheBuilder<Object, Object> builder) {
  38         super(consumer, representation, Costs.IMMEDIATE);
  39         cache = builder.build();
  40     }
  41
  42     public static <R extends SchemaSourceRepresentation> InMemorySchemaSourceCache<R> createSoftCache(
  43             final SchemaSourceRegistry consumer, final Class<R> representation) {
  44         return new InMemorySchemaSourceCache<>(consumer, representation, CacheBuilder.newBuilder().softValues());
  45     }
  46
  47     public static <R extends SchemaSourceRepresentation> InMemorySchemaSourceCache<R> createSoftCache(
  48             final SchemaSourceRegistry consumer, final Class<R> representation, final long lifetime,
  49             final TimeUnit units) {
  50         return new InMemorySchemaSourceCache<>(consumer, representation, CacheBuilder.newBuilder().softValues()
  51                 .expireAfterAccess(lifetime, units));
  52     }
  53
  54     @Override
  55     public CheckedFuture<? extends T, SchemaSourceException> getSource(final SourceIdentifier sourceIdentifier) {
  56         final T present = cache.getIfPresent(sourceIdentifier);
  57         if (present != null) {
  58             return Futures.immediateCheckedFuture(present);
  59         }
  60
  61         return Futures.immediateFailedCheckedFuture(new MissingSchemaSourceException("Source not found",
  62                     sourceIdentifier));
  63     }
  64
  65     @Override
  66     protected void offer(final T source) {
  67         final T present = cache.getIfPresent(source.getIdentifier());
  68         if (present == null) {
  69             cache.put(source.getIdentifier(), source);
  70
  71             final SchemaSourceRegistration<T> reg = register(source.getIdentifier());
  72             final FinalizablePhantomReference<T> ref = new FinalizablePhantomReference<T>(source, queue) {
  73                 @Override
  74                 public void finalizeReferent() {
  75                     reg.close();
  76                     regs.remove(this);
  77                 }
  78             };
  79
  80             regs.add(ref);
  81         }
  82     }
  83
  84     @Override
  85     public void close() {
  86         while (!regs.isEmpty()) {
  87             final FinalizablePhantomReference<?> ref = regs.get(0);
  88             ref.finalizeReferent();
  89         }
  90
  91         cache.invalidateAll();
  92         queue.close();
  93     }
  94 }