yang/yang-model-util/src/main/java/org/opendaylight/yangtools/yang/model/repo/util/SchemaSourceTransformer.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 static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.util.concurrent.AsyncFunction;
  13 import com.google.common.util.concurrent.Futures;
  14 import com.google.common.util.concurrent.ListenableFuture;
  15 import com.google.common.util.concurrent.MoreExecutors;
  16 import java.util.HashMap;
  17 import java.util.Map;
  18 import javax.annotation.Nonnull;
  19 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  20 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  21 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  22 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource;
  23 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceListener;
  24 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
  25 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  26 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  27
  28 public class SchemaSourceTransformer<S extends SchemaSourceRepresentation, D extends SchemaSourceRepresentation>
  29         implements SchemaSourceListener, SchemaSourceProvider<D> {
  30
  31     @FunctionalInterface
  32     public interface Transformation<S extends SchemaSourceRepresentation, D extends SchemaSourceRepresentation>
  33             extends AsyncFunction<S, D> {
  34         @Override
  35         ListenableFuture<D> apply(@Nonnull S input) throws Exception;
  36     }
  37
  38     private final Map<PotentialSchemaSource<?>, RefcountedRegistration> availableSources = new HashMap<>();
  39     private final SchemaSourceRegistry consumer;
  40     private final SchemaRepository provider;
  41     private final AsyncFunction<S, D> function;
  42     private final Class<S> srcClass;
  43     private final Class<D> dstClass;
  44
  45     public SchemaSourceTransformer(final SchemaRepository provider, final Class<S> srcClass,
  46             final SchemaSourceRegistry consumer, final Class<D> dstClass, final AsyncFunction<S, D> function) {
  47         this.provider = requireNonNull(provider);
  48         this.consumer = requireNonNull(consumer);
  49         this.function = requireNonNull(function);
  50         this.srcClass = requireNonNull(srcClass);
  51         this.dstClass = requireNonNull(dstClass);
  52     }
  53
  54     @Override
  55     public ListenableFuture<D> getSource(final SourceIdentifier sourceIdentifier) {
  56         return Futures.transformAsync(provider.getSchemaSource(sourceIdentifier, srcClass), function,
  57             MoreExecutors.directExecutor());
  58     }
  59
  60     @Override
  61     public final void schemaSourceEncountered(final SchemaSourceRepresentation source) {
  62         // Not interesting
  63     }
  64
  65     @Override
  66     public final void schemaSourceRegistered(final Iterable<PotentialSchemaSource<?>> sources) {
  67         for (PotentialSchemaSource<?> src : sources) {
  68             final Class<?> rep = src.getRepresentation();
  69             if (srcClass.isAssignableFrom(rep) && dstClass != rep) {
  70                 registerSource(src);
  71             }
  72         }
  73     }
  74
  75     @Override
  76     public final void schemaSourceUnregistered(final PotentialSchemaSource<?> source) {
  77         final Class<?> rep = source.getRepresentation();
  78         if (srcClass.isAssignableFrom(rep) && dstClass != rep) {
  79             unregisterSource(source);
  80         }
  81     }
  82
  83     private void registerSource(final PotentialSchemaSource<?> src) {
  84         RefcountedRegistration reg = availableSources.get(src);
  85         if (reg != null) {
  86             reg.incRef();
  87             return;
  88         }
  89
  90         final PotentialSchemaSource<D> newSrc = PotentialSchemaSource.create(src.getSourceIdentifier(), dstClass,
  91                 src.getCost() + PotentialSchemaSource.Costs.COMPUTATION.getValue());
  92
  93         final SchemaSourceRegistration<D> r = consumer.registerSchemaSource(this, newSrc);
  94         availableSources.put(src, new RefcountedRegistration(r));
  95     }
  96
  97     private void unregisterSource(final PotentialSchemaSource<?> src) {
  98         final RefcountedRegistration reg = availableSources.get(src);
  99         if (reg != null && reg.decRef()) {
 100             availableSources.remove(src);
 101         }
 102     }
 103 }