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.CheckedFuture;
  14 import com.google.common.util.concurrent.Futures;
  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.util.concurrent.ExceptionMapper;
  20 import org.opendaylight.yangtools.util.concurrent.ReflectiveExceptionMapper;
  21 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  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;
  26 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceListener;
  27 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
  28 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  29 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  30
  31 public class SchemaSourceTransformer<S extends SchemaSourceRepresentation, D extends SchemaSourceRepresentation>
  32         implements SchemaSourceListener, SchemaSourceProvider<D> {
  33     private static final ExceptionMapper<SchemaSourceException> MAPPER = ReflectiveExceptionMapper.create(
  34             "Source transformation", SchemaSourceException.class);
  35
  36     @FunctionalInterface
  37     public interface Transformation<S extends SchemaSourceRepresentation, D extends SchemaSourceRepresentation>
  38             extends AsyncFunction<S, D> {
  39         @Override
  40         CheckedFuture<D, SchemaSourceException> apply(@Nonnull S input) throws Exception;
  41     }
  42
  43     private final Map<PotentialSchemaSource<?>, RefcountedRegistration> sources = new HashMap<>();
  44     private final SchemaSourceRegistry consumer;
  45     private final SchemaRepository provider;
  46     private final AsyncFunction<S, D> function;
  47     private final Class<S> srcClass;
  48     private final Class<D> dstClass;
  49
  50     public SchemaSourceTransformer(final SchemaRepository provider, final Class<S> srcClass,
  51             final SchemaSourceRegistry consumer, final Class<D> dstClass, final AsyncFunction<S, D> function) {
  52         this.provider = requireNonNull(provider);
  53         this.consumer = requireNonNull(consumer);
  54         this.function = requireNonNull(function);
  55         this.srcClass = requireNonNull(srcClass);
  56         this.dstClass = requireNonNull(dstClass);
  57     }
  58
  59     @Override
  60     public CheckedFuture<D, SchemaSourceException> getSource(final SourceIdentifier sourceIdentifier) {
  61         final CheckedFuture<S, SchemaSourceException> f = provider.getSchemaSource(sourceIdentifier, srcClass);
  62         return Futures.makeChecked(Futures.transformAsync(f, function, MoreExecutors.directExecutor()), MAPPER);
  63     }
  64
  65     @Override
  66     public final void schemaSourceEncountered(final SchemaSourceRepresentation source) {
  67         // Not interesting
  68     }
  69
  70     @Override
  71     public final void schemaSourceRegistered(final Iterable<PotentialSchemaSource<?>> sources) {
  72         for (PotentialSchemaSource<?> src : sources) {
  73             final Class<?> rep = src.getRepresentation();
  74             if (srcClass.isAssignableFrom(rep) && dstClass != rep) {
  75                 registerSource(src);
  76             }
  77         }
  78     }
  79
  80     @Override
  81     public final void schemaSourceUnregistered(final PotentialSchemaSource<?> source) {
  82         final Class<?> rep = source.getRepresentation();
  83         if (srcClass.isAssignableFrom(rep) && dstClass != rep) {
  84             unregisterSource(source);
  85         }
  86     }
  87
  88     private void registerSource(final PotentialSchemaSource<?> src) {
  89         RefcountedRegistration reg = sources.get(src);
  90         if (reg != null) {
  91             reg.incRef();
  92             return;
  93         }
  94
  95         final PotentialSchemaSource<D> newSrc = PotentialSchemaSource.create(src.getSourceIdentifier(), dstClass,
  96                 src.getCost() + PotentialSchemaSource.Costs.COMPUTATION.getValue());
  97
  98         final SchemaSourceRegistration<D> r = consumer.registerSchemaSource(this, newSrc);
  99         sources.put(src, new RefcountedRegistration(r));
 100     }
 101
 102     private void unregisterSource(final PotentialSchemaSource<?> src) {
 103         final RefcountedRegistration reg = sources.get(src);
 104         if (reg != null && reg.decRef()) {
 105             sources.remove(src);
 106         }
 107     }
 108 }