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