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