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  * This program and the accompanying materials are made available under the
   4  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   5  * and is available at http://www.eclipse.org/legal/epl-v10.html
   6  */
   7 package org.opendaylight.yangtools.yang.model.repo.util;
   8
   9 import com.google.common.base.Preconditions;
  10 import com.google.common.util.concurrent.AsyncFunction;
  11 import com.google.common.util.concurrent.CheckedFuture;
  12 import com.google.common.util.concurrent.Futures;
  13
  14 import java.util.HashMap;
  15 import java.util.Map;
  16
  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> implements SchemaSourceListener, SchemaSourceProvider<D> {
  30     private static final ExceptionMapper<SchemaSourceException> MAPPER = ReflectiveExceptionMapper.create("Source transformation", SchemaSourceException.class);
  31
  32     public interface Transformation<S extends SchemaSourceRepresentation, D extends SchemaSourceRepresentation> extends AsyncFunction<S, D> {
  33         @Override
  34         CheckedFuture<D, SchemaSourceException> apply(final S input) throws Exception;
  35     }
  36
  37     private final Map<PotentialSchemaSource<?>, RefcountedRegistration> sources = new HashMap<>();
  38     private final SchemaSourceRegistry consumer;
  39     private final SchemaRepository provider;
  40     private final AsyncFunction<S, D> function;
  41     private final Class<S> srcClass;
  42     private final Class<D> dstClass;
  43
  44     public SchemaSourceTransformer(final SchemaRepository provider, final Class<S> srcClass,
  45             final SchemaSourceRegistry consumer, final Class<D> dstClass, final AsyncFunction<S, D> function) {
  46         this.provider = Preconditions.checkNotNull(provider);
  47         this.consumer = Preconditions.checkNotNull(consumer);
  48         this.function = Preconditions.checkNotNull(function);
  49         this.srcClass = Preconditions.checkNotNull(srcClass);
  50         this.dstClass = Preconditions.checkNotNull(dstClass);
  51     }
  52
  53     @Override
  54     public CheckedFuture<D, SchemaSourceException> getSource(final SourceIdentifier sourceIdentifier) {
  55         final CheckedFuture<S, SchemaSourceException> f = provider.getSchemaSource(sourceIdentifier, srcClass);
  56         return Futures.makeChecked(Futures.transform(f, function), MAPPER);
  57     }
  58
  59     @Override
  60     public final void schemaSourceEncountered(final SchemaSourceRepresentation source) {
  61         // Not interesting
  62     }
  63
  64     @Override
  65     public final void schemaSourceRegistered(final Iterable<PotentialSchemaSource<?>> sources) {
  66         for (PotentialSchemaSource<?> src : sources) {
  67             final Class<?> rep = src.getRepresentation();
  68             if (srcClass.isAssignableFrom(rep) && dstClass != rep) {
  69                 registerSource(src);
  70             }
  71         }
  72     }
  73
  74     @Override
  75     public final void schemaSourceUnregistered(final PotentialSchemaSource<?> source) {
  76         final Class<?> rep = source.getRepresentation();
  77         if (srcClass.isAssignableFrom(rep) && dstClass != rep) {
  78             unregisterSource(source);
  79         }
  80     }
  81
  82     private void registerSource(final PotentialSchemaSource<?> src) {
  83         RefcountedRegistration reg = sources.get(src);
  84         if (reg != null) {
  85             reg.incRef();
  86             return;
  87         }
  88
  89         final PotentialSchemaSource<D> newSrc = PotentialSchemaSource.create(src.getSourceIdentifier(), dstClass,
  90                 src.getCost() + PotentialSchemaSource.Costs.COMPUTATION.getValue());
  91
  92         final SchemaSourceRegistration<D> r = consumer.registerSchemaSource(this, newSrc);
  93         sources.put(src, new RefcountedRegistration(r));
  94     }
  95
  96     private void unregisterSource(final PotentialSchemaSource<?> src) {
  97         final RefcountedRegistration reg = sources.get(src);
  98         if (reg != null && reg.decRef()) {
  99             sources.remove(src);
 100         }
 101     }
 102 }