diff options
Diffstat (limited to 'infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/read/registry/CompositeReader.java')
-rw-r--r-- | infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/read/registry/CompositeReader.java | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/read/registry/CompositeReader.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/read/registry/CompositeReader.java new file mode 100644 index 000000000..91a195f44 --- /dev/null +++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/read/registry/CompositeReader.java @@ -0,0 +1,202 @@ +/* + * Copyright (c) 2016 Cisco and/or its affiliates. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package io.fd.honeycomb.translate.util.read.registry; + +import static com.google.common.base.Preconditions.checkArgument; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Optional; +import com.google.common.collect.ImmutableMap; +import com.google.common.collect.Iterables; +import io.fd.honeycomb.translate.read.ListReader; +import io.fd.honeycomb.translate.read.ReadContext; +import io.fd.honeycomb.translate.read.Reader; +import io.fd.honeycomb.translate.read.ReadFailedException; +import io.fd.honeycomb.translate.util.RWUtils; +import io.fd.honeycomb.translate.util.read.AbstractGenericReader; +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import javax.annotation.Nonnull; +import org.opendaylight.yangtools.concepts.Builder; +import org.opendaylight.yangtools.yang.binding.DataObject; +import org.opendaylight.yangtools.yang.binding.Identifiable; +import org.opendaylight.yangtools.yang.binding.Identifier; +import org.opendaylight.yangtools.yang.binding.InstanceIdentifier; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +class CompositeReader<D extends DataObject, B extends Builder<D>> extends AbstractGenericReader<D, B> { + + private static final Logger LOG = LoggerFactory.getLogger(CompositeReader.class); + + private final Reader<D, B> delegate; + private final ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> childReaders; + + private CompositeReader(final Reader<D, B> reader, + final ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> childReaders) { + super(reader.getManagedDataObjectType()); + this.delegate = reader; + this.childReaders = childReaders; + } + + @VisibleForTesting + ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> getChildReaders() { + return childReaders; + } + + @SuppressWarnings("unchecked") + public static <D extends DataObject> InstanceIdentifier<D> appendTypeToId( + final InstanceIdentifier<? extends DataObject> parentId, final InstanceIdentifier<D> type) { + final InstanceIdentifier.PathArgument t = new InstanceIdentifier.Item<>(type.getTargetType()); + return (InstanceIdentifier<D>) InstanceIdentifier.create(Iterables.concat( + parentId.getPathArguments(), Collections.singleton(t))); + } + + @Nonnull + @Override + public Optional<? extends DataObject> read(@Nonnull final InstanceIdentifier<? extends DataObject> id, + @Nonnull final ReadContext ctx) throws ReadFailedException { + if (shouldReadCurrent(id)) { + LOG.trace("{}: Reading current: {}", this, id); + return readCurrent((InstanceIdentifier<D>) id, ctx); + } else if (shouldDelegateToChild(id)) { + LOG.trace("{}: Reading child: {}", this, id); + return readSubtree(id, ctx); + } else { + // Fallback + LOG.trace("{}: Delegating read: {}", this, id); + return delegate.read(id, ctx); + } + } + + private boolean shouldReadCurrent(@Nonnull final InstanceIdentifier<? extends DataObject> id) { + return id.getTargetType().equals(getManagedDataObjectType().getTargetType()); + } + + private boolean shouldDelegateToChild(@Nonnull final InstanceIdentifier<? extends DataObject> id) { + return childReaders.containsKey(RWUtils.getNextId(id, getManagedDataObjectType()).getType()); + } + + private Optional<? extends DataObject> readSubtree(final InstanceIdentifier<? extends DataObject> id, + final ReadContext ctx) throws ReadFailedException { + final InstanceIdentifier.PathArgument nextId = RWUtils.getNextId(id, getManagedDataObjectType()); + final Reader<?, ? extends Builder<?>> nextReader = childReaders.get(nextId.getType()); + checkArgument(nextReader != null, "Unable to read: %s. No delegate present, available readers at next level: %s", + id, childReaders.keySet()); + return nextReader.read(id, ctx); + } + + @SuppressWarnings("unchecked") + private void readChildren(final InstanceIdentifier<D> id, @Nonnull final ReadContext ctx, final B builder) + throws ReadFailedException { + LOG.debug("{}: Reading children: {}", this, childReaders.keySet()); + for (Reader child : childReaders.values()) { + final InstanceIdentifier childId = appendTypeToId(id, child.getManagedDataObjectType()); + + LOG.debug("{}: Reading child from: {}", this, child); + if (child instanceof ListReader) { + final List<? extends DataObject> list = ((ListReader) child).readList(childId, ctx); + ((ListReader) child).merge(builder, list); + } else { + final Optional<? extends DataObject> read = child.read(childId, ctx); + if (read.isPresent()) { + child.merge(builder, read.get()); + } + } + } + } + + @Override + public void readCurrentAttributes(@Nonnull final InstanceIdentifier<D> id, @Nonnull final B builder, + @Nonnull final ReadContext ctx) + throws ReadFailedException { + delegate.readCurrentAttributes(id, builder, ctx); + readChildren(id, ctx, builder); + } + + @Nonnull + @Override + public B getBuilder(final InstanceIdentifier<D> id) { + return delegate.getBuilder(id); + } + + @Override + public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final D readValue) { + delegate.merge(parentBuilder, readValue); + } + + /** + * Wrap a Reader as a Composite Reader. + */ + static <D extends DataObject, B extends Builder<D>> Reader<D, B> createForReader( + @Nonnull final Reader<D, B> reader, + @Nonnull final ImmutableMap<Class<?>, Reader<?, ? extends Builder<?>>> childReaders) { + + return (reader instanceof ListReader) + ? new CompositeListReader<>((ListReader) reader, childReaders) + : new CompositeReader<>(reader, childReaders); + } + + private static class CompositeListReader<D extends DataObject & Identifiable<K>, B extends Builder<D>, K extends Identifier<D>> + extends CompositeReader<D, B> + implements ListReader<D, K, B> { + + private final ListReader<D, K, B> delegate; + + private CompositeListReader(final ListReader<D, K, B> reader, + final ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> childReaders) { + super(reader, childReaders); + this.delegate = reader; + } + + @Nonnull + @Override + public List<D> readList(@Nonnull final InstanceIdentifier<D> id, @Nonnull final ReadContext ctx) + throws ReadFailedException { + LOG.trace("{}: Reading all list entries", this); + final List<K> allIds = delegate.getAllIds(id, ctx); + LOG.debug("{}: Reading list entries for: {}", this, allIds); + + // Override read list in order to perform readCurrent + readChildren here + final ArrayList<D> allEntries = new ArrayList<>(allIds.size()); + for (K key : allIds) { + final InstanceIdentifier.IdentifiableItem<D, K> currentBdItem = RWUtils.getCurrentIdItem(id, key); + final InstanceIdentifier<D> keyedId = RWUtils.replaceLastInId(id, currentBdItem); + final Optional<D> read = readCurrent(keyedId, ctx); + if (read.isPresent()) { + final DataObject singleItem = read.get(); + checkArgument(getManagedDataObjectType().getTargetType().isAssignableFrom(singleItem.getClass())); + allEntries.add(getManagedDataObjectType().getTargetType().cast(singleItem)); + } + } + return allEntries; + } + + @Override + public void merge(@Nonnull final Builder<? extends DataObject> builder, @Nonnull final List<D> readData) { + delegate.merge(builder, readData); + } + + @Override + public List<K> getAllIds(@Nonnull final InstanceIdentifier<D> id, + @Nonnull final ReadContext ctx) throws ReadFailedException { + return delegate.getAllIds(id, ctx); + } + } + +} |