/*
* 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.checkNotNull;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Optional;
import com.google.common.collect.Iterables;
import com.google.common.collect.LinkedListMultimap;
import com.google.common.collect.Multimap;
import io.fd.honeycomb.translate.read.InitFailedException;
import io.fd.honeycomb.translate.read.Initializer;
import io.fd.honeycomb.translate.read.ListReader;
import io.fd.honeycomb.translate.read.ReadContext;
import io.fd.honeycomb.translate.read.ReadFailedException;
import io.fd.honeycomb.translate.read.Reader;
import io.fd.honeycomb.translate.read.registry.ReaderRegistry;
import io.fd.honeycomb.translate.util.RWUtils;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import javax.annotation.Nonnull;
import org.opendaylight.controller.md.sal.binding.api.DataBroker;
import org.opendaylight.yangtools.concepts.Builder;
import org.opendaylight.yangtools.yang.binding.DataObject;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Simple reader registry able to perform and aggregated read (ROOT read) on top of all provided readers. Also able to
* delegate a specific read to one of the delegate readers.
*
* This could serve as a utility to hold & hide all available readers in upper layers.
*/
public final class CompositeReaderRegistry implements ReaderRegistry {
private static final Logger LOG = LoggerFactory.getLogger(CompositeReaderRegistry.class);
private final Map, Reader extends DataObject, ? extends Builder>>> rootReaders;
/**
* Create new {@link CompositeReaderRegistry}.
*
* @param rootReaders List of delegate readers
*/
public CompositeReaderRegistry(@Nonnull final List>> rootReaders) {
this.rootReaders = RWUtils.uniqueLinkedIndex(checkNotNull(rootReaders), RWUtils.MANAGER_CLASS_FUNCTION);
}
@VisibleForTesting
Map, Reader extends DataObject, ? extends Builder>>> getRootReaders() {
return rootReaders;
}
@Override
@Nonnull
public Multimap, ? extends DataObject> readAll(
@Nonnull final ReadContext ctx) throws ReadFailedException {
LOG.debug("Reading from all delegates: {}", this);
LOG.trace("Reading from all delegates: {}", rootReaders.values());
final Multimap, DataObject> objects = LinkedListMultimap.create();
for (Reader extends DataObject, ? extends Builder>> rootReader : rootReaders.values()) {
LOG.debug("Reading from delegate: {}", rootReader);
if (rootReader instanceof ListReader) {
final List extends DataObject> listEntries =
((ListReader) rootReader).readList(rootReader.getManagedDataObjectType(), ctx);
if (!listEntries.isEmpty()) {
objects.putAll(rootReader.getManagedDataObjectType(), listEntries);
}
} else {
final Optional extends DataObject> read = rootReader.read(rootReader.getManagedDataObjectType(), ctx);
if (read.isPresent()) {
objects.putAll(rootReader.getManagedDataObjectType(), Collections.singletonList(read.get()));
}
}
}
return objects;
}
@Override
public void initAll(@Nonnull final DataBroker broker, @Nonnull final ReadContext ctx) throws InitFailedException {
for (Reader extends DataObject, ? extends Builder>> rootReader : rootReaders.values()) {
if (rootReader instanceof Initializer>) {
((Initializer) rootReader).init(broker, rootReader.getManagedDataObjectType(), ctx);
}
}
}
@Nonnull
@Override
public Optional extends DataObject> read(@Nonnull final InstanceIdentifier extends DataObject> id,
@Nonnull final ReadContext ctx)
throws ReadFailedException {
final InstanceIdentifier.PathArgument first = checkNotNull(
Iterables.getFirst(id.getPathArguments(), null), "Empty id");
final Reader extends DataObject, ? extends Builder>> reader = rootReaders.get(first.getType());
checkNotNull(reader,
"Unable to read %s. Missing reader. Current readers for: %s", id, rootReaders.keySet());
LOG.debug("Reading from delegate: {}", reader);
return reader.read(id, ctx);
}
@Override
public String toString() {
return getClass().getSimpleName()
+ rootReaders.keySet().stream().map(Class::getSimpleName).collect(Collectors.toList());
}
}