| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.nifi.distributed.cache.client.adapter; |
| |
| import io.netty.buffer.ByteBuf; |
| import io.netty.buffer.Unpooled; |
| import org.apache.nifi.distributed.cache.client.Deserializer; |
| |
| import java.io.IOException; |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * Implementation of {@link InboundAdapter} where the service response payload is expected to be |
| * a collection of values of type V. These are to be reassembled into a map using the keys |
| * provided by the caller. |
| * |
| * @param <K> the expected type of the service keys |
| * @param <V> the expected type of the service response values |
| */ |
| public class MapValuesInboundAdapter<K, V> implements InboundAdapter { |
| |
| /** |
| * An iterator used to traverse the caller-supplied keys, in order to reassemble the service map. |
| */ |
| private final Iterator<K> iteratorKeys; |
| |
| /** |
| * The deserializer to be used to construct the values in the service response object. |
| */ |
| private final Deserializer<V> deserializerV; |
| |
| /** |
| * Container for bytes queued from the service response {@link io.netty.channel.Channel}. |
| */ |
| private final ByteBuf byteBuf; |
| |
| /** |
| * The state of receipt of an individual service response token. |
| */ |
| private final InboundToken<V> inboundToken; |
| |
| /** |
| * The reassembled map resulting from the service call. |
| */ |
| private final Map<K, V> result; |
| |
| /** |
| * Constructor. |
| * |
| * @param keys the map keys requested by the caller |
| * @param deserializerV the deserializer to be used to instantiate the service response map values |
| * @param result container for the map entries reconstituted from the service response |
| */ |
| public MapValuesInboundAdapter(final Set<K> keys, final Deserializer<V> deserializerV, final Map<K, V> result) { |
| this.iteratorKeys = keys.iterator(); |
| this.deserializerV = deserializerV; |
| this.byteBuf = Unpooled.buffer(); |
| this.inboundToken = new InboundToken<>(); |
| this.result = result; |
| } |
| |
| /** |
| * @return the service method response map |
| */ |
| public Map<K, V> getResult() { |
| return result; |
| } |
| |
| @Override |
| public boolean isComplete() { |
| return (!iteratorKeys.hasNext()); |
| } |
| |
| @Override |
| public void queue(final byte[] bytes) { |
| byteBuf.writeBytes(bytes); |
| } |
| |
| @Override |
| public void dequeue() throws IOException { |
| while (iteratorKeys.hasNext()) { |
| inboundToken.update(byteBuf, deserializerV); |
| if (inboundToken.isComplete()) { |
| result.put(iteratorKeys.next(), inboundToken.getValue()); |
| inboundToken.reset(); |
| } else { |
| break; |
| } |
| } |
| } |
| } |