+++ /dev/null
-/*-
- * ============LICENSE_START=======================================================
- * ONAP Policy Models
- * ================================================================================
- * Copyright (C) 2019, 2021 AT&T Intellectual Property. All rights reserved.
- * ================================================================================
- * 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.
- * ============LICENSE_END=========================================================
- */
-
-package org.onap.policy.models.sim.dmaap.provider;
-
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Function;
-import org.onap.policy.common.utils.coder.Coder;
-import org.onap.policy.common.utils.coder.CoderException;
-import org.onap.policy.common.utils.coder.StandardCoder;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-/**
- * Data associated with a topic.
- *
- * <p/>
- * Note: for ease of implementation, this adds a topic when a consumer polls it rather
- * than when a publisher writes to it. This is the opposite of how the real DMaaP works.
- * As a result, this will never return a topic-not-found message to the consumer.
- */
-public class TopicData {
- private static final Logger logger = LoggerFactory.getLogger(TopicData.class);
-
- /**
- * Name of the topic with which this data is associated.
- */
- private final String topicName;
-
- /**
- * Maps a consumer group name to its associated data.
- */
- private final Map<String, ConsumerGroupData> group2data = new ConcurrentHashMap<>();
-
-
- /**
- * Constructs the object.
- *
- * @param topicName name of the topic with which this object is associated
- */
- public TopicData(String topicName) {
- logger.info("Topic {}: added", topicName);
- this.topicName = topicName;
- }
-
- /**
- * Removes idle consumers from the topic. This is typically called once during each
- * sweep cycle.
- */
- public void removeIdleConsumers() {
- Iterator<Entry<String, ConsumerGroupData>> iter = group2data.entrySet().iterator();
- while (iter.hasNext()) {
- Entry<String, ConsumerGroupData> ent = iter.next();
- if (ent.getValue().shouldRemove()) {
- /*
- * We want the minimum amount of time to elapse between invoking
- * shouldRemove() and iter.remove(), thus all other statements (e.g.,
- * logging) should be done AFTER iter.remove().
- */
- iter.remove();
-
- logger.info("Topic {}: removed consumer group: {}", topicName, ent.getKey());
- }
- }
- }
-
- /**
- * Reads from a particular consumer group's queue.
- *
- * @param consumerGroup name of the consumer group from which to read
- * @param maxRead maximum number of messages to read
- * @param waitMs time to wait, in milliseconds, if the queue is currently empty
- * @return a list of messages read from the queue, empty if no messages became
- * available before the wait time elapsed
- * @throws InterruptedException if this thread was interrupted while waiting for the
- * first message
- */
- public List<String> read(String consumerGroup, int maxRead, long waitMs) throws InterruptedException {
- /*
- * It's possible that this thread may spin several times while waiting for
- * removeIdleConsumers() to complete its call to iter.remove(), thus we create
- * this closure once, rather than each time through the loop.
- */
- Function<String, ConsumerGroupData> maker = this::makeData;
-
- // loop until we get a readable list
- List<String> result;
-
- // @formatter:off
-
- do {
- result = group2data.computeIfAbsent(consumerGroup, maker).read(maxRead, waitMs);
- } while (result == ConsumerGroupData.UNREADABLE_LIST);
-
- // @formatter:on
-
- return result;
- }
-
- /**
- * Writes messages to the queues of every consumer group.
- *
- * @param messages messages to be written to the queues
- * @return the number of messages enqueued
- */
- public int write(List<Object> messages) {
- List<String> list = convertMessagesToStrings(messages);
-
- /*
- * We don't care if a consumer group is deleted from the map while we're adding
- * messages to it, as those messages will simply be ignored (and discarded by the
- * garbage collector).
- */
- for (ConsumerGroupData data : group2data.values()) {
- data.write(list);
- }
-
- return list.size();
- }
-
- /**
- * Converts a list of message objects to a list of message strings. If a message
- * cannot be converted for some reason, then it is not added to the result list, thus
- * the result list may be shorted than the original input list.
- *
- * @param messages objects to be converted
- * @return a list of message strings
- */
- protected List<String> convertMessagesToStrings(List<Object> messages) {
- Coder coder = new StandardCoder();
- List<String> list = new ArrayList<>(messages.size());
-
- for (Object msg : messages) {
- var str = convertMessageToString(msg, coder);
- if (str != null) {
- list.add(str);
- }
- }
-
- return list;
- }
-
- /**
- * Converts a message object to a message string.
- *
- * @param message message to be converted
- * @param coder used to encode the message as a string
- * @return the message string, or {@code null} if it cannot be converted
- */
- protected String convertMessageToString(Object message, Coder coder) {
- if (message == null) {
- return null;
- }
-
- if (message instanceof String) {
- return message.toString();
- }
-
- try {
- return coder.encode(message);
- } catch (CoderException e) {
- logger.warn("cannot encode {}", message, e);
- return null;
- }
- }
-
- // this may be overridden by junit tests
-
- /**
- * Makes data for a consumer group.
- *
- * @param consumerGroup name of the consumer group to make
- * @return new consumer group data
- */
- protected ConsumerGroupData makeData(String consumerGroup) {
- return new ConsumerGroupData(topicName, consumerGroup);
- }
-}
Code Review / policy / models.git / blobdiff